COASTAL ARTILLERY 3:
Super-Heavy Coastal Guns
The origin of Finnish coastal artillery is so tightly linked to Russian coastal artillery batteries built by year 1917, that this might be a good place to write few words how Finland come up inheriting such a strong coastal artillery from Imperial Russia. During Russian - Japanese War of 1904 - 1905 Russia lost basically almost whole of its Baltic Fleet, which had been sent to Pacific once the Pacific Fleet had already been lost. This left Russian Navy very weak in Baltic Sea and forced it to take defensive role until the lost ships could be replaced, which was expected to take quite a long time. At that time St. Petersburg was Russian capital, so defending it against any possible hostile navy was obviously a high priority. Since Russian Navy had basically lost its Baltic Fleet, it was forced to take defensive stand in its plans against threat of much more powerful German Navy. Year 1913 Russia made a decision to build fortified coastal artillery system, which with sea mines would block access to Gulf of Finland from any enemy surface ships, this fortified coastal artillery system was named as Peter the Great's Naval Fortress. It contained multiple parts with large concentration of coastal artillery firepower in narrows in between city of Tallinn and Porkkala Cape and another line of coastal artillery around Kronstadt naval base. Later the plan was extended to include larger areas and create third line of defence in area in between city of Kotka and Kurgalsky Peninsula. Construction works for building the coastal artillery batteries continued until stopped by Russian Revolution in year 1917. Following Civil War in year 1918 Finnish military took over all the installations, which were in Finnish territory. As a result of these events Finland got such powerful coastal artillery that acquiring it by other means would been otherwise completely outside realistic financial capabilities of the new born state burdened by debts taken during the war.
When studying for writing this page I made quite a surprising observation. The best known battles of Finnish coastal artillery seem to be the ones fought against largest warships of Soviet Baltic Sea Navy during Winter War. Yet this was not the most important contribution of coastal artillery to Finnish military capability during World War 2. In fact the numbers of shells that the coastal artillery fired towards ground targets outnumbered the number of shells fired against ships in truly large margin. Yet the important role that Finnish coastal artillery played in providing artillery support to land front seems to be at least internationally far less commonly known. Admitted much of the credit for providing this often vital artillery support goes to heavy coastal artillery batteries, also some of the super-heavy coastal artillery batteries played role of equal significance.
It might be also worth noting that by field artillery specifications, the super-heavy coastal artillery batteries were practically always performing harassing fire (häirintätuli) type fire missions. This is because to slow rate of fire (around 0.5 - 2 shots/minute) of super-heavy coastal guns combined small number of shells typically fired in individual barrages fits to specifications that field artillery set as harassing fire. Harassing fire was a type of artillery barrage intended for harassing enemy troop movements and causing casualties to its troops, which was often fired with random intervals. However what the field artillery fire type specifications fail to take into account is the notable difference in size and effect on target in between shells used by field artillery and super-heavy coastal guns. Shortly noted the super-heavy howitzers of field artillery were in the same caliber range as the smallest of super-heavy coastal guns - while the most common field artillery pieces were little more than pea-shooters compared to super-heavy coastal guns.
Occasional reader might wonder why Finnish coastal artillery retained super-heavy coastal guns in its use so long, while most countries had either disbanded their coastal artillery or replaced its guns with missiles. One of the reasons for this was Paris Peace Treaty of year 1947, which among other things limited peace-time manpower of Finnish military, tonnage of Finnish Navy, number of combat aircraft allowed for Finnish Air Force - and banned missiles, torpedo boats and submarines from Finnish military. This later changed, but the change took its time. The first anti-ship missile systems acquired by Finnish Navy were Tuima-class (OSA-II class) missile boats equipped with MtO 66 (P-15U Termit / SS-N-2b Styx) anti-ship missiles acquired from Soviet Union in late 1960's. The same missile became the first anti-ship missile system acquired for Finnish coastal artillery. The next anti-ship missile system specifically acquired for Finnish coastal artillery was MtO 85 (RBS-15SF) acquired from Sweden in mid 1980's. Year 1990 Finland officially declared particular limitations of Paris Peace Treaty to be obsolete and void.
203/45 C
(203 mm coastal gun with 45 caliber barrel, model Canet)
(203 mm / 8" naval gun model 1892)
PICTURE: 203/45 C coastal gun in process of being evacuated from Mäkiluoto in September of 1944. Photographed by
Military Official Esko Suomela (SA-kuva photo archive, photo number 163907). CLICK THUMBNAIL TO SEE LARGER PIC (95 KB).
Calibre: |
203.2 mm (bagged ammunition) |
|
Barrel length: |
913.5 cm aka L/45 |
|
Weight in action: |
27200 kg (for the whole gun) |
|
Rate of fire: |
? shots/min |
|
Muzzle velocity: |
810 - 854 m/sec |
|
Traverse: |
360 degrees (*) |
|
Elevation: |
- 2 degrees, + 39-40 degrees |
|
Max. range: |
About 25 km |
|
Ammunition weight: |
93.5 kg (HE & APHE), 117 kg (HE) |
|
Ammunition types: |
HE, APHE, practice |
|
Country of origin: |
Russia |
(*) When permitted by gun position, typical Russian World War 1 battery front coastal artillery position often allowed sector of fire of only about 120 degrees.
Finnish use: Only three of these guns ever saw use with Finnish military, but they still succeeded seeing combat use in coastal artillery batteries of Pukkio and Mäkiluoto during World War 2.
203/50 VC:
(203 mm coastal gun with 50 caliber barrel, model Vickers on Canet gun mount)
(203 mm / 8" naval gun model 1905)
PICTURE: 203-mm coastal gun on Mäkiluoto in September of 1944. Educated guess is that this may be
203/50 VC, but that is not completely certain. Photographed by Military Official Esko Suomela (SA-kuva.fi photo archive, photo
number 163886). CLICK THUMBNAIL TO SEE LARGER PIC (112 KB).
Calibre: |
203 mm (bagged ammunition) |
|
Barrel length: |
1020 cm aka L/50 |
|
Weight in action: |
27500 kg (for the whole gun) |
|
Rate of fire: |
? shots/min |
|
Muzzle velocity: |
848 m/sec |
|
Traverse: |
360 degrees (*) |
|
Elevation: |
- ? degrees, + 40 degrees |
|
Max. range: |
about 28 km |
|
Ammunition weight: |
133 kg (HE) |
|
Ammunition types: |
HE, ? |
|
Country of origin: |
Britain |
(*) When permitted by gun position, typical Russian World War 1 battery front coastal artillery position often allowed sector of fire of only about 120 degrees.
Finnish use: There were only one of these guns in Finnish use, during World War 2 it served on Mäkiluoto Island.
These two models of 203-mm coastal gun were few in number in Finnish use, but still succeeded to see make their mark in Finnish military history during World War 2. The first of them was a Russian development directly based to Canet-guns, while another gun design originated from Vickers. The story of 203/45 C gun starts from Russia buying blueprints of 75-mm, 120-mm and 152-mm Canet naval guns in year 1891 and Obuhov starting to manufacture these three naval guns the next year. While the canon designs acquired from Canet proved highly useful, 152-mm gun was still too small to fulfil needs of Russian Navy. Hence already year 1892 Colonel A.F. Brink designed 203-mm naval gun (203/45 C) based to Canet designs and Captain A.P. Meller designed the resulting gun a gun mount for naval use. Captain Rosenberg designed breech system of this gun, which was likewise directly based to screw breech of used in Canet guns. Like numerous Russian naval guns of this era also this gun had recoil system with hydraulic buffer and spring recuperator placed under the gun barrel. This sort of placement of recoil system effectively limited the maximum elevation to +18 degrees, which substantially reduced the maximum range, which the ballistics would have allowed the gun to achieve. Obuhov Steel Works manufactured the gun in 1892 - 1907 plus one additional batch in year 1916. Russian Navy acquired these guns, later named in Finland as 203/45 C, for its armoured cruisers Rossija, Gromoboi, two cruisers both named Bayan, armoured cruiser Admiral Makarov, armoured cruiser Pallada and gunboat Khrabry. In addition the gun saw use as coastal gun and during Russian Civil War (1917 - 1922) was also used as railroad artillery. Also the Soviets used it as coastal gun, until apparently replaced with more modern artillery pieces in 1930's.
As noted the gun that Finnish military later named as 203/50 VC was developed by Vickers, Sons & Maxim, which had test-fired the first gun of this type in year 1905. Russia both acquired these guns from Vickers and obtained production license for them, but before Obuhov started manufacturing, some changes were introduced to structural design of the gun. Obuhov Steel Works manufactured the gun until year 1911 and due to World War 1 re-started its production its production in year 1914. Russian Navy acquired them for armoured cruiser Rurik, as secondary armament for pre-dreadnought battleships Andrey Pervozvannyi and Imperator Pavel I, pre-dreadnought battleships Evstafi and Ioann Zlatoust, battleship Sinop (once re-equipped) and ironclad Petr Veliky (once re-equipped).
PICTURE: 203/50 VC coastal gun in outdoor exbition of Kuivasaari Island. Lower section of gun mount is missing.
CLICK THUMBNAIL TO SEE LARGER PIC (113 KB).
These guns got brought to Finland as part of Peter the Great's Naval Fortress. Parts of this coastal artillery system were coastal artillery batteries of Mäkiluoto Island (in Finland) and Naissaar Island (in Estonia) building of which had started in year 1914. These two artillery batteries built to numerous coastal artillery batteries built in the narrow part in Gulf of Finland in between Helsinki and Tallinn as first stage of Peter the Great's Naval Fortress. At later stages this coastal artillery system intended to block access from enemy surface vessels to rest of the Gulf of Finland and Russian capital St. Petersburg, spread into much larger geographical area. The two coastal artillery batteries were originally intended to be only temporarily equipped with 203/45 C guns, which were to be replaced with 203/50 VC guns ordered by Russia from Vickers the previous year. However world wars are able to cause rear havoc on armament delivery plans, which is exactly what World War 1 did in this case - delivery of 203/50 VC guns got delayed and the guns arrived too late to be any use for Russian military. Before Russian revolution stopped all work for Peter the Great's Naval Fortress in year 1917 four 203/50 VC guns had finally been delivered to Mäkiluoto Island and installed to two twin gun steel turrets - only to be blown up by Russian military (or less likely Finnish Red Guard) after abandoning the coastal fort in year 1918. Apparently the whole 8-inch artillery battery on Mäkiluoto was so thoroughly destroyed that what remained was later sold for scrap metal. As part of Peter the Great's Naval Fortress another two 203-mm coastal artillery batteries had been intended to be built to Koö Island (near Hanko/Hango/Gangut peninsula) and Boxö Island (Ahvenanmaa / Åland Islands). But when captured year 1918 Koö coastal artillery battery was still incomplete and had no guns at all. The artillery battery on Boxö had four guns, but gun barrel of its 4th gun was missing.
Hence year 1918 Finnish military succeeded capturing only three 203/45 C coastal guns - all of which on Boxö Island. In addition it succeeded capturing single operational 203/50 VC gun, which may have been the 4th gun on Boxö - or may (more likely) have been captured in some other unknown location. When it came to these guns Finnish military naming system simply named 203 mm / 8" naval gun model 1892 as 203/45 C, as if it was part of Canet artillery system. Meanwhile 203/50 VC got its "VC" by being Vickers gun on Canet gun mount.
Ahvenanmaa / Åland Islands had existing historical status as demilitarised area (*), due to which year 1919 Finland dismantled the coastal artillery installations built by Russia during World War 1. This made the guns of Boxö coastal artillery battery available for new location, which was Island of Pukkio in municipality of Vironlahti in eastern Gulf of Finland. Planning work for Pukkio coastal artillery battery started year 1921 and the artillery battery became operational in year 1924. This coastal artillery battery had been planned and built for four 203-mm guns, but early on it had only two. The other two 203-mm guns were transferred to Pukkio by late 1920’s. This brought the total number in Pukkio to four guns, until two of the guns were transferred to Mäkiluoto Island around year 1933. In 1930's and during Winter War Finnish military officially referred Pukkio 203-mm coastal artillery battery also as Patteri 55 (Artillery Battery 55). The two guns remaining in Pukkio after year 1933 were both 203/45 C type and saw combat during Winter War.
(*) Ahvenanmaa / Åland Islands had been originally demilitarised in Paris Peace Treaty of year 1856 ending Crimean War. Year 1920 League of Nations solved the dispute in between Finland and Sweden about ownership of these islands by declaring them to be autonomic part of Finland, but also validated their area being demilitarised.
PICTURE: 203-mm coastal gun on Mäkiluoto in July of 1942. Photographed by Lieutenant P.J. Wiro (SA-kuva.fi
photo archive, photo number 96340). CLICK THUMBNAIL TO SEE LARGER PIC (152 KB).
