"Repulse" began a major refit at Portsmouth on 17 December 1918 intended to drastically improve her armour protection. Her existing six-inch armour belt was replaced by armour plates made surplus by the conversion of the battleship (originally ordered by Chile and purchased after the war began) to the aircraft carrier . The original armour was fitted between the main and upper decks, above the new armour. Additional high-tensile plating was added to the decks over the magazines. The ship's anti-torpedo bulge was deepened and reworked along the lines of that installed on the battleship . The bulge covered her hull from the submerged torpedo room to 'Y' magazine and the inner compartments of which were filled with crushing tubes. The bulges added to her beam and to her draught. The refit added about to her displacement and raised her metacentric height to at deep load. Three rangefinders were also added as well as eight torpedo tubes in twin mounts on the upper deck. Both flying-off platforms were removed. This refit cost £860,684.