Richelieu class battleship

Richelieu in September 1943, after refit, with the upper fire control director on fore tower suppressed, and many AA short-range guns added.
Career (France)
Namesake:	Richelieu
Laid down:	22 October 1935
Launched:	17 January 1939
Commissioned:	June 1940/October 1943
Decommissioned:	1967
Struck:	1968
Fate:	scrapped
Class overview
Name:	Richelieu
Builders:	Brest Navy Yard
Preceded by:	Dunkerque-class
Succeeded by:	Alsace-class (planned)
Planned:	4
Completed:	2 Richelieu Jean Bart
Cancelled:	1
Laid up:	3
General characteristics
Type:	Battleship
Displacement:	48,950 tonnes
Length:	248 m
Beam:	35 m
Draught:	9.60 m
Propulsion:	six Indret Sural boilers four Parsons geared turbines four 4-bladed propellers 150,000 hp (112 MW)
Speed:	32 knots (59 km/h)
Range:	7,671 nautical miles (14,207 km) at 20 knots (37 km/h); 3181 nautical miles (5,891 km) at 30 knots (56 km/h)
Complement:	911 men in 1950 (incomplete) 1,280 men during the Suez affair.
Armament:	8 x 380mm/45 Modèle 1935 guns in quadruple turrets at bow 9 × 152 mm DP Mle 1931 in 3 triple turrets DP Mle 1935 at the aft Richelieu in 1940-1942 12 x 100 mm CAD Mle 1931 16 x 37 mm CAD Mle1933 28 x 13.2 mm Hotchkiss (5 CAQ, 2 CAD, 4 CAS) Mle1929 Richelieu in 1943 12 x 100 mm CAD Mle 1931 14 × 40 mm CAQ Bofors 50 x 20 mm CAS Œrlikon Jean Bart in 1955 24 x 100 mm CAD Mle 1945 28 × 57 mm AA in 14 twin turrets 20 × 20 mm AA
Armour:	belt: 330 mm upper armoured deck: 150-170 mm lower armoured deck: 40 mm main turrets: 430-170 mm conning tower: 340 mm

The Richelieu class battleships were the last and largest battleships of the French Navy, staying in service into the 1960s. They still remain to this day the largest warships ever built by France. Designed in the 1930s to counter of threat of the Italian Vittorio Veneto class battleships, the Richelieu class were essentially scaled-up versions of the preceding Dunkerque class, featuring a main armament of eight 380 mm guns in two quadruple turrets in forward superfiring positions.

Four Richelieu class ships, of three different subclasses, were designed (but only three laid down) over the course of three naval construction programs, in 1935, 1936, and 1938. Only the two first units, Richelieu and Jean Bart, were ever completed, and saw service during World War II, first under Vichy control in Dakar (1940) and Casablanca (1942), then under the Allies' control, Richelieu participating in British Home Fleet and Eastern Fleet operations and supporting the French forces return to Indochina in late 1945. Jean Bart was not completed until the 1950s, and took part in the operations off Port Saïd (Egypt) during the Suez Crisis in 1956. Richelieu was scrapped in 1968, and Jean Bart in 1970.

Background

The Washington Treaty and its consequences

In 1922, the Washington Naval Conference, concluded by the Washington Naval Treaty, decided to stop, for ten years, any new battleship building, as a new naval armaments race was developing, between the United States of America, the United Kingdom, and Japan. The Treaty fixed for battleships to be built, the limits of 35,000 tons for standard displacement, and 406 mm (16-inches) for the main artillery calibre. France and Italy each were also allowed to replace, after 1927, two of their old battleships.

Germany was not subject to the Washington Treaty limitations, but to specific stipulations of the Treaty of Versailles, and was forbidden to build any warship with a displacement greater than 10,000 tons.

But the interest of building battleships seemed very questionable · , as, during World War I, no decisive victory had resulted from a cataclysmic clash between battleships, as the Japanese victory of Tsushima, more 17 years earlier. However, the war experience had clearly shown the problem of ensuring the safety of maritime commercial roads, for which cruisers appeared better suited than battleships, so by the late 1920s, all the countries which had signed the Washington Treaty undertook the building of new heavy cruiser classes. For France, the priority was the safety of the maritime liaisons between France and her African colonies or protectorates, on the axis Marseilles-Algiers, or Bordeaux-Casablanca-Dakar.

So, in the late 1920s, the most powerful battleships had been designed before the Washington Treaty, and were armed with four double turrets of 15-inches (381 mm)(Queen Elizabeth, and Revenge classes, and HMS Hood, ), or 16-inches caliber (406 mm) (Colorado, and Nagato classes). The Nelson class battleships themselves, built between 1922-1927, with three triple 16-inches turrets forward, were based on 1921 G3 battlecruiser concept. The top speed was, for most of them, of 21–24 knots (Revenge, Colorado, Nelson, Queen Elizabeth battleship classes), for a few ones of 27 knots (Nagato class battleships), with the notable exception, in Western waters, of the HMS Hood fast battleship, and the two Renown class battlecruisers, whose speed exceeded 30 knots.

But neither France nor Italy were intending to build battleships with similar characteristics as these of the most recent American, British, or Japanese mastodons, very heavily armed and armored. They were only decided to modernize their ageing battleships, refurbishing the propulsion machinery, and upgrading the main artillery, as the Treaty of Washington has authorized them to undertake much more radical modernizations than the other treaty powers. In the same way, both powers reserved the right to employ their capital ship tonnage allocation (70,000 tons) as they saw fit, subject to Treaty limits, not only two battleships of 35,000 tons, but also three 23,000 tons or four 17,500 tons.

The French battleships projects in 1926-1929

HMS Nelson, commissioned in 1927, which inspired the French battleship designers in the 1920s.

The Treaty of Washington, by greeting France the same global battleship tonnage of 175,000 tons as Italy, in a proportion of 1 to 3 to the United States and the United Kingdom, and 1 to 1.8 to Japan, was resented as humiliating. But the battleships were not the core of the French warship building programme, which was adopted by the French Parliament in 1924, under the name of Statut Naval. Its aim was that the French Navy was able to counter the both navies of Italy and Germany. But from 1924 to 1932, the annual Tranche Navale (litterally slice of the so-called Statut Naval) will have included only cruisers, destroyers, torpedo-boats, and submarines.

The French Admiralty, under Vice Admiral Salaün, discussed, in 1926-1927, ships designed as cruiser killers, able to outgun and outrun the Italian heavy cruisers, which were considered as the main threat against the maritime liaisons between France and North Africa, as the first unit built, Trento, had been laid down in 1925, and launched in 1926. The French designers considered a displacement of 17,500 tons which would have allowed them to build four units, respecting the maximum limit of 70,000 tons, which the Treaty of Washington had fixed for the replacements authorized for France. An artillery arrangement of two 305 mm (12-inches) quadruple turrets forward was examined, combining the choice of quadruple turrets made by the French designers of the prewar Normandie and the all forward arrangement of the Nelson battleship class. The speed would have been of 34-35 knots, the armor able to resist to 203 mm shells. But, finally, such warships would not have been able to fight in the battle line against the old Italian battleships · .

In 1927, studies were undertaken of ships designed as battlecruisers of 37,000 tons. A trial displacement of 37,000 tons would have been the equivalent of a standard Washington displacement of 32-33,000 tons, near the maximum limit for battleship displacement fixed by the Treaty of Washington. But it clearly appeared than the building of 35,000 tons battleships was surpassing the technical and financial capacities of the French Navy, as the building costs of the linked infrastructures (new building forms and graving docks) for hulls of about 230-250 m length allowing to reach a speed of 27-30 knots, would have been equivalent of those of two more battleships, and would have jeopardized the building programme of the other categorizes of warships, cruisers, destroyers, and submarines.

Moreover, in the same time, discussions at the Disarmament Subcommittee of the League of Nations had begun in Geneva, about the pursuit of naval armaments limitation policy. The United Kingdom was trying to obtain more drastic limitations than those of the Washington Treaty, as 25,000 tons for battleship maximum displacement, and 305 mm for battleship maximum caliber, and the French Government did not wanted to jeopardize these negotiations.

The retort to the German pocket battleships

Panzerschiffe Deutschland, laid down in 1929, here in 1936, commonly designated as pocket battleship

The battleship of 23,000 tons

Everything changed when, in February 1929, the German Reichsmarine laid down the keel of Deutschland, an armoured ship (in German Panzerschiffe), of 10,000 tons displacement, respecting formally the limitations of the Treaty of Versailles, actually at least 25 % heavier but this was not known at this moment. With two 280 mm (11-inches) caliber triple turrets, and a speed of 26 knots, this ship outgunned every so-called heavy cruiser with their 203 mm (8 inches) guns intended to respect the Washington Treaty limitations concerning the caliber of cruiser main artillery, and outran every battleship, except the three fastest British units, HMS Hood, HMS Renown and HMS Repulse. The type of Deutschland was commonly designated as a pocket battleship, being actually as her German denomination indicated well, an armoured cruiser.

The reaction of the French Admiralty was to prepare draft drawings for a ship which would outclass the German "pocket battleship", in armament, armor and speed. It appeared that the armament of the French previous projects might be retained, that the speed might be of 30 knots, and not necessarily superior, but the most important feature was that the armor had to be thicker to resist to 280 mm shells. These considerations were leading to a displacement of about 23,000 to 25,000 tons, which fits the maximum displacement that the United Kingdom found suitable in the naval armament limitations negotiations.