The two guns transferred to Mäkiluoto were 203/45 C and 203/50 VC. This combination of two different type of guns in same coastal artillery battery proved quite difficult since each gun had its own type of ammunition, which were not mutually compatible, but still the two guns were kept in service. Even if they were so few in number, Finnish coastal artillery put an effort in improving maximum range of its 203-mm guns. This was done in often-used method of modifying the guns by moving their recoil systems from under the gun on top of the gun, where they no longer limited maximum elevation. In addition existing ammunition was equipped with ballistic caps, which improved their ballistics. As a result of these two improvements the maximum shooting range of the guns increased about 5 kilometers.
During last weeks of Winter War in March of 1940 Soviet Baltic Sea Navy launched attack across ice of frozen Gulf of Finland to Kotka Coastal Defence Sector from Islands of Lavansaari and Suursaari. Finnish coastal artillery and various infantry units gathered to this sector of coast repulsed this attack. Pukkio coastal artillery battery took part to particular battles in 6th, 7th and 10th of March by shelling Soviet naval infantry units in these battles with total of 294 high explosive shells. Besides the casualties that they produced in target 203-mm high-explosive shells produced also certain obstacle value, since each shell produced through ice a hole about 8 - 10 meters in diameter. At that time Pukkio battery had only one gun remaining in action, this was due to gun barrel of the second gun being damaged beyond repair in beginning of these battles. At that time Soviet aircraft repeatedly targeted all coastal artillery installations of Kotka Coastal Defence Sector, but it was not the reason for this gun damage. What is known suggests the gun barrel had cracked due to neglecting to follow standard procedure concerning opening fire during cold winter weather, which required smaller propellant charge to be fired first to warm up the gun barrel, before continuing with full-power ammunition. Firing full-power ammunition without proper warm up in freezing weather put too much stress to massive gun barrel, which cracked. With the 294 shells fired in just few days gun barrel of the only gun that had remained operation also reached the end of its expected barrel life. When Pukkio Island ended up just barely on Soviet side of Finnish - Soviet border of year 1940 Moscow Peace Treaty, Finnish military evacuated all other equipment from this island, except the two 203-mm caliber gun barrels, neither of which was no longer in usable condition.
PICTURE: Map showing historical locations of 203-mm coastal artillery batteries in Finland . CLICK THUMBNAIL TO
SEE LARGER PIC (185 KB).
While 203-mm coastal artillery battery on Mäkiluoto Island did not see real combat use during Winter War, it did not escape the effects of the historical events following from this war. As part of demands included into Moscow Peace Treaty of 1940 Soviet Union got to rent large part of Hanko (/ Hango / Gangut) Peninsula for its military base, which with Soviet bases in Estonia was again designed to close Gulf of Finland from any potential Soviet enemy. But all the shipping routes in between this military base and Leningrad area had to bypass Mäkiluoto Island. Hence when Continuation War started 203-mm artillery battery on Mäkiluoto took part shelling Soviet shipping transporting men and materials to and from Soviet Hanko military base, until the Soviets evacuated their base in December of 1941. Finnish - Soviet Armistice Treaty of 1944 that ended Continuation War allowed the Soviets to replace their earlier Hanko military with new military base in Porkkala Cape - located with-in artillery range to Finnish capital Helsinki. Mäkiluoto Island fell inside the area, which the Soviets wanted for Porkkala military base, hence Finnish military evacuated the island taking 203-mm guns with them. While Finnish military declared sole remaining 203/45 C and 203/50 VC guns obsolete in year 1945, they remained in depot until change of situation allowed them to re-introduced to military use in early 1960's. At that time they were repaired and used to equip coastal artillery battery on Miessaari Island (in city of Espoo) in year 1963, but the particular coastal artillery battery was never really made operational. Year 1982 the guns were declared obsolete the second and final time. Luckily both guns have survived to this day with 203/50 VC being in private collection and 203/45 C in coastal artillery exhibition on Kuivasaari Island.
Both 203/45 C and 203/50 VC used bagged ammunition, but otherwise their ammunition had little in common. Ammunition inventory for 203/45 C contained armour piercing high explosive (APHE) shells, high explosive (HE) shells and practice rounds – these had all been equipped with ballistic caps. This gun had two kind of HE-ammunition available – light 93.3 kg shell with muzzle velocity of 849 m/sec, slightly heavier 93.5 kg shell with muzzle velocity of 854 m/sec and notably heavier 117 kg shell with muzzle velocity of 810 m/sec. The APHE-shell weight 93.3-kg and had muzzle velocity of 849 m/sec. Both HE- and APHE-shells had been loaded with TNT. According post-war ammunition manual only ammunition type available for 203/50 VC gun was high explosive (HE) shell weighting 133 kg and having muzzle velocity of 848 m/sec. But there may have been also other ammunition still available for this gun during World War 2.
234/50 BS
(234 mm coastal gun with 50 caliber barrel, model Bethlehem Steel)
PICTURE: Camouflaged and partially snow covered 234/50 BS coastal gun in Russarö Island in March of 1940.
(SA-kuva.fi photo archive, photo number 7612). CLICK THUMBNAIL TO SEE LARGER PIC (176 KB).
Calibre: |
233.68 mm (bagged ammunition) |
|
Barrel length: |
1168 cm aka L/50 |
|
Weight in action: |
99295 kg (for the whole gun) |
|
Rate of fire: |
2 shots/min (theoretical), 1.5 shots/min (practical) |
|
Muzzle velocity: |
811 - 846 m/sec |
|
Traverse: |
360 degrees |
|
Elevation: |
- 2.5 degrees, + 31 or + 33 degrees |
|
Max. range: |
About 25.5 km |
|
Ammunition weight: |
172 kg (all ammunition types) |
|
Ammunition types: |
HE, SAPHE, APHE, practice |
|
Country of origin: |
United States |
Finnish use: The only coastal artillery battery equipped with these guns in Finland was on Russarö Island. 1st of December 1939 this artillery battery fought a battle against Soviet cruiser Kirov and two destroyers escorting it.
These guns had been originally ordered by Chile from their American manufacturer Bethlehem Steel in year 1912, but probably due to British diplomatic pressure the deal fall through and Russia ended up buying all 14 guns in year 1914. The 9.2-inch / 234-mm caliber was uncommon in Russian use, hence these became the only guns of this caliber used in Peter the Great's Naval Fortress. The guns arrived through extremely long transport route, being shipped from New York through Panama Channel to Vladivostok and via railway through whole Russia to Petrograd (St. Petersburg). Ammunition that arrived with the guns was just enough for test-firing them, so regardless the rare calibre local ammunition production was set up in Russia.
Russian military reserved the 14 guns for equipping three coastal artillery batteries:
- Russarö Island (in Finland)
- Naissaari / Naissaar Island (in Estonia)
- Suurupi Peninsula (in Estonia)
Russarö Island bit south from tip of Hanko / Hango / Gangut Peninsula was obviously well chosen location for super-heavy coastal artillery battery. The Peninsula has played strategic importance in naval strategy already in numerous previous wars and had one of the roadsteds routinely used by Russian Navy during World War 1. In addition Russarö Island controlled starting point of coastal shipping route protected by archipelago leading eastwards along the coast.
Not only was 234-mm guns unusual artillery caliber in Russian use, but also compared to other Russian super-heavy coastal artillery batteries of that time Russarö 234-mm coastal artillery battery was quite unusual in many ways. For one it had six guns, while coastal artillery batteries equipped with similar guns on Naissaari/Naissaar Island and Suurupi Peninsula each had more typical four guns. In addition the guns also been placed in their own individual gun pits with the battery being built as three separate artillery sections of two guns each. Hence each artillery section of two guns had its own concrete massive, which was a notably more dispersed solution than typical Russian battery front of that era.
In manner typical to Peter the Great’s Naval Fortress local privately owned companies were involved in building Russarö artillery battery - quarrying work for the location was done by Granit Oy (Granit Ltd), while Mannerin Konepaja (Manner's Engineering Works) played important part in installing the guns. The guns had been equipped with large gun shields, which protected the gun crews and breech area from front and sides. The breech system used in them was screw breech with de Bange obturator - not very different from Canet breech system, which was common both in Russian and later in Finnish use. Recoil system had the typical combination of hydraulic buffer and spring recuperator. They had also been equipped with American gun laying system, which Finnish military bit later came to consider old-fashioned but easy to use.
PICTURE: Officers of German Navy pose with 234/50 BS coastal gun on Russarö Island in year
1918. Notice another gun visible in the background. Photo source Finnish Heritage Agency (Museovirasto), acquired
via finna.fi and used with CC
BY 4.0 license. CLICK THUMBNAIL TO SEE LARGER PIC (117 KB).
When Finnish military took over military installations of Russarö Island in year 1918, they found 234-mm coastal artillery battery relatively intact. Practically whole Russian garrison had left the island already before troops of German Ostsee Division had taken it over in early days of April 1918 as a preparation for landing their troops in nearby Hanko harbour. However (as apparently typical to coastal forts of this particular area) breech blocks of all six 234-mm guns were missing - presumably either the Russian garrison had taken the breech blocks with them when they abandoned the island or they had otherwise get rid of them. In addition German troops had taken four of the island's generators with them. Hence none of the guns could be used due to missing essential parts, but otherwise the situation was much better than in many other coastal artillery installations left behind by Russian military. Whatever the Russian military had done with the breech blocks, it had demanded planning and organised work teams, since each breech block weight 472-kg. Year 1919 Finland acquired approval of US government for acquiring new breech blocks, which were acquired from Bethlehem Steel. Once the new breech blocks arrived they were installed with the artillery battery again becoming operational around 1921 - 1922.
Finnish military named these guns as 234/50 BS with "BS" coming from name of the manufacturer - Bethlehem Steel. In 1920's these guns were the most modern super-heavy coastal guns in Finnish use, but in usual manner their efficiency was handicapped by the poorly designed gun mounts, which limited maximum range of the guns. Finnish military started its first attempts for modernising of 234/50 BS guns already in 1920's, but the actual modernisation work did not start until year 1935. Some 20 improvements and changes were performed for the guns around 1936 - 1937. These included structural changes made for gun mount, gun shield attachment and gun shield - allowing significant increase of maximum elevation, which in turn increased maximum range from about 18 km to 25 km. Other improvements introduced at that time included electrifying system used for setting elevation for each gun, improvements made to recoil systems and repairs of electrical systems. Applying improvements took a long time, but all six 234/50 BS guns were fully modernised before Winter War. In addition most of the artillery shells reserved for them were upgraded with ballistic caps, which also increased their range.
PICTURE: Map showing historical locations of 234-mm and 305-mm coastal artillery batteries in Finland.
CLICK THUMBNAIL TO SEE LARGER PIC (243 KB).
During Winter War these recent improvements made to 234-mm guns of Russarö coastal artillery battery gave a nasty shock for the Soviets. Second day of the war, 1st of December 1939, Soviet cruiser Kirov escorted by destroyers Stremitelnyj and Smetlivyj attacked Russarö coastal fort. The fort’s 234-mm artillery battery opened ranging fire from distance of 24 kilometers at 09:55. Kirov turned its right side towards Russarö and opened return fire from distance of 20 kilometers at 09:57, by which time 234-mm artillery battery had succeeded finding the correct fire setting values. With its shells now splashing to sea around the three ships, the artillery battery now shifted into fire for effect with all six guns. While neither Soviet nor Russian Navy have ever officially admitted this, apparently destroyer Stremitelnyj was severely damaged by hit or near hit to its left side and also cruiser Kirov damaged by one or several hit or near hits. Due to this after firing just 35 shells which did little damage beyond destroying lighthouse keeper's shack, Kirov and both destroyers turned away and left battlefield. Russarö coastal fort stopped shooting around 10:10, when the ships were getting outside range of its guns. Outcome of the battle was such that the Soviets apparently found necessary to repeatedly publicly deny the events, which at the same time suggest that that Soviet Navy was clueless about Finnish modernisation of guns how it effected their effective range. Even during later Continuation War Soviet propaganda radio broadcasts still kept making repeated claims that 234-mm guns of Russarö coastal fort could not have possibly damaged Kirov or its destroyer escort, because their range was not sufficient to return fire from distance of 20 kilometers. Cruiser Kirov and destroyers headed for repairs to Soviet naval base in Liepaja (Latvia).
