The weight problem was solved by adopting a new type of boiler, designated "Sural" (short for "suralimenté" [pressure-fired]); these boilers were much more compact than the type used in the "Dunkerque" class and the "Richelieu"s had a wider beam (allowing three boilers side-by-side instead of just two), so the boiler rooms could be reduced from three to two, with the total machinery space shortened considerably. Since the machinery spaces required heavy armor protection, this reduced the length of the hull that needed to be covered by the armor belt by almost . The belt was also decreased in thickness from 360 mm to 330 mm (though the angle of inclination was increased to compensate for the reduction); coupled with minor reductions in armor elsewhere in the ship, these changes offset the weight of the 152 mm battery and brought the displacement within Washington limits. Work on the design proceeded quickly, and on 14 August, the navy placed orders for the first two ships, and .