Oriskany-class Essex-class aircraft carrier

SCB-27 (also known as "Two Seven-Alpha" or "Two Seven-Charlie") was the United States Navy designation for a series of upgrades to the Essex-class aircraft carriers (both the short-hull and long-hull Ticonderoga versions), conducted between 1947 and 1955. These upgrades were intended to allow the World War II-era carriers to operate jet aircraft.
USS Oriskany, laid up incomplete at the conclusion of World War II, served as the prototype and was re-ordered to the SCB-27 standard. All but one of the SCB-27 modernized Essex carriers, the USS Lake Champlain, were further modified under the SCB-125 modernization program.