When it came to 234-mm coastal artillery battery on Russarö, what the Soviets had failed to destroy with military force during Winter War, they got very close getting with Moscow Peace Treaty of 1940 that ended the war. One of the terms of this treaty was military base in Hanko Peninsula, which Finland now had to rent to Soviet Union. The geographical area of this military base included also Russarö Island. The Finns had just ten days to evacuate the island, so early on Finnish military considered successful evacuation of 234/50 BS coastal artillery battery to be impossible. The most heaviest parts of these guns were gun barrels, which each weight about 30 tons, while each gun shield weight 16 tons and gun cradles 9 tons each. The island lacked transport equipment designed to transport materials this large and heavy from the artillery battery to its pier, which had been destroyed in bombing just before ending of the war. In addition Gulf of Finland was still covered in ice, which complicated shipping the parts from the pier to mainland. However Major Niilo Heino thought otherwise and found support to his idea from Engineer Lieutenant Gunnar Renqvist and weapons technician Werner Lindqvist. These three men succeeded convincing their superiors that if given work force of 200 men which had experience of transporting heavy machinery, 40 carpenters and 100 men they would be able to evacuate at least two of the guns to mainland with-in the time limit. This mostly civilian work force was swiftly gathered from companies Oy Crichton-Vulcan Ab (50 men), Ericsson (30 men), Kone ja Siltarakennus Oy (50 men) and Oy Strömberg Ab (50 men) combined with 50 soldiers from Petsari coastal fort plus another 30 soldiers from Turku and some construction workers from Ahvenanmaa / Åland Islands. Disassembling of the first guns started already before the peer was repaired. Each gun was assembled and its parts towed by hand on old narrow gauge railway to peer, from which icebreaker Apu took the gun barrels to harbour of Hanko one by one. Until building of rail cars especially built in the hurry for this purpose was completed, old rail cars intended for transporting ammunition were used for transporting the parts to pier in the narrow gauge railway. With last two guns, the work teams of Ströberg and Crichton-Vulcan were already competing against each other in which team would get its guns faster to the peer. This effort nothing less of a miracle resulted all six guns being evacuated from Russarö Island to Hanko harbour, the last gun arriving to Hanko just hours before the deadline.
PICTURE: The last gun barrel of 234/50 BS coastal artillery battery on its way to pier in 21st
of March of 1940. Moving gun barrel on narrow gauge railway by hand demanded close co-operation and physical effort of
practically whole work force. The narrow gauge railway in the island had been built during World War 1. (SA-kuva.fi
photo archive, photograph number 7188). CLICK THUMBNAIL TO SEE LARGER PIC (124 KB).
Finnish military soon made plans for the evacuated guns - three guns were to be installed on coastal fort in Island of Alskär (in municipality of Korppoo), but starting of Continuation War in June of 1941 changed those plans before they were implemented. After several months of battles the Soviets evacuated last troops from their military base in Hanko / Hango / Gangut Peninsula in early days of December 1941. Both Hanko Peninsula and Ryssarö Island fell back into Finnish hands and Finnish military started planning returning the 234-mm coastal artillery battery to its original positions in Russarö Island. Three of the guns were returned to Russarö Island in December of 1941 - spring of 1942. The first two guns of the artillery battery reached operational status in May of 1942. The third gun had been returned to Russarö bit later than the others and got operational in August of 1942. The fourth gun did not return to island until considerably later and was not test-fired until November of 1945. The last two guns were not returned from the depot until long after World War 2. Year 1944 there were plans for new 234-mm coastal artillery battery, which was intended for Island of Ulko-Tammio (SE town of Hamina). But ultimately this coastal artillery battery was never built and the remaining two guns stay in depot for rest of World War 2.
PICTURE: Back home at last - 234/50 BS coastal gun fires a shell during gunnery practice in August of
1942. Photographed by Military Official Esko Suomela (SA-kuva.fi photo archive, photo number 105764). CLICK THUMBNAIL TO
SEE LARGER PIC (151 KB).
Unlike all other existing Finnish super-heavy coastal artillery batteries, due to its location west of Soviet military base on Porkkala Cape, coastal guns over 120-mm in caliber did not need to be removed from Russarö Island due to demands of Allied Control Commission in year 1945. Hence its 234/50 BS artillery battery remained operational with the last two guns also being returned to their original positions in 1960 - 1962, with 5th and 6th gun of the coastal artillery battery reaching operational status in late 1962. All six guns also went through new set of modernizations in 1960's and remained in training use until year 1975. Coastal artillery shot with 234/50 BS artillery battery the last time in year 1976 - several years after it had fired last shots with 305/52 O guns. Hence one could claim that 234/50 BS actually outlasted more common and notably more powerful 305/52 O in use of Finnish coastal artillery by a margin. Four of the guns were removed and scrapped in year 1983, while two remaining guns were left in their original positions and became museum guns.
These guns used bagged ammunition. Their ammunition inventory included high explosive (HE) shells, armour piercing high explosive (APHE) shells, semi-armour piercing high explosive (SAPHE) shells and training shells used for live fire training & loading practice. All of these shell types were of similar weight – 172 kg, although muzzle velocities varied due to various available bagged propellant charge options. At least APHE and SAPHE shells had been equipped with ballistic caps, which enhanced their ballistic performance.
254/45 D
(254 mm coastal gun with 45 caliber barrel, model Durlacher)
(254 mm / 10" naval / coastal gun model 1891, model 1892 or model 1895)
PICTURE: 254/45 D coastal gun on Kuivasaari Island outside Helsinki. This is the only remaining gun of this
model in Finland. CLICK THUMBNAIL TO SEE LARGER PIC (133 KB).
Calibre: |
254 mm (bagged ammunition) |
|
Barrel length: |
1142 cm aka L/45 |
|
Weight in action: |
51500 kg (for the whole gun) |
|
Rate of fire: |
2 shots/min (theoretical), 1 shots/min (practical) |
|
Muzzle velocity: |
776 - 800 m/sec |
|
Traverse: |
120 degrees / 360 degrees (*) |
|
Elevation: |
- 10 degrees, + 30 degrees |
|
Max. range: |
about 27.5 km |
|
Ammunition weight: |
235 kg (HE & APHE) |
|
Ammunition types: |
HE, APHE, practice |
|
Country of origin: |
Russia |
(*) Depending type of gun-position. Originally Russian military had arranged these guns in "battery front" positions, which allowed each gun firing sector of only about 120 degrees. Guns in Finnish-built Kirkonmaa and Saarenpää coastal artillery batteries had 360 degree firing sector.
Finnish use: The most common super-heavy coastal gun in Finnish use with total 28 guns being used by Finnish coastal artillery. During World War 2 they saw heavy combat use on Saarenpää coastal artillery fort, with Kirkonmaa and Kellomäki artillery batteries also seeing some action.
Naval version of this gun was officially approved for Russian Navy year 1892 with the first order being made to Obuhov Steel Works already that same year. Russian Navy used its naval version as main guns on pre-dreadnought battleships Peresvet, Osljabja and Pobeda completed in 1901 - 1902 and pre-dreadnought battleship Rostslav (completed year 1900). The naval version was structurally lighter design, which proved to have issues with weak gun barrels and poor ballistics.
Also Russian coastal artillery found the gun suitable for its purposes – one reason to prefer it was that this gun was considered to be just barely light enough for the gun to be laid by hand. The coastal-gun version equipped with Durlacher gun mount being officially approved year 1895. The decision for approving the gun to military use was criticised already early on, because due to old-fashioned structural design the gun could be expected to have only a short lifespan before becoming obsolete. Two major existing factors made it obsolete - gun mount and type of gun laying method. The ascending gun mount used for this gun belonged to those developed by General Robert Augustovits Durlacher (later: Durljahov) and was old-fashioned already when introduced. The decision to favour gun design that had been intended to be laid by hand was also questionable considering by that time many countries had already introduced coastal guns with electrical gun laying systems. Obuhov Steel Works was the sole manufacturer of these guns. First coastal guns were ordered in year 1896, but since accident that happened in test-shooting of the naval-version resulted changes introduced for the gun re-entering to production, the first delivery of coastal guns was delayed until year 1899.
The gun on its own had pretty good ballistics, but in typical manner the design of gun mount substantially limited its maximum elevation and therefore the gun's maximum range. While Obuhov Steel Works was only manufacturer for the gun. The Durlacher ascending gun mount used with it had two manufacturers - Putilov and Bryarsk. Obuhov started manufacturing the gun mounts starting year 1899, while Bryarsk started its manufacturing in year 1904. Early Putilov-manufactured gun mount had maximum elevation of only +15 degrees (allowing maximum range of only 10.7 km), while later gun mounts came with maximum elevation of +20 degrees. Year 1905 Durlacher planned a modification for the existing gun mounts which when implemented allowed them to reach maximum elevation of +30 degrees resulting maximum range of 18.1 km. This modification was apparently implemented to all existing gun mounts and also resulted orders of new gun mounts for which modification had already been made, even if this again caused some debate. Just like smaller ascending gun mounts, also this gun mount had upper and lower parts on top of each other, with small rollers in between and used recoil dampening based on gravity and friction. During recoil the gun worked against its own weight because when moving backwards the upper part of gun carriage was forced to climb upwards on lower part against its own weight with the climb being at angle of five degrees. Once the climb had reached its high point, the gun returned back into its original position on its own weight.
PICTURE: Group of men from Civil Guard of Lavansaari Island photographed in front of
254-mm coastal gun during Finnish Civil War in year 1918. The gun carriage appears to have unusual design. Russian military
started construction of 254-mm coastal artillery battery on Ristniemi Cape of Lavansaari Island in year 1916.
The artillery battery fell into Finnish hands in year 1918, but since the island was
demilitarized after Tartto / Tartu / Dorpat Peace Treaty of year 1920, the guns were dismantled and moved
elsewhere. Group of men seen here have Japanese rifles. Photographer unknown.
Photo source Museum of Kymenlaakso (Kymenlaakson museo), acquired via finna.fi
and used with CC0 1.0 (Public Domain) license.
CLICK THUMBNAIL TO SEE LARGER PIC (171 KB).
Most super-heavy coastal guns have main pivot under middle of the gun mount, but in this case the main pivot was in front of the gun mount and the gun was laterally turned around it with a set of wheels rotating on rail under the rear section of gun mount. Hence horizontal gun laying of this gun by hand was hard physical labour - requiring team of four men, who due to exhaustion had to be replaced with another team after every 30 minutes. This gun laying method also proved so slow, that in reality the guns were not able to keep up following moving targets (ships) and had to aimed to shoot the point in which the enemy ship was heading and wait until it came into line of fire. During World War 1 there were plans for replacing this old gun laying method with electrical gun laying system, but apparently they were not implemented. The last but not least major problem with these guns was primer system, which often got stuck, considerably reducing reliability.
Russian military first used both naval- and coastal-gun version in combat during Russian - Japanese War (1904 - 1905), with one coastal artillery battery equipped with these guns being used by defence of Port Arthur. While Russian coastal artillery acquired additional 254-mm coastal guns during that war, it was already becoming quite clear that the gun had already lost its best edge against modern battleships. During World War 1 Russian military used 254/45 D guns both as super-heavy coastal artillery and long-range artillery. Two guns captured year 1916 also saw use in Bulgaria. Red Army got rid of most 254-mm coastal artillery batteries remaining in Russian territory already in 1920's, but some apparently remained in service to see action during the 2nd World War.
PICTURE: Coastal artillery batteries equipped with 254/45 D guns in Finland year 1918. CLICK THUMBNAIL
TO SEE LARGER PIC (188 KB).
This gun, which Finnish military named as 254/45 D was to become the most common super-heavy coastal gun in use of Finnish military during World War 2, even if was also the most outdated super-heavy coastal gun in Finnish use. Year 1918 Finnish Army took over numerous coastal artillery batteries equipped with 254/45 D coastal guns left behind but the Russians, but not all of these were in operational condition. Large majority of the 254-mm coastal artillery batteries built during Russian era were around Helsinki. These coastal artillery batteries around Helsinki had been built as part of Krepost Sveaborg (Sveaborg Fortress) in 1913 – 1917 and were located on five islands reaching from southwest to southeast side of the city. They contained six coastal artillery batteries of four guns each - total 24 guns. The first of these coastal artillery batteries was on Isosaari Island, for which four guns arrived from Kronstadt already in December of 1913. Later September of 1914 additional 12 guns arrived from Vladivostok in September of 1914, the last 8 guns did not arrive until year 1915.
PICTURE: Artillery battery of 254/45 D coastal guns on Kuivasaari Island outside Helsinki in May
of 1919. This sort of arrangement in which all four guns were placed side by side on barbette, which was single massive
concrete structure is commonly referred as "battery front" and allowed only rather limited firing sector for
its guns. Photographer unknown. Photo source Helsinki City Museum (Helsingin kaupunginmuseo), acquired via
finna.fi and used with CC
BY 4.0 Creative Commons license. CLICK THUMBNAIL TO SEE LARGER PIC (97 KB).
