US Navy ships collide in the Pacific The Essex was approaching the Yukon to get in position to be refueled when a steering malfunction occurred, and the two ships collided, said Commander Charlie Brown, a 3rd Fleet spokesman. The fleet statement said neither ship's fuel tanks or systems were compromised, but a full assessment of any damage was continuing. The Essex, an 260-metre vessel that resembles a small aircraft carrier, is due to return to San Diego on Thursday after 12 years based in Sasebo, Japan. It has a crew of about 1,200. U.S. Navy oil tanker USNS Yukon (AP) The Yukon is a 206-metre tanker that replenishes oil for other Navy ships in the Pacific fleet. It was launched in 1993, and all but three of its 92 crew members are civilians, according to the Navy's website.