Coast Guard Cutter Rush
High Endurance Cutter is the largest class of vessel in the United States Coast Guard, aside from the Polar Ice Breakers. The hull classification symbol is prefixed WHEC. The cutters are called "Hamilton class" after their lead ship, or "Secretary class" because they are named after secretaries of the Treasury Department (with the exception of "Hero Class cutters" Jarvis, Munro and Midgett,). They are powered by a CODOG (Combined Diesel or Gas) system consisting of two diesel engines and two gas turbines, and have Controllable pitch propellers. Equipped with a helicopter flight deck, retractable hangar, and the facilities to support helicopter deployment, these 12 cutters were introduced to the Coast Guard inventory in the 1960s. Beginning in the 1980s and ending in 1992, the entire class was modernized through the Fleet Rehabilitation and Modernization (FRAM) program, which included the replacement of the original 5 inch (127 mm)/38 caliber gun with a much more modern 3 inch (76 mm)/50 caliber weapon. The primary mission of these vessels is enforcement of laws and treaties and search and rescue (SAR) on the high seas, including the U.S. exclusive economic zone.