254-mm coastal artillery battery batteries near Helsinki in year 1918:
Artillery |
Name of |
Name of |
Number of |
Building |
Battery |
Island (FI) |
Island (RU) |
Guns |
completed |
45 |
Isosaari Island |
Stora Mjölö |
4 x 254/45 D |
autumn of 1915 |
46 |
Isosaari Island |
Stora Mjölö |
4 x 254/45 D |
May of 1916 (*) |
41 |
Rysäkari Island |
Rysskär |
4 x 254/45 D |
spring of 1916 |
42 |
Katajaluoto Island |
Mozzvelovyj |
4 x 254/45 D |
autumn of 1915 |
44 |
Kuivasaari Island |
Malej Mjölö |
4 x 254/45 D |
autumn - winter of 1915 |
49 |
Itä-Villinki Island |
Malenkij Villinge |
4 x 254/45 D |
year 1916? |
(*) This artillery battery was originally built for 279-mm coastal guns and modified for 254-mm guns in year 1916.
In addition to these there were coastal artillery batteries with 254-mm guns in Finnish territory located in eastern part of Gulf of Finland:
Artillery |
Name of |
Name of |
Number of |
Building |
Battery |
Island (FI) |
Island (RU) |
Guns |
completed |
? |
Fort Ino |
Fort Nikoevsky |
8 x 254/45 D |
? |
? |
Lavansaari Island |
Mostsnyj Island |
4 x 254/45 D |
? |
Because of Russian - German treaty during Finnish Civil War coastal guns around Helsinki had been disabled temporarily to make sure that Finnish Red Guards would not be able to use them. This work was done by removing certain key components of breech block from each gun, so once Civil War was gone coastal guns around Helsinki could be easily returned back to service. The guns on Ino coastal fort in southern shore of Carelian Isthmus were completely different matter - Russian military had blown up the whole coastal artillery installation of Ino while abandoning it in 14th of May 1918. Apparently none of 254/45 D guns from Ino were salvageable, while the guns of Lavansaari Island were captured pretty much intact. Hence the total number of 254/45 D guns taken to Finnish use was 28 guns. Tartto/Tartu Peace Treaty of year 1920 demilitarised certain islands in eastern parts of Gulf of Finland, these islands included Lavansaari Island, so the guns of Russian-built 254/45 D coastal artillery battery had to be soon transported elsewhere.
That "elsewhere" was south-east tip of Koivisto (Primorsk) Island, where Finnish military built its first own 254/45 D artillery battery of guns by using site of previous uncompleted Russian coastal artillery battery. Due to earlier Russian work in this site (intended for 152-mm coastal artillery battery), which was named as Saarenpää coastal artillery fort, the whole coastal artillery battery was built in just few months and became operational in already August of 1921. However for that very same reason this coastal artillery battery was built in Russian battery front fashion in a single massive concrete structure with their sector of fire limited to about 120 degrees. Considering the strategically important role of this coastal artillery battery that was defending south west flank of Finnish main defence line in Carelian Isthmus, this was soon found to be unsatisfactory and Saarenpää 254/45 D coastal artillery battery would get totally rebuilt circa 1936 - 1938 with number of its 254/45 D guns increased to six.
Kirkonmaa coastal artillery fort outside city of Kotka became location for the first completely Finnish designed and built coastal artillery battery for 254/45 D guns. Building of this coastal fort started year 1925 and construction work for the actual 254-mm artillery battery started in 1927 with this artillery battery reaching operational status in September of 1929. Guns for Kirkonmaa artillery battery had been transferred from one of the two artillery batteries on Isosaari Island. Unlike Saarenpää artillery battery built in year 1921, guns of Kirkonmaa super-heavy artillery battery had been dispersed in gun pits intended to be as inconspicuous as possible. Not only was the resulting artillery battery notably more difficult to spot, but its guns had 360-degree sector of fire.
PICTURE: 254/45 D coastal gun fires a shell during gunnery practice in July of 1942. This gun belonged to
coastal artillery battery on Rysänkari Island outside Helsinki. The gun is in gun pit of Russian World War 1 era battery
front type of artillery position to which the Finnish military has added somewhat improvised rear wall to provide additional
protection against bomb or artillery shell possibly landing behind the gun pit. Also notice rifle stand on the right.
Photographed by Military official Esko Suomela (SA-kuva.fi photo archive, photo number 95178). CLICK THUMBNAIL TO SEE LARGER
PIC (126 KB).
Year 1928 Finnish coastal artillery had all captured 28 guns in operational condition. Due to its gun mount 254/45 D was considerably more difficult to modernise than most other coastal guns, but in 1920's Finnish military started the development work by improving the ammunition. Much of the captured 254-mm high explosive projectiles had still been filled with gunpowder, which reduced their effect in target. Now gunpowder in these existing projectiles was replaced with much more potent TNT and ballistic caps were added to improve ballistics. Ballistic caps increased maximum range, but structural design of the Durlacher gun mount did not allow increasing maximum elevation in any other otherwise commonly used methods. All 245/45 D guns in Finnish use were installed under an open sky in parapet-type firing positions. In 1930's surfaced plans of installing 254/45 D into gun turrets to improve their protection, but again due to structural design of the gun mount, this proved very difficult. Ultimately these plans for installing these guns to gun turrets was abandoned once it became apparent in year 1939 that Finland might be able to buy more powerful and modern 305/52 O guns from France.
When World War reached Finnish shores in form of Finnish - Soviet Winter War in 30th of November 1939, Finnish coastal artillery had 26 of these guns in its operational use. These 26 guns were in following coastal artillery batteries:
name of the island: |
guns: |
Isosaari Island (Helsinki) |
4 |
Rysäkari Island (Helsinki) |
4 |
Katajaluoto Island (Helsinki) |
4 |
Itä-Villinki Island (Helsinki) |
4 |
Kirkonmaa Island (Kotka) |
4 |
Saarenpää fort (Koivisto Island) |
6 |
total: |
26 |
PICTURE: Coastal artillery batteries equipped with 254/45 D guns in Finland year 1939. CLICK THUMBNAIL TO SEE LARGER
PIC (198 KB).
245/45 D GUNS IN WINTER WAR
As mentioned 73rd Artillery Battery equipped with 254/45 D guns artillery on Saarenpää coastal artillery fort in south-east tip of Koivisto Island (Bolšoi Berezovyi Island) was completely rebuilt around 1936 - 1938. Totally new artillery positions had been built for it bit deeper in the island and with two additional 254/45 D guns added to the battery the number of its guns was increased to six. Presumably the two guns added at that time originated from Kuivasaari Island (outside Helsinki), whose 254/45 D artillery battery of four guns had been replaced with gun turret equipped with two 305/52 O guns. New Saarenpää 254-mm coastal artillery battery had dispersed artillery positions and its guns had 360-degree sector of fire. This new 254/45 D battery was officially referred also as 73rd Artillery Battery (73. Patteri) in 1930's and during Winter War. Battery front type firing position that it had previously used had been equipped with two smaller 152/45 C guns in year 1937 with two of the battery front gun pits modified for them. In addition to these the coastal fort had light coastal artillery section with two 57/58 H guns. As part of troop build-up done doing mobilisation for Winter War in October - November 1939 two field gun batteries had been added to troops of coastal fort. In addition it had been reinforced with two anti-aircraft artillery sections (of two guns) - one of them equipped with 75mm Zenit-Meller and second one with 47/40 O guns. Rebuilding of Saarenpää 254/45 D artillery battery allowed Finnish military to introduce its guns some new improvements, some of which later on proved less than successful. The main pivot was moved in middle of the gun mount and front end of the gun mount was placed on pair of wheels moving on rails - while this may have seemed to be a smart improvement, it changed the guns centre of gravity on its gun mount. The essential part of development process that apparently was neglected in this case was through testing of changes with large-scale test-firing, which hid the mistakes done in the development work until it was too late. When Winter War started the military personnel called to the artillery battery were mostly inexperienced reservists, which were now handed untested guns, which they would not get an opportunity to shoot with, until during the first battles.
PICTURE: 254/45 D coastal gun getting loaded. Photo taken in one of the islands outside Helsinki during
Continuation War. Photographed by Lieutenant P.J. Wiro (SA-kuva.fi photo archive, photo number 96329). CLICK THUMBNAIL TO
SEE LARGER PIC (155 KB).
Once war started 254/45 D guns of Saarenpää coastal fort showed alarming number of technical problems already early on. Once after the guns had fired just 18 shells total all six guns were out of action due to technical issues, which practically always followed the same soon to be familiar pattern - front axle and wheels breaking down after only few shots. To make things worse spare parts needed for replacing these broken parts were acquired in a hurry and apparently their quality proved to be less than satisfactory. As if this would not have been enough gun barrel of one of the six 254/45 D guns cracked in these early battles - reducing the total number of operational guns in 10-inch artillery battery to only five guns for rest of the war. Even with their constant technical problems Finnish gun crews still succeeded keeping enough of their operational in these early battles for the 10-inch battery to remain effective, but soon they would face a much harder test.
Soviet Red Army that was attacking against western parts of Finnish main defence line in Carelian Isthmus, Mannerheim-line, had noted to their displeasure the accuracy of deadly fire missions performed by Finnish 6-inch and 10-inch coastal artillery batteries. 9th of December Soviet Baltic Fleet received orders to silence Finnish coastal artillery batteries providing this fire support. The first Soviet attempt to destroy Saarenpää coastal artillery fort with their battleships took place already the next day - 10th of December 1939. The battleplan was rather simple - Soviet Navy had two modernized Gangut-class battleship on Baltic Sea and their 12-inch main guns were technically far superior to old 254/45 D coastal guns. Hence the Soviets could reasonably expect to be able to destroy coastal forts with naval units lead by these battleships.
PICTURE: Gun crew of 254/45 D coastal gun photographed during gunnery practice in July of 1942. This
gun belonged to coastal artillery battery on Rysänkari Island outside Helsinki. Notice camo nets. Soldier on the left
with headphones and microphone is in contact with battery's fire control and the white tubular package that soldier on the
right is carrying to gun is propellant charge. Photographed by Military official Esko Suomela (SA-kuva.fi photo archive,
photo number 95182). CLICK THUMBNAIL TO SEE LARGER PIC (165 KB).
