Mogador class destroyer
Encyclopedia
The Mogador-class large destroyer
s (contre-torpilleurs) 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. The design evolved from the extremely fast Le Fantasque
-class, being 300 tons heavier and carrying eight guns in semi-enclosed twin turrets rather than five guns in single open mounts. With their eight 138 mm (5.4 in) guns they approached a light cruiser
in firepower.
Both Mogador
and her sister Volta
were present during the British attack on Mers-el-Kébir on 3 July 1940, but only Volta managed to escape to Toulon
. Mogador was struck by a 15 inches (38.1 cm) shell in the rear hull that detonated her ready depth charge
s despite not actually detonating itself. This destroyed most of her stern above water, but she remained afloat and was repaired enough to be sent to Toulon on 1 November 1940 for reconstruction. Both ships were scuttled in Toulon Harbour
when the Germans tried to seize them on 27 November 1942.
-class with three new twin mounts carrying the same Canon de 138 mm Modèle 1929
gun as the earlier ships, but construction was suspended for a period while France and Italy negotiated some limits on their fleets and because the shipyards were already at full capacity. During this pause time was taken to modify the design to deal with the severe weather and conditions of the North Atlantic and to incorporate developments in propulsion technology that indicated that a larger hull could be used without any requiring any increase in weight. After a proposal for a catapult was abandoned because of insufficient reserve stability, an extra twin turret was decided upon to boost the ship's firepower. Volta was authorized in the 1934 Estimates together with the second Dunkerque
-class battleship.
as did the sides of the superstructure. The hull was entirely riveted, but all other joints were welded. Despite these efforts, top-weight was higher than on earlier classes of contre-torpilleurs because of the weight of the twin-gun turrets.
Accommodations were even more cramped and poorly ventilated than earlier ships because the ammunition hoists passed through the crew spaces, a problem for ships intended for long-endurance sorties into the North Atlantic. The lack of room in the hull forced a number of workshops and offices into the superstructure which added more weight high in the ship. There were three deckhouses abaft the break in the forecastle with intervals between them to permit the beam torpedo tubes to rotate, but these were no larger than in earlier ships which meant that space was at a premium.
The ships proved to be excellent sea-boats and were very capable in high seas as they could sustain 34 knots (66.6 km/h) in Sea State
4. "They were very steady ships, with a gentle roll period of seven seconds; they heeled only 2-3° with a strong cross-wind, and at only 7-8° at full rudder — a marked improvement over earlier contre-torpilleurs. Their comparatively high length to beam ratio, however, gave them a high coefficient of inertia, which made maneuvers in formation difficult."
Each shaft drove a three-bladed screw propeller that was 3.94 m (12.9 ft) in diameter. They suffered from severe cavitation at speed. The single semi-balanced rudder was chosen to reduce high speed resistance. It had an area of only 14.95 square metres (160.9 sq ft) and was moved by a weak steam-driven servomotor. On trials, the turning circle was measured at 800–850 m (874.9–929.6 yd) at 25 kn (30.4 mph; 49 km/h). In service it took 25–30 seconds to turn the rudder to its maximum 32° at speed and the ship's turning circle was approximately double that demonstrated on trials. The ships were so unhandy that the captain of the Volta cautioned in his log that "great care was needed when operating in company with the battleship Strasbourg
, because the latter ship was far more maneuverable."
The Mogador-class ships were designed for a speed of 39 kn (47.5 mph; 76.4 km/h), but this was comfortably exceeded on trials when Mogador achieved a top speed of 43.45 knots with 118320 shp for one hour. This was at "Washington" standard displacement so her earlier performance of 41.67 knots with 108424 shp at a load displacement of 3731 tonne was even more impressive.
