The T55 is a larger version of the T53, designed for U.S. Army helicopters.  Design work began in 1954.  Over 5 million hours  have been flown by 3,600 T55 engines (as of 1998).

models

• T55-L-11A: 3,750 hp (2796 kW)

specifications

• Turboshaft
• Compressor: 7-stage axial, 1-stage centrifugal
• Turbine: 2-stage gas generator, 2-stage free
• Pressure ratio: 8.2

used by

• Boeing Vertol CH-47 Chinook