The 1930 London Naval Treaty decided that the ten-years battleship holiday agreed at Wahington would be extended for further five years, until 1936, December 31. France and Italy were authorized, however, to build the remplacement tonnage which they were entitled to lay down in 1927 and 1929 in accordance with the provisions of the Treaty of Washington. Nevertheless, France and Italy refused to adhere to other qualitative limitations, which were mainly concerning cruisers. France argued that ship construction had just started in Germany of the armour-clad Deutschland, and following the rejection of the agreement by France, Italy was no longer prepared to accept new restrictions · .

In order to establish an agreed ceiling to new naval construction, bilateral talks took place between France and Italy, with the great encouragement of the United Kingdom, at the very beginning of 1931, and a basis of agreement was concluded on March 1. Up to 1936, both countries would have been allowed to build only two battleships each of 23,333 tons. But it was not possible to go further, as the Regia Marina was not satisfied of the 23,333 tons battleship Italian project, with three twin 381 mm turrets, and a profile reminiscent of the heavy cruiser Pola, then in construction: a very complete refit of the artillery and power plant of the Conte di Cavour battleships class will begin in 1933, and the studies on the 35,000 tons will be going on.

Dunkerque

However, in 1931, the French Admiralty explicitly confirm the choice of the battleship of 23,333 tons, as the battleship of 17,500 tons would have been too lightly armored, and the battleship of 35,000 tons would have required technical and financial capacities that outranged the possibilities of France. This battleship of 23,333 tons would have had a 213 m length, with a 27.5 m beam, two quad 305 mm/55 cal turrets forward, three quad 130 mm turrets Dual Purpose aft, a speed of 30 knots, an armored belt of 230 mm, and a horizontal protection of 150 mm. But when this proposal was submitted to the Parliament, in 1931 May, the discussion lasted two months, with much criticism, as it was difficult to understand why it was necessary to have a displacement double of the warship which was to be countered, and why it was not preferable to build a 35,000 tons battleship. So, in the 1931 Estimates, in July, funds were allocated only for further studies, with the proviso that the final characteristics should be subject to a thorough revision, the results of which would have to be submitted to the Parliament, before passing any building orders. Then, Vice Admiral Durand-Viel, the new Chief of Staff of the French Navy from 1931 January, requested further studies for upgrading the main artillery caliber, from 305 mm to 330 mm, to outgun the Italian battleships.

This resulted to an increase in displacement to 26,500 tons, a 2-meter increase in length, a 2.5-meter increase in beam, a slight reduction in maximum speed to 29.5 knots, the substitution of 330 mm/52 guns to 305 mm/55 ones, two more double 130 mm DP turrets, and a slight increase of the thickness of the armored belt, as on the armored decks · . In early 1932, the project was approved by the Parliament committees, and the Minister of Defence, François Pietri, succeeded to include it in the 1932 Estimates. So emerged the Dunkerque, which was ordered on 1932, October 26, and laid down on 1932, December 24.

After Deutschland, Admiral Scheer, on June 1931, and Admiral Graf Spee, on October 1932, had been laid down. So the French Navy asked to have quickly a second ship with the same characteristics as Dunkerque: she was included in the 1934 Estimates.

Facing Scharnhorst and Littorio

Battle cruiser Scharnhorst, before she was fitted, in the early months of 1939, with a clipper bow and before her main mast was placed 27 m afterwards

Originally, the Deutschland class was intended to count six units. On February 14, 1934, two more German battleships were ordered, officially, the fourth and fifth units of the Deutschland class, as the Third Reich has not yet denounced the Treaty of Versailles. But, during more than one year, there were discussions about their definitive characteristics, as the laying down of Dunkerque was leading to an upgraded version of the pocket battleship. Finally, they emerged as the only other class of little battleships, with the Dunkerque class, to be faster than the 1920s battleships, with a displacement substantially under the limits of the Treaty of Washington. Heavier than the Dunkerque class battleships (31,800 tons), with the hull dimensions of the Ersatz Yorck battlecruiser class, projected in 1915, they were strongly armored with a 350 mm belt, and bearing a horizontal armor equivalent to the later King George V, or Bismarck battleship classes. However they were only armed with nine 280 mm guns, the same calibre as the Deutschland class. A heavier caliber had been considered for the main artillery, and was preferred by Adolf Hitler, as the Dunkerque class battleships were armed with 330 mm guns. But when the final design of these ships was about to be settled, Germany was negotiating the 1935 Anglo-German Naval Agreement, and the British Government was pressing very strongly for a limitation on the battleship main artillery calibre. So reluctantly, an improved gun, with longer barrel, higher muzzle velocity, but the same 280 mm calibre was chosen. Gneisenau was laid down on May 6, 1935, and Scharnhorst, on June 15, 1935.

As the French Navy ship designers thought that Dunkerque class battleships' armor was able to resist to 280 mm calibre shells, there would not have been any necessity to conceive a heavier battleship class. But, in Italy, the new French battleships were considered as breaking the balance between the French and Italian battleship fleets in the Mediterranean waters. The new Italian battleships were intended by the Regia Marina to counter the Dunkerque class battleships, but also the more heavily armed battleships of the British Mediterranean Fleet. Duce Benito Mussolini announced, on May 26, 1934, the decision of Italy to fully use the right of building battleships as they were resulting of the naval limitations treaties. Some days later, the Stefani news agency announced the laying down of two 35,000 tons battleships, armed with nine 381 mm guns, which received in October 1935 the names of Littorio and Vittorio Veneto.

The battleship Littorio during speed trials, in 1939, without AA battery, fire control directors, or aircraft installations.

The time had come to build the first French 35,000 tons battleship. But time was missing to achieve a design for a new heavier battleships class. The French Navy Board, (Conseil Supérieur de la Marine, French equivalent to the British Board of Admiralty) recommended, unanimously, on June 25, 1934, to not modify the 1934 Naval Program, and to order the building of a new Dunkerque class battleship, improving the vertical armored protection: Strasbourg laying down was ordered on July 16, 1934.

Eight days later, on July 24, 1934, the French Navy Board defined the characteristics of the new French battleships as follows :

• displacement: 35,000 tons standard
• main armament:eight/nine guns of 380/406 mm calibre
• secondary armament: to be capable of fire against surface targets and long -range anti-aircraft fire
• speed: 29.5-30 knots
• protection; belt 360 mm; upper armored deck 160 mm; lower armored deck 40 mm; underwater protection as Dunkerque

Thirteen months later, the Service Technique des Constructions navales, (S.T.C.N.), French equivalent of the Department of the Director of Naval Construction, in the Royal Navy, established a definitive project which was submitted to the Minister, on August 14, 1935, adopted on August 31, and Richelieu was laid down, on October 22, 1935. So acting, France was not respecting the Washington Treaty and the 1930 Treaty of London, as more of 88,000 tons of new battleships, instead of 70,000 tons, have been ordered, since 1922 and before December 31, 1936. But, on June 18, 1935, the Anglo-German Naval Agreement had been signed, between the United Kingdom, without consulting France, and the Third Reich, cancelling de facto the limitations of the Treaty of Versailles concerning the limitations of displacement of the various types of warships, and granting Germany the right of building a war navy within the limit of 35% of the total tonnage of the Royal Navy. Having lost the hope of being able to counter both the German and Italian Navies, as the Versailles and Washington Treaties allowed it, France considered that the Dunkerque class battleships were the answer to the Scharnhorst class and the Richelieu class battleships the answer to the Littorio class.

Germany went a step further, laying down two new battleships, Bismarck in November 1935, and Tirpitz in June 1936. These ships, strongly armoured as their protection absorbed more than 40% of their standard displacement, with a very large beam of 36 m, got a very classic design, eight 380 mm calibre guns in double turrets, two forward and two aft, the secondary anti-ship artillery in six double 150 mm turrets on sides. A powerful anti-aircraft artillery in sixteen 105 mm guns in eight double turrets, and numerous 37 mm and 20 mm mountings, controlled by six high-angle directors was unmatched anywhere  : officially declared as 35,000 tons, their tonnage was more than 42,000 tons standard and even nearing 50,000 tons full load.

The French answer was the laying down of the second Richelieu class battleship, Jean Bart, in December 1936.

Design

Richelieu, as designed, before the 1943 refit in New York

The Richelieu class had a planned standard displacement of 35,000 tons, equal to the limit fixed by the Washington Treaty, with a main armament of eight 380 mm guns in two quadruple turrets. Three ships in two subclasses were laid down: all had the main turrets in forward superfiring positions, while the fourth unit was planned with one turret forward and the other aft. There were also differences among subclasses in the secondary artillery and the aircraft installations planned to be fitted, as well as minor differences between Richelieu and Jean Bart resulting from the completion of the latter unit ten years after the former one.

Richelieu and Jean Bart

Vice admiral Durand-Viel, Chief of Navy General Staff, was very concerned about the continuity between the Richelieu battleship class and the preceding Dunkerque battleship class, whose lead ship had been ordered only two years before.

Armament

Main artillery

The French Navy Board had indicated, in July 1934, a minimum calibre, 380 mm, which was dictated by the choice of the Regia Marina, and a maximum, 406 mm, which was still the limit fixed by the Washington Treaty. For the number of guns, eight was the minimum determined by the practice for spotting efficient salvos, and it was one of the reasons for which the Regia Marina had not been satisfied by the 23,300 tons battleship project of 1931, with six 381 mm guns only. The maximum of nine guns corresponded to a battery of three triple turrets, as on the new Italian battleships.