At normal displacement they carried only 120 tonne of oil, but carried 360 tonne of oil at normal load and 710 tonne at deep load. Endurance was estimated during their trials at 4345 nautical miles (8,046.9 km) at a speed of 15 knots (29.4 km/h) using the cruise turbines and 2664 nautical miles (4,933.7 km) at a speed of 24 kn (29.2 mph; 47 km/h) with the main turbines. This was never attained during service because the consumption by the auxiliary machinery was underestimated.
as the preceding Le Fantastaque-class destroyers. 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. The motors were initially installed within the mountings, but were moved to the outer sides of the turrets to free up room inside the turrets.
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 millimetres (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 in the meantime. 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. The magazines were designed to store 1440 138 mm shells, 180 rounds per gun, plus there was a separate magazine for 85 starshells which supplied turret Nr. 2.
Two twin 13.2 millimetre (0.519685039370079 in) Hotchkiss machine gun
mounts were fitted as anti-strafing
weapons. These had a high rate of fire at 450 rpm, but this was hampered by the awkward 30-round magazine feed. Initially they were mounted on each side of the forward superstructure at deck level and fitted with gun shield
s to protect them against the spray. Trials revealed the limitations of these positions with poor arcs of fire and the gun shields obstructed the aimer's view of the target. Following the completion of the trials the guns were relocated to a new deckhouse between the bridge and turret Nr. 2 and their gun shields removed. 2500 rounds per barrel were stored in the forward magazines.
were fitted on each beam between the funnels and two twin Modèle 1928D launchers were located on the beam, abaft the second funnel. The placement of each launcher on the beam significantly increased each launcher's arc of fire (25° to 150°) in comparison to the Le Fantastaque's centerline mount (60°-100°). However this was not without cost as her torpedo broadside was weaker by one tube than the older class, but the extra launchers positioned close to the ship's side imposed, more importantly, a weight and stability penalty.
All of her mounts used the 550 millimetres (21.7 in) Modèle 1923DT torpedo
with a 308 kg (679 lb) warhead. This 2068 kg (4,559.2 lb) torpedo used a four-cylinder, radial Brotherhood alcohol engine to power it at two set speeds. The fast speed was 39 knots (21.2 m/s) to a range of 9000 metres (9,842.5 yd) while the slow speed setting was 35 knots (19.1 m/s) to a range of 13000 metres (14,217 yd).
Twin depth charge
tunnels were built into the rear hull of the Mogador-class ships. Each tunnel housed eight Guirard depth charges, with another sixteen stowed in the rear magazine. They were launched by remote control in patterns of four using a chain system. Since no sonar
equipment was fitted these depth charges were unlikely to actually damage a submarine.
Fixed pairs of mine rails were mounted above the stern and each pair could carry five Bréguet B4 mines. These could be extended using removable section stowed between decks to carry another thirty mines if necessary.
and sent the range to the post central 'artillerie where it was fed into a modernized Modèle 1929 electro-mechanical computer which calculated the firing solution and transmitted it to the turrets. The turrets could also be controlled locally if necessary.
The torpedo control system was much the same, although entirely separate from the gunnery system. 8 x 30 target designation binoculars were mounted on each side of the bridge and transmitted the target's bearing to the torpedo director located above the primary gunnery DCT above the bridge. It used a separate 5 metres (16.4 ft) OPL Modèle 1935 stereoscopic rangefinder to provide the bearing and range to a Modèle 1933 mechanical computer which calculated the torpedo firing angle. This was sent to the remotely-controlled torpedo tubes and the command to fire could be given by either the torpedo director or either of the secondary positions on the wings of the bridge.
(X61) and Volta
(X62). Steel was cut on both contre-torpilleurs beginning in late 1934, Mogador at the Arsenal de Lorient
and Volta at At. & Ch. de Bretagne Nantes
, although assembly didn't begin until the autumn of the following year. Industrial unrest disrupted their construction and it wasn't until January 1938 that Mogador was handed over to the French Navy for sea trials. Volta followed three months later. However, neither ship was formally accepted by the French Navy for another year. Mogador wasn't commissioned (clotûre d'armament) until 8 April 1939 and Volta on 6 March 1939.
