Video of what NOT to do!!! Caldercraft “Imara” fitted out with a 4” Boiler/Twin Clyde steam plant with whistle. While perhaps exciting to view, this owner is making one serious error.
He has the boiler safety valve set at too high a pressure causing the Clyde engines to lift off their cylinder faces (best seen as the misty clouds when viewing the two engines from the rear)
This a safety feature of oscillating engines that are able to operate as a “secondary” safety valve when the steam pressure is excessive. A consequence of operating the plant like this, with the boat on the water, would be a much reduced running time because of the loss of steam.
Source: Unknown - Recognition will be entered on proof of source received.