Method of operating an engine assembly

A method of operating an engine assembly including a turbine having a turbine shaft and an intermittent internal combustion engine having an engine shaft, the method comprising:

• rotating the engine shaft at a first rotational speed;
• driving a turbine with exhaust gases of the intermittent internal combustion engine to rotate the turbine shaft and to drive a rotatable load with the turbine shaft, the engine shaft being mechanically disengaged from the turbine shaft such that the engine shaft rotates independently from the turbine shaft;
• increasing a rotational speed of the engine shaft from the first rotational speed until the turbine shaft reaches a second rotational speed;
• after the turbine shaft has reached the second rotational speed, adjusting the rotational speed of the engine shaft until the turbine shaft and the engine shaft are drivingly engageable with each other;
• and
• drivingly engaging the turbine shaft with the engine shaft such that both the turbine shaft and the engine shaft are in driving engagement with the rotatable load.