Four improved Mogador-class ships were ordered in 1939 to be named Kléber, Desaix, Hoche and Marceau, but their construction was suspended due to the start of World War II
. Their design was continually modified in light of wartime experience, but the original plan for dual-purpose
130 mm (5.1 in) guns had to shelved when it became apparent that they could not be developed in a timely manner, and they reverted to the main armament of the Mogadors. The anti-aircraft armament was reinforced with the substitution of four 100 mm (3.9 in) anti-aircraft guns for the single twin 37 mm mount. But these plans came to nought when France surrendered in June 1940.
Mogador and Volta comprised the 6th Large Destroyer Division (6e Division de contre-torpilleurs) and were assigned to the Force de Raid
based at Brest
when the war began. This group's purpose was to hunt German blockade runners and raiders and to escort convoys that might be in danger from the same. From 21 to 30 October 1939 the Force de Raid escorted the KJ.4 convoy to protect it against the German pocket battleship Deutschland
which had sortied into the North Atlantic before the war began. A sortie by the German battleships Gneisenau and Scharnhorst
into the North Atlantic on 21 November prompted the Force de Raid to sail from Brest to rendezvous with the British battlecruiser HMS Hood
and patrol the area south of Iceland
, but the German ships were able to return safely under the cover of heavy weather without being engaged.
Both ships were refitted in early 1940 and a number of minor changes were made. The necessary improvements identified for the main armament during their sea trials a year earlier were finally implemented, the canvas cover for the back of the turrets was replaced by a rolling door, new radios were installed, and shields were fitted to the anti-aircraft machine guns and the searchlights. A SS-6 sonar
was fitted in June 1940, but proved to be ineffectual.
During the British attack on Mers-el-Kébir on 3 July 1940, Mogador was severely damaged during by a hit from a 15 inches (38.1 cm) shell in the rear hull that detonated her ready depth charges. Volta was also present, but managed to escape in company with the battleship Strasbourg and other ships. Mogador was repaired enough to reach Toulon several months later, but was still undergoing repairs and modifications in Toulon
in November 1942. Both Mogador and Volta were scuttled in Toulon Harbour
on 27 November 1942 to prevent their capture by Germany. Both were refloated in 1943 by the Italians, but neither was repaired and both were eventually broken up.
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...
s (contre-torpilleurs) of the French navy
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...
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
French battleship Dunkerque
The Dunkerque was the first unit of a new class of warships of the French Navy built in the 1930s, officially rated as battleships, or even «navires de ligne» , as Dunkerque and Strasbourg constituted, from the commissionig of Strasbourg to some days after Mers-el Kebir, the «1ère Division de Ligne»...
-class battleships. The design evolved from the extremely fast Le Fantasque
Le Fantasque class destroyer
The Fantasque class of six large, very fast destroyers was ordered under the French naval programme of 1930...
-class, being 300 tons heavier and carrying eight guns in semi-enclosed twin turrets rather than five guns in single open mounts. With their eight 138 mm (5.4 in) guns they approached a light cruiser
Light cruiser
A light cruiser is a type of small- or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck...
in firepower.
Both Mogador
French destroyer Mogador
Mogador was the lead ship of the French Navy's . Named for the Moroccan town, she was built before the outbreak of World War II. The ship was heavily damaged during the British attack on Mers-el-Kébir on 3 July 1940, but was later repaired and sailed to Toulon...
and her sister Volta
French destroyer Volta
Volta was a of the French Navy. Named for the West African river, she was built before the outbreak of World War II and was the penultimate contre-torpilleur built by the French Navy. Along with her sister ship , Volta was designed in an effort to build a ship capable of out-fighting every other...
were present during the British attack on Mers-el-Kébir on 3 July 1940, but only Volta managed to escape to Toulon
Toulon
Toulon is a town in southern France and a large military harbor on the Mediterranean coast, with a major French naval base. Located in the Provence-Alpes-Côte-d'Azur region, Toulon is the capital of the Var department in the former province of Provence....
