Apamama Atoll, in the Gilbert Islands, was occupied and developed as an air base simultaneously with other islands of the group, Tarawa and Makin, and for the same reasons. The atoll, approximately 15 miles long and 6 miles wide, contains a large, well-protected lagoon with an extensive anchorage area. The islands of the atoll have an elevation of about 12 feet, the soil being soft on the sea side but firmer on the lagoon side, consisting of coarse loosely packed sand.

     The initial landing on Apamama was made November 24, 1943. The 95th Battalion followed on November 28, after minor enemy resistance had been overcome, the task being to build an air base.

    A 4,000-by-150-foot fighter strip, O’Hare Field, was ready December 10, and the first plane landed on December 13. Extension to 6,000 feet for bomber operations was accomplished by December 21. The 95th Battalion continued the development of the field until March 1944, when CBMU 557 reported to relieve the battalion. At this time, installations at O’Hare Field consisted of a 7,700-by-200-foot coral-surfaced bomber strip, with an additional 1,950-foot sand strip; 21,000 feet of taxiways, with 100 coral-surfaced hardstands, 125 by 150 feet; and quonset huts for ready rooms and repair ships. The final aviation facilities were greater than planned, as the location provied of strategic importance for bombing missions to adjacent Japanese bases in the Gilberts and Marshalls.

    The Seabees also constructed 19 miles of coral-surfaced roads, a 12,000-barrel tank farm with a 5,000-foot submarine pipe line, and a causeway to serve an as access pier for unloading  and making minor repair to LST’s and smaller craft. Storage space was provided by six prefabricated huts; quonset huts were erected for hospital facilities, offices, and work shops. Personnel were housed in tents.

    The total number of natives employed at the peak of construction operations was 426. They proved entirely satisfactory as unskilled workers if sufficient supervision was provided. They were used extensively in the handling of cargo on the beach, and for procuring and placing coconut logs for pier construction. There was an abundance of suitable coral for airstrip and road surfacing, although the source was available only at low tide.

    During the construction period, there were four minor air raids, resulting in the loss of one B-24 and slight damage to taxiways and hardstands. Neither the terrain nor the weather presented any obstacles to construction.

    By May 1944, Apamama had definitely become a rear base, ist mission of supporting the campaigns in the Marshalls completed. CBMU 557 continued maintenance operations until the fall of 1944, when the base was decommisioned.