The quadruple turret arrangement was saving more than 25% weight on turret armoring, compared to four double turrets, while retaining the same firepower, but it appeared quickly that the 380 mm caliber was the largest feasible for a quadruple turret. With a 32 m beam, and 406 mm (16-inch) caliber guns, the Nelson class battleships had accommodated only triple turrets. But on the Dunkerque, with 31 m beam and 330 mm (13-inch) guns, the four barrels of each turret were not yet mounted independently in individual mounts because this would have meant an unduly large barbette diameter. For that reason the right and left hand pair of barrels were placed in a common mount each. It will not have been the case on the fore and aft 14-inches quadruple turrets of the British King George V class battleships, which had 34 m beam and 356 mm caliber, 3-meter more beam and only 1-inch more calibre than on Dunkerque.

The drawback of the quadruple turret was the risk of receiving a single unlucky shot which would destroy one turret, and would cripple one half of the main battery: the quadruple turrets of Dunkerque class battleships had been divided internally, with a 25 to 40 mm bulkhead to localise damage. This device will be noted as effective at Mers-el-Kebir, when the first British 381 mm shell, striking Dunkerque, rebounced on the 330 mm turret II, killing all servants in the right half turret, as the left one remained operational.

But the all forward arrangement of two quadruple turrets, and more broadly the proximity between the magazines of the main artillery turrets, induces the greatest risk, crippling the totality of the main battery, or even provoking the loss of the ship. On Dunkerque, to avoid this risk, the forward turrets had been positioned 27 m apart from one another, more than on the Nelson class battleships. Nevertheless, the French Navy studied various other solutions, with three turrets (one quadruple and two double, two triple and one double, or three triple). In every case, with three turrets, there would has been an excess of weight, in comparison with two quadruple turrets, and, in counterpart, a propulsion plant power reduced to 100,000 hsp, and a speed loss of 2.5  knots, for a little benefit of distributing the main armament on a greater length. So following the proposal of the head of STCN, the Chief of Navy General Staff choose as early as November 1934 the all forward arrangement with two quadruple turrets.

The main artillery turrets of Richlieu, with the 20mm AA Oerlikon guns fitted on the forecastle during the 1943 US refit

The solutions used on Dunkerque class battleships were retained on Richelieu, in a scaled up version: all forward disposition, in two 2476 tons quadruple turrets Model 1936, built by Saint-Chamond, weighing 3,096 tons with the weight of the barbette. It was nearly 1,000 tons more than the about 1,500 tons quadruple turrets of Dunkerque or triple turrets of Littorio. The world heaviest turrets will have been the three-460 mm gun turrets on Yamato with 2,774 tons, the U.S. Navy heaviest built turrets, the 1704 tons turrets of Iowa class battleships, the heaviest Royal Navy turrets ever built, the three-406 mm gun turrets of Nelson class battleships weighing 1568 tons, and the four-356 mm gun turrets of King George V, weighing 1550 tons.

Each Richelieu turret was divided in two half turrets, by a 25 to 45  mm bulkhead. The guns, in the half turrets, were in pairs, and although each gun was in a separate cradle, the relative movement of the guns of each pair was limited. The guns were so close (1.95 m, only 0.30 m more than on Dunkerque) that a wake effect between shells fired simultaneously by a half turret lead to an excessive dispersal, which has not been corrected before 1948 on Richelieu. The turrets were positioned 33 m apart from one another, 6 meters more than on Dunkerque.

The weight of one barrel was 110 tons, less than the 181 tons barrel onYamato, or the 130 tons barrel on Nelson, nearly the same weight as the 112 tons barrel on Nagato, the 109 tons barrel on Bismarck, the 107 tons barrel on Iowa, the 102 tons barrel on Littorio, or the 97 tons Queen Elizabeth barrel, and more than the 80 tons King George V barrel.

The maximum angle of elevation of guns on the Model 1936 turret was 35°.With a 830 m/s muzzle velocity, the maximum range was theoretically 41,500 m, practically 37,800 m. The rate of fire was from 1.3 rounds per minute to 2 rpm. The maximum training speed was 5°/s, and the maximum elevating speed 5.5°/s. The 380 mm shell was an Armor Piercing Capped (APC) shell, registered in the French Navy as Obus de Perforation (OPf). The OPf Model 1935 was an extrapolation of the 330 mm OPf Model 1935, in use on the Dunkerque, except for its moulded base forming a boat tail which assisted in keeping the shell stable in flight. The 380 mm shell was 1,905 m long and weighed 884 kg, less than the 406 mm Massachussets shell (1224 kg), which hardly stroke Jean Bart, at the battle of Casablanca (1942), and some kilos more than the weight of the 381 mm shells of HMS Barham or HMS Resolution (875 kg), which near missed Richelieu at the battle of Dakar (1940).

The OPfK Model 1935 incorporated a dye bag and fuze (dispositif K) to colour ( yellow for Richelieu and orange for Jean Bart) not only splashes but hits, thereby facilitating spotting for ships operating in formation while in combat. No Highly Explosive (HE) variant of the 380 mm shell was originally provided. A total of 832 APC shells are intended to be provided, slightly fewer than in the Dunkerque class battleships (896 rounds).

Remote Power Control (RPC) was to be fitted for both training and elevation; however the failure of the Sautter-Harlé-Blondel system fitted on the Dunkerque class battleships resulted in a loss of confidence in the application of this technology to heavy armored turrets, and it was never fitted.

Secondary artillery

On the background, the quarter deck (August 14, 1943 picture), with four quad 40mm Bofors mountings, and nine 20mm Oerlikon AA single mountings, on the formerly aviation hangar. On the fore ground, two single 20 mm Oerlikon mountings on the roof of the axial 152 mm turret

The French Navy had been precursor in fitting dual-purpose battery on battleships, in the early 1930s, and seven years later, with the shortcomings of the 130 mm and 152 mm DP turrets and of the 37 mm twin automatic AA mountings, the solution of having a low-angle secondary battery and a high-angle tertiary battery was a feature of the new battleships in construction, as in the German and Italian navies.

For the secondary artillery, all early projects were keeping the 130mm caliber, in five quadruple Dual-Purpose turrets, at the same position as on the Dunkerque class battleships, but with quadruple turrets amidships, instead of double turrets. A tertiary anti-aircraft 75mm zénithaux battery was considered, to complement the 130 mm DP battery of the early design sketch.

As, in that time, the torpedo surface attacks were considered more dreadful than aircraft bombing, a heavier calibre was required for the anti-ship battery. Since the Nelson class battleships, the Royal Navy has adopted a six 152 mm double turrets battery as secondary artillery on battleships. The Kriegsmarine had chosen 150 mm guns on Scharnhorst, and the Regia Marina was fitting the 35,000 tons battleships with 152 mm calibre guns. It was decided to adopt triple 152 mm turrets, as fitted on the most recent light cruisers, Émile Bertin and La Galissonnière class cruisers which were then being built. The S.T.C.N. proposed two solutions, five 152 mm turrets, and six 75 mm single mountings, or four 152 mm turrets, without the fifth turret (central axial), or with two center line aft turrets in superfiring position, and eight 75 mm single mountings, but it was difficult to install this AA battery, keeping it out of the blast effects of the main and secondary batteries.

The French Navy Board, in April 1935, resolved to fit Richelieu with five 152 mm turrets in the same disposition as the 130 mm battery on Dunkerque. It was decided that these 152 mm turrets had to be dual-purpose, and that the tertiary 75 mm AA battery had to be abandoned, as the substitution of 152 mm DP turrets, weighing 306 tons to the 130 mm turrets, weighing 200 tons, was inducing an excess of weight of about 500 tons. It was also decided to install a new weight-saving propulsion plant, developing the same power, 150,000 hsp, but using Sural (suralimenté) boilers, instead of the more conventional boilers fitted on Dunkerque. It was thence possible to reduce the number of boilers rooms from three to two, which allowed a reduction of the length of the citadel of nearly five meters, and consequently the weight of the armored belt. As other weight-reduction measures, the thickness of the armored belt was reduced, from 360 mm previewed, to 330 mm, and its inclination increased from 11°30' to 15°24' to compensate the thickness reduction. The thickness of the longitudinal bulkheads, of the conning tower, and of the turrets and barbettes of the 152 mm guns were reduced too.

The triple 152 mm Model 1936 Dual Purpose turret, was an extrapolation of the 152 mm Model 1931 Low-Angle turret. The guns, mounted on separate cradles, were 1,85 m apart. The training speed was 12°/second, and the elevation speed 8°/s. The gun maximum elevation was 90°, with theoretically loading at every elevation. The muzzle velocity was 870 m/s. The shells used, against sea targets, were Semi Armored Piercing (SAP) shells, registered in the French Navy as OPfK Model 1931, with dye bag, weighing 56 kg, or 57,1 kg (OPfK Model 1937). Against aircraft, the 152 mm/55 Model 1930 guns were firing High Explosive (HE) shells, registered OEA (Obus Explosif en Acier) Model 1936, weighing 54,7 kg, or 49,3 kg (OEA Model 1937). Starshells, registered as OEcl (Obus Eclairant) Model 1936, weighing 47 kg, were to be provided for the amidships turrets. The rate of fire was 6.5 rounds per minute, against sea targets, and 5 rpm against aircraft. The maximum range against sea targets, with a 45° elevation, was 24,500 m. Full RPC was fitted. On Richelieu, the planned ammunition outfit was two thousands SAP shells, nearly one thousand HE shells and 650 illuminating shells, for three triple turrets fitted.

