Forums » Ask a Question

Use this forum to post your questions to our experts – you need to be logged on to do it (you can register here ), then scroll down to the bottom of this page and click the blue Post Thread words

If you can help answer the question, feel free to post a reply – you need to be logged on to do it (you can register here ), then hit the reply button on the thread.

 

To go back to the experts page click here>>

AuthorMessage
nhkatabay
nhkatabay

Posted: Wed Apr 13, 2011 12:41pm

Post Subject: cruising

What is the optimum cruising speed and RPM for a narrow boat to use the least amount of diesel and be most gentle on the engine yet still not taking 2 hrs to do 4 miles.

Tony-B
Tony-B

Posted: Wed Apr 13, 2011 1:45pm

Post Subject: cruising

This question is impossible to answer because the optimum boat speed varies from canal to canal & section to section as the depth and width alter. You need to learn to watch the wash and water movement so you can judge the optimum speed. The optimum cruising revs will depend upon how well the propeller is matched to the boat and and the fuel consumption curve for your particular engine. To a degree it tends to be academic because most narrowboats return between 1 to 1.5 litres per hour. The only time this varies is when owners decide to try to drive the boats too fast for the width and depth of the canal. Your boat should be propped to allow the engine to develop maximum torque. If this gives an excessive speed on tickover then you would reduce pitch so the boat went slower. Typically I would expect the answer would be between 1000 and 1500rpm. Tony Brooks

kelper
kelper

Posted: Sat May 14, 2016 3:19pm

Post Subject: cruising

To take less than two hours to do four miles just travel at 2mph or more! ;-) Seriously, to answer your question, the most economic speed to get from A to B will be the speed that doubles the consumption of the boat when stationary. That means, if your boat consumes 0.5 litre per hour when moored with normal electrical load (shore power disconnected, then themost economical speed will be when your consumption is 1 litre per hour. but I don't think it worth your time trying to measure your consumption at varying speeds. Remember that the power consumed by the propeller follows a cubic law - doubling the speed will consume 8 times the power. I suggest to travel at 3mph; it will be quiter and require less effort on the tiller. If you run too slowly you may cause glazing on the cylinder liners.

Most Read

Newsletter Sign Up

Canal Boat monthly newsletter
Sign up to receive our regular email newsletter

Our Privacy Policy

Like us on Facebook



Follow us on Twitter

Cache: Disabled for this object  Total Queries: 44.  Total Objects: 163.  Total Unserialized: 4. Total Runtime: 0.28 seconds.