The Gilbert Islands, which include Tarawa, Apamama, and Makin, are a group of coral atolls lying athwart the equator. Formerly held by the British, they were seized by the Japanese at the outbreak of the war, a move of great strategic significance as they were in close proximity to islands in our possession and immediately south and east of important Japanese bases in the Carolines and Marshalls. Bases in these islands, therefore, became essential steps in our movement toward Japan.
The assault on Tarawa on November 20, 194, was bitterly contested. Heavily fortified, and garrisoned by several thousand Japanese troops on Betio, the principal island of the atoll, it had been attacked repeatedly from the air for weeks preceding the assault, and on the previous day had been heavily bombarded by surface craft. Although these attacks silenced the Japanese heavy guns, wrecked everything above ground, and killed approximately half the enemy troops, many dugouts, pillboxes, and bomb-proof shelters were still intact or usable.
The enemy was able to concentrate his forces beside the only beach where a landing was possible and in spite of air and surface fire support, our casualties were heavy. The assault lasted nearly four days, at the end of which time the island was considered secure, although subjected to air raids and isolated sniper action.
During the remainder of 1942, Army and Navy planes based at Tarawa carried out repeated attacks on enemy holdings in the Marshall islands and at Nauru, inflicting considerable damage on ships and shore installations.
Tarawa, a triangular-shaped atoll, is composed of a series of islands in a reef, covering 22 miles in length. The enclosed lagoon, about 17 miles long and tapering from 9 miles to less than a mile in width, is open to the west, though partially barred by a section of the submerged reef.
Betio, lying at the southwest corner of the Tarawa atoll, measures roughly 2¼ miles in length by less than half a mile in width. The reefs of Tarawa average 500 yards in width, the outer reef being about 2 feet higher than the lagoon reef. The beach is from 30 to 50 yards wide, rising only 5 or 6 feet.
Unforeseen wind and tide conditions uncovered the inner reef to such an extent tht it became impassable to assault craft after the landing of the first wave. Ensuing waves were then forced to lie to under heavy fire or disembark their troops at a distance from the beach, in water so deep that wading ashore was extremely difficult. Heavy casualties and the loss of invaluable time resulted.
The first echelons of the construction battalions scheduled for Tarawa, the 74th and 98th, arrived in the lagoon November 24, 1943, D-plus-4, and advance reconnaissance went ashore as soon as the islands were declared secure. The 74th immediately began unloading LSTís on Betio. The construction on Buoto Island, was held up on unloading until the final location of the airstrip was decided.
On November 27, a pontoon barge, which had been assembled on the ship, brought the first of the 98thís equipment to the beach. This equipment was used in the construction of a causeway to facilitate the unloading of the small boats and barges, and the work of clearing the fighter and bomber runways was started the next day. By the 29th the entire battalion personnel was ashore except for a crew of 70, left aboard ship for stevedoring purposes.
A temporary camp was established near the beach, and by December 8, the galley was able to serve the first hot meal. The permanent camp was begun on the other side of the island, but work was retarded through lack of manpower, all available hands being used to expedite completion of the airstrip. On December 4, the second echelon arrived to relieve the manpower shortage, and work on the camp went ahead.
The early completion of an operational strip was the primary objective. By December 18th, or 20 days after work was started, a 4000-foot fighter strip on the eastern end of the bomber strip was usable, and two days later the first planes arrived.
Despite interruptions by enemy air raids, work progressed on the two strips. The taxiways and runways were surfaced with a 10-inch compacted layer of coral, mined from the lagoon below the level of high tide. In order to attain a more durable wearing surface, a coarse grade of coral, approximately one and a half inches in diameter, was worked into the top six inches of the original layer, providing an excellent runway surface. The completed bomber strip was 7,050 feet long with a surfaced width of 200 feet, and had 27 hardstands. The fighter strip was 4,000 feet by 150 feet and had 18 hardstands. More than 6,000 feet of taxiways were built, leading to an additional 25 hardstands.
Besides the landing fields and their own camp, the 98th built all the necessary housing and living facilities for 1,300 men of the unit which operated the field, a 100-bed quonset-type hospital, ammunition and bomb storage, a control tower, an aviation-gasoline tank farm of 500,000-gallon capacity and ready tank storage of 20,000 gallons. They also moved 30,000 cubic yards of coral fill in the construction of a 2,200-foot causeway at the western end of the landing field.
When the 74th Battalion went ashore at Betio, by far the most heavily defended island in the atoll, organized resistance had ceased, although many snipers were at large, and groups of Japanese were barricaded in underground shelters and in block-houses.
