Tomozuru Incident of 12 March 1934, in which a top-heavy torpedo boat capsized in heavy weather, caused the IJN to investigate the stability of all their ships, resulting in design changes to improve stability and increase hull strength. Ryūjō, already known to be only marginally stable, was promptly docked at the Kure Naval Arsenal for modifications that strengthened her keel and added ballast and shallow torpedo bulges to improve her stability. Her funnels were moved higher up the side of her hull and curved downward to keep the deck clear of smoke. Shortly afterward, Ryūjō was one of many Japanese warships caught in a typhoon on 25 September 1935 while on maneuvers during the "Fourth Fleet Incident." The ship's bridge, flight deck and superstructure were damaged and the hangar was flooded. The forecastle was raised one deck and the bow was remodelled with more flare to improve the sea handling. After these modifications, the beam and draft increased to and respectively. The displacement also increased to at standard load and at normal load. The crew also grew to 924 officers and enlisted men. Machinery The ship was fitted with two geared steam turbine sets with a total of , each driving one propeller shaft, using steam provided by six Kampon water-tube boilers. Ryūjō had a designed speed of , but reached during her sea trials from . The ship carried of fuel oil, which gave her a range of at . The boiler uptakes were trunked to the ship's starboard side amidships and exhausted horizontally below flight deck level through two small funnels. Flight deck and hangars Ryūjō was a flush-decked carrier without an island superstructure; the navigating and control bridge was located just under the forward lip of the flight deck in a long glassed-in "greenhouse", whilst the superstructure was set back from the ship's stem, giving Ryūjō a distinctive open bow. The flight deck was wide and extended well beyond the aft end of the superstructure, supported by a pair of pillars. Six transverse arrestor wires were installed on the flight deck and were modernised in 1936 to stop a aircraft. The ship's hangars were both long and wide, and had an approximate area of . Between them, they gave the ship the capacity to store 48 aircraft, but only 37 could be operated at one time. After the Fourth Fleet incident, Ryūjōs bridge and the leading edge