The battle in between Soviet battleship Oktyabrskaya Revolutsiya and Finnish Saarenpää coastal fort 18th of December 1939:
time: |
Event: |
09:48 |
Three Soviet S-class destroyers spotted. |
10:07 |
Six TB-1 bombers escorted by five I-15 fighters bomb the coastal fort. Bombs fell |
to fields near the garrison. |
|
10:19 |
Two Soviet I-16 fighters overfly 254/45 D artillery battery. |
10:30 |
Three SB-bombers bomb the coastal fort. Some bombs fell in between observation |
tower and 254/45 D artillery battery. |
|
11:15 |
Three TB-1 bombers bomb the coastal fort. Bombs fell near 152/45 C artillery battery. |
12:18 |
Oktyabrskaya Revolutsiya (O.R. from now on) spotted. Distance 25 - 30 km. |
12:25 |
O.R. fires preparation shots to warm up its 305-mm main guns. |
12:20 |
Soviet bomber drops bombs near observation tower. Alarm made in coastal fort to |
prepare for incoming artillery fire. |
|
12:39 |
Saarenpää coastal fort opens fire with its 254/45 D artillery battery from measured |
distance of 22.2 km. |
|
12:46 |
Due to faulty readings originating from Muurila distance measuring point, Saarenpää |
had to halt its fire. Correct readings received starting 12:45. All 24 shells fired by 254/45 D |
|
artillery battery by that time had fallen short by significant margin due to false readings. |
|
12:54 |
O.R. opened fire towards Saarenpää coastal fort with ranging shots. Estimated target |
area that it used was area around observation tower. |
|
12:58 |
O.R . shifts into fire for effect with all its twelve 305-mm guns. |
13:00 |
Seven Soviet bombers bomb the coastal fort, bombs fell near 254/45 D artillery battery. |
13:04 |
Saarenpää 254/45 D artillery battery re-opens fire, but one after another its guns start |
experiencing technical problems, which put them out of action. |
|
13:22 |
Also smaller Soviet warships are bombarding coastal fort with their guns. |
13:37 |
All guns of 254/45 D artillery battery now out of action due to technical problems. |
13:50 |
O.R . stops firing and heads towards Saarenpää coastal fort. |
13:55 |
O.R . re-opens fire from distance less than 20 km. |
13:58 |
Saarenpää 152/45 C artillery battery opens fire towards closest destroyer. |
14:00 |
4th gun of 254/45 D artillery battery finally back in action and opens fire. All other four |
guns still out of action due to technical problems. |
|
14:15 |
O.R. is changing course. |
14:21 |
4th gun of 254/45 D artillery battery continues shooting towards O.R. Shoots repeatedly |
until ordered to stop shooting at 14:25. |
|
14:30 |
Soviet fighters bomb 254/45 D artillery battery with incendiary bombs that fell to area |
in between artillery battery and beach, setting the forest on fire. |
|
14:34 |
Soviet fighters constantly circling over the coastal fort and strafing it with machineguns. |
14:35 |
O.R . is heading off, distance 27.7 km. |
14:48 |
O.R. no longer visible. |
Ammunition spending: |
|
Soviet: |
|
- Oktyabrskaya Revolutsija: About 300 of 305-mm artillery shells. |
|
- Soviet aircraft: About 200 bombs and unknown number of machinegun rounds. |
|
Finnish: |
|
- Saarenpää 254/45 D artillery battery: 3 HE-shells and 49 APHE-shells. |
|
- Saarenpää 152/45 C artillery battery: 9 HE-shells and 30 HE-shells with time fuse (against aircraft). |
|
- Saarenpää 40-mm Bofors anti-aircraft gun section: 306 rounds (against aircraft). |
|
- Saarenpää 37-mm Maxim automatic cannon section: 53 rounds (against aircraft). |
|
- Rifle-caliber ammunition: Unknown number (against aircraft). |
Casualties of Saarenpää coastal fort from this 18th of December battle were five men wounded. In addition vitally important telephone connections had been damaged and the telephone network was down. Some buildings had also been damaged or destroyed. Two old brick-structure bunkers originally built as ammunition storages, which Finnish coastal artillery had converted as shelters for artillery battery personnel had been destroyed. Forest around the artillery battery had been levelled. According observations made after the battle, the artillery fire from O.R. had been relatively inaccurate with its shell hits spreading to area about four square kilometers in size. The Soviet battleship had used its MBR-2 flying boat for observing its fire, while 152/45 C coastal artillery battery succeeded forcing the flying boat to keep its distance, Finnish guns failed to shoot it down. During the battle two Soviet destoyers had closed the fort to distance of only about 10 km, until 152/45 C artillery battery had forced them to retreat, which may have made a considerable difference, since with the destroyers forced beyond effective range of their main guns left O.R. as only Soviet warship effectively able to target 10-inch coastal artillery battery. Right after the battle considerable effort and hard work was put in fixing the technical problems at least temporarily to get the guns back into action with parts cannibilized from guns most difficult repair. These repairs succeeded returning four out of six (or five considering the one gun with cracked gunbarrel) guns back into action. This proved to be a smart move, since the situation was far from over - with another Soviet battleship coming to "visit" the coastal fort already the next day. Officers of the coastal fort also come up with a battle plan to next time first open fire with only one gun and keep shooting with just that single gun only until technical problems put it out of action, at which point fire would be opened with the next gun. The key point for this plan was to try use the guns sparingly in attempt to avoid situation in which all guns would have been out of action at the same time, in other words avoid leaving the coastal fort defenseless.
The battle in between Soviet battleship Marat and Finnish Saarenpää coastal fort 19th of December 1939:
time: |
Event: |
08:35 |
Three Engels-class destroyers spotted. |
09:01 |
Air raid alarm in the coastal fort. |
09:13 |
Six bombers attack the coastal fort. This starts series of air raids considerably more |
Powerful than day before that continued almost sun down. However the aircraft now |
|
seemed to have performed their attacks from higher altitude. |
|
11:10 |
Leningrad-class, Grosnyi-class and seven smaller ships spotted. |
11:21 |
Battleship Marat and escorting ships spotted. Marat sent two Beriev MBR-2 sea planes, |
which went circling the coastal fort, probably acting as forward observers. Escorting ships |
|
Included one Grosnyi, two Engels-class and four other warships. |
|
11:55 |
Marat shots preparation shots to warm up its 305-mm main guns. Distance 30.3 km. |
12:18 |
Distance to Marat 23.0 km. |
12:25 |
Marat opens fire with its 305-mm guns from distance of 21.6 km. Already the first shells |
hit just 100 meters in front of observation tower and Marat shifts immediately into |
|
fire for effect with all its 305-mm guns. |
|
12:29 |
Saarenpää 254/45 D artillery opens fire with one gun only (as planned). |
12:36 |
Telephone connections of the coastal fort are down. |
12:43 |
Marat is changing course. |
12:44 |
Distance to Marat less than 20 km. Saarenpää opens fire with all its working 254/45 D guns, |
although at that moment all but two guns are already out of action due to technical |
|
problems, so only two guns are now actually shooting. |
|
12:55 |
Marat stops shooting, turns away increasing speed. |
13:04 |
254/45 D artillery battery ordered to stop shooting, distance to Marat 23.8 km. |
Ammunition spending: |
|
Soviet: |
|
- Battleship Marat: About 150 - 170 pcs 305-mm shells (34 salvos). |
|
- Soviet aircraft: About 200 bombs. |
|
Finnish: |
|
- Saarenpää 254/45 D artillery battery: 35 APHE-shells. |
|
- Saarenpää 152/45 C artillery battery: 13 HE-shells with time fuse (against aircraft). |
|
- Saarenpää 40-mm Bofors anti-aircraft artillery section: 243 rounds (against aircraft). |
|
- Saarenpää 37-mm Maxim automatic cannon section: 176 rounds (against aircraft). |
|
- Rifle-caliber ammunition: 6,700 rounds (against aircraft). |
Losses that Saarenpää coastal fort suffered in its battle against Marat were slight - there were no casualties, but several more buildings had suffered damage and telephone network was down again. Also, as before 254/45 D guns had suffered from technical problems and had broken down one after another - resulting situation in which the artillery battery had at most being able to shoot with only two of its guns simultaniously at most. Artillery fire from Marat had been remarkably accurate if compared to artillery fire from Oktyabrskaya Revolutsiya just day before. However the number of shells it had fired had been notably smaller and it had left the battlefield in somewhat of a surprising manner, which caused suspicion about possible reason for such a move. Just before Marat turned to leave, three range measuring stations of the coastal fort reportedly spotted a puff of smoke on Marat at the moment when its guns were not firing. Due to this Finnish military came to conclusion that one of the artillery shells may have hit Marat, although later Soviet and Russian official histories have denied the ship suffering any damage on that day.
Mainly due to their inherent lack of stability warships were far cry of ideal platform for long-range gunnery. Hence military theories of the era gave highly favourable ratio of 4 : 1 for effectiveness of coastal artillery versus naval artillery. However this theory assumed both coastal and naval guns to be similar caliber and have similar rate of fire. If looking just to rate of fire, the outcome was far less favourable than expected. In theory (four or five functional) guns of Saarenpää 254-mm artillery battery should have been able to fire total 8 - 10 shots/minute, or in practice if anything had worked properly at least total 4 - 5 shots per minute, which would still been very modest rate of fire compared to total of 12 - 21 shots per minute (assuming all 12 main guns could be fired simultaneously, which was only possible if the ship had its broadside towards coastal fort) Gangut-class battleships. But since on average the number of 10-inch guns remaining in action was about two guns the actual rate of fire for the whole 10-inch coastal artillery battery was seriously outgunned compared to Gangut-class battleship. Moreover there was notable disparity in between 10-inch coastal guns (firing 235-kg artillery shells) versus 12-inch naval guns (firing 450 or 470-kg artillery shells). It is also noteworthy that if either of the battleships would have gotten closer to the coastal fort, they could have also used their secondary (16 x 120-mm) guns to further increase their considerable superiority of firepower.
As a whole, even if the coastal artillery battery failed to do any real damage to the Soviet battleships, it still won the battle in that sense that the Soviet plan of destroying Finnish coastal artillery batteries obviously failed. While Marat reported that it had destroyed the coastal artillery battery, in fact Saarenää 254-mm artillery battery continued to provide artillery support to Finnish troops already the next day. 73rd Artillery Battery of Saarenpää coastal fort took part in providing this artillery support by firing such a large number of 254-mm high explosive shells to ground targets, that it made the number of shells it had used against battleships to look minuscule in comparison. At the same time even with its old guns and technical problems 73rd Artillery Battery became the Finnish super-heavy coastal artillery to see most combat during whole World War 2. While the air raids against Saarenpää coastal fort became less frequent after December of 1939, during Winter War it still earned the unfortunate title of probably most heavily bombed coastal artillery installation in a world by that time. By the time Saarenpää coastal fort was finally evacuated due to Soviet troops advancing on mainland behind the island the fort was located Soviet aircraft had bombed with about 2,000 heavy bombs and estimated 10,000 smaller bombs. Also Soviet field artillery started to shell Saarenpää starting 1st of February, typically responding to its fire missions fired to ground targets with counter-battery fire. This became a regular event especially since starting 10th of February Saarenpää fort was typically shooting fire missions to land front several times a day. Even with all this bombing and shelling the coastal fort remained operational and continued to provide artillery support until advancing Soviet troops in late February threatened to cut off the island, Koivisto Island, on which this coastal fort was located. The threat of being cut off resulted Finnish military evacuating Koivisto Island in 23rd of February 1940. By that time the Saarenpää coastal fort had suffered total losses of 24 killed in action and 33 wounded. The total ammunition spending of 73rd Artillery Battery by 23rd of February contained at least 725 high explosive shells and 90 armour piercing high explosive shells - more than any other Finnish super-heavy coastal artillery battery ever before or later. The evacuation from Koivisto Island happened with troops marching on ice by foot to Gulf of Viipurinlahti. Under these circumstances evacuating of heavy and super-heavy coastal guns was totally impossible, hence all 254/45 D and 152/45 C guns of Saarenpää coastal fort were destroyed by their crews just before the coastal fort was evacuated.
PICTURE: One of the destroyed Winter War era 254/45 D coastal guns of Saarenpää coastal fort
photographed in November of 1941. Gun barrel has been destroyed and the partially snow-covered gun has old camouflage net
on top of it. Photographed by Lieutenant Tauno Lautamatti (SA-kuva.fi photo archive, photo number 60560). CLICK THUMBNAIL
TO SEE LARGER PIC (184 KB).
Another Finnish coastal artillery battery, whose 254/45 D guns saw combat use during Winter War, was on Kirkonmaa Island outside city of Kotka. Building of Kirkonmaa coastal fort had started in year 1925 with construction work of its 254-mm artillery battery beginning in year 1927. This artillery battery had four 254/45 D guns originating from Isosaari Island. This coastal artillery battery with dispersed gun positions hidden in the islands terrain and modified gun mounts allowing its guns to have 360-degree firing sector. March of 1940 Soviet naval troops marching on ice from islands of Suursaari and Lavansaari on ice tried to land Kotka coastal defence sector, which was defended by coastal forts of Kirkonmaa, Rankki and Pukkio. Kirkonmaa 254-mm artillery battery fired bit over 100 high explosive shells towards these troops and played key role with another coastal forts in repulsing the attack. In contrast with experiences of Saarenpää fort, Kirkonmaa had very little problems with its 254/45 D guns besides primer systems occasionally getting stuck, which was a basic defect of these guns for their whole service career.
Coastal artillery batteries equipped with 254/45 D guns in January and September of 1944:
number of guns: |
||
name of the island: |
January: |
September: |
Isosaari Island (Helsinki) |
3 |
3 |
Rysäkari Island (Helsinki) |
3 |
3 |
Katajaluoto Island (Helsinki) |
3 |
3 |
Itä-Villinki Island (Helsinki) |
4 |
4 |
Kirkonmaa Island (Kotka) |
4 |
4 |
Saarenpää fort (Koivisto Island) |
3 |
- |
Kellomäki (Carelian Isthmus) |
3 |
- |
total: |
23 |
17 |
(Based to Suomen linnoittamisen historia 1918 - 1945 pages 484 - 485). Coastal artillery batteries of Kellomäki and Saarenpää were lost in summer of 1944.
PICTURE: Coastal artillery batteries equipped with 254/45 D guns in Finland January 1944. CLICK THUMBNAIL TO SEE LARGER
PIC (200 KB).