. Mogador was struck by a 15 inches (38.1 cm) shell in the rear hull that detonated her ready depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
s despite not actually detonating itself. This destroyed most of her stern above water, but she remained afloat and was repaired enough to be sent to Toulon on 1 November 1940 for reconstruction. Both ships were scuttled in Toulon Harbour
Scuttling of the French fleet in Toulon
The French fleet in Toulon was scuttled on 27 November 1942 on the order of the Admiralty of Vichy France to avoid capture by Nazi German forces during Operation Lila of the Case Anton takeover of Vichy France.- Context :...
when the Germans tried to seize them on 27 November 1942.
Design
The Mogador was authorized in the 1932 Estimates as an improved version of the Le FantasqueLe Fantasque class destroyer
The Fantasque class of six large, very fast destroyers was ordered under the French naval programme of 1930...
-class with three new twin mounts carrying the same Canon de 138 mm Modèle 1929
Canon de 138 mm Modèle 1929
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 of the Fantasque and Mogador classes.-Description:...
gun as the earlier ships, but construction was suspended for a period while France and Italy negotiated some limits on their fleets and because the shipyards were already at full capacity. During this pause time was taken to modify the design to deal with the severe weather and conditions of the North Atlantic and to incorporate developments in propulsion technology that indicated that a larger hull could be used without any requiring any increase in weight. After a proposal for a catapult was abandoned because of insufficient reserve stability, an extra twin turret was decided upon to boost the ship's firepower. Volta was authorized in the 1934 Estimates together with the second Dunkerque
French battleship Dunkerque
The Dunkerque was the first unit of a new class of warships of the French Navy built in the 1930s, officially rated as battleships, or even «navires de ligne» , as Dunkerque and Strasbourg constituted, from the commissionig of Strasbourg to some days after Mers-el Kebir, the «1ère Division de Ligne»...
-class battleship.
General characteristics
Their construction was strengthened to handle the severe weather conditions of the North Atlantic as one of the requirements for their intended role as scouts and escorts for the Dunkerque-class battleships of the Force de Raid. Longitudinal construction was used throughout with frames spaced 1.8 metres (5.9 ft) apart and subdivided by twelve transverse compartments. Stress-bearing parts of the hull used 60 kg/m² grade steel while the remainder of the hull used 50 kg/m² grade steel. To save weight all internal partitions used DuraluminDuralumin
Duralumin is the trade name of one of the earliest types of age-hardenable aluminium alloys. The main alloying constituents are copper, manganese, and magnesium. A commonly used modern equivalent of this alloy type is AA2024, which contains 4.4% copper, 1.5% magnesium, 0.6% manganese and 93.5%...
as did the sides of the superstructure. The hull was entirely riveted, but all other joints were welded. Despite these efforts, top-weight was higher than on earlier classes of contre-torpilleurs because of the weight of the twin-gun turrets.
Accommodations were even more cramped and poorly ventilated than earlier ships because the ammunition hoists passed through the crew spaces, a problem for ships intended for long-endurance sorties into the North Atlantic. The lack of room in the hull forced a number of workshops and offices into the superstructure which added more weight high in the ship. There were three deckhouses abaft the break in the forecastle with intervals between them to permit the beam torpedo tubes to rotate, but these were no larger than in earlier ships which meant that space was at a premium.
The ships proved to be excellent sea-boats and were very capable in high seas as they could sustain 34 knots (66.6 km/h) in Sea State
Sea state
In oceanography, a sea state is the general condition of the free surface on a large body of water—with respect to wind waves and swell—at a certain location and moment. A sea state is characterized by statistics, including the wave height, period, and power spectrum. The sea state varies with...
4. "They were very steady ships, with a gentle roll period of seven seconds; they heeled only 2-3° with a strong cross-wind, and at only 7-8° at full rudder — a marked improvement over earlier contre-torpilleurs. Their comparatively high length to beam ratio, however, gave them a high coefficient of inertia, which made maneuvers in formation difficult."
