Hello! |
You might find a lot on this site , see link http://www.merlinrocket.co.uk/design%20guide/cover%20page.html |
Funnily enough I did exactly the same thing for one of my first year projects at Southampton Uni, and found the design guide as per Alan F's comments plus also the much famed Merlin Rocket book by Mssrs Park & Holt most useful. I think I ended up with a fully battened, smooth skined and asymmetic kited beast and this was before the RS400 came along ....... |
The Dinghy Year Book 1958 has a really good article on the development of Merlin hull shapes from the original Merlin through Rockets to Holt, Proctor, Adur and Rigden designs in the 1950's - with some line drawings. It was written by Ian Proctor so it might be a bit biased but it does explain how his different designes evolved. |
Ellie, I found reading Frank Bethwaite's book even harder than my engineering degree at Southampton...be warned! |
I have got a copy of the Merlin Rocket book, but these are valuable items that seem to trade for a small fortune on e-vil-bay also if you really want to get technical a large book by a mr Marchaj with all sorts of formulae in as well as some of the Ian Proctor books on dinghy racing which has a fair bit on the early years of the Merlin. You are welcome to a loan of some or all if helpful for your project |
Ellie, |
David - any chance of a copy too? I am playing with fitting a Tasar rotating ali mast on my boat in the spring, as I have finally worked through Frank's rig section in his bible. I know this has been done with large (stiff) section masts, but the Tasar rig is fundamentally different. I'll also simplify the controls as I am convinced that there has to be a better way forward. Regretably this is something else that the Aussies are better than us at ..... |
Try the library for the Merlin Rocket book. If they don't have a copy they may be able to get Swindon's copy on inter-library loan. |
Didnt Chris (cant rem which one) write his dissertation on the MR class? |
Andy, [email protected] |
Andy , Did you know that Rein Zivold experimented with putting a spinnaker onto the Tasar , I believe he found the top mast too soft. Early Tasar top masts bent very easily and were retrospectively fitted with stiffners.The Tasar that I recently sold to your Dad had an unstiffened top mast so beware! I belive that the Aussies are experimeting ( informaly) with carbon topmasts with extra controlled flex to match the new mylar sails.Second Hand Tasar masts are rare as hens teeth and very expensive to replace!! |
Ellie, you should speak to my Dad he has loads of old plans and could form a living history project. |
I did a similar thing many moons ago and picked the brains of N12 designer Mal McDougal, who designed a 16 foot skiff, which was the basis of my project. Your best port of call would be the designers and builders. They would have perfect nuggets of information, lines drawings, pictures from which to make comparisons. Why not try Winders, Kevin Driver, Linton or if you can get hold of him - Phil Morrison. Take a notebook and buy 'em a beer! Good luck! |
Yeah, thanks Allen, I have already had a quick noesy at that, it is handy! |
Ellie - I have sent you an email about the "58 article. |
There is a paper in one of the Cheasapeake symposia by Bob Ames on 14 design, although this is not contemporary it is quite analytical and in particular considers deadrise angles of Benedicts, Cross's etc. If you are at the Institute you should be able to find it in the library, thats where I got my copy. |
This link to Keith Callaghan's site is helpful for the 1970's http://www.bluelightning.co.uk/Merlins/merlins.htm |
On the subject of Tasar rigs its worth noting that the Tasar rig was a huge compromise. The hand built wood masts on NS14s and Cherubs that Bethwaite made were longer in chord: 4 inches, maybe a little bit slimmer and much more flexible. That was sone by making the front half of the mast non structural balsa. They were still pretty heavy though. I'm sure the same trick could be done with a carbon section and some kind of polyurethane foam for the fairing. The Cherub rigs carried spinnakers just fine, but the hoist was not very far above what were already rather low hounds for the class. |