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
stevedal
stevedal

Posted: Wed Jun 06, 2012 6:50pm

Post Subject: narrowboat steering

Hello there. My 35ft narrow boat has always had a slight tendency to veer slightly to the left if the tiller is released, however since the installation of a replacement engine and exterior skin tanks (old engine was air-cooled), the problem has become markedly worse. I accept that the skin tanks are largely responsible for this, but is there anything I can do to minimise this condition, eg, remove some of the leading edge of the rudder, for example? The prop is 15" x 12". Pictures attached. Many thanks in advance.

narrowboat steering
Tony-B
Tony-B

Posted: Wed Jun 06, 2012 8:37pm

Post Subject: narrowboat steering

First of all this forum is not a lot of use for posting pictures so email them to Tony@TB-Training.co.uk. Also please give details of both the old and new engine, any differences in gearbox reduction ratio, if the prop has been matched to the new engine, and finally if the "tanks" indicates that you now have a tank on each side of the swim, both of similar size. At the moment I suspect the prop may be spinning faster then it did with the old engine but need to see the pictures and get the details before I can say much more. Tony Brooks

stevedal
stevedal

Posted: Thu Jun 07, 2012 11:05am

Post Subject: narrowboat steering

Thank you Tony for your prompt response. Previous engine was Hatz 2l30z with prm 160 Now is Thornycroft 80d with prm delta. Photos to your email address. Skin tanks are either sidnd identical.

Tony-B
Tony-B

Posted: Thu Jun 07, 2012 1:50pm

Post Subject: narrowboat steering

I can not find any data on the old engine like HP and at what revs so it is hard to assess how the new engine compares. Your photos shows nothing that would cause the problem although the rudder blade looks slightly bent in the vertical. The skin tanks are symmetrical so should not be the cause. The balance on the rudder (the bit in front of the stock) could be a little larger but the you may have it too close to the prop and in any case I very much doubt it would make a significant difference. If you can bolt a strip of steel onto the leading edge leaving couple of inches between it and the prop give it a try, it may reduce the force on the rudder if that is the problem. If the problem is the rudder feels fine but the boat now sheers to the left without creating excessive force on the rudder my suspicion is that it is the pitch on the rudder paddle wheeling the stern sideways. I fear you learn to live with it. Tony Brooks

stevedal
stevedal

Posted: Thu Jun 07, 2012 4:06pm

Post Subject: narrowboat steering

The old engine was a Hatz 2L30Z, german origin producing around 15hp at approx 2500rpm. It was never a very quick boat. Sorry I can't be more precise but it's been long gone together with the specification data! The Thornycroft is obviously more powerful than that. someone did point out that there may be a bit too much propshaft showing, but I can't see that that would make a great deal of difference. Out of gear the boat The problem is with pressure on the rudder, which increases with speed. Many thanks.

stevedal
stevedal

Posted: Thu Jun 07, 2012 4:09pm

Post Subject: narrowboat steering

Sorry, disregard the words ' out of gear'.

Tony-B
Tony-B

Posted: Thu Jun 07, 2012 4:15pm

Post Subject: narrowboat steering

So the veer to the left if the tiller is released is not what you meant. From the last post it seems the rudder is pushing to the left and if this is the case then extending the balance up to about 1/3 of the main blade area may help BUT you may have to move the prop to accommodate the extension. The other thing may be that you are now trying to drive it too fast on narrow, shallow canals but I still think it may well be related to the pitch of the prop. Tony Brooks

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: 43.  Total Objects: 162.  Total Unserialized: 3. Total Runtime: 0.76 seconds.