254/45 D GUNS IN CONTINUATION WAR (June 1941 - September 1944)
Only two Finnish coastal artillery batteries equipped with 254/45 D guns used their guns in combat during Continuation War. The less successful of these two was 28th Super Heavy Artillery Battery (28. Järeä Patteri) built to Kellomäki in southern shore of Carelian Isthmus. The starting point for this super-heavy coastal artillery battery was a decision made in December of 1941 to place Kellomäki one 254/45 D gun for the purpose of shelling Kronstandt. July of 1942 these plans were changed as super-heavy coastal artillery battery equipped with three 254/45 D guns. The guns for Kellomäki artillery battery were transferred from coastal forts defending Helsinki, with coastal forts on Isosaari Island, Katajaluoto Island and Rysäkari Island each providing one gun. The location chosen for this new super-heavy coastal artillery battery - on top of a steep climb rising from the beach so close to the frontline soon proved to be a serious error in judgement. The location was just 12 kilometers from the frontline, similar distance from closest Soviet coastal artillery fort (Totleben) and some 18 - 20 kilometers from Kronstadt. Hence basically so vulnerable that that it did not take a crystal ball to note that if the guns of this artillery battery would even open fire, they could be expected to attract immediate large-scale counter-battery action. Hence this artillery battery only fired one test shot and then remained silent for rest of the trench war period. Only once the Soviet offensive started in Carelian Isthmus did its guns take part in battles for one day only - 10th of June 1944. It may be considered rather ironic that the first fire mission given to this artillery battery came with the goal of it attracting counter-battery fire and get Soviet coastal artillery batteries to target it to stop them shelling trenches of Finnish infantry. As expected this goal was soon achieved with firestorm of heavy and super-heavy artillery shells raining on Kellomäki artillery battery. With two of its three guns suffering from technical issues the unit succeeded firing only 32 high explosive shells, all of them to land front, before closing Soviet troops threatened to over-run its area and the artillery battery had be abandoned. Before leaving the artillery battery its only working gun was destroyed, ammunition bunkers blown up and buildings set on fire.
PICTURE: Kellomäki coastal artillery battery middle of construction in August of 1942. This photo of partially
assembled 254/45 D gun illustrates well structure of the gun mount. Photographed by Lieutenant Pauli J. Wiro (SA-kuva photo archive,
photo number 103965). CLICK THUMBNAIL TO SEE LARGER PIC (162 KB).
Another more successful super-heavy coastal artillery battery in eastern Gulf of Finland was 254/45 D artillery battery of Saarenpää coastal fort on Koivisto Island (Bolšoi Berezovyi Island), which was rebuilt in 1942 - 1943. When Finnish military recaptured the island in November of 1941, they found Saarenpää coastal fort in exactly the same state that had been when abandoned in February of 1940 - all demolished guns lay destroyed in their gun pits, but the artillery positions remained in usable condition. Repairing of the installations to usable condition started with removal of previously demolished guns from their gun pits. Rebuilding work for the super heavy artillery battery in Saarenpää started May of 1942 with decision about equipping it with three 254/45 D guns being made in July of 1942. Since demolition work done in 1940 had concentrated in destroying gun barrels, six destroyed guns provided much of the parts needed for assembling three operational guns. But not everything could be recycled, demolition work had done a very through work in destroying gun barrels, so three barrels were transferred to Saarenpää from coastal forts defending Helsinki. Two gun barrels originating from coastal fort on Katajaluoto Island and one gun barrel from Kuivasaari Island arrived to the artillery battery in early August of 1942. Three 254/45 D guns of this super artillery battery were installed to the gun pits earlier used by 1st, 4th and 6th guns of Winter War era 73rd Artillery Battery. This repair work resulted the first gun becoming operational in late November and other two in mid December of 1942.
Continuation War era Saarenpää 254/45 D artillery battery got re-named several times. It started as 82nd Artillery Battery (82. Patteri) of 8th Coastal Brigade and originally arrived to Koivisto Island with 152/45 C guns. May of 1942 the unit was renamed as 25th Super Heavy Artillery Battery (25. Järeä Patteri) and became part of (Artillery) Group Heiskanen (Osasto Heiskanen) in November of 1942 until being re-named back as 25th Super Heavy Artillery Battery in October of 1943. Besides occasional search of Soviet desantti (paratroopers/spies) this unit did not see much combat until Soviet offensive started in Carelian Isthmus in 9th of June 1944. Until then the frontline had been outside range of its guns and Soviet naval activity had been quite limited, but now that changed. With frontline ever moving closer the artillery battery begun shooting fire missions to land front starting 16th of June. Already the next day 1st gun of the artillery battery started suffering technical problems with gun laying systems not working and then front support starting to buckle. All repair attempts failed to get the 1st gun working properly, which left the artillery battery with only two operational guns. Repeated air raids against the coastal fort started 19th of June, in which day it was bombed by Soviet aircraft at least six times. During one of these air raids there was a direct hit to gun pit of 1st gun, which set on fire gunpowder that had been stored in there. The fire spread to rooms of the gun pit, where the gun crew had taken shelter, killing 5 and wounding 14 men. 2nd and 3rd gun continued to provide artillery support to land front and shoot Soviet ships that had been spotted, even if the more air raids made against the artillery fort in the following days. 21st of June 1944 was the last day for this unit. Its two guns that still worked run out of high explosive (HE) shells in the morning and in lack of better ammunition from that on used armour piercing high explosive (APHE) shells also for fire missions that they shot to land front. In addition by the end the artillery battery was also running short on gunpowder. By that day 25th Super Heavy Artillery Battery had shot at least 85 artillery shells to land front and another 70 shells against Soviet warships, but these figures were far from complete for the last days of the artillery battery. Just in its last day the unit fired at least 74 shells not included to those numbers. Around noon gun crews of this artillery battery destroyed their guns and then joined the troops getting evacuated from the island to western shore of Viipurinlahti Gulf.
254/45 D GUNS IN POST-WAR ERA
Regardless of being very much outdated already by World War 2 standards, 254/45 D guns apparently had a good reputation among Finnish soldiers. As noted, early 1945 Soviet-led Allied Control Commission banned Finnish coastal for having guns larger than 120-mm in caliber in part of coast east of Soviet base in Porkkala. Since all Finnish coastal forts equipped with 254/45 D guns were in that area, they were all removed from coastal forts and transported to inland gun depots. Since numerous old super-heavy artillery batteries defending Helsinki equipped with 254/45 D had not seen combat use during World War 2, their gun barrels tended to be less worn than those of other more modern super-heavy coastal guns. Hence Finnish military suffering from tight funding was still considering putting these old guns back to active use. Plans made at that time included putting old materials to use by modifying gun mounts of 234/50 Be guns for 254/45 D guns, but also even more ambitious plans made by Finnish Navy for building sixteen twin gun turrets equipped with 254-mm guns from year 1950. Year 1959 a political decision was made to return super-heavy coastal guns to coastal forts, but when it came to these guns the only real result from this decision returning of only one gun to Katajaluoto Island in year 1962. Even that single 254/45 D never really returned to active use, instead its transport to Katajaluoto Island apparently served as a pilot project used as a test for later transports of 305/52 O guns and once ready the gun was among other things used for testing of gunpowder.
Year 1962 study was made to compare performance, required resources and expenses of super-heavy 254/45 D coastal gun versus heavy 152/50 T coastal gun. Outcome of the study was that coastal artillery battery equipped with 152/50 T guns was almost as effective in performance-wise as one equipped with 254/45 D guns, but at the same time required much less resources with significantly smaller expenses. Hence there was little need for 254/45 D guns from that on and all further plans considering possibly returning them to use of coastal artillery were cancelled. All guns that remained in depots were scrapped in 1970's. The gun from Katajaluoto Island was moved to coastal artillery exhibition on Kuivasaari Island in year 1992 and is nowadays one of the only two guns of this type remaining anywhere. The only other remaining gun is in former Port Arthur in China.
Like other super-heavy coastal guns also 254/45 D used bagged ammunition. Ammunition inventory for this gun included three versions of high explosive (HE) shells, two versions of armour piercing high explosive (APHE) shells and practice round. Other artillery shells used with it in exception of practice round and old cast-iron HE-shell all weight 235 kg, these two exceptions each weight 225 kg. Oldest version of the HE-shells was cast-iron shell filled with black powder and lacked ballistic cap, while the two more recent HE-shell versions had been loaded with TNT and had been equipped with ballistic caps to improve their ballistics. Both APHE-shell versions had been equipped with ballistic caps and had TNT as their explosive. It is worth noting that 254-mm guns were apparently chosen as main guns of Finnish coastal defence ships Ilmarinen and Väinämöinen, built in early 1930’s because their ammunition was compatible with 254/45 D coastal guns already existing in Finnish use.
305/52 O
(305 mm / 12" naval/coastal gun model 1907)
PICTURE: Kuivasaari twin gun turret with its two 305/52 O guns. CLICK THUMBNAIL TO SEE LARGER PIC (87 KB).
Calibre: |
304,8 mm (bagged ammunition) |
|
Barrel length: |
1585 cm aka L/52 |
|
Weight in action: |
about 150,000 kg (gun) |
|
Rate of fire: |
||
- Örö single mount: |
1 shots/min (theoretical), 0.5 shots/min (practical) |
|
- Twin gun turret (per gun): |
1 shots/min (theoretical), 0.5 shots/min (practical) |
|
- Single turrets: |
? |
|
Muzzle velocity: |
723 - 920 m/sec |
|
Traverse: |
360 degrees (*) |
|
Elevation: |
||
- Örö single gun mount: |
- 0 degrees, + 29 degrees |
|
- Twin gun turret: |
- 1.5 degrees, + 38 degrees |
|
- Ristiniemi single turret: |
- ? degrees, + ? degrees |
|
- Isosaari single turret: |
- ? degrees, + 52 degrees |
|
Max. range: |
||
- Örö single gun mount: |
32 km (before renovation) / 36 km (after renovation) (**) |
|
- Twin gun turret (***): |
41 - 42 km |
|
- Ristiniemi single turret: |
? km |
|
- Isosaari single turret: |
over 50 km |
|
Ammunition weight: |
355 - 470 kg (HE & APHE), 453 kg (SAPHE) |
|
Ammunition types: |
HE, SAPHE, APHE, practice |
|
Country of origin: |
Russia |
Finnish use: The most powerful coastal gun in Finnish use. Only nine guns were captured in 1918 and by Winter War 8 of them had been taken to active use. Only coastal artillery batteries equipped with these guns to see heavy fighting was Ristiniemi artillery battery during late Winter War, while also Mäkiluoto saw some combat use in first year of Continuation War.
This was the most powerful cannon ever used on Russian and Soviet warships. It was designed and manufactured by Obuhov Steel Factory, which had year earlier developed version with L/50 barrel, for which this gun with L/52 long barrel was based. It was officially approved to use of Russian Navy in year 1907, with first delivery made in year 1908. The same gun was also soon approved for use of coastal artillery, but coming up with decision about type of gun mount for this purpose took more time. It was manufactured in only relatively limited numbers with grand majority of production happening before Russian Civil War, which first slowed down and then practically stopped the manufacturing until last guns being delivered circa year 1921. While the sources do not exactly agree on total number of manufactured guns, the total production was likely just 152 guns and most certainly under 200.
Russian battleships equipped with these guns, which reached operational status:
- Gangut class, built for Baltic Sea Fleet:
- Gangut (Oktyabrskaya Revolutsiya), completed 1914.
- Petropavlovsk (Marat), completed 1914.
- Sevastopol (Parizkaja Kommuna), completed 1914.
- Poltava (Frunze), completed 1914.
- Imperaritsa Mariya class, built for Black Sea Fleet:
- Imperatritsa Mariya, completed 1915.
- Imperatritsa Ekaterina Velikaya (Svobodnaja Rossiya), completed 1915.
- Imperator Alexandr III (Voliya / General Alekseyev), completed 1917.
The guns used in battleships were installed in TM-3-12 triple- turrets. But likely as a way of saving in expenses much of the guns issued to coastal artillery were installed en barbette type open positions as battery front arrangement. There were also plans of installing coastal guns to steel turrets already early on, with eight twin gun steel turrets ordered from that purpose from St. Petersburg Metal Factory already in 1910. Two of these twin gun turrets were intended for Krasnaja Gorka coastal fort and another two turrets for Ino coastal fort. Both Russian Main Artillery Administration (GAU) and Naval Administration organised their own planning competitions for steel turrets intended for use of coastal artillery around 1911 - 1913. But it seems likely that due to material and/or manufacturing related problems caused by World War 1 the resulting turrets did not see wide-spread use until Russian revolution destroyed plans concerning their use in year 1917. Year 1915 Russian Naval Administration reverted its plan for installing 305-mm to steel turrets and started installing them on open positions en barbette with single gun mounts originally introduced by St. Petersburg Metal Factory in year 1910. One can only presume that the reason for this sort of decision was related to steel turrets not being available and en barbette solution was considered better than nothing. Admitted this sort of arrangement was probably also cheaper, faster to manufacture and quite likely also more reliable to operate than untested new steel turret design. What is known suggests that at least three super-heavy coastal artillery batteries, each equipped with four guns, were built during World War 1. However the plans concerning gun turrets were not completely abandoned either - apparently additional 14 twin gun turrets were placed under construction during World War 1 - although it remains uncertain how many of them actually completed. The massive construction work involving building of Peter the Great's Naval Fortress was far from complete when Russian revolution stopped all work in 1917 and what is known not even all 305-mm coastal artillery batteries built en barbette style were yet completed by that time. From all of those 305-mm coastal artillery batteries that Russian military had intended to be built in Finland, only the ones built in Ino coastal fort were fully completed in 1917. Being the most powerful artillery weapons in Russian inventory at that time, Soviet Union continued use and development of these guns and their ammunition. In 1930's the Soviets used triple gun turrets originating from Gangut-class battleship Poltava to built coastal artillery battery in Vladivostok and in 1950's turrets were used to built another coastal artillery battery in Sevastopol. These two particular costal artillery batteries remained operational until 1990's. Three remaining Gangut class battleships saw use in World War 2 along Soviet coastal artillery batteries, some of which such as Coastal Artillery Battery 30 in Sevastopol (Maxim Gorky I) and Krasnaja Gorka coastal fort gained considerable reputation.
