US Naval Advance Bases


US Naval Advance Bases were built globally by the United States Navy during World War II to support and project U.S. naval operations worldwide. A few were built on Allied soil, but most were captured enemy facilities or completely new. Advance bases provided the fleet with support to keep ships tactically available with repair and supply depots of facilities, rather than return them to the continental United States. Before Japan declared war on the United States the U.S. Navy had a single fleet-sized advanced base in the Territory of Hawaii at Naval Station Pearl Harbor. During the war the U.S. Navy Seabees built over 400 advance bases categorized by size. Naval bases were either Lions or Cubs while airfields were either Oaks or Acorns. Lions and Oaks were major facilities while Cubs and Acorns were minor. PT Boats typically would get a Cub and airfields with single runways were Acorns. The larger bases could provide refueling and overhaul; loading of troopship and cargo ships; and preparing amphibious assault ships. Some became major repair depots. The Seabees developed auxiliary floating drydocks which were able to repair battle damage and do regular maintenance in the field, saving ships trans-pacific trips for repair. A few bases also were developed to be R and R for all U.S. personnel. Most Advance Bases were built by the US Navy's Seabees in Naval Construction Battalions. At the start of the war civilian contractors were employed in construction. The Seabees in World War II built most of the airfields used by the United States Army Air Forces and United States Marine Corps, as they had the ships and cranes needed to transport the vast amount of equipment needed at the advance bases. The US Army and United States Coast Guard also operated out of many of these facilities. Seabees could build new or repair damaged runways, and with advancements in heavy bomber technology lengthen runways as needed. A few Naval Advance Bases were built for the Korean War and Vietnam War.

Advance bases

Built at the bases were personnel housing, piers, roads, shops, power plants, water plants, along with large storage depots containing fuel, ammunition, food, and other consumable supplies. Fuel for ships, airplanes and vehicles was in much demand; 25,000,000 barrels of fuel was shipped to Pacific bases in just June 1945. During World War 2, in Guam alone one million gallons of aviation gasoline were needed each day. Over 325,000 Seabees troops built bases. The many bases were needed for the logistics needs of the troops around the world. On the home front many new ships and boats were built the West coast and East coast, Great Lakes and the Gulf of Mexico. Under the Emergency Shipbuilding Program and War Shipping Administration contracts went out to shipyards and Ironwork works companies across the country. Ports were needed for many new cargo ships to dock, such as the 2,710 Liberty ships and 531 Victory ships built, plus the many new tankers and new warships. In the South Pacific, Seabees operated coral pit mines, as crushed coral was used for runways, roads, sidewalks, and more. Many runways were built using steel Marston Mats. At some bases Seabees built sawmills, to produce local timber. Floating pile drivers were used to build piers, docks, and wharves. If pile driving was not suitable, a floating wharf was built. To protect ships and the ports, they needed to build and repaired quickly and runways. Sometimes Seabees set up electric generator lighting and worked around the clock to complete runways. For housing, offices, mess halls, and depots a vast number of quonset huts of different sizes were built. The Pacific island hopping campaigns, gave new work to be done each day.
At the end of World War 2, almost all of the bases were closed, many were abandoned. A vast amount of vehicles, supplies and equipment at the bases was deemed not needed and too costly to ship to the U.S. Bringing the gear home also would have hurt home front industries, as there was already a vast amount of military surplus. Much of the equipment was destroyed. Some was given to the local governments as a thank you for the land use. Some of the abandoned bases were used for local military, some turned into towns and ports, like Naval Advance Base Espiritu Santo. Some of the abandoned airfields turned into local and international airports, a post-war Seabees legacy.
The need for advance bases during World War II was so great, that in some cases some Pacific Ocean islands were too small for the demand. So in 1943, the US Navy created Service Squadrons. A Service Squadron was a small fleet of ships that acted as an advance base. A service squadron would have: tankers, Fleet oilers, Troopship-barracks ships, refrigerator ships, ammunition ships, supply ships, floating docks, different kinds of barges and repair ships. They provided diesel, ordnance, aviation fuel, food stuffs, and all other supplies.

Active bases

Major advance bases