Propulsion
The Mogador-class ships retained the unit arrangement of their propulsion spaces used in earlier contre-torpilleurs. They used a new high-pressure Indret boiler rated at 3500 kilopascals (507.6 psi). While this gave more power for its weight and size, it proved to be fragile and difficult to maintain. Each set of Rateau-Bretagne geared turbines was rated at 46000 shp and consisted of four main turbines, a high-pressure, a medium-pressure and two low-pressure with a reversing turbine in each of the main low-pressure turbine cases. There were also two small cruise turbines operating in parallel in each engine room. At low speeds steam was directed to the cruise turbines, but at higher speeds it was diverted to the high-pressure turbine. At 25 kn (30.4 mph; 49 km/h) the cruise turbines were decoupled entirely using a Vulcan clutch. This didn't work properly and several ship's captains recommended that the cruise turbines be deleted from future classes entirely. Each of the two shafts was driven by single reduction gearing. The port shaft was driven by the rear engine room and was significantly shorter than the starboard shaft which was driven by the forward engine room. This caused a significant disparity between the turning circle, depending on which direction the ship was turning.Each shaft drove a three-bladed screw propeller that was 3.94 m (12.9 ft) in diameter. They suffered from severe cavitation at speed. The single semi-balanced rudder was chosen to reduce high speed resistance. It had an area of only 14.95 square metres (160.9 sq ft) and was moved by a weak steam-driven servomotor. On trials, the turning circle was measured at 800–850 m (874.9–929.6 yd) at 25 kn (30.4 mph; 49 km/h). In service it took 25–30 seconds to turn the rudder to its maximum 32° at speed and the ship's turning circle was approximately double that demonstrated on trials. The ships were so unhandy that the captain of the Volta cautioned in his log that "great care was needed when operating in company with the battleship Strasbourg
French battleship Strasbourg
The Strasbourg was a more heavily armoured Dunkerque-class battleship of the French Navy, labeled as a "fast battleship". Faster than full battleships, but not as heavily armed or armoured as them, they were designed to counter the threat of the German "pocket battleships" - the Deutschland-class...
, because the latter ship was far more maneuverable."
The Mogador-class ships were designed for a speed of 39 kn (47.5 mph; 76.4 km/h), but this was comfortably exceeded on trials when Mogador achieved a top speed of 43.45 knots with 118320 shp for one hour. This was at "Washington" standard displacement so her earlier performance of 41.67 knots with 108424 shp at a load displacement of 3731 tonne was even more impressive.
At normal displacement they carried only 120 tonne of oil, but carried 360 tonne of oil at normal load and 710 tonne at deep load. Endurance was estimated during their trials at 4345 nautical miles (8,046.9 km) at a speed of 15 knots (29.4 km/h) using the cruise turbines and 2664 nautical miles (4,933.7 km) at a speed of 24 kn (29.2 mph; 47 km/h) with the main turbines. This was never attained during service because the consumption by the auxiliary machinery was underestimated.
Arguably the greatest weakness of these ships lay in their inability to generate sufficient electrical current to power the multitude of auxiliary motors on which their advanced machinery and complex gun mountings were dependent. Their DC
Direct currentDirect current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
electrical supply was only 115V, whereas larger cruisers with power-operated turrets had a 230V system. Electrical power was generated by two Alsthom turbo-generators rated at only 120 kW with two small diesel generatorDiesel generatorA diesel generator is the combination of a diesel engine with an electrical generator to generate electrical energy....
s rated at 44/52kW for use when the ship was alongside. The latter provided only for the ship's minimum lighting and electricity needs, and fires had to be lit in at least one of the boilers in order to train the turrets or elevate the guns for practice or maintenance. Many of the auxiliary motors themselves were also seriously underpowered, particularly the servomotors for the gun mountings (which were slow to train and elevate) and for the rudder (which contributed to the ship's poor maneuverability. In technological terms Mogador and Volta were ships with the armament of a light cruiser in the hull of a destroyer; the contre-torpilleur as a type had been pushed past the limits of its capabilities.
