Canon de 138 mm Modèle 1929
Encyclopedia
The Canon de 138 mm Modèle 1929 was a medium calibre naval gun of the French Navy
used during World War II
. It was used on the large destroyers (contre-torpilleurs) of the Fantasque and Mogador
classes.
monobloc barrel as well. It weighed 4275 kilograms (9,424.8 lb), but the later Modèle 1934 weighed 4275 kilograms (9,424.8 lb) for some reason, but appears to have been otherwise identical.
. The mount could depress -10° and elevate to +30°, which gave it a maximum range of 20000 metres (21,872.3 yd). Ammunition was brought up to the handling room by hoist from the magazines. From there the shells were transferred to the "guttering" (gouttières) which encircled the mount and allowed the shells to line up with the gun's breech regardless of the gun's angle of bearing. Powder cartridges were fed into similar center-line chutes. The gun had a nominal firing cycle of 4 or 5 seconds with its automatic spring rammer, but the dredger hoists transporting the shells and cartridge cases slowed the rate of fire down to 7 rounds per minute. This gun was only used on the large destroyers (contre-torpilleurs) of the Fantasque class.
class. The guns were housed in separate cradles that could be coupled together and could elevate to a maximum of 30° and depress 10°. The underpowered electric motors gave a maximum training speed of 10° per second and a maximum elevating speed of 14° per second. They were initially installed within the mountings, but were moved to the outer sides of the turrets to free up room.
The pusher-type ammunition hoists ran up a fixed shaft in the center of the mount. The shells and their powder charges were transferred to a tipping drum that was rotated to match the bearing angle of the guns and then loaded. This system was adapted from that used for the fixed 130 mm (5.1 in) ammunition used in the Le Hardi class destroyers. Unfortunately it was not well suited for separate-loading ammunition. Each gun had its own separate shell and powder hoist, for a total of four hoists. The tipping drum had four matching separate trays to move the ammunition to the gun. Each shell was power-rammed, but the propellant charges had to be hand-rammed. Theoretically the guns could be loaded at any angle, but the power rammer was so weak that it could not ram shells at angles above 10°. This problem, coupled with the "poor quality of manufacture of the guns, the unsatisfactory profile of the breech, resulted in a firing cycle of only 3-4 rounds per minute during the early trials with jams and failures frequent", rather than the planned 10 rounds per minute. A further problem was that there only two loaders assigned to the gun crew; they tired quickly during prolonged firing.
Gunnery trials were conducted when Volta was on her sea trials in mid-1939 and were "an unmitigated disaster" for the reasons given above. Some fixes were identified, notably modifications to the breech, installation of split loading trays and reinforcement of the catapult rammers, but they had to wait until the ships' next refit to be implemented. But even these modifications were only stop gaps and an entirely new loading system was deemed necessary, but since this was expected to take 10-12 months to develop the current system would have to be used. Both Volta and Mogador were refitted in January 1940 and had their turrets modified, although loading still could not be done at angles higher than 10°. The surrender of France
in June 1940 ended any work on a new loading system. Five-round ready racks for each gun were added to the sides of the turrets during the refit to compensate for any problems with the loading systems.
French Navy
The French Navy, officially the Marine nationale and often called La Royale is the maritime arm of the French military. It includes a full range of fighting vessels, from patrol boats to a nuclear powered aircraft carrier and 10 nuclear-powered submarines, four of which are capable of launching...
used during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. It was used on the large destroyers (contre-torpilleurs) of the Fantasque and Mogador
Mogador class destroyer
The Mogador-class large destroyers of the French navy were laid down in 1935 and commissioned in 1939. They were extremely fast, very large destroyers intended to act as scouts for the two fast Dunkerque-class battleships...
classes.
Description
The 50-caliber Mle 1929 was a lengthened version of the Modèle 1927. It used the semi-automatic action of the older gun as well as its horizontal sliding block breech. It had an autofrettedAutofrettage
Autofrettage is a metal fabrication technique in which a pressure vessel is subjected to enormous pressure, causing internal portions of the part to yield and resulting in internal compressive residual stresses. The goal of autofrettage is to increase the durability of the final product...
monobloc barrel as well. It weighed 4275 kilograms (9,424.8 lb), but the later Modèle 1934 weighed 4275 kilograms (9,424.8 lb) for some reason, but appears to have been otherwise identical.
