It is an inertia starter, it does drive a flywheel through gears at high rpm. The usual technique is to wind the flywheel to full speed (about 2 rev/sec on the handle, 18,000 rpm on the flywheel) and then remove the starting handle and engage the starter drive dog which drives the crankshaft directly and rotates the engine.
However, it is possible to continue winding the handle when the starter is engaged, and in this case the handles are driving the crankshaft directly, through the flywheel drive. This is not really necessary and only helps a little in some difficult starting conditions, but it is seen on some film of original engine starting.
Eng