development problems and neither air group ever had all of its intended aircraft. Coupled with a shortage of trained pilots, neither ship ever used its aircraft during combat. Other changes After the loss of the fast battleship at the Naval Battle of Guadalcanal in late 1942 to rudder damage, the IJN decided to reinforce the protection of the steering compartment and to create an auxiliary steering compartment. The protection of the former was strengthened by the addition of a concrete wall at least in thickness and some of the armour removed from the turrets was used to protect the latter. The double bottom below the former positions of aft turrets was converted to hold fuel oil; this increased the ships' endurance to at a speed of 16 knots. A pair of Type 22 surface-search radars were also fitted during the conversion. The removal of the secondary armament, the rear turrets and their supporting structures was generally compensated by the addition of the flight deck, hangar, AA guns and more fuel, and the metacentric height increased to at full load as a result of the reduction in the displacement by over to . This also reduced the draught to . The overhang of the flight deck at the stern increased the overall length to and the beam was slightly reduced to . Ships Service Upon commissioning, the sister ships were assigned to the 1st Battleship Division of the 1st Fleet. Hyūga had an explosion in one of her main gun turrets that killed 11 men and injured 25 in 1919; the following year she accidentally collided with and sank a schooner, losing two crewmen. Before the start of the Pacific War, both ships frequently exercised off the coasts of the Soviet Union, Korea and China in addition to training in Japanese waters. Ise hosted Edward, Prince of Wales, and his aide-de-camp Lieutenant Louis Mountbatten in 1922 during the prince's visit to Japan. In Korea Bay when the 1923 Great Kantō earthquake struck, they sailed to Kyushu where they loaded supplies for the victims on 4 September. Together with two other battleships and a pair of light cruisers, Ise sank the destroyer in 1926 during gunnery practice. Ises AA armament was upgraded in 1931 and Hyūgas two years later. The latter ship was modernized in 1934–36 and Ise in 1935–37, both at Kure Naval Arsenal. During the Second Sino-Japanese War, the sisters