Work to refine the hull shape was conducted in the Admiralty experimental tank at Haslar, Gosport. As a result of experiments, the beam of the ship was increased by over that initially intended to improve stability. The hull immediately in front of the rudder and the balanced rudder itself followed naval design practice to improve the vessel's turning response. The Admiralty contract required that all machinery be below the waterline, where it was considered to be better protected from gunfire, and the aft third of the ship below water was used to house the turbines, the steering motors and four steam driven turbo-generators. The central half contained four boiler rooms, with the remaining space at the forward end of the ship being reserved for cargo and other storage.