Reversing and deadstick manoeuvring

[Minos]

I read a book recently written by an american wooden boat designer/builder who has sailed all over the world and built yachts and motor boats all shapes and sizes. Interestingly he insists his rudders are not faired, so they are all 2" wide with sharp corners. His theory is the passage of the angular shape throught the water sets off a different flow pattern to an "aerodynamic" rudder which sort of makes the rudder have the effect of a bigger rudder, if that makes sense. Our NB rudders are pretty thin of course so maybe a thicker, "squarer" rudder might work better..? Like a heavy wooden cruiser our narrowboats are not built for speed so the notion that a rudder has to slip through the water is maybe at odds with the general design.

That's an interesting point - suggesting that rudder design is entirely an affectation when it comes to narrowboats.

 

A few minutes with Google, and I have learned that with yachts the rudder needs to be foil shaped because it needs lots of lift and to work in conjunction with the keel to twist the boat into the desired direction. The fairing on the leading edge of the rudder affects the lift-to-drag ratio, which needs to be maximised in order to maintain speed and steering.

 

The margins really matter when working with wind powered craft - so a lot of work (and a lot of heavy duty maths) goes into rudder design. The margins probably don't make as much difference on a narrowboat, but when an advantage is available, why not use it?

 

I have not heard the term 'deadstick' before. I think I get the general gist, but what exactly does it mean, and where does it come from?

 

 

dead stick is more a plane term, but means coming in without power. or on a boat in neutral, or with a dead engine

 

It struck me as the most succinct way to describe the problem.

[The Pipe]

Well there's one thing for certain the boat will do exactly as you want so long as no-one is watching and vice versa.

 

The point about the butty is right - and look at the size of yacht rudders.

 

I read a book recently written by an american wooden boat designer/builder who has sailed all over the world and built yachts and motor boats all shapes and sizes. Interestingly he insists his rudders are not faired, so they are all 2" wide with sharp corners. His theory is the passage of the angular shape throught the water sets off a different flow pattern to an "aerodynamic" rudder which sort of makes the rudder have the effect of a bigger rudder, if that makes sense. Our NB rudders are pretty thin of course so maybe a thicker, "squarer" rudder might work better..? Like a heavy wooden cruiser our narrowboats are not built for speed so the notion that a rudder has to slip through the water is maybe at odds with the general design.

 

Maybe someone already has a boat with a "thick" rudder?

Yes Gazelle has a fat rudder a modified Schilling profile and if I could work out how I would post details the rudder is about 5" wide at the front.

[The Pipe]

[img

]http://s1227.photobucket.com/albums/ee432/jimthepipe/[/img]

 

One fat narrowboat rudder. I think I may try a NACA 21 profile next.

Edited September 28, 2011 by Jim Evans

[Maffi]

The other memorable occassion was observed by no one except the Moorings Warden, when I had to move the boat backwards along the full length of the BW moorings at Thrupp and past all the club moorings to the bridge outside the pub. He stood on the front with a pole and was impressed that he did not have to use it once.

Have done this regularly almost weekly from Gunpowder Wharf to the The lift Bridge and never touch the tiller until I need to stop to open the bridge. If your tick over is slow put it in gear and stand on the bow with a pole. Steer the stern by moving the bow. Rose Skinner of nb Frendship (a proper boater) has taught many of the locals to do it this way. At 88 she is still the best boater on the Oxford Canal.

[Tiny]

Coming in to let crew (the wife) off at locks I normally chop out of gear and deadstick to the bank letting the boat come in parallel a close enough to step off at the back at which point a kick of forward then back on dead stick gets the front moving away. Of course I only do this if I plan to hang waiting in mid stream for the lock which depends on what is happening, wind, current and so on.