Tinian Naval Base
Tinian Naval Advanced Base was a major United States Navy sea and air base on Tinian Island, part of the Northern Mariana Islands on the east side of the Philippine Sea in the Pacific Ocean. The base was built during World War II to support bombers and patrol aircraft in the Pacific War. The main port was built at the city and port of San Jose, also called Tinian Harbor. All construction was carried out by the Navy's Seabees 6th Naval Construction Brigade, including the main two airfields: West Field and North Field, serving the United States Army Air Forces's long-range Boeing B-29 Superfortress bombers. The Navy disestablished the Tinian Naval Advanced Base on 1 December 1946.
Background
Tinian, the third of the three largest islands of the Mariana Islands, is located south of Saipan across the 3-mile-wide Saipan Channel. Tinian, north to south, is 12 miles long and east to west 6 miles wide. It has mostly flat terrain, perfect for runways. Along with the other Mariana Islands, Tinian was claimed for Spain by Ferdinand Magellan in 1521. Guam was seized by the United States in the Spanish-American War, and Spain sold the remaining islands to Germany. They were occupied by Japan during World War I and became part of Japan's South Seas Mandate. Japan developed Tinian into a large sugar plantation with a sugar refining plant, and built three small runways on the island. The civilian population was about 18,000 in 1941.Operation Forager involved the conquest of the Mariana Islands. It was intended that they would be developed into a major naval base for the surface ships and submarines of the Pacific Fleet, as a staging and training area for ground troops, and as a base from which long-range Boeing B-29 Superfortress bombers could attack Japan. American forces landed on Tinian on 24 July 1944, and the island was declared secured on 1 August, although there were still many Japanese soldiers holding out in the caves on the southern end of the island. At the time of the landing, there were three Japanese airfields on the island: two in the north, one with a runway long and the other long, and one in the west with a runway. There was also a small, incomplete airstrip in the center of the island.
Construction
Early works
Responsibility for construction on Tinian was assigned to the 6th Naval Construction Brigade, under the command of Captain Paul J. Halloran. His staff, along with that of the US Army's 64th Engineer Topographic Battalion, drew up plans for the development of Tinian at Pearl Harbor in the months leading up to Operation Forager. These called first for the rehabilitation of the Japanese airstrips in the north and west, then for them to be lengthened to in length so bombers could operate from them, and ultimately for their extension to for the B-29s.For this work, Halloran had the 29th and 30th Naval Construction Regiments. The former, under Commander Marvin Y. Neely, initially consisted of the 18th, 92nd and 107th Naval Construction Battalions, and the 1036th Naval Construction battalion Detachment; the latter, under Commander Jonathan P. Falconer, the 67th, 110th and 121st Naval Construction Battalions. A third regiment, the 49th Naval Construction Regiment, was formed on 2 March 1945 from the 9th, 38th, 110th and 112th Naval Construction Battalions, under Commander Thomas H. Jones.
Elements of the 18th and 121st Naval Construction Battalions landed on Tinian with the assault troops on 24 July, with the remainder arriving on 27 July. That day, the 121st commenced the rehabilitation of the airstrip in the north, filling in the bomb and shell craters. By that evening, an airstrip long and wide was ready for use, and it was fully restored to its full length the next day. On 29 July, a P-47 landed and took off again. The 9th Troop Carrier Squadron was brought forward from Eniwetok, and its Douglas C-47 Skytrains, together with the Curtiss C-46 Commandos of VMR-252, delivered 33,000 rations from Saipan on 31 July. On the return trip they carried wounded to hospitals on Saipan.
A third battalion, the 67th Naval Construction Battalion, arrived on 2 August. With the island declared secure, the seabees were released from the control of the V Amphibious Corps to the 6th Naval Construction Brigade, which became operational on 3 August. Additional naval construction battalions arrived over the following weeks and months: the 92nd from Saipan in August and September; the 107th from Kwajalein on 12 September; the 110th from Eniwetok in September and October; the 13th and 135th on 24 October; the 50th on 19 November, the 9th on 1 December, and the 38th and 112th on 28 December.
The Seabees completed and extended the second Japanese airstrip in the north, which became North Field Strip No. 3 in September. They then rehabilitated the severely damaged airstrip in the west as a airstrip for fighter planes. Navy patrol planes commenced operations from the two North Field airstrips, but work to upgrade them to handle the B-29s could not be carried out while they were in use. A new runway was built in the west, which became known as West Field Strip No. 3. The airstrip was completed on 15 November. In addition to the runway, there were of taxiways, 70 hardstands, 345 Quonset huts, 33 repair and maintenance buildings, 7 magazines and a tall control tower.
