were also added, some of which were portable and could be mounted on tie-down points on the flight deck. Two Type 94 high-angle fire-control directors, one on each side of the ship, were fitted to control the Type 89 guns. Four Type 95 directors controlled the 2.5 cm guns and another pair were added in early 1943. Early warning was provided by two Type 2, Mark 2, Model 1 early-warning radars. The first of these was mounted on the top of the island shortly before she was completed in July 1942 and the other was added later in the year. This latter system was fitted on the port side of the hull, outboard of the aft lift. A smaller Type 3, Mark 1, Model 3 early-warning radar was added in 1944. Construction and career Hiyō was laid down on 30 November 1939 by Kawasaki on Slipway No. 4 at their shipyard in Kobe. She was yard number 660 and had the name Izumo Maru. The ship was purchased on 10 February 1941 by the Navy Ministry and she was temporarily referred to as No. 1002 Ship (Dai 1002 bankan) to keep her conversion secret. She was launched on 24 June 1941 and commissioned on 31 July 1942 with Captain Akitomo Beppu in command. The ship was assigned to the Second Carrier Division of the 1st Air Fleet after commissioning and became flagship of Rear Admiral Kakuji Kakuta on 12 August. After spending the next few months working up, Hiyō arrived at Truk, together with her sister Jun'yō, on 9 October, to begin operations against American forces in the Guadalcanal area as part of the 3rd Fleet. On the night of 16 October, the two carriers were ordered to attack the American transports off Lunga Point, Guadalcanal, and they moved south to their launching point north of Lunga. At 05:15 local each ship launched nine A6M Zeros and nine B5Ns. One of Jun'yōs B5Ns was forced to turn back with mechanical problems; the rest reached their objective and discovered two destroyers bombarding Japanese supply dumps on Guadalcanal around 07:20. Hiyōs aircraft attacked seven minutes later without effect, and the American ship shot down one B5N and damaged another which was forced to make a crash landing. Jun'yōs eight B5Ns engaged and also failed to hit their target, not least because they were attacked by Marine Grumman F4F Wildcat fighters at 07:32.