Fuel tankers providing underway replenishment of petroleum products to Navy ships and shore installations. The backbone of naval fuel logistics supporting sustained operations worldwide.
Military Sealift Command operates the T-AO Fleet Replenishment Oilers as a component of the Combat Logistics Force (CLF). These tankers, designed to supply the US Navy and allied forces with diesel and jet fuel at sea, help naval vessels stay on patrol longer without needing to refuel in port.
The tanker fleet includes the Kaiser Class (T-AO 187-204) and the newer John Lewis Class (T-AO 205 and beyond). Fifteen Kaiser Class vessels were built starting in 1986, but they are being phased out in favor of the John Lewis Class; the Walter S. Diehl (T-AO 193) has already been decommissioned.
Supply US Navy and allied forces with diesel and jet fuel at sea through underway replenishment operations
Access to wider range of piers and ports - no ammunition means no anchoring required, can pull directly into port
Help naval vessels stay on patrol longer without needing to refuel in port, extending operational capabilities
15 vessels built starting 1986, being phased out. Walter S. Diehl (T-AO 193) already decommissioned
20 total planned, first delivered July 2022. Built by General Dynamics NASSCO starting 2018
Double hulls required after 1990 Oil Pollution Act. Only 3 Kaiser class have double hulls vs single hull majority
Note: The John Lewis class has slightly less fuel capacity but larger crew size. Only 3 Kaiser class vessels (Patuxent, Laramie, Rappahannock) have double hulls compliant with OPA 90 regulations.
Tanker assignments are often seen as standard and not particularly high-paying. However, many mariners enjoy the unique aspects of tanker life, including the steadier pace and consistent operations. Some CIVMARs even choose to stay on tankers if they prefer the ship or its schedule.
Wider range of ports accessible - no ammunition restrictions mean direct pier access
More predictable pace with consistent fuel transfer operations
Smaller crew size tends to attract more experienced, if older, mariners
Mariner Insight: "If you're considering a tanker assignment, you might find that being 'Tanker Trash' is more enjoyable than you'd expect—give it a try and see for yourself!"
Information based on current T-AO operations and sailor experiences
Deployment schedules and operations may vary based on fleet requirements