PICTURE: West gun Fort Örö 305/52 O artillery battery. While this looks like a gun turret it really is not.
The box-shaped structure is just thin sheet metal and intended to protect breech area of the gun and gun crew from rain and snow. Concrete
roof rotating with the gun can be seen just below it. Photo taken in year 2016. CLICK THUMBNAIL TO SEE LARGER PIC (126 KB).
FROM 1918 TO 1920's
When Finland declared independence in December of 1917 there were only two coastal artillery installations equipped with 305/52 O guns in Finnish territory. These were:
- Ino coastal fort (Carelian Isthmus):
- 4 x 305/52 O gun in two twin gun turrets.
- 4 x 305/52 O gun as single guns in barbette-type open positions.
- Örö coastal fort:
- 4 x 305/52 O gun as single guns in barbette-type open positions.
Apparently both 305-mm artillery batteries in Ino coastal fort had become operational before Russian revolution stopped all fortification building works in 1917, but 305-mm artillery battery on Örö Island was not such a clear-cut case. The Russians had building of Örö super-heavy coastal artillery battery in January of 1915 and originally the battery had been intended to be equipped with four 234/50 BS guns, before the plans changed for four 305/52 O guns. The Örö artillery battery, or Artillery Battery 60 as the Russian military called it, became operational in spring of 1916, but as a whole its construction was still incomplete when Russian revolution started. By that time the guns had been installed and could be operated manually, but electric systems were still missing and certain parts of the construction work had not been finished.
PICTURE: Photo taken year 1918 from 305-mm twin gun turrets of Ino Fort after blown up and abandoned by the
Russian military. Source of photograph Finnish Heritage Agency (Museovirasto) via finna.fi
and used with CC BY 4.0 license. CLICK THUMBNAIL TO SEE LARGER
PIC (96 KB).
When Finnish military took over these coastal forts in 1918, it took neither of them to its own immediate use. 14th of May 1918 was the last day of Finnish Civil War, but also the day in which the Russian military abandoned Ino coastal fort and blew up its guns. Hence all its coastal artillery batteries were either damaged or destroyed. One 305/52 O guns of single gun mount artillery battery had relatively small damage and was repaired into operational condition of sort by using breech block brought from Örö, June of 1919 that gun was used to fire three shells to Kronstadt. While this gun was nominally operational at that time, operating it without functioning electrical systems reduced the rate of fire next to nothing. Year 1920 Finnish - Russian Tartto / Tartu / Dorpat Peace Treaty included terms according which Finland was to destroy Ino Coastal Fort - work which Finnish military implemented in very effective manner. While none of 305-mm guns of Fort Ino had been captured in usable condition, they still contained plenty of gun parts that were intact, which at 1920 were in danger of being sold as scrap metal by officials of Sotasaalistoimisto (Bureau of Captured Materials). Fortunately some far-sighted soldiers salvaged much of useful gun parts, until General K. Kivekäs succeeded stopping the overzealous officials. The most important of these salvaged parts were five 305/52 O gun barrels, which were transferred elsewhere. What might be more difficult to understand is why 305-mm artillery battery on Örö Island was not taken in Finnish use at that time either. The fact remains while the guns had been captured almost intact, as a whole the coastal artillery battery was still somewhat uncompleted and breech systems of these guns were missing some vitally important parts. The total number of 305/52 O coastal guns taken over by Finnish military in year 1918 was nine guns, from which five originated from Ino and four from Örö Island.
PICTURE: The another 305mm coastal artillery battery of Ino Fort photographed soon after being captured by
Finnish Army in year 1918. The Russians had tried destroying also guns of this battery, but one of its guns (likely the one in
the foreground) could be repaired into working condition by replacing breech block. As can be seen this battery had single gun
mounts placed in barbette-type open positions as battery front. Source of photograph Finnish Heritage Agency (Museovirasto)
via finna.fi and used with CC BY
4.0 license. CLICK THUMBNAIL TO SEE LARGER PIC (130 KB).
With 254/45 D guns being the de facto standard issue super-heavy coastal gun for Finnish coastal artillery, it took until late 1920's before Finnish coastal artillery understood the need for more powerful guns. Maybe the most important cause that resulted to this change of opinion was the realisation that 12 inches was of the smallest artillery caliber, which could be expected to be effective against battleships. Also location of Örö Island was considered by many to be less than ideal for the Finnish purposes - the most important place to protect was obviously capital - Helsinki. Hence year 1927 a motion was made to re-locate four guns for defence of Helsinki - two guns to Isosaari Island, one gun to Kuivasaari Island and one gun to Santahamina military base. While this plan was not implemented, later both Isosaari and Kuivasaari would receive coastal artillery batteries equipped with these guns.
PICTURE: 305/52 O coastal gun of Örö coastal fort in its new modernised artillery position in
October of 1941. Photographed by Military Official S. Puronne (SA-kuva.fi photo archive, photo number 60027). CLICK
THUMBNAIL TO SEE LARGER PIC (121 KB).
Finnish military introduced 305-mm coastal guns to its by starting with renovation of existing artillery battery on Örö Island. Russian World War 1 era built 305/52 O coastal artillery battery on Örö Island had its four guns installed on as two artillery sections of two guns each. In a sense one could note that this artillery battery was at least partially dispersed, since its artillery sections (of two guns each) had some distance between them. Photographs taken in early 1920's already show sheet metal shelters built around breech systems of each gun to provide protection against weather. Their guns had been installed on single gun mounts in barbette-type open artillery positions whose concrete massives had no rear wall. Finnish renovation work modified their gun pits into circular type with concrete roof that rotated with the gun. At the same time the renovation also equipped with electrical systems built for gun laying and loading of guns. Örö 305-mm artillery battery became operational circa year 1930. On the long run this renovation proved unsatisfactory and resulted building of modernised artillery positions started in late 1930's, at which time two of Örö's 305-mm guns were also transferred to new Ristiniemi coastal artillery battery.
The new modernised artillery positions for Örö 305-mm artillery battery were built by using one gun pit from each artillery section (massive). Since there were only two guns, their gun positions were now de facto properly dispersed with modernised gun pits also providing better shelter than the old renovated positions. While they had no real steel turrets, breech system area of each gun was covered by steel structure, which provided it protection against elements and some protection from shell fragments. Renovation of these improved artillery positions was not completed until just before starting of Continuation War, with the two guns in them being test-fired in June of 1941.
MÄKILUOTO AND KUIVASAARI
The successful renovation of 305/52 O artillery battery on Örö Island opened doors for building additional modern 305-mm coastal artillery batteries. The next ones in line after it were Mäkiluoto and Kuivasaari, whose 305-mm artillery batteries received funding in year 1931. Both places were to get a modern twin gun steel turret, with two guns placed side by side in the same turret. During World War 1 Russian military had been building 356-mm coastal artillery battery on Mäkiluoto Island, and while the guns never arrived the island, two incomplete twin gun steel turrets intended for the purpose had been brought there and were now put into good use. The turret that was closer to completion was used in Mäkiluoto and modified for two 305-mm coastal guns. The resulting Mäkiluoto gun turret was test-fired in year 1933, but according some sources building it was not totally completed until year 1935.
Building of second twin gun turret to Kuivasaari Island took considerably more work and due to only one crane being available, work on Kuivasaari Island was not started until heavy works that required lifting of heavy materials had been finished in Mäkiluoto. The turret foundation was quarried into bedrock in one of the gun pits of earlier Russian built battery front concrete massive for 254/45 D coastal guns. Once construction work for turret foundation was ready, the turret ring weighting about 100 (metric) tons was transported from Mäkiluoto to Kuivasaari on a coal barge in December of 1931. Once the turret ring had been safely transported to Kuivasaari Island and installed to turret foundations, transport of the other heavy parts could be started. While Kuivasaari gun turret was officially opened in May of 1934, it did not operational until summer of 1935.
The financing needed for building of gun turrets to Mäkiluoto and Kuivasaari was directly linked to secret Finnish - Estonian military co-operation, which if needed (if attacked by Soviet Union) was intended to block access of Soviet Baltic Sea Navy from Kronstadt to rest of the Baltic Sea. At least in theory Finnish 305-mm twin gun turret on Mäkiluoto Island and two Estonian 305-mm twin gun turrets on Aegna Island were intended with help of other coastal artillery, minefields, coastal defence ships and submarines, were intended to close Gulf of Finland in line Tallinn - Porkkala peninsula. While Mäkiluoto gun turret had this sort of international strategic importance, Kuivasaari gun turret was intended mainly for boosting up coastal defences of Finnish capital - Helsinki, which until then had based to coastal artillery batteries equipped with 254/45 D guns.
PICTURE: Mäkiluoto twin gun turret with its two 305/52 O guns. Photo taken in September of 1941. Photographed by
Military Official Suomela (SA-kuva.fi photo archive, photo number 51927). CLICK THUMBNAIL TO SEE LARGER PIC (133 KB).
RISTINIEMI
The last Finnish 305-mm coastal artillery battery build before World War 2 was Ristiniemi coastal artillery battery built to Ristiniemi Cape in Säkkijärvi municipality on western beach of Viipurinlahti Gulf just before Winter War. Year 1931 decision had been made to built coastal artillery battery of three or four 305-mm guns to Ristiniemi to allow closing Viipurinlahti Gulf and coastal shipping routes leading to west from Soviet Navy in such case that the coastal artillery batteries in Koivisto Islands would have been lost. Funding for Ristiniemi coastal artillery battery was made available in year 1936 with construction work starting already that same year. Before building of this artillery battery started the number of its 305/52 O guns was reduced to two, which were installed to new Finnish-built single gun steel turrets. As mentioned the guns used for building it were transferred from Island of Örö, whose 305-mm artillery battery from that on had only two guns. The guns installed to Ristiniemi were modernised and test-fired in Örö already before their transfer in year 1937. Most of the construction work in Ristiniemi was made in 1938 - 1939 with the artillery battery coming operational in autumn of 1939. This coastal artillery battery officially named as Artillery Battery 66 (Patteri 66) had its gun turrets located in extremely dispersed manner - there was almost kilometer in between them. Its 1st gun turret was referred with nickname "Kallio" ("Rock") while 2nd gun turret was known as "Kiviharju" ("Stone Ridge").
Ristiniemi was the only coastal fort to use its 305-mm coastal guns in battle during Winter War. When the war started in November of 1939, this coastal fort did not see much action early on, since frontline that had stopped in front of Mannerheim-line was well outside range of its guns and Soviet warships were busy with Saarenpää coastal fort until ice inhibited further naval operations. Only February of 1940 frontline started moving closer, with the coastal fort taking part in desperate battles in attempt to stop Soviet troops pouring across ice-covered Viipurinlahti Gulf and in end of the war the coastal fort was basically in the frontline. Ristiniemi 305-mm artillery battery started shooting fire missions to land front in 20th of February 1940. But that same day it also lost half of its firepower, when presumably due to failure to pre-heat the massive gun barrel in freezing weather with a smaller warming shot and instead starting by firing a shell with full power propellant charge. As a result of this failure gun barrel of 2nd gun ("Kiviharju") cracked with section about meter long breaking off from the muzzle of the gun. Finnish military did not exactly have much of an inventory of extra gun barrels for 305/52 O guns - once Ristiniemi was build 8 out of 9 captured guns were in active use and replacing the gun barrel weighting about 50,000 kg was not exactly easy either. Hence rest of Winter War Ristiniemi coastal fort had to do with just one operational 305-mm coastal gun. In that situation the remaining 1st gun ("Kallio") was put into hard use, which took its toll. When it came to estimated average service life of 305/52 O gun barrel the Russian/Soviet estimate was 300 shots, while Finnish estimate was just 150 - 200 shots. By end of Winter War in 13th of March 1940 remaining 305-mm gun of Ristiniemi fort fired total 298 shells and in last days of the war bore of this gun was so worn out, that the shooting accuracy was gone. During battle of nearby Tuppura Island (another coastal fort), this sole 305-mm coastal gun fired 58 high explosive (HE) shells in a single day against Soviet troops attacking over ice to the island. As a result the gun was in constant danger of overheating, which caused problems with its primer well and recoil behaviour. 305-mm high explosive shells broke massive holes in the ice, sending number of Soviet tanks and soldiers to cold watery grave. The Soviets responded by repeatedly bombarding Ristiniemi - in worst days Soviet aviation bombed it with rate of 600 - 700 bombs per day. Yet Ristiniemi coastal fort remained in Finnish hands to the last day of the war and when Finnish troops evacuated the coastal fort, before they destroyed its gun turrets before abandoning the fort.