The 152 mm Model 1931 Low-Angle turret proved to be highly satisfactory, at least comparable to the German single or twin 150 mm guns turrets, or the Italian triple 152 mm turrets Model 1934 or 1936. But for anti-aircraft purpose, the 152 mm Model 1936 turret was considered as complex and fragile, with a too slow rate of fire against rapid-moving aerial targets, with a deficient RPC, and prone to jamming in loading at angles superior to 45°. The reason of this failure had to be looked for in the too great weight, 227 tons without the barbette, of the 152 mm DP Model 1936 turret, nearly 55 tons heavier than the 172 tons for the 152 mm Model 1931. It must be noted that there will not have been other examples of 152 mm guns used as anti-aircraft battery, but, post war, two U.S. Navy cruisers of the Roanoke class and three Royal Navy cruisers of Tiger class, with much more performing RPC and control fire direction devices than the French ones used just before WWII.

As, at the very beginning of the war, on November 1939, it became evident that the projected 37 mm ACAD Model 1935, automatic anti-aircraft twin mountings, would not be provided in time for the completion of Richelieu, a drastic revision of the AA battery was needed. The amidships 152 mm turrets had to be landed, and twelve 100 mm/45 Model 1930 guns in six twin 100 mm mountings, CAD Model 1931, were intended to be fitted, as they had been on the last 10,000 tons Treaty cruiser Algérie, and were intended on the planned De Grasse class cruisers. To respect the priority of completing Richelieu first, four mountings had to be removed from the reconstructed battleship Lorraine, and two from a battery near Marseilles. The 152 mm amidships turrets were not even mounted on Jean Bart, neither barbettes installed. The 100 mm mountings were fitted on Richelieu, in Avril-May 1940.

The 100 mm CAD Model 1930 turrets were dual-purpose. SAP shells (100 mm OPf Model 1928) weighing 15  kg, were fired on sea targets, with a muzzle velocity of 765 m/s and a 15,800  m maximum range, but it seems that 10 rounds per gun only were embarked, as it was considered that the anti-ship fire would be mainly insured by the stronger 152  mm guns. HE shells (100 mm OEA Model 1928) weighing 13,5 kg, were fired on aerial targets, with a muzzle velocity of 780  m/s and a 10,000 m ceiling (at 80° maximum elevation). The rate of fire was 10rpm. Illuminating shells (100  mm OEcl Model 1928) were provided, in replacement of the 152  mm OEcl Model 1936, which seemed, if they had been provided, to have been landed with the 152 mm amidships turrets, as they were not mentioned in the war time ammunition inventories.

The 100 mm guns proved to be the most reliable arms of Richelieu in her early war carrier, till 1942.

Anti-aircraft light artillery

For the short range anti-aircraft defence, the French Navy had planned to develop, for the Dunkerque class battleships, an automatic version (37 mm ACAD Model 1935) of the 37 mm semi-automatic anti-aircraft twin mountings (CAD Model 1933) which had a 30 to 40 rpm rate of fire theoretically. Hand loaded, using six-round box magazine, the rate of fire was practically 15 to 20 rpm, as in the same time, the British Pom Pom gun, or the Swedish designed Bofors 40 mm/L60 gun had a 120 to 200 rpm rate of fire. Thence the 37 mm ACAD Model 1935 was expected to have such a rapid rate of fire. But in 1940, only a a prototype ACAD mounting designated Model 1936 was trialed aboard the old patrol sloop Amiens and apparently successfully used during the Dunkirk evacuation.

Six 37 mm ACAD Model 1935 mountings would have had to be fitted, four abeam the after funnel superstucture, and two abeam turret II. Four fire control directors, equipped with a two-meter range finder and linked to the mountings by a RPC system driven by Sautter-Hallé electric servo-motors, were intended to be installed, two, for the forward mountings, abaft turret II, one deck higher, and two for the after mountings, abeam the mountings, one deck higher. This 37 mm battery would have been complemented by six or eight 13.2  mm Hotchkiss quadruple MG mountings, CAQ Model 1929, on the upper platforms of the forward and after tower.

Fire control direction

The most conspicuous difference in the Richelieu profile with the Dunkerque, was the mounting of the fire control director system aft, not on a separate tower located behind the funnel, but on a kind of mack, so that the funnel opening was taken out obliquely aft underneath the control position tower.

Otherwise, the fire control director system was closely modeled as on Dunkerque.

Three fire control directors were mounted one over the other atop the fore tower, with, bottom up, the director A, for the main artillery, with a 14-meter triple stereoscopic OPL (Optique de Précision de Levallois-Perret) range finder, and for the 152 mm artillery, two fire control directors, with, in the director 2, in central position, for anti-ship gunnery, a 8-meter double stereoscopic OPL range finder, and in the director 1, in upper position, for anti-aircraft gunnery, a 6-meter double stereoscopic OPL range finder.

The same noteworthy weight accumulation in the heights of the fore tower, as on Dunkerque, proved to be a shortcoming, when the Richelieu was torpedoed at Dakar, as a whiplash effect on the main mast around which they were mounted, provoked more serious avaries on the directors of the fore tower, than on the after tower, which was however nearer of the torpedo explosion.

On the after tower, there was only the auxiliary director for the 152 mm artillery (director 3) with a 6-meter double stereoscopic OPL range finder. The auxiliary director for the main artillery, (director B), was between the funnel and the axial aft 152 mm turret, with an 8-meter double stereoscopic OPL rangefinder.

All the directors were gastight and were fitted with light steel plating against the MG attacks of strafing aircraft.

Each main artillery turret was fitted with a 14-meter double stereoscopic OPL range finder, as each 152 mm turret, with a 8-meter double stereoscopic OPL range finder. Two directors with a 3-meter OPL range finder provided for the flag staff, were installed on the wings of the admiral’s bridge.

When the 100 mm AA battery was fitted, they were replaced by directors fitted with a 4-meter OPL range finder for the fire control of this battery. Two directors also fitted with 4-meter range finder were then mounted on the navigation bridge, one deck lower. There was also a 3-meter SOM (Société d'Optique et de Mécanique de haute précision) stereoscopic tactical range finder atop the bridge.

As on the Dunkerque class battleships, the directors provided raw target data to the transmitting station located beneath the armored decks, with continuous transmission to the director and the guns.

Look out and target designation facilities were similar in principle to those of Dunkerque. The lower lookout station (veille basse) for close-range contacts was on platform 3 of the fore tower. The middle level (veille éloignée) for both surface and aerial contacts was on platform 6, and the upper look out station (veille haute) was primarily for spotting torpedoes and mines on platform 9.

For night firing, there were five 1.20 m searchlight projectors, one atop the admiral's bridge, and two on either side of the funnel structure.

Aircraft installations

As on Dunkerque, aircraft installations (aircraft hangar, crane and two catapults, for four seaplanes) were fitted on Richelieu's stern. The materials were the same, 22 m trainable catapults operated with compressed air, which could launch a 3.5 tons aircraft at 103 km/h, a recovery crane with a capacity of 4.5 tons. The aircraft were hull seaplanes Loire 130 type, single-engined (720 hp Hispano-Suiza 12-cylinder liquid cooled) with a 3,500 kg weight, a 210 km/h maximum speed, a 165 km/h cruise speed at 1,500 m, two 75 mm MG and two 75 kg bombs.

The differences in aircraft facilities with Dunkerque resulted of the disposition of the Sural boilers, three side by side on the boilers rooms, instead of two, so there was only one boiler room under the funnel, instead of two. Consequently, the aft 152 mm turret on center line,(turret VII), was on frame 68.85, on Richelieu, versus on frame 44.30, on Dunkerque, as the aft lateral secondary turrets were respectively on frame 54,45, versus 53.30 · . Incidentally, turret VII was abaft turrets V and VI, on Dunkerque, which corresponded to the French traditional mode of turret numeration, from bow to stern, but turrets V and VI were abaft turret VII on Richelieu. With 36,50 m on the quarterdeck between the aviation hangar and the stern, on Richelieu, instead 30 m on Dunkerque, this enabled a second catapult to be worked in, the catapults being offset to port and starboard en échelon with an elevator between them . The planes were moved on rails from the hangar to the elevator where they were placed on both catapults.

Two planes were to be stowed in the 25 m long hangar, on the same level, wings folded, in line, instead to be placed on the two platforms of a two-tiers hangar lift, and two on the catapults, wings deployed.

