Wednesday, December 7, 2016

Weapons of War: De Bange 155 mm long cannon model 1877 - 155 K/77

When the Soviet Union invaded Finland in November 1939, the Finnish military was severely under equipped in many areas. Artillery was one of these areas and Finland set about buying and deploying any artillery piece it could get. This meant getting many old, outdated pieces from the armouries of European countries like France and Britain.

One of these older pieces was the French de Bange 155mm Long modèle 1877.

The 155 L de Bange was a result of a French artillery committee meeting held in the aftermath on the Franco-Prussian War. The committee discussed new Fortress and Seige artillery models and on the 16 April 1874 settled upon the 15.5cm caliber as the new standard piece. In 1876 three competing prototypes were tested at Calais but it was the design by French Artillery Colonel Charles Ragon de Bange that won the day (it probably helped that he was Director of the "Atelier-de-précision" (Paris arsenal's precision workshop) in the Central Depot in Paris.

Like with all De Bange’s cannons, it used the De Bange breech obturator system, which basically used the force of the firing charge to push back an asbestos pad that sealed the rear breech and thus directing all the pressure forward, increasing velocity and reducing danger. It was inspired by the rubber o-rings in use on the Chassepot rifle.

(The de Bange system and how it works)
The French Government placed an initial order in 1877 for 300 pieces and by the turn of the 20th Century about 1,400 were produced. The vast majority were posted to the fortresses of the Séré de Rivières system but 200 were reserved as offensive siege artillery.

The biggest downside to the 155 L de Bange, and by extension all de Bange guns, was they had no recoil system and as such needed to be realigned after every shot. The gun could jump back a metre or two after firing and thus presented a problem in terms of accuracy and rate of fire. While obsolete, the French military used them throughout the First World War and even in the early stages of the Second World War (France still had 305 pieces at various locations, including the Maginot Line).

The Finnish overlooked the downsides of recoil issues due to the desperateness of the situation they now found themselves in. French was unwilling to sell large amounts of modern artillery (the number amount to less than 30 field guns with a modern recoil system) but happily parted with older, more obsolete models such as the 155 L de Bange. The Finns preferred the French 19th century guns over the similar Russian models as they were of better quality and had more reliable ammunition.

These guns developed an exaggerated reputation within the Finnish military. Due to their ability to ‘jump’ and need to be realigned after every shot, the earned the nicknames "Hyppyheikki" ("Jumping Henry") and "Hyppyjaakko" ("Jumping Jack") and jokes such as, "Why does "hyppyheikki" need two observers?…The first observer will keep track of where the projectile lands while the second observer will check where the gun goes". While not totally undeserving, they are exaggerated. With proper preparation of positions, the use of earth slopes and wedges, the guns recoil could be reduced greatly and the need to realign is not as great. Luckily for the Finns, they were on the defensive and thus having prepared positions was something they could do.

48 155 L de Bange and 48,000 shots were sent to Finland, taking a route from France to Narvik, Norway by ship, then the guns were transported by rail to the Swedish/Finnish border town of Tornio. They would then need to be offloaded and reloaded onto Finnish trains as Finland used a narrower gauge. Then they would go from Tornio to various depots in the South for inspection and issue. Due to the long, arduous journey, none of the guns reached front lines during the Winter War. However they were still issued.

They were given the designation 155 K/77 and 44 were assigned to Fortification Artillery Battalions of the heavily fortified Salpa-line and the other 4 were were given to the Coastal Artillery, where they were fitted with special mounts and designated 155/27 BaMk. They were assigned to Fort Herrö in Ahvenanmaa (Åland) Islands until end of the Continuation War. Due to their good range (12.3 km), high degree of accuracy (produced by the gain-twist rifling) and reliability, the Finns used them mainly in a counter-battery role. The first use of these heavy pieces in action was at the Siege of Hanko (an area leased to the Soviet Union as part of the Winter War Peace terms, designated as a Naval Base, it had a contingent of mainly Red Army troops numbering abour 26,000). They saw most use in the Svir River area, with 36 guns assigned there. When the Soviets pushed their grand offensive in 1944, the Finnish forces started to withdraw, as the 155 K/77 were old and heavy, they were lower on the priority list for pulling back and eventually 24 guns were destroyed to prevent the Soviets from gaining them.

With the remaining 12 guns, they were assigned to the newly established Syväri Fortification Battalion 1 and were used in the defence of Koirinoja, firing their last shots on the 13th July 1944. It is quite possible that these were the last shots fired from 19th century canons with no recoil systems anywhere in the world.

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