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What makes a boat competitive?

Postby JCampbell on Mon Feb 17, 2014 10:42 pm

There have been a number of posts about what should be done to make timber boats faster. There is also some general discussion about advantages of FRP boats.

I would ask: what are the differences between the FRP hulls and timber boats that make timber boats slower and how can these differences be minimised.

We have been told that Jack Felsenthal was not slow at the Vic states in a timber boat. Can someone give any quantifiable reasons why this skipper/boat combination was not slow?

My first timber boat, 1668, weighed 48kg. I have finished as high in the nationals in that boat as in a FRP. 1668 was built using meranti ply and fibreglassed inside and out. I felt this boat had a stiff floor. My reaction to my first sail in a FRB boat was that it was soft compared to 1668.

My (almost finished) 1842 is stiff behind the centreboard case bulkhead due to battens and tanks and in front of the web bulkhead due to the curve in the ply. However, it is soft between the bulkheads where the floor is flatter. The change to the length of battens may fix this and I might try to add them in the front tank if possible. I have heard talk that the FRB boats are stiffer "under the mast".

There is a comment that FRP boats can be built with the reinforcement placed where it is needed. Is this consistent with Section B part 5? I originally read this to mean a consistent specification but maybe I am a bit naive about details like this.

The YMS is a subtly different shape to the original and these differences surprised me when I worked out what they were. I have asked committee members unofficially to what extent the templates could be altered. I have not received any responses to this. So I tried to take paper templates of the YMS which was not extremely accurate. However, when these were put over 1842 there were noticeable differences. The bottom panels are warped to make them straighter on the keel. I estimate the difference to be about 7mm. It is interesting that the top of the stem was located well short of that on 1842. I think that this could be due to a fine bow at the web bulkhead. Anyone have any ideas on this? Next I have to take some "V" measurements for comparison.

I would prefer that the real cause (if any) of slow timber boats be found and a "one design" solution be incorporated into the building notes and rules. A second, less preferred option would be to leave the building specification as is and allow builders an additional X sqm of ply and Y metres of 16x16 timber to incorporate as they see fit.

John Campbell
1935
1842
1668
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Re: What makes a boat competitive?

Postby Aten on Mon Feb 24, 2014 1:19 pm

I am starting to think that boat weight isn't critical. I am guessing but I think that extra weight gained by stiffening would be well offset by the performance gain. I am waiting for the new rules to be made available so I can get a copy and see what can be done in regard to this.
What's a couple of kilos on the boat when I am carrying many extra kilos on myself? I reckon my poor down wind performance in the gusty nationals was a result of me being just over 90kg. I believe 75kg would be ideal weight. A couple of extra kilos on the boat seems insignificant when compared this way.
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Re: What makes a boat competitive?

Postby JCampbell on Mon Feb 24, 2014 8:05 pm

Aten,

Look at the Sabre Home Page (you will have to scroll down a way. The rule proposals and results are there.
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Re: What makes a boat competitive?

Postby Aten on Mon Feb 24, 2014 8:18 pm

I don't have a copy of the rules so the amendments aren't much good to me at the moment. Going to wait until they are finalised before I purchase a set.
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Re: What makes a boat competitive?

Postby Aten on Mon Feb 24, 2014 8:19 pm

Is the amount of fibreglass used on ply boats specified in the rules?
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Re: What makes a boat competitive?

Postby JohnL on Thu Feb 27, 2014 10:10 pm

John,

I have been doing a lot of thinking about this topic as I am considering building a new hull later in the year.

You comment that you think the FRP boat is softer in the cockpit area and stiffer under the mast area.

Do you have any ideas why this should be?

My current thoughts relate to the hull stiffness forward of the shrouds, flexing in the centre case area, and the flex under the mast.

Perhaps you could comment on what happens when you tension the forestay?

There seems to be a lot written about the centre case bulkhead flexing, which I think is a result of the top of the centre case flexing. I calculate that there is about 60kg side load on the top of the centre case. Please comment?

