The Navy's Military Sealift Command Explained: Why It Uses Civilians Instead Of Sailors

When you see ships carrying American troops and matériel, you expect them to be owned and operated by the U.S. Navy. However, some of the ships that carry the fuel, supplies, and other matériel the Army, Navy, and Air Force need are instead under the Military Sealift Command.

The Military Sealift Command is commanded by a U.S. Naval officer — currently Rear Adm. Philip Sobeck  — but it's mostly staffed civilians, called civil service mariners. Furthermore, instead of carrying the USS prefix given to the names of U.S. Navy combat ships, the names of Military Sealift Command ships begin with USNS, which stands for United States Naval Ship. Although they're still government-owned, they're crewed by civilians, aren't armed, and are not commissioned. Because of this, they are considered non-combatant civilian ships.

But why did the U.S. establish the Military Sealift Command in the first place? And why did it replace Navy sailors with civil service mariners?

When the U.S. was fighting the Germans and the Japanese simultaneously during World War II, four separate government agencies managed the oceanborne transportation of troops, vehicles, weapons, and other supplies its armed forces needed. So, in 1949, the Department of Defense established the Military Sea Transportation Service to simplify and streamline logistics.

Its first mission into an active war zone was during the Korean War, when it transferred the 24th Infantry Division from Japan to Pusan, South Korea. It was renamed the Military Sealift Command during the Vietnam War, in which it delivered 54 million tons of equipment and supplies, as well as 8 million tons of fuel to the front lines. Since then, it has continued to serve and support America's armed forces, including operations in Iraq and Afghanistan.

Much like there are different types of modern warships, the Military Sealift Command also operates several ship types: fleet oilers, special mission ships, prepositioning ships, service support vessels, dry cargo and tankers, fleet ordnance and dry cargo ships, and expeditionary fast transport ships. These ships let it do everything from refueling and rearming ships at sea to placing U.S. military equipment, vehicles, and personnel near potential hot spots.

From 1970 to 1974, the U.S. Navy faced declining defense spending, so Adm. Elmo Zumwalt Jr., then chief of naval operations, experimented with transferring the operation of a Navy oiler to the Military Sealift Command. The ship was stricken by the U.S. Navy and given an all-civilian crew. This reduced the crew's size, especially as the ship, the Taluga, had its weapon systems removed.

Furthermore, it had better operational readiness due to the civilian practice of rotating crews even while the ship was still in the theater of war. This is the opposite of the Navy's practice of keeping a ship's crew together throughout its deployment — sometimes up to four years. The experiment was deemed a success, with the civilian-manned ships determined to be cheaper to operate and have better availability. 

Because of this, the Navy's combat logistics force was exclusively operated by civilian crews by 2003. Even other vessels, like auxiliary ships, command ships, and expeditionary mobile bases, have started employing civilians as part of their crews.