Airfields
Responsibility for the development of North Field was assigned to the 30th Naval Construction Regiment. Falconer divided the work into phases, and designated a battalion as the "lead" on each phase, with overall responsibility for the work in the phase, and the other battalions acting as subcontractors. The first phase, the extension of North Field Strip No. 1 to, along with the construction of the necessary taxiways, hardstands and aprons, was assigned to the 121st Naval Construction Battalion. The work was completed nine days ahead of schedule, and the first B-29 landed on the completed airstrip on 22 December. The next phase was the extension of North Field Strip No. 3 to. This work was undertaken by the 67th Naval Construction Battalion as the lead battalion, and was completed on a day ahead of schedule on 14 January 1945. The 13th Naval Construction Battalion became the lead on the third phase, the construction of North Field Strip No. 2, between and parallel to the other two runways. The final runway, parallel to the other three, was assigned to the 135th Naval Construction Battalion and was completed on 5 May 1945, five days ahead of schedule. All four strips were widened to.The task would have been easier if the plateau had been wider. As it was, the wide plateau required large amounts of fill. Another complicating factor was the decision to have the B-29 taxi under their own power instead of being towed reduced the maximum taxiway grade from to percent, and required another of earth to be removed. When work was completed on 5 May 1945, North Field had four parallel runways, apart, with of taxiways, 265 hardstands, 173 Quonset huts and 92 other buildings. All runways and taxiways were paved with of asphalt concrete over a base course of at least of rolled coral on a subbase of pure coral. Its construction involved of excavations and of fill.
The 49th Naval Construction Regiment was assigned responsibility for the construction of the West Field airstrips. This new regiment began activities under a temporary title on 1 January 1945 before it was formally activated on 2 March. Work on West Field commenced on 1 February. Two parallel airstrips were developed, apart, each long and wide. The two runways, of taxiways, 220 hardstands and 251 administration, maintenance and repair buildings. Work on West Field Strip No. 2 was completed on 2 April and West Field Strip No. 1 followed on 20 April.
The 9th Naval Construction Battalion detached from the 49th Naval Construction Regiment on 25 May under orders to move to Okinawa, and departed on 19 June, followed by the 112th, which was detached on 5 July and embarked three days later. The 49th Naval Construction Regiment was then absorbed by the 29th Naval Construction Regiment.
Fuel
Initially, fuel had to be supplied in drums. Later, aviation gasoline was drawn from a barge known as YOGL anchored in Tinian Harbor. Tank farm construction commenced in September 1944 and on 3 November it became the responsibility of the 29th Naval Construction Regiment, with the 18th Naval Construction battalion as the lead battalion. The fuel storage and distribution system was completed by 8 March 1945. This included storage tanks for of diesel oil, of motor gasoline and of aviation gasoline. Fuel was pumped over a submarine pipeline from an oil tanker moored north of Tinian Harbor and distributed over of pipeline. Two dispensing points were provide at West Field and four at North Field.Harbor
Until work on the harbor was completed in March 1945, nearly all cargo was brought ashore by landing craft mechanized and landing craft tank. Cargo handling was supervised by the Army port superintendent, Major Gordon E. Soruton. Tinian Harbor became operational on 2 August 1944, with the 1036th Naval Construction Battalion Detachment, a two-company unit, unloading vessels into LCTs in the stream, which were unloaded on the beaches by Army and Marine work parties.The half-strength 27th Naval Construction Battalion arrived on Tinian on 19 November 1944, and the 1036th Naval Construction Battalion Detachment took over on the beach while unloading in the stream was handled by the two companies of the 27th Naval Construction Battalion and the Army's 510th Port Battalion. The first three companies of its five companies arrived in November 1944. The beach work parties were relieved, and henceforth the three stevedore units handled all cargo. The 1036th Naval Construction Battalion Detachment was absorbed by the 27th Naval Construction Battalion on 20 January 1945.
Early works on the harbor were carried out by the 50th and 92nd Naval Construction Battalions, which drove of piling that eventually formed part of the south bulkhead, and by the 107th Naval Construction battalion, which built a ramp from the shore to the reef. In November 1944, the 50th Naval Construction Battalion commenced a major project to build permanent harbor facilities that could berth up to eight Liberty ships at a time.
The new harbor consisted of a south bulkhead, a quay wall, and two piers parallel to the cargo ship bulkhead and connected to it by an causeway. A breakwater was built upon the existing reef consisting of 120 circular sheet piling cells that were in diameter and filled with coral. The task of dredging a deep channel and deep berths was undertaken by the 31st Naval Construction Battalion, which was part of Service Squadron 12. Dredging was completed on 20 January 1945, and the harbor works were completed on 6 March.