I would think that the area from about the web bulkhead back would need to be very stiff to promote early planning.

The decisions I feel I need to make include width, height and length of the floor battens, how much timber to include in the top of the centre case, and wether I use stronger timber than Western Red Cedar in the gunwales.

I would like to include a brace from the top of the web bulkhead to the bottom of the bow, but this is not allowed.

John Ladewig 1940
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Re: What makes a boat competitive?

Postby HelterSkelter on Fri Feb 28, 2014 12:00 am

I have made a number of inquiries regarding the stiffness or otherwise of wood v FRP. The repetitive comment is '8mm sandwich foam v 4mm ply with 2 coats of glass, are you kidding'. Frankly that is the answer. A raw FRP hull is stiffer than a completed wooden boat. Other reasons exist like chine stringers, stronger supporting tank sides, FRP frames, stiffer framing and construction of the centre board case the list goes on.

The position would be vastly different if the powers at be had controlled the FRP construction to the wooden hull specifications but the bird has flown the coup and we have to work within the Rules we have.

But having said that surly it is time for the Class to replace the antiquated wooden boat specifications and building process with modern techniques particularly framing. One only has to look at the Contender Class where timber and FRP boats are very similar competitively with wood having the edge and stiffness.

I am certain a wooden boat with modern framing techniques will be stiff and still under weight as less glass will be needed but whether this construction will be as fast as the FRP hull I frankly don't know but it will be closer.

The second boat in the 2013 Victorian State Titles was timber but it was sailed by the laser radial national champion and he did get light wind. The reality is that all the top positions are generally filled by FRP boats.

What is the answer, I don't know but lets modernise the Specification and construction techniques of the wooden hull, this will make construction for the amateur builder easier and accept the position of those like me who love wooden boats should compete in the wooden boat section and restrict the Nationals Trophy to the first wooden boat. There I've said it. I wonder why some don't agree.

Of course the Association could withdraw the current A Class certificates from the existing FRP boats and require that FRP boats in the future be a max 5mm constant sandwich foam, no chine stringers, centre case constructed as per wooden Specification, centre case and web bulkheads be 4mm with wooden specs framing but in glass and suddenly you don't have a stiff hull. A glass boat builders comments not mine but it reveals the true situation.

Hey I'm not being critical of FRP boats but my goal is to keep the Association successful by realising things need to be done or we will loose members as FRP is too expensive.

HelterSkelter 1906
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Re: What makes a boat competitive?

Postby GuestMember on Fri Feb 28, 2014 11:04 am

Hi all

I would like everyone to please stop trying to change the Sabre as it is these changes that makes the older boats slower and it is a never ending cycle that WILL, yes WILL eventually destroy the class and there will be no way to put it back together.

Please take some time to take a look at other countries and you will see that the biggest threat to the Sabre is intenational boats like RS and unless we make the class very strong and not destroy all the current boats.

At the end of the day there are not 2000 Sabres since 1978, this is not a large class!
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Re: What makes a boat competitive?

Postby GuestMember on Fri Feb 28, 2014 1:18 pm

I am a little curious that it seems assumed a wooden boat is slower than glass. If you look back through Nationals results (last 10 years), there was always a mixture of builds with wood dominant in wins.

The results have shifted since aorund 2009/2010 to glass but prior, both builds were competing side by side successfully be it wood, YMS or Botteril glass etc. Why was wood ok then but noted as not being competitive now ?

Having owned 3 wooden boats historically I love the look of the wood. Maintanence however takes away time which I can invest elsewhere - be it paininting, varnishing or a larger job like reglassing etc.

FRP removes these issues. I would suggest FRP is just as much about convenience as it is about performance. I also noted there are just as many glass boats at the back, middle and front of the fleet as there are wood.

Additonally glass boats come ready to race. Fittings on, mast rake sorted, etc. In a busy world with long hours, young kids and other family commitments getting the time to sail on Saturday is often a big enough challenge. The above provides a sailor the opportunity to be competitive day one - which of course you pay for.

Ashley
Cookie Monster 1886
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