The greatest obstacle to be overcome was the condition of the island. As a base, it had been wrecked. Chaos, ruins, a litter of corpses and decaying food dumps extended over the entire 285 acres. Flies and mosquitoes, with ideal breeding conditions, existed in countless swarms; all water sources were brackish and polluted, with only salt water available for washing purposes. The menace to health was immediate and alarming, and it was little short of miraculous that no epidemic browke out, although dengue and dysentery appeared. The battalion lost no time in correcting these conditions.
Although no casualties were suffered by Seabee personnel, there was air raid damage to installations, stores, and equipment. Vehicles were burned or destroyed; others were perforated by bomb fragments, which also did considerable damage to tents; and heavy tire damage was caused, not only by the actual explosion of bombs, but by sharp fragments which littered roadways and the strip.
Literally every square foot of the island had to be cleaned, cleared and graded in order to begin with the installations and improvements. The necessity of unloading supplies on the tidal flat required a disproportionate number of men and created serious maintenance problems due to the exposure of equipment to the corrosive effect of sea-water and to damage from coral entering working part. Carryalls and tractors were similarly damaged when removing coral from the reef. All grading and excavating work was rendered hazardous by buried mines and unexploded shells, as well unpleasant by the decomposed bodies frequently uncovered. In the latter connection, Seabees were used extensively as burying details for both enemy and American dead.
Almost as soon as heavy equipment was ashore, the 74th went to work on the enemy airstrip. The existing installations consisted of an air base with all necessary appurtenances. The strip was 4,400 by 150 feet, surfaced with coral concrete of an average thickness of two inches, underlaid with a poorly compacted coral fill. Ut was relatively undamaged by the bombardment and assault, and temporary repairs made it possible for a squadron of fighters to land fifteen hours after the first Seabees went shore, and to operate continuously thereafter.
Six days later, six medium bombers landed and commenced patrol operations. The wheel loads of these planes proved so much greater than those of Japanese aircraft that the concrete strip surface began to fail rapidly and way condemned. It was removed and replaced, ahlf the width at a time, continoues flight operations being maintained on the remaining half, and on December 17, 1943, twelve B-24ís were staged through the field. Existing hardstands and taxiways were used and were later enlarged and augmented.
When the strip was completed, it was 6,600 by 400 feet, and totally coral-surfaced. The original schedule planned the strip to be operational for B-24ís by D-plus-45; the 74th bettered this date by 18 days.
Aside from the air strip, the only Japanese installation of any value was a badly battered, coral-fill quay. It was repaired, but was so unstable that it could be used only for foot traffic and jeeps. As soon as manpower was available, work was started on a 1900-by-32-foot wharf. As there was no timber available for piling, it was necessary to use the rails from an abandoned narrow-gauge Japanese railroad. These piles were braced with Japanese reinforcing rod. Pierced plank was attached with wire to the rails and rods, and sheathed on the inside with light corrugated iron. The resulting structure was then filled with compacted coral.
Additional work of the 74th included housing and messing facilities for aviators and ground crews, and a tank farm of twelve 1,000-barrel tanks with two ready-gas stations, 7,200 feet of buried pipe-line, and 4,500 feet of submarine line for the handling of aviation gasoline. One of the larger Japanese bomb shelters was cleaned and renovated for use by the Medical Corps as an operating room and as shelter for patients during air raids.
The water supply was obtained from evaporators, and 19 wells producing brackish water were drilled to supply them. Evaporators with a total daily capacity of 20,000 gallons were installed and two 15,000-gallon and four 5,000-gallon wood-stave storage tanks erected, together with 7,000 feet of underground pipe-line.
In addition to high-priority jobs, other important construction and maintenance work was subsequently carried out. Surveyors, who had preceded the construction gangs under hazardous conditions, located important sites on Betio and the adjacent islansd and made maps of them. Communications, power and light, and refrigeration facilities were built, together with all construction necessary for base operation. After adequate living quarters were set up, they were improved by additions necessary for morale, such as a post office, theatre, and shipís service. Stevedoring work was aided by native labor, which had been returned to the island and which proved most satisfactory.
Considerable work was done in converting enemy equipment to our own use, as well as salvaging our own worn-out and damaged equipment. A small but effective detail was assigned to diving and salvage. This group recovered equipment and removed obstacles from the ocean floor and on several occasions examined and reported on hull damage to ships. Another group carried out extensive demolition work ashore.
worked in close and friendly cooperation with the occupying force of Marines,
each making use of the othersí equipment and facilities until the departure
of the 74th on March 1, 1944.