–Jordan, The Contre-Torpilleurs of the Mogador Class, p. 59
Main guns
The Mogador-class ships were designed to use four newly designed twin-gun Modèle 1934 "pseudo-turrets" that used the same Canon de 138 mm Modèle 1929Canon de 138 mm Modèle 1929
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 of the Fantasque and Mogador classes.-Description:...
as the preceding Le Fantastaque-class destroyers. 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. The motors were initially installed within the mountings, but were moved to the outer sides of the turrets to free up room inside the turrets.
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 millimetres (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 in the meantime. 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. The magazines were designed to store 1440 138 mm shells, 180 rounds per gun, plus there was a separate magazine for 85 starshells which supplied turret Nr. 2.
Anti-aircraft suite
A single 37 millimetres (1.5 in) twin-gun Modèle 1933 anti-aircraft mount was installed on the rearmost deckhouse forward of turret Nr. 3. It used the 50-caliber semi-automatic Canon de 37 mm Modèle 1925 gun. It had a conventional sliding breech and used six-round cartridge boxes which gave it a maximum rate of fire of only 30-40 rounds per minute. This mount was used in lieu of the intended power-driven Modèle 1935 twin-gun mount which was to use a new 48-caliber, fully automatic 37 mm gun that was expected to be able to fire at a rate of 165 rounds per minute, but the new gun was still in development when the ships were commissioned. 250 rounds were stored near the mount, but the main magazine, which held an additional 1,250 rounds, was adjacent to the forward 138 mm magazines. This required a loader to move forward 50 metres (54.7 yd) to pick up each 12.8 kilograms (28.2 lb) cartridge box and carry it back to the waiting gun crew.Two twin 13.2 millimetre (0.519685039370079 in) Hotchkiss machine gun
13.2 mm Hotchkiss machine gun
The 13.2 mm Hotchkiss machine gun was a heavy machine gun designed and manufactured by Hotchkiss et Cie from the late 1920s until World War II where it saw service with various nation's forces, including Japan where the gun was built under licence....
mounts were fitted as anti-strafing
Strafing
Strafing is the practice of attacking ground targets from low-flying aircraft using aircraft-mounted automatic weapons. This means, that although ground attack using automatic weapons fire is very often accompanied with bombing or rocket fire, the term "strafing" does not specifically include the...
weapons. These had a high rate of fire at 450 rpm, but this was hampered by the awkward 30-round magazine feed. Initially they were mounted on each side of the forward superstructure at deck level and fitted with gun shield
Gun 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...
s to protect them against the spray. Trials revealed the limitations of these positions with poor arcs of fire and the gun shields obstructed the aimer's view of the target. Following the completion of the trials the guns were relocated to a new deckhouse between the bridge and turret Nr. 2 and their gun shields removed. 2500 rounds per barrel were stored in the forward magazines.
Underwater weapons
The Mogador-class ships were designed for anti-surface warfare rather than anti-submarine work and they were given a large torpedo battery in consequence. Two triple Modèle 1928T torpedo launchersTorpedo tube
A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels...
were fitted on each beam between the funnels and two twin Modèle 1928D launchers were located on the beam, abaft the second funnel. The placement of each launcher on the beam significantly increased each launcher's arc of fire (25° to 150°) in comparison to the Le Fantastaque's centerline mount (60°-100°). However this was not without cost as her torpedo broadside was weaker by one tube than the older class, but the extra launchers positioned close to the ship's side imposed, more importantly, a weight and stability penalty.
