# Tug question



## thunderd (Apr 18, 2005)

I saw a photo posted the other day describing a tug as "hydroconic", I can't find the word in the dictionery can someone please tell me what it means?


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## John Rogers (May 11, 2004)

I think it has something to do with metal ship building. A company in England used the name as a trademark.
I will dig into it more.


I found this if it helps.

THESES (M.Sc.) -- Univ. of strathclyde, division of ship and marine technology, U.k., 1988 
h t t p : / / d a t a b a s e . i r a n d o c . a c . i r 
This study is concerned with developing a procedure for generating a developable surface with computer programs.A brief reveiw of the manual graphical approach is made and then a hydroconic hard chine hull form design procedure is carried out in order to take adveantages of the speed and precision of the computer. A design algroithm for such a hull is developed and with regard to the production aspect the equivalent flat plate shape outline is produced by author computer program. Finally a program to calculate the corresponding longitudinal centre of buoyancy for the generated hull form is produced.


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## thunderd (Apr 18, 2005)

Thanks John I had a bit of a problem with some of the terminology but I did get the drift of it all, I'm grateful my friend


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## meechingman (Feb 20, 2005)

Hydroconic hulls, used for tug and small craft, are basically a series of hard chines rather than a smooth curve. How someone came up with the idea, I don't know, but it was back in the 50's. Check the gallery for some pix and drawings if you haven't seen them already, and in my gallery, look at a picture of the tug Meeching (1960) on the gridiron at Newhaven, that shows the hull shape clearly. I'll see if I can get permission from our local museum to post a picture of Meeching's launch that also shows it.

I actually saw a small sailing yacht on a trailer a week or two ago, with a steel hydroconic hull. Never seen one before and couldn't get to my camera in time.  

Andy G

PS. I don't know if it's a characteristic of all hydroconic tugs, but Meeching was 'lively' at sea. My Dad was her skipper when she rolled to 50 degrees in a force 9. She bounced back, though!


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## sandman (Jun 11, 2005)

I was skipper of a small tug built and owned by appledoreshipbuilders,on this design and we were out in a f8 and she rolled like a pig,but a good seaboat


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## japottinger (Jun 16, 2004)

The Hydroconic principle as applied to hulls was patented by consultant naval architects Burness Corlett, and was licensed out to a number of builders at home and abroad. Some Aberdeen trawlers were built by Mitchison shipyard to this design.


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## meechingman (Feb 20, 2005)

Interesting info here. John 236, would you say that your double chine hulls could be classed as hydroconic? I wonder what made Burness Corlett's design so different that they could patent it?

There's an unceremonious pict of the Meeching on a groyne off Oostende in the gallery of Marsat2. That shows the chines pretty well.

Andy G


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## japottinger (Jun 16, 2004)

Not sure the legal aspect and how they managed to patent the idea, but I think the theory was that all plates could be developed as a function of a plain cone, without any double curvature.


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## WLH (May 15, 2005)

We had several trawlers in Granton built on the 'hydroconic' principle, they were
commonly refered to as ''Hydrocomic'' boats, though far from humerous when working in gale conditions.....................WLH


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## meechingman (Feb 20, 2005)

My Dad would have loved the term Hydrocomic to describe Meeching's rolling. I looked at the museum today and the only photo of her launch is a press cutting that won't reproduce. In the musuem somewhere are the original b/w pix but they're not in the index file! I'll have another search.  

That pic does show that she's a double chine design, as all the Harris tugs seem to be.

Andy G


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