Coastal artillery batteries equipped with 305/52 O guns in December of 1939:
type and number of guns: |
|||
location: |
as single guns: |
in twin gun turrets: |
in single turrets: |
Örö Island |
2 |
- |
- |
Mäkiluoto Island |
- |
2 |
- |
Kuivasaari Island |
- |
2 |
- |
Ristiniemi Cape |
- |
- |
2 |
total: |
2 |
4 |
2 |
PICTURE: Map showing historical locations of 234-mm and 305-mm coastal artillery batteries in Finland. CLICK
THUMBNAIL TO SEE LARGER PIC (243 KB).
305-mm coastal artillery batteries on Örö, Mäkiluoto and Kuivasaari did not see any real combat use during Winter War. Guns of Ristiniemi coastal fort in western shore of Viipurinlahti Gulf were lost, with their remains found as they had been left when Finnish Army recaptured the area in beginning of Continuation War in summer of 1941. Örö, Mäkiluoto and Kuivasaari remained in Finnish hands and active use for Continuation War (1941 - 1944).
BIZERTE GUNS
Imperator Alexandr III was the last completed Russian dreadnought battleship of Imperaritsa Mariya class built for Russian Black Sea Fleet. It was not completed until year 1917 and after Bolshevik revolution it was renamed as Volya (Freedom). The ship surrendered to the Germans in 1918 and once Germany surrendered later that year was handed over to the British, who then gave it to White Russians, who renamed the ship as General Alekseyev. Russian Civil War did not go well for the White Russians, who year 1920 evacuated their troops from Crimean Peninsula via Bosphorus until their warships ultimately ended up being interned to port of Bizerte in Tunisia, which at that time was a French colony. General Alekseyev was one of these warships, which slowly gathered rust in Bizerte until the French finally scrapped her in year 1936. While the ship was scrapped, the French were smart enough to strip the guns from the ship and mothball them for possible further use.
Once the interest of Finnish military concerning 305-mm coastal guns had sparked in early 1930's, the limited number of modern super-heavy coastal guns in its use became apparent. Hence in 1930's Finland intended to acquire more super-heavy coastal guns, but the delivery times from for example Krupp and Bofors proved to be much too long. France had dozen 305/52 O guns stripped from battleship Imperator Alexandr III, which would have suited well to Finnish needs, but the pre World War 2 attempt of buying them failed to reach a deal. French business name A. Klaugine had offered the 305-mm and 130-mm guns from Imperator Alexandr III already just before Winter War, but French government had interfered and stopped the deal. Finnish - Soviet Winter War that brought public opinion world-wide for supporting Finland changed things and ultimately 12th of January 1940 France decided to donate Finland all 305-mm and 130-mm guns originating from Imperator Alexandr III. February of 1940 these guns often referred as "Bizerte guns" were loaded into three Finnish ships for transport:
- Juliette: 4 x 305/52 O gun
- Karl Erik: 4 x 305/52 O gun
- Nina: 4 x 305/52 O gun + 18 x 130/50 V gun
The first two ships succeeded reaching Finland with their cargo, but Nina was captured by German military in port of Bergen when Germany invaded Norway in April of 1940. Guns that had been onboard Nina ended up to use of German coastal artillery with 305/52 O guns being used to equip Batterie Mirus on Guersey in English Channel and 130/50 V guns being used to equip German coastal artillery batteries in Norway.
The eight 305/52 O guns that successfully reached Finland were soon put to use - they were used to repair three captured Soviet 305/52O-Raut railway guns and allowed Finnish military to start planning strengthening of its coastal artillery in most important areas. Those plans resulted in building new 305-mm artillery battery on Isosaari Island to improve defensive capability of Helsinki and plan of building second twin gun turret to Mäkiluoto Island. The artillery battery built on Isosaari had two single steel turrets designed by Engineer-Captain Salonius with the other structures being designed by Engineer-Lieutenant Gummerus. Finnish company Oy Karhula built the actual steel turrets, which were simply referred as länsitorni (west-turret) and itätorni (east-turret). The artillery battery was a well-dispersed one, with turrets being located almost on opposite ends of the island. Isosaari gun turrets were the last evolutionary step in Finnish development gun turrets for 305/52 O coastal guns. They were much more lightly armoured than earlier Mäkiluoto & Kuivasaari turrets, but at the same time made possible higher maximum elevation of about 52 degrees, allowing guns to achieve maximum range of over 50 kilometers. The whole construction plan for these turrets relied more on solid granite (rock) as protection of the underground parts instead of ferroconcrete and due to improved design each turret needed two less underground floors than previous gun turrets. Construction work for the artillery battery started with rock mining in autumn of 1941. Work progressed slowly especially early on due to shortage of skilled manpower and installation of actual gun turret for east-turret did not start until January of 1944. The work with west-turret was running even slower. When construction work had to stopped in January of 1945 due to orders of Allied Control Commission, the east-turret was apparently almost complete, while west-turret was far from complete with only the parts on top of actual turret rotated having been installed by that time. The construction work for second twin gun turret of Mäkiluoto Island was even slower than in Isosaari and by end of Continuation War had barely started before being cancelled in September of 1944.
PICTURE: Spare gun barrel for 305/52 coastal gun. After arrival of Bizerte guns Finnish coastal artillery batteries received
spare barrel for each of their 305/52 O guns. These gun barrels are 15.85 meters long and weight about 50 (metric) tons.
Photo taken on Kuivasaari Island. CLICK THUMBNAIL TO SEE LARGER PIC (160 KB).
CONTINUATION WAR & POST-WAR ERA
During Continuation War 305/52 O guns of both Örö and Mäkiluoto were used in battle, although in both cases only in year 1941. Soviet military base in Hanko / Hango / Gangut Peninsula was with-in range for Örö. Hence in during first few months Örö's 305-mm coastal artillery battery shot fire missions to Hanko harbour, Russarö coastal fort, shelled Russian ships moving in area in between Porkkala Cape and Naissaar Island, plus 26th of July shelled Soviet warships taking part in battle of Bengskär Island. Most of the combat activities concerning Örö coastal fort happened in June - August of 1941, with the combat calming down after that until last Soviet troops were evacuated from their military base in December of 1941.
305-mm coastal artillery battery on Mäkiluoto Island saw even less action, with its guns only occasionally shelling Soviet ships. 3rd of December 1941 when it shelled ships evacuating last Soviet troops from Hanko military base, it hit transport ship VT-521 (passenger ship Josef Stalin), which had already been damaged by three naval mines, with 305-mm shell hitting its aft now detonating explosives stored there. Other Soviet ships succeeded evacuating some 1,740 men from VT-521, after which it drifted to Estonian coast, where the Germans captured about 3,000 men still remaining aboard.
As noted, when Continuation War ended in September of 1944, Finnish military had been building 2nd twin gun turret for 305-mm coastal artillery battery on Mäkiluoto Island. This construction work had barely started, which turned to be a blessing of sort for the Finns, since Soviet Armistice Treaty terms included renting military base on Porkkala Cape for period of 50 years and area of the base included also Mäkiluoto Island. Due to Soviet demands the existing gun turret with its two 305-mm coastal guns had to be left them intact, but the building materials reserved for the second turret were evacuated. January of 1945 Soviet-led Allied Control Commission banned Finnish coastal artillery from having guns of larger caliber than 120-mm in part of coast east of Soviet military base in Porkkala Cape. Both Kuivasaari and Isosaari 305-mm coastal artillery batteries in this area, so their guns were removed from coastal forts and taken to Parola depot deep inland. Örö Island was west from Porkkala Cape, so its guns did not need to be evacuated. As part of larger political game the Soviets returned area of Porkkala base, whose military value had been reduced by introduction of atomic weapons, to Finland already in year 1956 - but not before first thoroughly destroying Mäkiluoto gun turret and its guns. Later Finnish military sold remains of Mäkiluoto 305-mm twin gun turret as scrap metal.
PICTURE: East turret of 305/52 O artillery battery on Isosaari Island. This was the last development among gun turrets
designed in Finland for 305 mm Obuhov coastal guns. While Mäkiluoto and Kuivasaari double turrets had five floors in their structure,
this turret desing has just three, making it much more compact. Photo taken in year 2016. CLICK THUMBNAIL TO SEE LARGER PIC (152 KB).
Allied Control Commission left Finland after Paris Peace Treaty had been signed in year 1947. Even with the changes of political situation, it took until year 1959 to come up with political decision to returning super-heavy coastal guns back to coastal forts. 305-mm coastal guns were returned to Kuivasaari Island in year 1960 and its twin gun turret was again operational starting June of 1961. Isosaari got its guns back in autumn of 1961 with guns being installed to its two single turrets in 1961 - 1963. The two single gun turrets on Kuivasaari Island became operational in year 1968. As mentioned due location of Örö Island the two 305/52 O guns in there did not have to be evacuated in year 1945 and they remained in use until last shots fired in year 1971. Kuivasaari twin gun turret also remained in use until its electrical systems deteriorated to unacceptable level in early 1970's. Isosaari turrets remained apparently operational until 1970's with its guns shooting their last shots in year 1971 and maintenance continuing until late 1970's. Nowadays all super-heavy coastal guns remaining in Finland are museums guns and this incudes also all 305/52 O guns. West turret of Isosaari coastal fort was dismantled in summer of 1982 and sold as scrap metal, while the east turret has survived as a museum item to this day. Also Kuivasaari turret was renovated as a museum piece in early 1990's and similar renovation of Örö guns started in year 1998.
During the service career of 305-mm Obuhov cannon, there was quite a lot of development work done for its ammunition, but also for the gun mounts, since as typical to cannons of that era the maximum elevation limited the maximum range to which the gun was otherwise capable. These guns also had two variations of propellant chamber - naval version and coastal artillery version, from which coastal artillery version was larger, therefore allowing use of more powerful propellant charge. The development work for improving ammunition had started already in imperial Russia. The first artillery shells that Russian military introduced for it weight 375 kg, had muzzle velocity of about 700 m/sec and maximum range of only about 25 km. Only few years later Russian military come up with a new 470 kg artillery shells, which had muzzle velocity of over 800 m/sec and maximum range of about 30 kilometers. Finnish development work equipped existing artillery shells with ballistic caps designed to improved ballistics and new better propellant charge - pushing the muzzle velocity up to 920 m/sec and maximum range to over 40 kilometers - and if allowed by elevation, to maximum range of about 50 kilometers.
Finnish ammunition inventory for 305/52 O guns included variety of high explosive (HE) shells, semi-armour piercing high explosive (SAPHE) shells, armour piercing high explosive (APHE) shells and practice shells. Much of the ammunition had been equipped with ballistic caps. Practice shells which could used either for loading practice or used for shooting practice (with notably smaller propellant charge) had been manufactured from cast iron. At least one 355 kg APHE shell had presumably been originally introduced by Russian military for 305-mm naval gun model 1895 (L/40), but due to being captured in quite a large numbers was equipped with ballistic cap and did a long career with Finnish military. Another APHE-shell common in Finnish use was Russian model 1911 shell, which weight 470-kg and was one of the few 305-mm shell designs not equipped with ballistic cap. SAPHE-shells on the other hand had ballistic caps. Not all ammunition was Russian-manufactured. Among HE-shells there were in addition of 470-kg model 1911 type shells presumably American-manufactured 470-kg HE-shell. In addition also captured old HE-shells originally manufactured for 305-mm naval gun model 1895 and later modified & equipped with ballistic caps for this gun.
Considering in Finnish use this gun was intended to fight Soviet battleships, which were equipped with similar guns, the comparison to their ammunition and capabilities might be interesting. Shortly noted while Finnish 305/52 O coastal guns had slower rate of fire than Gangut-class battleships, they had longer maximum range and due to being land-based were expected to be notably more accurate. Since they were also being much smaller targets, these coastal guns would have been more than worthy adversaries to Soviet World War 2 era battleships, something which was never tested in battle.
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