76-ton guns prompted the naval command to abandon the as-yet untested 100-ton weapons. A modified version of the 76-ton gun with a longer barrel and that had been adapted to use new propellant charges was developed; these changes gave it higher muzzle velocity, which allowed its shells to penetrate as well as the 100-ton gun had been expected to perform. The Amiral Baudins were too advanced in their construction to allow their design to be revised, but the other four vessels of the program, which became and the three Marceau-class ironclads, had not yet begun building. Their design, which was prepared by the naval engineer Charles Ernest Huin, was radically altered from the Amiral Baudin arrangement to what would become the standard for future French capital ships for the next two decades. The large caliber guns were increased to four, one forward, one aft, and a wing mount on either side amidships to maximize end-on fire (which was emphasized by those who favored ramming attacks). By the time the design for these new ships was being finalized in early 1880, very large guns had fallen out of favor in the French Navy, so new 52-ton guns were substituted. The Navy had intended to build all four vessels to the same design, but after work began on the first vessel in June 1880, the shipyard realized that Huin's design, which had been modified dozens of times by different elements in the French naval command, was unworkable. The proposed hull dimensions were insufficient for the weight of armament to be carried. The shipyard engineers proposed widening the beam and increasing displacement to correct the problem, but Hoche was too far advanced in construction to allow the necessary changes without breaking up the existing hull structure. The other three ships, which became the Marceaus, had not been laid down and could be modified, and they retained the barbettes of the earlier ships. Characteristics and machinery The ships of the Marceau class were long between perpendiculars, with a beam of and a draft of . They displaced . As was customary for French capital ships of the era, their hull featured a pronounced tumblehome shape and incorporated a ram bow. Marceau was completed with a comparatively light superstructure, but Neptune and Magenta received very large structures that contributed to poor stability. The ships' hulls were divided into watertight compartments by thirteen transverse bulkheads and