Boom off the horizontal

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Garry R
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Post by Garry R » Tue Oct 05, 2004 1:03 pm

My old Merlin 1728 has an alloy mast with a rectangular section tracked boom. When rigged, the boom seems to be well off the horizontal, dipping down to the transom even before the kicker is applied - well certainly compared to other pictures of vintage Merlins on the Merlin/Ranelagh site . I am not sure of the cause of this - could the mast be raked too far back or is there something else awry? And how does one tell what the correct angle of the mast should be? The shrouds go through the deck to the adjusters and then the jib is hoisted with integral forestay and tensioned with a Highfield lever so there may be problems there I suppose. The mast steps into an adjustable socket on the hog and I did not change its position during the rebuild but it is possible that the mast position is a little further astern due to replacement of the cross member which the mast rests against. This of course would rake the mast back but how do you tell? Any help/advice appreciated.

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Ed
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Post by Ed » Tue Oct 05, 2004 1:33 pm

Hi Garry,

As I mentioned before.....there are merlin rigs......and merlin rigs.....being largely a development class, people have tried all sorts of things to try and get a little bit of an advantage. The horrible Merlin droop boom was just one of these. Someone worked out that as the sail area is worked out simply from the luff and the foot measurement (Luff x foot /2) then you couild drop down the boom and extend the sail area....for free. However it looks silly.....is horrible to sail with...and I sincerely doubt it makes you any the faster.

Of course it might also be the rake of the mast.....which would of been pretty upright in those days....although the mast bent enough to make up for it! I am really guessing.....but if there is more than 12ins of rake measured at boom height, I would think that was too much....but would expect 6-9ins.....although have to admit this really is a bit of a guess.....I can't really remember too much what it should be.

So....sorry....my guess is that was the way the sail was cut.

cheers

eib
Ed Bremner
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Garry R
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Joined: Fri Sep 17, 2004 1:01 pm
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Post by Garry R » Tue Oct 05, 2004 1:46 pm

Thanks for that Ed. Certainly one sail seems to make it much worse than the other. And you are right - my aching knees after last weekend with all the ducking down below this low slung boom are testament to man's ludicrous obsession with speed. If there is no gain without pain I should be at the front of the fleet!!!!!!!!! But I will rig it up at home and see whether there is a mast rake problem. As I said, I hauled up the sail on Sunday and thought "What the hell is going on here!!" Another downside is that the slightest heeling and the boom drags in the water!!

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Ed
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Post by Ed » Tue Oct 05, 2004 2:33 pm

Yeah.....it was generally a pretty crap idea.... I also pulled one up the mast once....I think that one of Rozzers original mains was like that....thought no-way am I going to get under that boom and found another main.

Good luck

cheers

eib
Ed Bremner
CVRDA


Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it

Rupert
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Post by Rupert » Tue Oct 05, 2004 3:29 pm

Try Europe sailing if you think your boom is low....I used to leave the elbow holding the tiller extension in the air by mistake, and ended up with huge lumps where I got it wrong. Perfected sailing while clutching one elbow with other hand. Then came to my senses and sold the boat...
Rupert

chris
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Post by chris » Wed Oct 06, 2004 2:10 pm

Somewhere on the merlin website there's a article 'How to make old merlins go again ' or something like that. It does talk about mast rake, and also says get new sails made that fit your old rig as any other secondhand ones probaly will be no good. If the article's not there now let me know as I think I made a copy somewhere.
Chris

Garry R
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Joined: Fri Sep 17, 2004 1:01 pm
Location: Chapel Allerton Somerset

Post by Garry R » Thu Oct 07, 2004 9:24 am

Had a look at the mast step arrangement and have found that the set screws holding the tufnol block in position were slack - one of them crumbled when I tried to unscrew it and another was in a bit of a state. The whole thing seemed keen to slide so I wonder if it had actually shifted every time I rigged it leading to ever increasing rake!!! Anyhow it has all been removed now and there are new 2BA screws winging their way northwards to sort it out. Thanks for the information on Old Merlins - the info is there and was absorbed last night.

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