Does that rudder work??

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csonics
Anne from Little Britan
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Does that rudder work??

Post by csonics » Wed Nov 18, 2009 5:09 pm

Posted on behalf of farmerden:

farmerden
Warming the Engine


Joined: 19 Apr 2008
Posts: 70
Location: Shawnigan Lake,B.C.
Posted: Sun Sep 07, 2008 8:50 pm Post subject: Does that rudder work??
I noticed in your pictures of Windermere 2008 a picture of a rudder [ I think the rudder might belong to Annabelle] Do you have any info on it? Farmerden :
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Maltelec
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Joined: 23 Sep 2007
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Location: Cumbria, UK
Posted: Mon Sep 08, 2008 2:54 pm Post subject:
Well I know the boat manuveres up and down the lake in a graceful manner.

I am assuming you mean this picture:

Image

I believe you are right in thinking it is Annabelles' rudder.

Ignoring the top and bottom parts, the rudder is otherwise a standard rudder shape, so I can't see any reason why it should not work well.
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farmerden
Warming the Engine


Joined: 19 Apr 2008
Posts: 70
Location: Shawnigan Lake,B.C.
Posted: Tue Sep 09, 2008 1:57 pm Post subject: rudder
There's a lot more to that rudder than meets the eye.Not only the horizotal blades but the amount ahead of the vertical stem,the fact that the rudder is wing shaped [wider at front than rear] Maybe the owner can comment on it's performance! Den
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farmerden
Warming the Engine


Joined: 19 Apr 2008
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Location: Shawnigan Lake,B.C.
Posted: Tue Sep 09, 2008 9:29 pm Post subject:
The rudder type is a Schilling. Again does it work?? Den :
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P.F.Cuthbert@Classicfm.ne
Steam on Deck


Joined: 24 Nov 2007
Posts: 52
Location: Cheshire, UK
Posted: Wed Sep 10, 2008 3:29 pm Post subject:
I seem to recall that there is an article in Funnel on the construction and use of a Schilling rudder.

Unfortunately, I am not at home with my library, so cannot give you chapter and verse. Any other SBA folk recall this article?

Pete
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Edward
Lighting the Boiler


Joined: 01 Oct 2007
Posts: 39
Location: Ambleside, Cumbria, UK
Posted: Thu Sep 11, 2008 6:50 am Post subject:
Dear Farmerden ,

Since you identified the rudder as a Schilling I presume you know the various claims made for the type and the design parameters , (other readers can find quite a good summary in Wikipedia if they Google it .)

I assume that the claims made for it are valid at the rather larger sizes
that hard-boiled commercial operators use rather than the smaller steam launches that most of us are interested in , otherwise they wouldn't use them . So I guess your question is whether they offer any advantages for smaller vessels .

As far as I know Annabelles' owner is satisfied with the performance but as I believe it is the only rudder that has been fitted one can't draw any comparisons .

In 1993-94 a Schilling rudder was fitted to SL Petunia by her owner , Peter Frost as he was not satisfied with her turning performance (particularly when going astern.) He wrote about this in a one page article in edition 83 of The Funnel (December 1994) and I think this must be the article to which Peter Cuthbert refers .

Some of the article is a general technical description , (the Wikipedia entry could almost be a reprint of this) but what will , I hope , interest you is the subjective comparison he makes of "before and after".
To quote from his article :
"...have been pleased with the results. The astern performance has improved from poor to satisfactory , inasmuch as that by judicious use of the helm and engine an astern course can be held and a turn initiated . The ahead performance has changed from good to spectacular . With maximum helm of 40 degrees and increasing engine power the boat will turn in a diameter less than three times its own length due to the rudder deflecting the propellor stream at a broad angle. "
"The changed rudder form does not appear to have reduced the boats' speed at cruising revs , and the stern wave is definitely flatter than before , indicating that the top and bottom plates do have the claimed effect."

So it would seem that Schilling rudders DO work better than conventional ones at fairly small sizes on hulls of reasonably conventional shape ; SL Petunia has a beam of 6' and a waterline length of 23' , prop 3 blades 12"x16" . The original rudder was described as follows "...dimensions 450mm high x 300mm fore and aft and 45mm maximum thickness ,ie the thickest part of the aerofoil , in way of the coupling . 75mm of the breadth is forward of the stock , giving 25% balance . " The distance from the prop isn't given but as no mention is made in the Funnel article of changing the position of the stock, or putting in a crank in order to meet the requirements of the Schilling rudder one can draw ones' own conclusion.

Sadly Peters' health is such that he is unlikely to be able to comment . He is not a member of this Forum and I don't think Annabelles' owner is either.

I hope all this has been of some help and answers your question.

Yours sincerely , Edward .
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farmerden
Warming the Engine


Joined: 19 Apr 2008
Posts: 70
Location: Shawnigan Lake,B.C.
Posted: Thu Sep 11, 2008 9:59 pm Post subject:
I really appreciate you guys answering my questions.It amazes me that I can ask a question ,send it out,and get an answer from half-way round the world ! What do we have in common? We're Steamers!!! Thanks Den
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