All of her mounts used the 550 millimetres (21.7 in) Modèle 1923DT torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
with a 308 kg (679 lb) warhead. This 2068 kg (4,559.2 lb) torpedo used a four-cylinder, radial Brotherhood alcohol engine to power it at two set speeds. The fast speed was 39 knots (21.2 m/s) to a range of 9000 metres (9,842.5 yd) while the slow speed setting was 35 knots (19.1 m/s) to a range of 13000 metres (14,217 yd).
Twin depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
tunnels were built into the rear hull of the Mogador-class ships. Each tunnel housed eight Guirard depth charges, with another sixteen stowed in the rear magazine. They were launched by remote control in patterns of four using a chain system. Since no sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
equipment was fitted these depth charges were unlikely to actually damage a submarine.
Fixed pairs of mine rails were mounted above the stern and each pair could carry five Bréguet B4 mines. These could be extended using removable section stowed between decks to carry another thirty mines if necessary.
Fire control
The centralized fire control system was similar to that of the Le Fantastaque-class with 12 x 72 target designation binoculars on each side of the bridge linked by Granat transmitters to the director control towers located atop the bridge and abaft the second funnel. Each DCT had a 5 metres (16.4 ft) OPL Modèle 1935 stereoscopic rangefinderCoincidence rangefinder
A coincidence rangefinder is a type of rangefinder that uses mechanical and optical principles to allow an operator to determine the distance to a visible object....
and sent the range to the post central 'artillerie where it was fed into a modernized Modèle 1929 electro-mechanical computer which calculated the firing solution and transmitted it to the turrets. The turrets could also be controlled locally if necessary.
The torpedo control system was much the same, although entirely separate from the gunnery system. 8 x 30 target designation binoculars were mounted on each side of the bridge and transmitted the target's bearing to the torpedo director located above the primary gunnery DCT above the bridge. It used a separate 5 metres (16.4 ft) OPL Modèle 1935 stereoscopic rangefinder to provide the bearing and range to a Modèle 1933 mechanical computer which calculated the torpedo firing angle. This was sent to the remotely-controlled torpedo tubes and the command to fire could be given by either the torpedo director or either of the secondary positions on the wings of the bridge.
Construction
This class only consisted of MogadorFrench destroyer Mogador
Mogador was the lead ship of the French Navy's . Named for the Moroccan town, she was built before the outbreak of World War II. The ship was heavily damaged during the British attack on Mers-el-Kébir on 3 July 1940, but was later repaired and sailed to Toulon...
(X61) and Volta
French destroyer Volta
Volta was a of the French Navy. Named for the West African river, she was built before the outbreak of World War II and was the penultimate contre-torpilleur built by the French Navy. Along with her sister ship , Volta was designed in an effort to build a ship capable of out-fighting every other...
(X62). Steel was cut on both contre-torpilleurs beginning in late 1934, Mogador at the Arsenal de Lorient
Lorient
Lorient, or L'Orient, is a commune and a seaport in the Morbihan department in Brittany in north-western France.-History:At the beginning of the 17th century, merchants who were trading with India had established warehouses in Port-Louis...
and Volta at At. & Ch. de Bretagne Nantes
Nantes
Nantes is a city in western France, located on the Loire River, from the Atlantic coast. The city is the 6th largest in France, while its metropolitan area ranks 8th with over 800,000 inhabitants....
, although assembly didn't begin until the autumn of the following year. Industrial unrest disrupted their construction and it wasn't until January 1938 that Mogador was handed over to the French Navy for sea trials. Volta followed three months later. However, neither ship was formally accepted by the French Navy for another year. Mogador wasn't commissioned (clotûre d'armament) until 8 April 1939 and Volta on 6 March 1939.
Four improved Mogador-class ships were ordered in 1939 to be named Kléber, Desaix, Hoche and Marceau, but their construction was suspended due to the start of 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...
. Their design was continually modified in light of wartime experience, but the original plan for dual-purpose
Dual purpose gun
A dual purpose gun is a naval artillery mounting designed to engage both surface and air targets.-Description:Second World War-era capital ships had four classes of artillery: the heavy main battery, intended to engage opposing battleships and cruisers ; a secondary battery for use against enemy...