Protection

Ship	Protection (tons)	Protection (%)	Displacement (tons)	With fuel (tons)	Fuel load
Richelieu	16,045 16,045	39.2 42.4	(normal) 40,927 (standard) 37,832	2,905 -	1/2 -
Dunkerque	11,040	35.9	(normal) 30,750	2,860	3/4
Strasbourg	11,785	37.3	(normal) 31,570	2,860	3/4
Iowa	18,700	41.6	(standard) 45,000
Bismarck	17,540 17,258	43.92 41.30	(light) 39,931 (standard) 41,781
King George V	12,500	34.8	(standard) 35,000
Littorio	13,600	36.03	(standard) 37,750

On Richelieu, the weight of protection was 16,045 tons, and corresponded to 39;2 % in the weight distribution, for a 40,927 tons normal displacement, with 2,905 tons of fuel (half of full load). This figure may be compared to those given for Dunkerque, 35,9 %, or Strasbourg, 37,3 %, but with a 30,750/31,570 tons normal displacement, with 2,860 tons of fuel (¾ of full load). The comparison with foreign battleships is more difficult to set up. The figures given for the Iowa class battleships are 18,700 tons for the protection weight and 41,6 % of 45,000 tons standard displacement, which corresponds for Richelieu to more than 42% of standard displacement. For Bismarck, the figures are 17,258 tons or 17,540 tons for the protection weight, and from 43,92 % to 41,30 %, as the percentage is calculated with 39,931 tons light displacement or 41,781 tons standard displacement · . As all these figures are very near one another, it is clear that they are all superior to those given for the King George V class battleships, 12,500 tons and 34,80 %, or for the Littorio class battleships with 13,600 tons weight of protection and 36 % of 37,750 tons standard displacement.

Armor

• The armored belt, with an inclination of 15°24’, was 327 mm thick, between frame 51.50 and frame 182.95, from 3.38 m above the waterline to 2.50 m under the water line. The forward bulkhead, at frame 182.95, and the after bulkhead, at frame 51.50, extended from the main deck to the 30 mm floor of the munitions magazines, and were 233 mm thick. The forward bulkhead thickness was increasing to 355 mm between the first and the second platform decks.
• The upper armored deck at main deck level was 150 mm thick above the machinery plant and was increasing to 170 mm above the main artillery magazines. The lower armored deck was 40 mm thick, and extended to frame 233, improving the protection of the forward part of the ship, left unprotected on Dunkerque. Abaft the after transverse bulkhead, there was, at first platform deck level, a 100 mm armored deck with angled sides in form of a carapace above the shafts, increasing to 150 mm above the steering gear.
• On the conning tower, the armor was 340 mm thick on face and sides, 280 mm on rear, and 170 mm on the roof.
• The main turrets were protected with a 405 mm thick armor on the barbette, above the upper armored deck; 430 mm on the faces, inclined to 30°, from 170 mm to 195 mm on the roof, 270 mm on turret I rear wall and 260 mm on turret II rear wall. This thickness on the rear walls, lesser than on Dunkerque or Strasbourg, with about 340–350 mm, was explained by the use of a cemented steel on Richelieu.
• The 152 mm guns turrets were less armored than the Dunkerque quadruple 130 mm turrets, with a 100 mm thickness on barbettes, 130 mm on the faces angled at 45°, 70 mm on sides and roof, and 60 mm on the rear.

The British King George V class battleships and HMS Vanguard will have had a thicker armored belt than Richelieu (356 mm), but their turrets will have been less protected (330 mm), as the horizontal armor (152 mm) will have been equivalent, but their command spaces will have been only protected against splinters.

The U.S. Navy battleships will have had an equivalent armored belt (330/340 mm) as Richelieu, on the North Carolina and South Dakota classes, and a little less thick (310 mm) on the Iowa class. The main artillery turret protection was less thick (406 mm) on the North Carolina class, equivalent (430 mm) on the Iowa class, and thicker (457 mm) on the South Dakota class. The horizontal armor was a little less thick (104 mm) on the North Carolina class, equivalent (127/165 mm) on the South Dakota and Iowa classes. The conning tower was better protected, with 406 mm on the North Carolina and South Dakota classes, and with 445 mm on the Iowa class.

The Italian Littorio had a thicker armored belt (350 mm) than Richelieu, but otherwise, they were less protected, with 350 mm on the main artillery turrets, 260 mm on the conning tower, 50 mm on the upper armored deck et 100 mm on the main deck. The German Bismarck class battleships had a less thick armor than Richelieu on the main artillery turrets (356 mm), thicker on the conning tower(356 mm), equivalent for the armored belt (320 mm), and for the horizontal armor(80 mm + 115 mm).

Underwater protection

As on Dunkerque, the underwater protection consisted in a sandwich of void spaces, light bulkheads, liquid loading compartments or compartments filled with rubber-based water-excluding compound (ébonite-mousse), and a heavy internal holding bulkhead to absorb the explosion of a torpedo head.

The compartment outboard of the inclined armor belt had a maximum depth of 1.5 m, and had a filling of ébonite mousse. Inboard this compartment, there was a 18 mm bulkhead, inclosing a void compartment 0.9 m deep, then an oil fuel bunker 3.4 m deep (0.5 m less than on Dunkerque), then a 10 mm bulkhead, containing a void compartment 0.67 m deep, backed by a 30 mm torpedo bulkhead of special steel. The maximum depth was around 7 meters. The reduction of 0.5 m comparing with Dunkerque was necessary to accommodate three boilers side by side in the boiler rooms.

This figure of 7 m width was impressive, compared with the 4.10 m on King George V, 5 m on Scharnhorst,or 6 m on Bismarck. The Italian Littorio class battleships had a peculiar underwater protection system, designed by the Italian chief designer, Generale Ispettore del Genio Navale Pugliese, which incorporated a cylindrical expansion space of 3.8 m diameter. During the British aircraft attack of the Italian battleship fleet in Taranto, on November 11, 1940, it did not succeed to avoid the sinking of Littorio in shallow water. But the Achilles' heel of battleships facing torpedo attacks was their vitals which could not be protected, as Bismarck's rudder in May 1941, or Richelieu's shaft, at Dakar, in 1940, or HMS Prince of Wales's shaft off Kuantan, in December 1941.

Propulsion

The French designers of Richelieu had various constraints: a 33.5 m beam to accommodate the barbettes of four 380 mm gun turrets, a 245 m long hull, limited by the length of the Navy shipbuilding infrastructures, thus a ratio length/beam of 7.3. All this induced a machinery developing 150,000 shp, to reach the 29.5/30 knots, requested by the French Navy Board. It was then the greatest machinery power installed on a battleship. It will have been surpassed only on U.S. Navy Iowa class battleships in 1943-1944. An equivalent speed had been reached, with less power (144,000 hsp) on HMS Hood, but with a 262 m hull, a 42,000 tons displacement, and a ratio length/beam of 8, but without shipbuilding restraint nor any displacement Treaty limit. All British or U.S. battleships, built in the late 1930s, having to respect the 35,000 tons displacement limit had a speed of 29 knots (King George V class), or 28 knots (North Carolina or South Dakota classes), they were 225 m or 215 m long, with a propulsion plant developing respectively 110,000, 120,000, or 130,000 shp · . The Italian Littorio class battleships reached 30knots, with a 230 m hull and 140,000shp. The German battleship Bismarck had a 29 knots speed with 138,000 shp, and reached 31 knots with 150,000 shp forcing, but her ratio length/beam, was only 6.9 as she had, for the same hull length as Richelieu, a wider beam (36 m).

The propulsion was assured by six Indret boilers, and four Parsons turbines. The boilers were of a new type, so-called suralimenté, which meant pressure-fired, thence the abbreviation of Sural boilers. These boilers were operated at a pressure of 27 kg/cm² (350°C), as on Dunkerque, but forced circulation and pressure firing resulted in steam production per m³ well in excess of conventional boilers (14.4 kg/m³). They were 6.30 m long versus 5.33 min on Dunkerque, 4.65 m height versus 5.34 m, and moreover 4;50 m wide versus 6.50 m. Thence, due to the 2-meter greater beam of Richelieu, it was possible to install three boilers side by side in two boiler rooms, instead of three rooms, as on Dunkerque. Boiler Room 1 was underneath the fore tower, with, from starboard to port, boilers n°10, n°11, and n°12, followed by the forward Engine Room housing the geared turbines for the wing shafts. Boiler Room 2 directly underneath the funnel, with boilers n°20, n°21, and n°22, produced the steam for the turbines of the center shafts, in aft Engine Room. A 18 mm bulkhead separated the forward Engine Room from the Boiler Room 2, dividing the machinery plant in two independent units.

In each Engine Room, there were two sets of turbines, each driving a four-bladed propeller with a diameter of 4,88 m. Each set comprised a single High Pressure (27 kg/cm²) turbine, a Medium Pressure (10 kg/cm²) turbine, and Low Pressure forward and reverse turbines (1.25 kg/cm²and 4 kg/cm²). Four turbo generators, each of 1500 kW, were distributed, for two of them, in the forward engine room, and, for the after pair, in a separate compartment directly abaft the main machinery spaces, adjacent of the magazines for the after 152 mm turrets.

The maximum fuel load for peace-time cruising was 5,866 tons, but in wartime, this figure was reduced to 4,700 tons, to maximise the effectiveness of the underwater protection system, as filling the liquid loading compartments to the brim create additional pressure on bulkheads, instead of absorbing the pressure of explosion. The radius was 9,850 nmi at 16 knots, 8250 nmi at 20 knots, and 3,450 nmi at 30 knots.

During speed trials, in April 1940, developing 123,000 shp, 30 knots were maintained, with near 42,000 tons displacement, and in June, 32 knots were maintained during 3h30, with 43,800 tons displacement and 155,000 shp, and 32.68 knots were reached with 179,000 shp forcing.

The battleships of the Supplementary Programme 1938 bis

In 1937, Italy ordered two more Vittorio Veneto class battleships, to be laid down in 1938. The French reaction was to order two more battleships of the Richelieu class, with an improved design, as the French naval building capacities necessitated some delay in order to have these units laid down.

