National 12 inward opening transom flap

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Jon Rawson
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Joined: Thu Jul 27, 2006 9:56 pm
Location: West Wiltshire

National 12 inward opening transom flap

Post by Jon Rawson »

Advice please - I now have National 12 No. 2268. I hope to bring her back to something approaching her former glory to sail in CVRDA events. There is a little information about my boat, called Hi-Fi, on the class site and a distant picture of unknown age. She is believed to be a 'Clean Sweep' design from about 1965, clinker ply construction. The last owner obviously looked after her well and overall she is pretty solid although requiring a complete strip and repaint and general repairs. The main problem area is the transom. Around the lower rudder fitting it has been split by the screws and rot has set in so a new section will need to be grafted in.
She is fitted with ply 'quarter' buoyancy tanks at the stern with thin plywood panels in the transom on the outside of the tanks. Internally this leaves only a narrow section of the transom exposed near the rudder. Here is fitted an inward opening transom flap that is 10.5 cm tall. Current flap is ply, sealed with rubber strips and held in place with elastic. I am unsure whether this would be more trouble than it is worth and whether I may be better off doing away with it when repairs are made. Please does anyone know whether this inward opening flap may have been an original fitting from the 1965 era? I have no wish to alter an historic boat but if it is unlikely to be original and was an idea by a past owner it can perhaps go and I will carry an extra bucket. Fitting an outward opening flap in the narrow gap between the tanks is not an option because of the rudder stock. I suspect there may not be many Clean Sweep 12's left, nothing of similar buoyancy tank layout is pictured on the Owners Association site and I have already posted my query there but no real answer yet.
Thanks.
JimC
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Re: National 12 inward opening transom flap

Post by JimC »

I find it hard to believe that you couldn't get a vertically hinged flap to open wide enough to be of enough use to be worthwhile, even with the rudder there. Could you post a photo? It doesn't really matter if it gets partially closed on one side if the other is still open when the rudder is turned.
Jon Rawson
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Joined: Thu Jul 27, 2006 9:56 pm
Location: West Wiltshire

Re: National 12 inward opening transom flap

Post by Jon Rawson »

Good point in that of use would indeed be better than unable to use. The 'hole' is 10.75 cm high and 9.5 cm wide. Pintles and gudgeons combined should give a clearance of about 3 cm from the transom to the back of the rudder stock (less the thickness of a flap). Stock will be about 4.5 cm wide so the flap should open about 3.5 cm and about 4.75 with the rudder turned. Being 5'10" wide she is going to hold a lot of water for a short boat. I guess the answer is going to be fit a side hinged perspex flap and have two buckets. I have (I hope) attached a photo. Thanks.
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Hi-Fi 2.JPG
Hi-Fi 1.JPG
JimC
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Re: National 12 inward opening transom flap

Post by JimC »

Gosh, that is unusual. With that general layout she looks more like a Cherub than a National to me. I can't believe that transom drain setup, or even the patches are original. The whole quarter tank setup looks like a retrofit, and I wouldn't be at all surprised if the same were true of the foredeck layout. I don't think I've ever seen a 12 with the foredeck angled back like that. Structurally its way superior to having the straight across setup, but it does compromise how far forward the crew can get in light airs. Am I right in thinking the foredeck beams are coming back to *aft* of the shroud position? That's odd indeed and I wonder if at some stage the shrouds were back there where the decks join.

I've just found the vintage photo of your boat on the 12 website ( http://www.national12.org/blahdocs/uplo ... a_6893.jpg ). I think we can categorically say that she didn't have the quarter tanks, the transom patches or the centre drain then. I wouldn't like to make a call on the foredeck layout from that photo.

I'm no kind of expert at all on National 12s, and I have no real sense of the class development history. Having said that though really then it goes back to how much you want to do. I reckon I would be tempted to replace the entire transom to get rid of those horrible ply patches. There might be a temptation to lose both the quarter tanks and the angled foredeck and return her to a more conventional 12 layout, which is how I in my ignorance would guess she was built, but suddenly its a huge job. I think you should post those photos on the class forum. Another view to post would be a photo looking forwards showing the centreboard and under foredeck area.
Stephen Hawkins
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Re: National 12 inward opening transom flap

Post by Stephen Hawkins »

The fordeck looks very similar to my N12 Sparkle.

The rear tanks, however do not. I would remove them and put a new transom in.

I would upload a picture I cannot make the size criteria. But you can find plenty of pictures of my N12 Sparkle on the N12 website.

