Abstract: A control system for a steam turbine which system includes apparatus for adjusting steam flow to regulate turbine shaft speed and a transducer for providing signals indicative of turbine shaft speed, is provided with a feedback control system which modifies the shaft speed as a function of torque of the turbine. The feedback control system regulates a speed command signal which modifies the operation of the steam flow adjusting apparatus to thereby limit torque. The torque signal is developed by measurement of first stage shell pressure in the steam turbine and conversion of a signal representative of pressure to a signal representative of torque. In one embodiment, the conversion process involves utilization of plural look-up tables in a microprocessor implemented control system. The look-up table data is provided from characteristic curves of the steam turbine.