The second London naval disarmament conference failure had marked the end of the international naval armament limitation policy. Japan had withdrawn from the conference on January 15, 1936. Italy also declined to sign the treaty. A so-called "escalator clause" had been included at the urging of the American negotiators, allowing the signatory countries of the Second London Treaty (France, the United Kingdom and the United States) to raise the battleship main artillery caliber limit from 14 inches (356 mm) to 16 inches (406mm), and the limit for battleship displacement from 35,000 tons to 45,000 tons, if Japan or Italy still refused to sign after April 1, 1937. Ultimately the U.S.A. adopted 16-inch guns for their new fast battleship classes, whereas the United Kingdom chose to respect the Second London Naval Treaty limitations for the King George V class battleships. Germany was not concerned, as she had not been invited to the second London naval disarmament conference, but officially the battleships Bismarck and Tirpitz did have 380mm guns and 35,000 tons. France decided to respect the limitation of 35,000 tons and 380 mm, as long as no continental European power had overtaken them. Bearing such considerations in mind, the new Chief of the Navy General Staff (Chef d'Etat-major Général de la Marine), Admiral Darlan, ordered, in December 1937, a study of new designs for two battleships, as the Dunkerque trials were allowing a more critical regard of her design, especially her all forward quadruple turret main artillery, and her dual purpose (anti-aircraft and anti-ship) secondary artillery of relatively light caliber.

Three projects were studied, the first (project A) with the same quadruple arrangement forward as the Richelieu, but different secondary artillery dispositions, the second (project B) with one quadruple turret forward and one quadruple turret aft, the third (project C) with two fore triple turrets and one triple turret aft, in every case with a 380 mm caliber. The project C was leading to an excess of 5,000 tons over the limit of 35,000 tons, so it was not proposed to the Chief of Navy General Staff.

In June 1938, the French Admiralty's choice was tightly linked with the necessity of a maximum use of the shipyards where very large ships could be built. The Salou graving dock n°4, in Brest Navy Yards, was intended to be ready for a new battleship building in January 1939, when Richelieu had to be floated out, as all other building for large ships were in use. On the Caquot dock, Jean Bart was being built and expected to be launched in August 1939, on N°1 slipway in Penhoët Shipbuilding Yards, in Saint-Nazaire, where SS Normandie and Strasbourg had been built, Joffre aircraft carrier was being built from November 1938, till 1941. Consequently, it was not possible to let the Salou building dock empty for at least six months, waiting to start building a Project B design battleship, as it necessitated at least one year to come up with definitive drawings, after it had been ordered. Thence the Project A design was chosen for the first battleship to be laid down in the Salou building dock. The Caquot dock could then be used for the second battleship to be laid down.

Admiral Darlan chose the project A variant 2 for the first ship of the second pair of Richelieu class to be laid down; she received the name of Clemenceau. He chose the project B variant 3ter for the second ship, a design in which he was much involved, and named her Gascogne, the French province where he was born, meaning too that this new battleship was a transition ship to a new battleship class named again from province names.

When, in the summer of 1939, the French intelligence services warned the French Admiralty that the keels of two German battleships had been laid down, supposed to be of 40,000 tons tonnage and with 406 mm guns, but actually Plan Z H-39 class battleships, it was decided to design a ship free of the limitations of 35,000 tons and 380 mm. On the basis of the studies of the 1938 Project C, new battleship designs emerged, which led to the so-called Province or later Alsace class battleships which were never even ordered.

Clemenceau

On Clemenceau, the main artillery arrangement was fitted as it has been done on Richelieu and Jean Bart. But the 152 mm battery would have been consisted of four triple turrets of 152 mm caliber, two amidships (one on each side), and two aft in superfiring position. Admiral Darlan, Chief of the Navy General Staff, considered that the three 152 mm turrets battery aft, on Richelieu, was a mistake, as two turrets in centerline position provided the same broadside of six guns, and saving nearly 300 tons, allowed to have six more 100 mm AA turrets. Two 100 mm AA turrets would have been positioned in front of the fore tower in superfiring position abaft the fore 380 mm turret, and four turrets, abeam the funnel and the axial aft 152 mm turrets, and abaft the 152 mm amidships turrets. As the fire arcs of the 152 mm turrets amidships were intended to be mainly directed forwards, the 100 mm AA battery would have been prevented enough for their blast effects. Moreover these 100 mm turrets would have been fully enclosed, with a 30 mm plating against splinters. This new model of turrets was known as the 100 mm CAD Model 1937, and so called mine sweeper sloop type, as it was intended to be installed on the Elan and Chamois mine sweeper sloop classes, on Le Fier destroyer class too, and as secondary battery on the De Grasse cruiser class, to be commissioned in the late 1930s, or early 1940s.

But this new arrangement had some consequences. The second aft turret in superfiring position had a greater part of its barbette above the main armored deck, and necessitated more 100 mm plating. Thence the armour thickness of the 152 mm turret faces wad reduced to 116 mm (instead of 130 mm), as the armored belt was reduced to 320 mm, and the rear plates of the main turrets to 250 mm. The auxiliary fire control director abaft the funnel, for the 380 mm battery, was to be mounted from two to three metres higher than in the preceding units, necessitating a greater height for the funnel. Two more fire control directors with OPL 5-meter stereoscopic range finders, for the 100 mm AA battery, would have been installed on sides of the fore tower. Thence, to save weight, particularly in the heights, the fire control director, for the 152 mm battery in anti-ship purpose, on Richelieu in central position on the fore tower, would have not been installed, but the two remaining fire control directors, for 152 mm battery, on the aft tower and on the fore tower in upper position, would have been fitted with a stereoscopic 8-meter OPL range finder. With these arrangements, improved anti-ship and anti-aircraft artillery in regard of which was intended to be originally fitted on the pair Richelieu-Jean Bart, Clemenceau would have marked a progress, relatively to her predecessors.

Last consequence, the center line arrangement of the 152 mm turrets aft placed the extreme aft turret (turret VI) in frame 54,45, as, on Richelieu, the extreme aft turret (numbered turret VII), in center line position, was on the frame 68,85. Thus, the aviation hangar would have been shortened for nearly fifteen meters. But the suppression of the lateral turrets aft, which were, on Richelieu precisely on the frame 54,45, allowed to have a broader hangar. The two sea planes intended to be sheltered, wings folded, in the hangar, would have been accommodated, side by side, instead of in line. Otherwise, the aviation facilities would have been the same as on Richelieu.

The short-range anti-aircraft battery would have had to be constituted of six twin ACAD Mode 1935 mountings, installed, with their fire control directors, nearly on the same positions as on the Richelieu, but the two forward mountings were abeam the after end of barbette for turret II, and for the four after mountings, one deck higher. New quadruple 37 mm zénithaux mountings, intended to be used against dive-bombing aircraft, would have had to be installed on each side of the quarterdeck, near the aviation hangar.

Gascogne

The most conspicuous feature of Gascogne is the return to a main artillery arrangement with a four-380 mm gun turret aft. This rearrangement of armament also resulted a shift of superstructures forward so that these were now mounted almost exactly midships and no longer at a considerable distance aft of the midship position as in the first units of the Richelieu class.

The Gascogne secondary artillery would have been consisted of three triple turrets of 152 mm caliber, all on axial line, two in superfiring position forward and one between the funnel and the aft 380 mm turret, with eight anti-aircraft dual mountings of 100 mm caliber, on sides.

As the magazines of 152 mm guns were near of the magazines of the main artillery turrets, which constituted an increased risk, the armour of the 152 mm turrets had to be improved. First, in July 1938, it was proposed to increase the turret armor thickness to 190 mm on faces (instead of 130 mm), 120 mm on roofs, and 100 mm on sides (instead of 70 mm), the barbettes remaining to 100 mm. In February 1939, a rebalancing was proposed, with a thickness of 150 mm for the barbette, 155 mm for the turret face, from 135 mm to 85 mm for the turret sides. A thinner upper armoured deck had been considered, reducing its thickness to 150–140 mm, instead of 170–150 mm, but there is no proof that such a decision was actually taken, beyond a S.T.C.N. recommendation dated March 5, 1938.

The 100 mm AA battery had to be increased from six to eight CAD Model 1937 fully enclosed turrets. In the December 1938 designs, aircraft installations were intended to be fitted at the ship's center, with trainable catapults between the fore tower and the funnel, and a hangar at the base of the after tower, but the consequences in positioning the 100 mm AA battery too near of the main and secondary batteries, resulted, in February 1939, in positioning again the aircraft installations at the ship's stern. A single catapult would have had its pedestal countersunk in the quarterdeck, with an internal hangar in a recess under the first deck, with a lift to hoist the seaplanes to the level of the first deck in order to avoid the blast effects of the rear 380 mm turret firing, which had caused to position one deck higher the aft 381 mm turret, on the Vittorio Veneto class battleships. The hull seaplanes would have been of a new twin-motored type, Farman/NCAC NC 420, with an increased radius, whose prototype was almost complete in June 1940, but never flew. Two seaplanes would have been stowed in the hangar in line, and a third one would have been parked on rails, on the quarterdeck, at starboard of the aviation hangar.

The eight 100 mm CAD Model 1937 turrets would have been positioned in four groups of two, amidships, in the four corners of the superstructure. Each group of two turrets would have had a fire control director, with a 5-meter OPL range finder, for the forward groups, on each side of the fore tower, and for the aft turret groups, atop of the after tower. Thus, the secondary director for 152 mm battery, would have been suppressed, and the fire control direction of the secondary battery insured by the upper director of the fore tower, for anti-ship gunnery, and by the directors of the 100 mm battery, for anti-aircraft gunnery.

