Email: Can't slow down

Published: Friday, 10 June 2011

If hire boats can slow down when passing moored craft, perhaps some private boats can't.

 

There seems to be an increasing tendency to fit more and more powerful engines in canal craft. Could it be that even with the engine idling some boats are still not going particularly slowly?

Looking at engines exhibited at the NEC a few months back I noticed that 1000 rev/min was the usual idle speed, and typically this went with a maximum speed of 3000 rev/min. This means that if the propeller and gear ratio is chosen to give a maximum speed through the water of only 6mph, then the boat will be doing 2mph at idle which in some situations could be too fast.

If the propeller is chosen to get over 6mph, with a satisfyingly low engine speed when cruising canals, the boat will go faster still on idle. It does happen, I know I have steered just such a boat and it was not much fun at times. Of coarse you can knock it out of gear and lose steerage—not a good idea.

Could it be that hire companies shun over-powerful engines and end up with boats that will actually drive slowly when required? That would make coming in to moorings easier as well (and safer.)

Ian Reid, Gentleman of Leisure(?)