Modèle 1929
The Mle 1929 gun was used in single, hand-worked and trained, center-pivot mountings that weighed approximately 11.7 tonne that were fitted with a 5 millimetre (0.196850393700787 in) thick gun shieldGun shield
thumb|A [[United States Marine Corps|U.S. Marine]] manning an [[M240 machine gun]] equipped with a gun shieldA gun shield is a flat piece or section of armor designed to be mounted on a crew-served weapon such as a machine gun or artillery piece, or, more rarely, to be used with an assault rifle...
. The mount could depress -10° and elevate to +30°, which gave it a maximum range of 20000 metres (21,872.3 yd). Ammunition was brought up to the handling room by hoist from the magazines. From there the shells were transferred to the "guttering" (gouttières) which encircled the mount and allowed the shells to line up with the gun's breech regardless of the gun's angle of bearing. Powder cartridges were fed into similar center-line chutes. The gun had a nominal firing cycle of 4 or 5 seconds with its automatic spring rammer, but the dredger hoists transporting the shells and cartridge cases slowed the rate of fire down to 7 rounds per minute. This gun was only used on the large destroyers (contre-torpilleurs) of the Fantasque class.
Modèle 1934
The Mle 1934 gun was installed in twin-gun, electrically powered Modèle 1934 base-ring "pseudo-turrets" that weighed 34.6 tonne that were fitted with a 10 millimetre (0.393700787401575 in) thick, open-backed gunhouse. These were mounted on the large destroyers (contre-torpilleurs) of the MogadorMogador class destroyer
The Mogador-class large destroyers of the French navy were laid down in 1935 and commissioned in 1939. They were extremely fast, very large destroyers intended to act as scouts for the two fast Dunkerque-class battleships...
class. The guns were housed in separate cradles that could be coupled together and could elevate to a maximum of 30° and depress 10°. The underpowered electric motors gave a maximum training speed of 10° per second and a maximum elevating speed of 14° per second. They were initially installed within the mountings, but were moved to the outer sides of the turrets to free up room.
The pusher-type ammunition hoists ran up a fixed shaft in the center of the mount. The shells and their powder charges were transferred to a tipping drum that was rotated to match the bearing angle of the guns and then loaded. This system was adapted from that used for the fixed 130 mm (5.1 in) ammunition used in the Le Hardi class destroyers. Unfortunately it was not well suited for separate-loading ammunition. Each gun had its own separate shell and powder hoist, for a total of four hoists. The tipping drum had four matching separate trays to move the ammunition to the gun. Each shell was power-rammed, but the propellant charges had to be hand-rammed. Theoretically the guns could be loaded at any angle, but the power rammer was so weak that it could not ram shells at angles above 10°. This problem, coupled with the "poor quality of manufacture of the guns, the unsatisfactory profile of the breech, resulted in a firing cycle of only 3-4 rounds per minute during the early trials with jams and failures frequent", rather than the planned 10 rounds per minute. A further problem was that there only two loaders assigned to the gun crew; they tired quickly during prolonged firing.
Gunnery trials were conducted when Volta was on her sea trials in mid-1939 and were "an unmitigated disaster" for the reasons given above. Some fixes were identified, notably modifications to the breech, installation of split loading trays and reinforcement of the catapult rammers, but they had to wait until the ships' next refit to be implemented. But even these modifications were only stop gaps and an entirely new loading system was deemed necessary, but since this was expected to take 10-12 months to develop the current system would have to be used. Both Volta and Mogador were refitted in January 1940 and had their turrets modified, although loading still could not be done at angles higher than 10°. The surrender of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...
in June 1940 ended any work on a new loading system. Five-round ready racks for each gun were added to the sides of the turrets during the refit to compensate for any problems with the loading systems.
Ammunition
The Mle 29 and Mle 34 primarily used two different shells, each propelled by 12.09 kilograms (26.7 lb) of BM 11 in a separate brass cartridge case. Beginning in January 1940 OPFK shells with dye markers were carried. These were intended to allow each ship to distinguish between its shell-bursts and those of other ships by use of coloured dyes. An illumination shell was also used, but details are unknown.| Shell name | Weight | Filling Weight | Muzzle velocity |
|---|---|---|---|
| OEA Modèle 1932 high-explosive | 40.6 kg (89.5 lb) | 4.1 kg (9 lb) | 840 m/s (2,755.9 ft/s) |
| OPF Modèle 1924 semi-armour-piercing Armor-piercing shot and shell An armor-piercing shell is a type of ammunition designed to penetrate armor. From the 1860s to 1950s, a major application of armor-piercing projectiles was to defeat the thick armor carried on many warships. From the 1920s onwards, armor-piercing weapons were required for anti-tank missions... |
40.6 kg (89.5 lb) | 2.4 kg (5.3 lb) | 800 m/s (2,624.7 ft/s) |