A turbine combustion chamber is provided with deflectors on the cold side generating vortices in a secondary gas flow into the chamber, thereby confining the flame front under variable operating conditions and cooling the chamber walls. The high-speed cantilever shaft has a longitudinal duct and an array of fine orifices in the wall of the shaft for directing pressurized oil jets that impinge on the shaft bearings with little relative speed to increasing wetting of the bearing components. Oil is supplied to the duct by means of a positive-displacement pump directly driven by the output shaft. The pump output pressure is monitored to signal the end of the start-up sequence when the turbine reaches sufficient speed. The turbo-engine further includes devices for decoupling vibrations between the three systems thereof, including a loosely-mounted removable spline pivotable at both ends for coupling the high-speed shaft to the step-down gearbox.