The six 37 mm AA Model 1935 mountings would had to be installed with four mountings abeam the forward turret (two on the forecastle and two a little abaft, one deck higher), with their directors amidships, between the fore and the aft tower, and the two after mountings would have been positioned abeam the after superstructure with their directors a little forwards, one deck higher. The 37 mm zénithaux quadruple mountings would have had to be repositioned amidships between the fore and after towers, because, on the quarterdeck, as on Clemenceau, they would have been excessively exposed to the blast from the aft main turret.

History

Richelieu

Richelieu at Dakar, in 1941, as there were three fire control directors atop the fore tower, and neutrality tricolor bands on turret II

The keel was laid down on 22 October 1935 in Brest. The hull was floated out on January 17, 1939. Richelieu then left the Salou graving dock, to be armed in one of the Laninon docks at Brest Navy Yards. The bow and the stern, built separately, were attached there, as the Salou graving dock was only 200 m long. Machinery trials began at the end of March 1940.

In April 1940, Richelieu went to sea for the first time. In late May and mid-June, the Commanding Officer, Captain Marzin carried out speed and gunnery trials, reaching 32 knots, and firing a few shots from her main and secondary batteries. Due to the advance of German troops, Richelieu hastily left Brest bound for Dakar on June 18, having on board 250 shells but only 48 powder charges for her main battery. Escorted by the destroyers Fougueux and Frondeur, she reached Dakar on June 23.

Dakar, under Vichy's orders

HMS Hermes whose aircraft torpedoed Richelieu, at Dakar, on July 7, 1940, and in the background, HMS Dorsetshire

As the local political conditions seemed very dubious in regard of the acceptance of the armistice between France and Germany, Captain Marzin decided to proceed to Casablanca two days later, shadowed by a powerful British battle group. Richelieu was sent back to Dakar by the French Admiralty on 28 June where she moored in the outer roadstead, protected only, on the side of the high sea, by a line of five freighters. Her anti-aircraft artillery was very weak. The 152 mm turrets could not fire on aerial targets, as the corresponding uppermost range finder on the fore tower had not been put in service; moreover, shells and powder charges were lacking. Only the six 100 mm turrets were usable. The short range anti-aircraft artillery was only four double 37 mm mountings, four quadruple 13.2 mm Hotchkiss machine guns, and two twin 13.2 mm MGs.

The 22 June 1940 armistice prompted British anxiety that the French Navy would be taken over by the Axis Powers. This led to attacks from the Royal Navy against the French warships (Operation Catapult), to seize them (in British harbours), sink them (at Mers el-Kebir), or intern them (at Alexandria). During the night of July 7 to 8, five days after the attack on the French fleet at Mers-el-Kebir, a team from HMS Hermes attempted to damage Richelieu with depth charges moored under her stern, but they did not explode. In the morning, Swordfish bombers from Hermes torpedoed Richelieu below the armored deck. This caused a 40' long hole, and disabled the starboard propeller shaft; flooding caused her stern to touch bottom. One torpedo is likely to have hit the depth charges moored during the night. The crippled battleship was pumped out after a few days and made seaworthy for emergencies, and moored inside Dakar harbour.

On 24 September, Richelieu took part in the defence of Dakar against British and Free French forces. There was a gunnery duel between Richelieu and the British battleships HMS Barham and HMS Resolution: the HMS Barham was hit twice by the shore batteries manned by ratings from Richelieu. In the engagement the Richelieu was struck by two 15-inch shells, causing no serious damage, in spite of 250 near misses. Richelieu was damaged in the battle the first time her main battery had fired: a 380 mm shell blew back and disabled two guns in the number 2 main turret: this was traced to the use of a wrong type of propellant. There was no more firing during this day with the N°2 main turret. On the day after, N°1 main turret was used instead. The propellant was changed, with the SD19 propellant of the reconditioned Strasbourg powder charges, however this caused serious problems regarding range-finding. In 1941, an inquiry commission under Admiral de Penfentenyo de Kervérégen concluded there had been a mistake in the design of the shell base.

During the two days, the Richelieu fired a total of 24 rounds. No hits were recorded. The third day, as HMS Resolution had been struck by a torpedo from a French submarine, the British and Free French force retired.

Temporary repairs were completed in Dakar, some light anti-aircraft mountings were added, partly taken from the wreck of the destroyer Audacieux, severely damaged by a heavy cruiser during the battle.

During the first months of 1941, Richelieu was the first French battleship to be fitted with French early radar (designated as "electro-magnetic detection"). On April 24, 1941, Richelieu could sail at 14 knots (26 km/h), on three engines, the fourth propeller having been removed. During July 1941, three Loire 130 seaplanes were shipped.

On the Allies' side

Richelieu arrives in New York with her damaged turret II. The uppermost fire control director on the fore tower had to be dismantled for her to pass under Brooklyn Bridge

After French forces in Africa joined the Allies after the Allied landings in North Africa, in November 1942, Richelieu sailed for refitting at the New York Navy Yard on 30 January 1943.

The three ruined barrels of Richelieu's upper main battery turret were replaced by barrels previously fitted on Jean Bart, the second unit of the Richelieu class, which was staying at Casablanca. The fourth barrel from Jean Bart was used for trials at the Dahlgren firing range.

The seaplane equipment (hangar, catapults and crane) had been removed. The space thus spared on the stern was used to mount 40 mm anti-aircraft guns on the rear deck. The overall anti-aircraft armament was massively reinforced, with 48 20 mm AA guns in single mounts replacing the original 13.2 mm Hotchkiss machine guns, and 14 quad 40 mm turrets replacing the original 37 mm semi-automatic guns. Adoption of US-pattern secondary batteries made providing ammunition easier; a special factory had to be set up to produce ammunition for the main battery. She remained with only two range finders on the fore tower, and the rear mast was shortened. She was fitted with air and surface warning radar, but the U.S. Navy has been reluctant to provide radars for gunnery practice purposes. All these modifications increased the displacement by 3,000 tons. After sea trials (with a maximum speed of 30.2 knots) the refit was declared complete on 10 October 1943.

Richelieu sailed for Mers el-Kebir on 14 October and thence to Scapa Flow, arriving on 20 November. She served with the British Home Fleet from November 1943–March 1944, participating in an operation off the Norwegian coast in January 1944. She was then transferred to the British Eastern Fleet to cover for British battleships undergoing refit. This was despite reputedly strong anti-Gaullist sympathies on board and limitations with her radar and ammunition (only available from US sources). She arrived at Trincomalee, Ceylon (now Sri Lanka) on 10 April 1944, in time to join the attack by Task Force 65 on Sabang on 19 April (Operation Cockpit) and on Surabaya in May 1944 (Operation Transom), and to serve in Operations Councillor and Pedal in June. On 22 July, she sailed to attack Sabang and Sumatra (Operation Crimson) and returned to Trincomalee on 27 July.

Relieved by HMS Howe, Richelieu returned to Europe. After about a week in Toulon, she sailed for Casablanca, where she arrived on 10 October 1944, for careening. She was refitted in Gibraltar in January 1945, and rejoined the Eastern Fleet till the end of the war against Japan, arriving back at Trincomalee on 20 March 1945. Now with Task Force 63 of the British East Indies Fleet, she joined in more bombardments of Sabang in April and of the Nicobar Islands in late April to early May. The next operation, to intercept the Haguro, was abortive.

Richelieu refitted at Durban in from 18 July to 10 August, and arrived via Diego Suarez at Trincomalee on 18 August, learning of the Japanese surrender on 15 August. She left Trincomalee on 5 September to participate in the liberation of Singapore, Operation Tiderace. While she was passing down the Straits of Malacca on 9 September, at 07:44 a magnetic mine detonated 17 metres (19 yd) to starboard. She eventually limped into Singapore at noon on 11 September.

Post war

After 1946, she had the classic existence of a warship, during peacetime, alternating training times, shipping the President of the French Republic, for a visit in French West Africa colonies in 1947, manoeuvering, with the Arromanches aircraft carrier, formerly HMS Colossus, when she joined the French Navy, or officially visiting Britain or Portugal. During a careening in Toulon, on 1951, she was fitted with French-built radar devices, and received one new-built 380 mm gun and three guns seized by the Germans, two having been installed during the war in shore batteries in Norway and in Normandy, the third having been used for trial at Meppen (Germany) in the Krupp's proving ground.

Once in her career, on January 30, 1956, she manoeuvered with Jean Bart during a few hours, before being based in Brest as gunnery training school. Placed in reserve in 1958, she was, in 1968, decommissioned and sold to Italian ship scrappers.

Jean Bart

From Saint-Nazaire to Casablanca

Jean Bart, laid down in December 1936, being built in the large Caquot dock in Penhoët, later named "Jean Bart dock", was expected to leave it in October 1940. In May 1940, it was decided that the uncompleted battleship had to be sent in a safer place, rather in Britain or in French Africa, out of range of the Luftwaffe. The ship was afloat in the fitting-out basin, which was however separated from the navigational channel by an earth dam. When it appeared that the Battle of France was on way to be won by the Wehrmacht, by late May, work on dredging the earth dam was begun, in order to be ready at a high tide, on June 20. Half the propulsion machinery, boilers and turbines, was fitted to be worked when necessary. On June 18, as the German Panzer divisions were approaching, the Commanding Officer was ordered to be ready to leave immediately for Casablanca or to scuttle the ship. It was not before the middle of the next night that the dredging work was finished with very narrow margins for the battleship to pass through, and in the early hours of 19 June, nearly in view of the German vanguards, Jean Bart, barely 75% completed, her steam engines never having been worked before, under the threat of German bombers, was taken out of her St. Nazaire's dock by four tugs, and reached by her own steam Casablanca, Morocco, on June 22, the average speed on the final leg of the journey reaching 22 knots.

