Construction and improvements to captured facilities were given to Navy Seabee construction brigades 8th, 10th, 70th and 11th. The 1181st
US Army Engineer construction joined in the construction projects. Some construction brigades came ashore during the landings as support combat engineers. As soon as the beaches were secured, the construction brigades began fixing and improving beach exit roads and bridges. Construction brigades were given the dangerous task of clearing
land mines and demolitions. The other high priorities for the Construction brigades were
fresh water and the repair and expansion of the
airfields on Okinawa, once they were captured. Construction brigades worked in shifts around the clock, due to the high priorities of these tasks. Seabee 43rd Naval Construction Regiment landed with the troop on the east coast of Okinawa. The next Seabee landings were the 36th, 40th, and 87th Seabee Battalions in late April from
Naval Base Saipan on
LST ships. Seabees built their own loading zone for the heavy equipment needed for
road work and
runway repair and improvement. Heavy rains sometimes slowed and stop the work. Work on
Yontan Airfield and
Kadena Airfield started on April 3 and both were ready the next day by the efforts of 1901st Aviation Engineer Battalion and Seabee 624. The repaired runways were used by
fighter aircraft and
reconnaissance aircraft. Seabees added a tank farm for fuel storage. On April 28, Seabee started construction of new runway that could handle the needs of
Bombers at Yontan Airfield. There were now 95,000 construction troops on Okinawa, improving and building facilities. Next repair and improvement started at
Bolo Airfield and
Yonabaru Airfield. When completed Yonabaru Airfield was 6,500 feet long. Due to poor drainage at
Awase Airfield, the captured runway was abandoned, for later work. From June 15 to Awase Airfield completion on June 30, Seabees did massive
earthwork project to drain and fill the Awase runway. Awase Airfield became a fighter aircraft base. Seabee 36th Battalion began building a new 5,000-foot fighter aircraft runway nearby to Awase starting on April 23. On May 6 Seabees of the 40th Battalion began the repair and improvement of the
Chimu Airfield. On the
Katsuren Peninsula at Katchin Hanto Seabees of the 7th Battalion started work on a
seaplane base, that opened on July 1. Also at Katchin Hanto Seabees built a large supply depot. For unloading all the needed cargo harbor facilities at Katchin Hanto, Tengan and Baten Ko at
Buckner Bay were built. At Tengan a breakwater and pier was built. A number of anchored pontoon piers and causeways were built to get over the
coral reefs. Seabees used many
tugboats and
barges to get cargo ashore. Most ships could not get to pontoon causeways, so ships would unload into barges, barge cargo was then loaded into trucks. Additional piers and causeways were built at City of Kin on Chimu-Wan Bay,
Awase,
Machinato, Chimu Wan, Yonabaruand, City of Kuba Saki and Bisha Gawa. Unten Ko on Motobu Hanto and Chimu Wan became a supply depot with boat repair,
naval mine depot. Each depot has an
ammunition depot outside of the main depot. A ship repair depot was established at Baten Ko. Buckner Bay and Chimu Wan became massive supply depots. Port at Awase became an aircraft repair depot, with the docking of aircraft repair ships and
Combat Aircraft Service Unit. On June 1, 1945, the original Seabees Battalion were given a break as replacements arrived and took over unloading the massive amount of cargo still needed for operation. The new units were: Seabee 3rd, 4th, 11th, 12th, 23rd, 27th, and 36th Special Battalions, the Seabee 81st, 28th, and 148th Pontoon Battalions, and the Seabee 137th and 139th Trucking Battalions. June rain slowed the supply chain on muddy roads, priority cargo was unloaded first due to this slow down. Okinawa Island was declared secured on June 22, 1945. By July 1 supply chain problems were gone. Seabee also built the Third Amphibious Corps evacuation hospital at Yontan and Special Augmented Hospital 3, 4, 6 & 7. Seabee built degaussing station at Tsuken Shima, and a joint Headquarter communications center. All this work was interrupted from the landing to victory by air attacks, troops and Seabee were bombed, strafed and
Kamikaze attacked on ships. On the ground, sniper fire, artillery, mortar fire, land mines and booby traps were a constant danger for work crews. Seabee repaired the remaining airfields at
Ie Shima Airfield, Futema Airfield,
Machinato Airfield and Tsuken Shima Airfield. By August, the troops peaked at 87,000 construction and engineering troops on Okinawa in 36 naval construction battalions, 21 Army engineer aviation battalions, 14 Army combat engineer battalions, and 7 Army engineer construction battalions. ==Post War==