A synchronizing stationary clutch system for compression braking in a two spool gas turbine engine is provided by the present invention. The synchronizing stationary clutch system allows the two shafts of a two spool gas turbine engine to be reliably coupled at any given speed of either shaft. This coupling ability is useful to a gas turbine engine functioning in a land vehicle for the purpose of slowing the forward momentum of a rolling vehicle. The clutch system may also allow the use of auxiliary power from an electrical motor to start the engine.