Only one of her two 380 mm main turrets had been installed by then, the guns of second turret had to be left or were lost with the sinking of the cargo shipping them. Her 152 mm (6.0 in) secondary battery was also non-installed, and it was replaced by anti-aircraft machine guns. No range finder was fitted.

Jean Bart, moored in Casablanca harbour, stayed uncompleted as facilities to complete her were completely lacking.

On November 8, 1942, Allied landings in French North Africa (Operation Torch) begun. Jean Bart, with her 380 mm guns opened fire to the U.S. warships covering the landings, range finding been cooperated with the shore stations of Sidi Abderhamane and Dar Bou Azza, the data being sent by phone to the battleship. But she was quickly silenced by the second hit from 406mm guns of USS Massachusetts battleship, which jammed the turret rotating mechanism on the French battleship. The sixth of the seven 406mm shells which hit her, exploded in a magazine of 152 mm turret, which was empty as these turrets had not been installed. In normal war circumstances, it would have had the most catastrophic consequences. The armour weakness of these magazines was known, and wad intended to be corrected on Gascogne. On November 10, her 380 mm turret having been overhauled, Jean Bart near missed the USS Augusta, Task Force 34 flagship. Bombers from the aircraft carrier USS Ranger soon inflicted her severe damages, two heavy bombs hitting the bow and the stern, and the battleship settled into the harbor mud with decks awash.

A lengthy completion

After the French North Africa forces joined the Allies, Jean Bart was made seaworthy to be refitted with the help of the U.S.A., as Richelieu. The wish of the French Admiralty, presented by Vice Admiral Fenard, Chief of the French Naval Mission, to complete Jean Bart in U.S. shipyards was discussed during 1943. But the U.S. Navy authorities considered the task as exceeding their capacities, for the ship was too different from the equivalent U.S. warships, and every specific materials were lacking. Instead of completing her as designed, it was proposed, in May 1943 to complete her with only one main artillery turret, with 340 mm guns taken on the French battleship Lorraine which had joined the Allied forces, after she had stayed from 1940 to 1943 in Alexandria. Fifteen U.S.-built dual-purpose 127mm double turrets, sixteen Bofors 40 mm quad mountings, numerous Oerlikon 20 mm mountings, and aircraft installations for six planes (Grumman Avenger or Fairey Barracuda bombers and Hellcat or Seafire fighters), would have transformed Jean Bart into a kind of hybrid battleship-aircraft carrier. An second proposal, less expensive, always with the same main artillery turret, seventeen 127mm double turrets, and twenty Bofors quad 40 mm mountings, would have resulted in a kind of AA battleship. Admiral King, Commander in Chief, United States Fleet and Chief of Naval Operations, decided finally, in March 1944, to not agree any French proposals, and Jean Bart stayed in Casablanca.

The question of the completion of Jean Bart was once more discussed by the French Admiralty in 1945. Had she to be scrapped ? completed as a classic battleship as designed ? transformed into an aircraft carrier ? On September 21, 1945, the Higher Council of the Navy agreed rapidly she had not to be scrapped. The discussion to choose between the other possibilities seems to have been rather unsatisfying. Mr. Louis Kahn, Chief Naval Constructor, French Navy, who had designed the Joffre class aircraft carrier in the late 1930s, presented a project for a transformation into an aircraft carrier operating forty/fifty four planes, for a cost of 5 billion Francs, and within a delay of five years. Some admirals, namely Admiral Fenard, formerly chief of the French Naval Mission to the U.S.A., and Admiral Nomy, who had been a Naval Aviation pilot, and will be later Chef d'Etat-major Général de la Marine (1951–1953), found surprising that so few planes were being accommodated on a ship with a displacement of 40,000 tons, as equivalent ships in other navies were operating twice more planes. In the minutes of the September 21, 1945 meeting of the Navy Higher Council, Rear Admiral Barjot wrote: "The design of aircraft carrier presented to the Council is called, by a member, "caricature" in regard to a project which would be established with the wish to create an efficient aircraft carrier...Despite the war learnings, the outdated myth of big gun goes on dominating our naval doctrine...It was surprising enough to see in 1945 the Navy General Staff supporting, doctrinally, against the aircraft carrier solution, the battleship solution".

It is exact that the British aircraft-carrier HMS Eagle, laid down in 1942, which will be launched in 1946, with a displacement of 36,000 tons (46,000 tons full load), was by then designed for accommodating 80 planes. But it would be fair to remind too that the French experience of battleship converted into aircraft carrier, Bearn, was rather unsuccessful, her slow speed, having led to use her only as aircraft transport ship.

It was decided finally to complete Jean Bart as an integral battleship, with the aim to get, in a delay of five years, a command ship, heavily anti-aircraft armed, with a capacity of naval bombing for attack against land.

Jean Bart left Casablanca in August 1945 to Cherbourg, where was, by then, the only usable French graving dock on the French Atlantic coast, and entered in one of the Brest Laninon docks only on March 1946. Work progressed slowly as the Brest Navy Yards had to be rebuilt in the meantime, after severe war destruction. The battleship emerged with a much more compact fore control tower, topped by only one range finder (Richelieu had two ones after her refit). In 1948, she received an additional bulge to limit the increase of draught, due to the planned fitting of a stronger anti-aircraft artillery; her beam reached 35,5 m. After gunnery and speed sea trials during which the top speed has reached more than 32 knots,

A short career

Jean Bart was officially commissioned on January 16, 1949, but the anti-aircraft short range artillery, mainly twelve 100 mm dual mountings, and fourteen Bofors licensed 57 mm dual mountings, was not fitted before 1952-1953 Jean Bart was admitted in active service on May 1, 1955. She shipped soon the President of the French Republic in an official visit to Copenhagen, and goes on to Oslo. On July, she take part, in New York, to ceremonies of the 175th anniversary of landing in Newport of French troops led by the Comte de Rochambeau, during the American War of Independence. On October 21, in Toulon, Jean Bart succeeded to Richelieu as flagship of the South Group of Schools.

During her active career, Jean Bart had a complement of 750 to 900 men, for 1500 as previewed. She reached to more than 1200 men, when she was about to be sent in operations during the crisis of Suez Canal, but even at this time, only one 380 mm turret, and the axial 152 mm turret could be manned.

In 1956, she take part to the operations off Port-Saïd, during the crisis of Suez Canal, but the French bombing support on land operations was not ensured by the four shots fired by her 380 mm guns against land, but by the French Aeronavale Corsairs, and the main operational contribution of Jean Bart was to ship the 1st Foreign Parachute Regiment from Algiers to Cyprus.

After having fired the last French Navy 380 mm gun shots on July 1957, Jean Bart was placed in reserve, on August 1, 1957, and served as school ship for the gunnery training schools in Toulon. Afterwards, there were some projects, in 1957-1958, to modernize her anti-aircraft artillery, with new 100 mm turrets (Model 53 in place of Model 45), later to transform her into a guided missile battleship, as had been USS Mississippi, but no French-built missile was existing by then, so it was proposed to use the U.S. Terrier missile. In 1964, as a command ship was looked for by the Pacific Center of Nuclear Experiments, the cruiser De Grasse was preferred to Jean Bart, more expensive to be transformed.

Decommissioned in 1968, Jean Bart was scrapped on 1970, near Toulon, leaving the Turkish Yavuz, formerly SMS Goeben, only survivor afloat in European waters of the battleship era.

In fact, Jean Bart has been overall an experimental battleship, never fully operational, mainly because of budgetary cutbacks, but also because, when Jean Bart was completed, the battleship was no more the capital ship for the French Navy, as three aircraft carriers Arromanches, La Fayette, and Bois Belleau were operated during the 1950s, in bombing support against land in Indochina, later in Algeria or during the Suez Crisis. But finally, she was very useful post war as a testing bench for new French-built naval AA guns and radars.

Clemenceau and Gascogne

The third unit, Clemenceau, was laid down in the Salou graving dock, as soon as Richelieu had freed it. Work progressed slowly, as Clemenceau did not have priority in naval building, with regard to the first pair of the Richelieu class. So, in mid-1940, nearly eighteen months later, she was only 10% completed as a hull section of 130 m. Taken by the Germans as a war booty, she was registered by the Kriegsmarine as Battleship R, but the Germans never seriously considered continuation of construction work. Made buoyant, presumably in 1941, to vacate the building basin, and towed to Landevenec, or moored near the submarine base, this uncompleted hull was sunk, during a U.S. air raid at the beginning of the offensive to free Brest, on August 27, 1944, and scrapped post war.

In the late 1950s, the name of Clemenceau was given to the first modern post war French-built aircraft carrier Clemenceau.

The fourth unit, the planned Gascogne, was intended to be laid down, in "Jean Bart dock" at Saint-Nazaire, as soon as Jean Bart had freed it. No work was ever begun, as the keel was not laid down, due to the German occupation. Just some material, predictably stored, would have been declared war booty and registered as Battleship S.

See also

Media related to Richelieu class battleships at Wikimedia Commons

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