Sparkle is a similar age - 2383
Steve Hawkins

1967 National 12 2383 "Sparkle"
JimC
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Re: National 12 inward opening transom flap

Post by JimC »

The mast looks a long way aft by modern National standards, or is that just an optical illusion?
Jon Rawson
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Joined: Thu Jul 27, 2006 9:56 pm
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Re: National 12 inward opening transom flap

Post by Jon Rawson »

Thanks for the replies - I was a bit thrown by the vintage photo to which Jim C has kindly posted the link as when it was downloaded and enlarged to say 400% there appeared to be patches of a different shade that follow the shape of the ply inserts in the transom and these are clearly absent on the other boat in the picture, 2216. And yet the rear tanks can not be seen. Revisiting the photo I do not think they are there either. The fore deck beams do come aft of the shroud position. I will post a picture taken from a similar angle to the vintage picture and one of the side of the fore deck showing the shroud position. I can not locate it now but a few months ago I did find another brief mention on the Owners Association of the Clean Sweep design as looking a bit like a Salcombe Yawl, which 2268 does resemble a little. I do not have any experience of N12's so I can not comment of the mast position but she seemed an interesting project. As per suggestions of Jim and Stephen I think I will lose the rear tanks and do something about the transom. I have some spare buoyancy bags. The tanks are awfully flimsy anyway. As the boat is almost half as wide as it is long I guess some sensible bracing in addition to the existing cross member would shore the rear corners up a bit. The chap I bought her from (who has since moved) had her for 30 years and reckoned she was a fast design. Came with original spec wooden boom but recent Proctor mast and crisp sails. Hull had been outside under three covers for previous 6 years. The book 'The story of the National 12's published in 1966 (I have been given a copy) lists Clean Sweep 1870 sailed by the designer A. Stone as being 6th in the 'Burton Cup' in 1961 and 1962, 5th in 1963. Eventually 2268 will race again!
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Hi-Fi 6.JPG
Hi-Fi 5.JPG
Michael Brigg
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Re: National 12 inward opening transom flap

Post by Michael Brigg »

Jon Rawson wrote:I did find another brief mention on the Owners Association of the Clean Sweep design as looking a bit like a Salcombe Yawl, which 2268 does resemble a little.
I think the vintage picture you have here is also of the 2268 sailing in Salcombe. That is Salcombe Yacht Club in the background. Would seem to suggest the source of the design influence?
Michael Brigg
Stephen Hawkins
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Location: The much maligned Swindon Town

Re: National 12 inward opening transom flap

Post by Stephen Hawkins »

Here are some pictures of a Starfish design N12 (Pendle Witch), which is also a comparable glue clinker design. The N12s were getting wider at this time.

This boat and my boat lack the bracing that is such a feature of your boat. Perhaps a previous owner was scared of over doing the rig tension. I have seen other boats of this era having some bracing, but it normally its is only a brace leading from the front edge of the centre board case to the hull sides.

Small tank in the front but only bags in the back - I like this simple arrangement

This boat had transom flaps, in the normal fashion, but my starfish, Sparkle did not, until put them in.

The picture shows the deck has been removed, but the frame work is similar, save for the last deck frame.

There is a lot of extra wood in there.

Cheers
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DSC00190.JPG
DSC00191.JPG
DSC00184.JPG
Steve Hawkins

1967 National 12 2383 "Sparkle"
Jon Rawson
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Joined: Thu Jul 27, 2006 9:56 pm
Location: West Wiltshire

Re: National 12 inward opening transom flap

Post by Jon Rawson »

Thanks for the posts - Pictures of Starfish design very interesting. N2268 has a full height tank at the front which I will leave in. In the photo of the front / shroud area the highfield type lever that can be seen on the cross brace is one of the pair that operate the shroud tension (on or off), A wire leads from the lever and round a pulley that is bolted to the chain plate and then up through the side deck. The brace is needed for the lateral tension of this system. Whether it is a good idea or not is another matter. The pulleys look of considerable age so presumably it works? Rear cross brace probable not needed if similar boats not so equipped. Chain plates, mast gate and surround all made from aluminium as was rudder stock, all look home made. Rudder stock not straight and weighed in at 2.4 Kg so that will not be going back on. I am in need of a stock that will accommodate a 28 mm wide blade or a complete stock, rudder and tiller. If anyone has one they do not need I would happily pay the going rate, whatever that is.
JimC
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Re: National 12 inward opening transom flap

Post by JimC »

Jon Rawson wrote:Whether it is a good idea or not is another matter. The pulleys look of considerable age so presumably it works?
It all looks very sensibly engineered to me. Most boats of that sort of age were distinctly underengineered in that region: that's why 470s used to fall apart in about half a season for instance. The helm will probably need to work hard on getting the weight forward in the light because the crew is a bit limited, but that's not rocket science.
Jon Rawson wrote:I am in need of a stock that will accommodate a 28 mm wide blade or a complete stock, rudder and tiller. If anyone has one they do not need I would happily pay the going rate, whatever that is.
Probably easier to make one. They tend to be all different so that way you know it will fit. Its not the most difficult of things to make, you just need some photos of a well designed one.
Jon Rawson
Posts: 31
Joined: Thu Jul 27, 2006 9:56 pm
Location: West Wiltshire

Re: National 12 inward opening transom flap

Post by Jon Rawson »

Thanks to all who have posted replies. Having established what the boat will look like when finished I consulted the oracle (chris of this forum) when I saw him last night. I think I now know the way forward with the restoration. I have the bits to make a stock if necessary and a kind offer of a ready made one. Thanks again.
Stephen Hawkins
Posts: 534
Joined: Wed Nov 04, 2009 11:41 am
Location: The much maligned Swindon Town

Re: National 12 inward opening transom flap

Post by Stephen Hawkins »

Good luck with it.

Hopefully might see you next year.
Steve Hawkins

1967 National 12 2383 "Sparkle"
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