The new design gave a length of 81 metres and a beam of 18.08; this made "Bretagne" 8 metres longer and 2 metres wider than "Napoléon". With a draught of 8.35 metre, the ship had a volume of just under 20 000 m³. The engine, provided by the Indret workshop, occupied a 30-metre long compartment and was designed for 1200 shp but could develop up to 3327 shp in peak power from eight boilers, each with six furnaces. Though direct transmission by an axis, it moved a four-blade, 6.3-metre propeller which could be retracted into a vertical shaft, only 1.3 metre wide thanks to the geometry of the blades. The ship carried 590 tonnes of coal, giving her an autonomy of 14 days at 10 knots, and 6 days at her top speed of 14 knots. With three month worth of food for the 1200-man complement, and one month worth fresh water completed by a distillation device to desalinate seawater, she could stay at sea for 40 days.