Posted: Mon Aug 09, 2010 1:15pm

This is a 57ft 2009 narrowboat with an isuzu 42, but I don't know who did the shell. On revs above 800 water pours out of the tiller stock. Our engineer says it can't be fixed by shuving foam in - whatever that means - and we'll have to live with it. We think it is really bad engineering. The rudder stock has just 2 nuts securing it. The swan neck does not have a nut on top of it. At the top collar there appears to be thee allen key sockets, and a grease nipple, but the upflow of water washes out any grease within hours of applying. Is ir possible to remove the whole of the present assembly when the boat is next being blacked and insert a better engineered watertight arrangement? Is there a simpler alternative? Advice very gratefully received. Thank you.

Posted: Mon Aug 09, 2010 2:57pm

Dear John, This is not uncommon, but from your description the volume of water and the fact that it does it apparently in ahead is. Often it occurs when the throttle is opened with the tiller over to make a turn. To be sure I would need to look at the back end when it is out of the water but it sounds to me as if the propeller too close to the rudder so the water that the prop throws off by centrifugal force is being directed straight up the rudder tube. It is always possible that you could have the whole thing re-designed but I can not comment without seeing the upper bearing (if there is one) and how it is supported. Your description makes me thing there is an upper bearing so it may be possible to change it for one using a nylon bush or one with a seal in the bearing assembly but if the bearing is not sealed to the deck you may still get water pouring out. What you need to do is to prevent the prop throwing water up the tube and there are several ways of going about it with the boat out of the water but I think you may well be able to make a considerable difference with it in the water. Go down through the weed-hatch and feel around for where the rudder stock enter the bottom of the rudder tube. My guess is that you will find between 1/4 & 1/2" gap around the stock but with the stock probably offset to some degree. If you can find such a gap get hold of some close cell foam "rubber" (furniture foam)of similar thickness and cut it into square section strips. Then wrap it around the stock and use a screwdriver to push as much as you can up into the gap. The up flow of water should cause the foam to ride up the tube and stop at the top. My feeling is that this will greatly reduce the water flow. Once the boat is out of the water see how much stock there is between the uxter (swim) plate and the top of the rudder. If you have enough gap make up a shallow "top hat" of metal with the crown the same size as the stock and the brim wider than the hole. Cut this in half so you can get it around the stock. Cut two large washers of any suitable material (neoprene?) and slit each to the centre. Work the two washers onto the stock with the slits 180 degrees apart. Push them up under the hull and fit the two halves of top hat inverted so the brim is holding the washers against the uxter plate. Secure the top hat with a stainless steel hose clip (acknowledgement to Canal World Web Forum contributor). Tony Brooks

Posted: Tue Aug 10, 2010 9:11am

Thank you. This certainly gives me something to go on. The clarity of your wording is really helpful. John R