How The Seabees Won World War II for America

January 12, 2020 Topic: History Blog Brand: The Buzz Tags: World War IIMilitaryU.S. NavyAsia-Pacific

How The Seabees Won World War II for America

The Allied victory during World War II would not have been possible without the hard work and ingenuity of the Seabees, the U.S. Navy’s Construction Battalions.

Another problem at Normandy was the unpredictable shoreline, which undulated in underwater ripples of sand bars parallel to the beach that could trap the large landing craft (LSTs) far offshore. The solution, based on the pontoon system, was barges consisting of joined pontoons 30 boxes long and six wide. It was called the Rhino Ferry.

The Rhinos would dock with an LST in deep water. The ship would then transfer half its cargo at a time onto the “ferry,” and two huge outboard motors would then power the barge to the shore. After unloading, the barges would return for the second half of the LST’s load.

The 81st and 111th NCBs––which had worked on the Italian landings–– were given the task of constructing, testing, and operating the Rhinos. On D-Day, 11 Rhinos would be employed in the first waves at Omaha Beach, growing to 20 as soon as possible; 11 more would be used at Utah Beach.

On June 5, LSTs began to pull the Rhinos out of British ports toward France. The going was slow in the choppy seas and took all night; it would be 5:30 am before they were in position. The Rhinos were designed to operate in waters with a three-foot swell, but the swells off Normandy that day were six feet and over.

It was dangerous work getting the rhinos lashed and secured to the front of their LSTs. Accidents slowed progress as Seabees and machine operators began loading 75 to 80 trucks, tanks, and bulldozers onto the barges in the heaving swells.

Even with the help of tug boats and small landing craft pushing from astern, it was noon before the first of the ferries reached shore at Utah Beach, much to the relief of all on board. At Omaha, meanwhile, the Rhinos were stopped before they could reach shore. German obstacles of steel, concrete, and mines–– not to mention sunken and disabled landing craft––stood in their way.

Only one Rhino, commanded by Lieutenant Robert Stilgenbauer, reached shore on D-Day, and that was because he failed to see the signal to stop. Somehow he made it through the obstacles to the beach and unloaded his cargo, but by the time he was through offloading the heavy vehicles, the tide had gone out, leaving him stranded on the beach until the tide returned. No other Rhino would land at Omaha until D-Day plus 1.

 Before Stilgenbauer landed, the first Allied troops ashore were Seabees of Naval Combat Demolition units and soldiers of the Army Corps of Engineers. These men were trained demolition experts who worked as fast as they could in the growing light before dawn to remove the obstacles. When they were spotted by alert German sentries, they came under severe fire and suffered casualties. Still, they blew up enough of the obstacles to open up the beaches for the landing craft.

As Seabees were destroying obstacles ashore and wrestling with Rhinos at sea, about 10,000 more men of Naval Construction Regiment 25 (25th NCR), a temporary amalgamation of several battalions, were installing causeways and piers at Utah and Omaha Beaches.

While the Rhinos brought in the first wave of heavy vehicles, these causeways would, over time, deliver millions of tons of equipment and supplies of all types to the insatiable Allied armies until November 1944, when French and Dutch ports were retaken from the Germans. The Seabees were then tasked with obstacle removal and repair of those port facilities.

The Seabees’ dominion was the ocean shore, where they excelled at supporting and supplying the Army and Marines. There was one major exception.

When General George S. Patton’s Third Army reached the Rhine River, detachments of the 627th, 628th, and 629th Construction Battalion Maintenance Units (CBMU), wearing Army uniforms at Patton’s request so they would not be mistaken for the enemy, were on hand with small boats (300 in all), construction equipment, and the ubiquitous pontoons to ferry the soldiers, tanks, and supplies across the mighty river.

During the course of the war, the Seabees performed above and beyond the call of duty. At Guadalcanal, Seabee cooks fed every Marine that came to them as long as the food lasted. It became a sense of honor with the Seabees throughout the war to feed every sailor, Marine, soldier, or airman who asked.

