Duquesne class, Marine National (Long Patrol)

The Duquesne class carried eight-inch guns but was conceived in the older light-cruiser framework before treaty categories hardened.

French treaty limits and worldwide commitments shaped a fast eight-inch cruiser descended from the Duguay-Trouin light cruisers.

Duquesne traded protection for exceptional speed, illustrating how rapidly extra knots consumed treaty-limited displacement.

Speed could let a solitary cruiser choose an engagement, but it was a weaker defence once Duquesne had to protect convoys or fight at close range.

A long, narrow hull and roughly 118,000 shaft horsepower delivered 34 knots, but the fuel-radius figures expose the operational cost of sustained speed.

Duquesne paired eight 203 mm guns with anti-aircraft weapons, torpedo tubes, and a catapult aircraft, concentrating offensive reach on a lightly protected hull.

Watertight subdivision and separated machinery supported survival and economical cruising, while the twin-rudder arrangement left a large tactical turning circle.

Duquesne's A and X turrets shared the middle level, while B and Y stood at different heights, putting the four main turrets on three levels.

London Treaty categories turned Duquesne's eight-inch battery into a heavy-cruiser designation without creating room for the protection that role demanded.

Duquesne and Tourville spent three years interned at Alexandria with Force X before joining the Free French and returning to service.

Admirals René-Émile Godfroy and Andrew Cunningham kept Force X intact at Alexandria through negotiation rather than repeating the violence of Mers-el-Kébir.

Later anti-aircraft improvements made the elderly cruisers more useful, but their original lack of armour remained a serious Mediterranean concern.

Large French flags painted on the cruisers marked their neutrality-patrol status during the Spanish Civil War, while their assignment still reflected their light-cruiser origins.

Scouting, commerce raiding, and destroyer killing each explain part of Duquesne's speed, but none clearly repays the range and protection sacrificed for 34 knots.

National prestige may help explain why France accepted severe design costs to field exceptionally fast cruisers.

Duquesne's machinery burden shows how maritime infrastructure and long-term industrial investment shaped naval design.

An all-forward battery could concentrate protection and avoid routing propeller shafts beneath the guns, but France would have needed new turret arrangements to exploit it.