Hamilton

Condenser wheel. If the engine had to be turned off in an emergency then after you turned the emergency stop wheel you would "trap" the steam in the boilers which of course is not safe. So you would then turn the wheel with the handle and this connects the boiler directly to the condensing system so you can recycle the steam until either the problem with the engines were fixed or you if you were shutting down then just put out the fire in the boilers and recycle the steam until everything cooled down.