In the Russell Islands north of Guadalcanal, one cook, a chef before the war, convinced the Navy to buy an entire herd of local cattle. Processing the meat and baking his own buns, he operated a hamburger stand, serving his Seabees and the island’s more numerous Air Corps personnel––all at no cost to his customers.

While the Army was still struggling on the beaches of Normandy, the 2nd and 4th Marine Divisions landed on Saipan on June 15. Landing with them were the 18th and 121st NCBs. On June 19, the Marines captured Aslito airfield and turned it over to the Seabees, who hurriedly filled in bomb craters, removed shrapnel and debris, and smoothed over the mile-long runway so that the first American plane could land there just two days later.

At Saipan, as everywhere else, the Seabees did more. There was a small wrecked Japanese railroad that ran from the shore to the airport. The construction men restored the bombed-out rail bed and track while repairing the locomotive and cars.

The task took four days, and then the train carried everything from bombs to fuel from the landing site to the airfield, much to the relief of the men who would have had to haul it by hand otherwise.

The next American target was Guam. On July 21, the 3rd Marine Division and the 1st Marine Brigade waded ashore, followed closely by the 25th NCB. The Seabees immediately began unloading cargo, sorting it out, and moving it across the beach to the intended units.

The 25th had the support of the 2nd Special Battalion. The Seabees had created several of these “specials” for specific tasks, such as stevedores, demolition, and ordnance clearance, road building, lumberjacking and milling, machine repair, maintenance, and more. The 2nd was recruited from among stevedores and dockworkers as experts at loading and rapid unloading of cargo.

At a second landing site on Guam, Seabees, driving a waterproof tractor, assisted with unloading LSTs stuck on a reef. They then guided tanks through the shallowest water to reach the shore while under fire.

By the end of the first week of the invasion, Seabees were at work improving Apra Harbor, the only natural harbor on the island. Despite all their work being destroyed by a typhoon in October, they redoubled their efforts to make Apra a first-class harbor.

Next came the invasion of the nearby island of Tinian, three miles south of Saipan. There was only one beach on Tinian, and it was heavily defended; the rest of the island contained natural obstacles like cliffs and swamps.

On the north shore of Tinian were 15-foot cliffs that the enemy considered unassailable; they didn’t think about the Seabees. Captain Paul Halloran, a civil engineer who commanded the 6th Construction Brigade, designed a special device for an LVT (Landing Vehicle, Tracked) that carried a ramp with cross ties.

Upon reaching the shore, the LVTs (affectionately called Doodlebugs) dropped their ramps against the cliffs and rolled over them to reach the top. While the Japanese waited in the south, the 4th Marines scrambled over the northern bluffs and outflanked them. The July 24 invasion was all over by August 1.

The Seabees were nothing if not anxious. In the midst of several battles, Seabees could be found surveying and mapping areas still under enemy control. On Guadalcanal, they had to be told to stop using dynamite close to the front lines because it disturbed the target alignment of artillery pieces.

On Tinian, Captain Halloran led a crew to survey a site for a runway. One of the Seabees noticed that several Marine tanks were pointing their guns at them. When the officer went to investigate, a tank officer told him that they had not taken that ground yet and to leave and come back in a few hours. The situation led to more humor about who arrived first.

After the enemy was cleared out, the Seabees went to work on what would become the largest airport in the world. Six separate runways had to be cut and filled, scraped and leveled, surfaced and maintained. Each one was at least a mile and a half long and a city block wide.

Two hundred dump trucks worked 20 hours a day (two 10-hour shifts), followed by four hours of maintenance. The airfields were built to accommodate the huge Boeing B-29 Superfortress bombers that were arriving to bomb Japan into submission.

The Seabees created housing, kitchens, hospitals, water storage, fuel and ammunition dumps, and sanitation facilities for 40,000 men (15,000 of them were Seabees).

Perhaps for their own amusement, they laid out a street grid for Tinian that was patterned after the grid of Manhattan. An ammunition dump in the center of the island was known as “Central Park.” Even the streets were named after their counterparts on Manhattan. Tinian today still retains many of these New York street names.