130 mm (5.1 in) guns had to shelved when it became apparent that they could not be developed in a timely manner, and they reverted to the main armament of the Mogadors. The anti-aircraft armament was reinforced with the substitution of four 100 mm (3.9 in) anti-aircraft guns for the single twin 37 mm mount. But these plans came to nought when France surrendered in June 1940.
History
Force de Raid
The Force de Raid was a French naval unit based at Brest until 1940. It included some of the most modern capital ships of its day organised into two squadrons, commanded at the outbreak of World War II by Vice Amiral Marcel Gensoul...
based at Brest
Brest, France
Brest is a city in the Finistère department in Brittany in northwestern France. Located in a sheltered position not far from the western tip of the Breton peninsula, and the western extremity of metropolitan France, Brest is an important harbour and the second French military port after Toulon...
when the war began. This group's purpose was to hunt German blockade runners and raiders and to escort convoys that might be in danger from the same. From 21 to 30 October 1939 the Force de Raid escorted the KJ.4 convoy to protect it against the German pocket battleship Deutschland
German pocket battleship Deutschland
Deutschland was the lead ship of her class of heavy cruisers which served with the Kriegsmarine of Nazi Germany during World War II. Ordered by the Weimar government for the Reichsmarine, she was laid down at the Deutsche Werke shipyard in Kiel in February 1929 and completed by April 1933...
which had sortied into the North Atlantic before the war began. A sortie by the German battleships Gneisenau and Scharnhorst
Scharnhorst class battleship
The Scharnhorst class were the first capital ships, alternatively referred to as battlecruisers or battleships, built for the German Navy after World War I. The class comprised two vessels: the lead ship Scharnhorst and Gneisenau...
into the North Atlantic on 21 November prompted the Force de Raid to sail from Brest to rendezvous with the British battlecruiser HMS Hood
HMS Hood (51)
HMS Hood was the last battlecruiser built for the Royal Navy. One of four s ordered in mid-1916, her design—although drastically revised after the Battle of Jutland and improved while she was under construction—still had serious limitations. For this reason she was the only ship of her class to be...
and patrol the area south of Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
, but the German ships were able to return safely under the cover of heavy weather without being engaged.
Both ships were refitted in early 1940 and a number of minor changes were made. The necessary improvements identified for the main armament during their sea trials a year earlier were finally implemented, the canvas cover for the back of the turrets was replaced by a rolling door, new radios were installed, and shields were fitted to the anti-aircraft machine guns and the searchlights. A SS-6 sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
was fitted in June 1940, but proved to be ineffectual.
During the British attack on Mers-el-Kébir on 3 July 1940, Mogador was severely damaged during by a hit from a 15 inches (38.1 cm) shell in the rear hull that detonated her ready depth charges. Volta was also present, but managed to escape in company with the battleship Strasbourg and other ships. Mogador was repaired enough to reach Toulon several months later, but was still undergoing repairs and modifications in Toulon
Toulon
Toulon is a town in southern France and a large military harbor on the Mediterranean coast, with a major French naval base. Located in the Provence-Alpes-Côte-d'Azur region, Toulon is the capital of the Var department in the former province of Provence....
in November 1942. Both Mogador and Volta were scuttled in Toulon Harbour
Scuttling of the French fleet in Toulon
The French fleet in Toulon was scuttled on 27 November 1942 on the order of the Admiralty of Vichy France to avoid capture by Nazi German forces during Operation Lila of the Case Anton takeover of Vichy France.- Context :...
on 27 November 1942 to prevent their capture by Germany. Both were refloated in 1943 by the Italians, but neither was repaired and both were eventually broken up.
External links
- Plans de bateaux: MOGADOR 1937 — plans and photos of Mogador
- Plans de bateaux: Notice du VOLTA 1936 — plans of Volta
- Mogador-class at uboat.net