De Grasse

Design

By 1936, the Marine Nationale was looking for the next generation of cruisers to succeed the then-modern La Galissonnière-class of ships. Still adhering to the limitations imposed by the 1936 London Naval Treaty, France sought to construct a new type of light-cruiser under the 8,000 ton benchmark. Rationally, as successors to the 7,500 ton La Galissonnière-class cruisers, the new light cruiser De Grasse would use the extra displacement to improve on the deficiencies discovered on the preceding light cruisers: specifically, the aviation facilities, the armament suite, and propulsion.

Originally designed in 1936, the cruiser was planned to have no less than two aircraft catapults, and the facilities to carry up to three individual aircraft. Furthermore, a series of lifts and tracks between the hangar and catapults were implemented to automate the process of launching aircraft. By positioning the dual-hangar amidships, De Grasse would use a single-funnel design, as opposed to her predecessor. The space on top of the hangars was used to install light AA and secondary fire directors. However, it was discovered that the aviation facilities were very cramped and she would be top heavy in this configuration. Therefore, by the 1938 design proposal, she was limited to a single hangar, which meant a rearrangement of light AA and fire control.

De Grasse’s main armament was of particular concern (due to the underperformance of her predecessors). After a few design proposals, it was decided to use the same rifles and configuration as La Galissonnière-class, but the turrets themselves would be modified triple-gun versions of the dual-purpose guns mounted on battleship Richelieu. Although they were heavier, these new mounts would have the ability to engage both surface and air threats, as they could elevate the guns up to +70˚. Additionally, these new mounts had the ability to reload at any elevation, offering a significant increase in rate of fire. Since the hoists for the shells and power were displaced off to the side of the guns, the turret could fit the smaller dimensions of a cruiser.

Similarly, there was a revision of the AA suite of the De Grasse class. They would mount the completely novel twin 100mm Mle 1933 DP guns in fully-enclosed pseudo turrets – type avisos-dragueurs. Not only were they better protected, but they could also be directed via centralized fire control. Unfortunately, due to weight and necessary space for dedicated magazines, only a few could be fitted. The three guns were all placed aft, which gave excellent rear cover but poor front cover. To compensate for this weakness in her AA arrangement, four (4) twin 37mm Mle 1933 AA guns were positioned forward. Another improvement from the La Galissonnière class, De Grasse mounted 2 triple 550mm torpedo tubes, one on each side, amidships.

To ensure there was not any loss of performance due to the increase in displacement, an improvement in main propulsion was required. While the internal layout was similar to her predecessors, new machinery was installed in place of the old. Boilers that were akin to the models used in contre-torpilleurs – which would operate at higher-pressure loads – and turbines that could be configured for multi-pressure work were installed. Ultimately, her designers were able to increase De Grasse’s power from 100,000 to 110,000 shaft horsepower, resulting in a top speed above 32 knots.

In the end, De Grasse was a cruiser that shared design characteristics of the La Galissonnière class and cruiser Algérie. Her hull was superficially similar to her predecessors, albeit with a more flared and narrow bow to increase sea keeping. Her superstructure was akin to the heavy cruiser: built around a central tower and a single funnel amidships. De Grasse used a combination of high tensile steel and duralumin – on the hull and superstructure, respectively – to decrease displacement and top weight. To save design time, a similar armor profile as the La Galissonnière class was used on De Grasse as well.

With her design finalized, De Grasse was laid down on 28 August 1939 at the Lorient Naval Dockyards. The commencement of the Second World War in September 1939 halted her construction, and she was not launched until 11 September 1946. In 1951, she was towed to Brest Naval Yard and was finally completed as an anti-aircraft cruiser with a radically different main battery configuration. She was commissioned into the Marine Nationale on 10 September 1956.

Service

Despite being laid down nearly two decades earlier, De Grasse finally entered service in 1956, becoming the flagship of the French Mediterranean Squadron. Her service in the Mediterranean was largely uneventful, serving there from 1956 until she was taken out of service momentarily in 1964. Following two years of conversions, she re-entered the Marine Nationale as the flagship of the Nuclear Testing fleet, bound for the French Polynesia. There she would remain until she was decommissioned in 1973, and sold for scrap in 1974.

Historical Accuracy

• De Grasse is represented in World of Warships in the configuration she would have had if she had been completed using her original design. Her as-built armament in 1956 was reminiscent of the Atlanta-class light cruisers of the U.S. Navy, comprised of eight (8) twin 127mm dual-purpose turrets.

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  De Grasse as completed.

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  A bow view of De Grasse.

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  De Grasse, date and location unknown.

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  Colbert, sister ship to De Grasse. She retains her armament as completed.

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  Colbert post-modernization.