MERLIN ROCKET FORUM

Topic : Mast Ram

Hi all,

I appreciate that this has been discussed before, and i have searched on the forum for the other threads, and found them intersting reading.

I have merlin 1137, which only needs a coat of varnish to the deck and a coat of paint to the hull, to be finished restoring it. I am starting to think about putting the rigging back together. When i rescued the boat from rotting in the previous owners back garden, the rigging was all ready in pieces, adn although i have sailed her, it was only five times before the restoration started and the rig was never quite right. Now i have a much better idea of what i am doing with sails i appreciate that what was wrong with my rig was the huge gap between the front of the mast and the back of the mast gate, allowing far too much bend in my mast. I have been offered a mast ram to place in this position to solve the problem and allow me some control on the bend.

Do you in your opinion as informed merlin sailors think that on a boat of this age, it would be a viable idea to use fixed shrouds,a highfield lever for jib tension and a mast ram for control of the bend and rig tension. Also the ram i have been offered is not of a strut type so controls the position of the mast in the mast gate, not further above, will this be a problem?

Thanks for any advice you can offer

Adam Wilson

1137


Posted: 20/01/2007 10:48:57
By: Adam
I'd say chocks would probably be better if the rest of the rig is period (Gold proctor mast).

Highfield for the jib will be fine - she's an old lady and won't appreciate too much compression. There will be no bow tank so take it easy even with the lever as there is only fresh air and perhaps a single deck beam holding the sides apart.

Good luck.


Posted: 20/01/2007 11:40:53
By: Chris
Thank you for the reply,

If i was to stiffen up the hull with some bracing to ensure the old girl was not to fold up with the stress, do you think it would be possible to add a more flexible rig, with some more control?

Would anybody please be able to let me have some information about the design of 1137? as i am unaware to who designed her and who built her?

Adam

MR 1137


Posted: 21/01/2007 12:29:21
By: Adam
have a look at below link.

I know it's of a deck stepping modification, but the idea is same.

http://www.merlinrocket.co.uk/gallery/view_photo.asp?folder=gallery/building_and_repairs/deckstepping_3125&file=3125_rear_view.jpg

Posted: 21/01/2007 15:59:05
By: Miles
Proctor Mk XII built by Wyche and Coppock. Will be a good river boat.

To be honest i tend to think these boats are best left alone. Sure, people on the thames have spent pots of money carbonising old hulls to do better on the river but if you're not after being at the front of the thames fleet you could easily ruin a lovely old boat.

It's the sort of job where half measures are never good enough if you know what i mean.


Posted: 21/01/2007 18:23:38
By: Chris
thats great thanks


Posted: 29/01/2007 20:44:38
By: Mark
I once owned 1357 and that had a mast ram mounted just under the deck. It was a horizontal lever about 16" long across the boat, pivot on one side, short piece of wood pivoted off that, which pushed against the front of the mast and at the other end 2:1 purchase to cleat on underside of foredeck, gave about 1¼" travel, see flying fifteen mast strut in the P&B catalogue to get the idea. Cheap, simple and effective.


Posted: 29/01/2007 22:12:05
By: Paul
If you just want to stop the deck lifting with the extra tension in the rig, I do remember reading an article by Henry Wright in one of the old year books 1986? where he suggested using a wire strop in front of the mast and attached to hog and deck beam.

Perhaps some one can find the article?

When I owned 2143 I just used chocks as a mast ram, there are also plenty of mast ram ideas in the book 'Dinghy Systems'
ISBN1-85310-392-6 [Chisnell and Hodgart]


Posted: 30/01/2007 09:35:18
By: Miles
Many Larks (including mine) have a stainless rod tying deck down to hog which could be an idea worth pinching.. Never seen it on a hog stepped Merlin but the kingpost on a deck stepped should have the same effect. 
Can photograph if required.


Posted: 31/01/2007 13:05:50
By: Pat 2121
Just a thought - is the huge gap between front of mast and front of slot in foredeck because the rig is set up with much too much rake, and it is that and not the bend causing your problem?  Chocks are likely to be enough for river sailing.  If the deck needs tying down with a bit of wire then something else is more flexible than it should be I expect - the perils of 45-year old cascamite.


Posted: 31/01/2007 13:20:17
By: Andrew M
Hello Adam

Please send me your address and E mail and I will add you to our Vintage mailing list.

I have been reading the advice sent to you and I am sure that it is all well intentioned, but please don't dream of trying to stiffen hull with struts or wire. You will only create more problems.

Please give me a ring and I am sure that I will be able to help you

Bis 0208 231 8911


Posted: 31/01/2007 17:29:56
By: Mervyn Allen
I fitted 1620 with two s/s rods linking deck on either side of the mast gate to a s/s plate actually going through the hog below the mast step. We also have a lever mounted horizontally just below the deck to operate mast ram,- works fine.


Posted: 01/02/2007 10:08:46
By: Rod & Jo
Hi mervyn,

I was not actually thinking of going that far, and may well just stick with chocks, i do know that my set up is not great so am planning on doing some tunning when the boat is back on water after the winter repaint and varnish.

All i was thinking of was being able to have was a certain amount of movement on the water so as to be able to straigthen up the mast when sailing downwind. Not a massive amount as i appreciate that the boat and rig are very old, and will not be able to give the amount of bend/rake a modern rig will.

My email address is [email protected], also my cheque is in the post to the association, so will very shortly be a member.

Adam


Posted: 02/02/2007 11:51:15
By: Adam
Also, has anybody got any photos of the set up of similar aged boats that they could send me. so i can appreciate what i am aiming for when looking and putting the rigging back together, when looking at photos of the modern merlins, in does not help to visualise the systems in these older boats at all!! as i am sure many of you appreciate!

Thanks for all the help so far,

Adam


Posted: 02/02/2007 11:53:55
By: Adam
I wouldn't aim to be able to adjust the mast rake on the water; in any kind of a wind you will end up with the mast overboard. It will be much better to get the rake right for upwind work, then use other controls to get the best downwind performance, and concentrate on things like trim. In any case you can get no serious tension on the forestay in a boat from this epoch by using the shrouds, you have to use the mainsheet. Dan (Alsop) has an excellent article in the technical bits.

Remember that, because of the lack of serious tension, if you have spreaders they will need to push the shrouds much more out of a straight line than is recommended for modern boats, in order to have the same effect on mast bend.


Posted: 02/02/2007 17:15:18
By: Rod & Jo
just to stick in the regular comment that it's always much more informative to actually see the systems in place on a boat than in pictures - where are you?  Why not contact your nearest club rep and see if they have other boats of your age you could look at that are set up well.  There are always a number of ways of achieving the same end - if you are looking to get your mast more upright downwind then maybe it's too raked upwind.  As Rod said, these boats don't alter rake much and depower with use of loads of cunningham kicker and mainsheet tension with a traveller either at the transom or in the middle.  See previous tuning threads for the dangle technique of measuring mast rake

Andrew


Posted: 05/02/2007 09:58:10
By: Andrew M
Adam,

This may be of interest to you

http://cgi.ebay.co.uk/RWO-mast-ram-for-racing-sailing-dinghy_W0QQitemZ180082434589QQihZ008QQcategoryZ98953QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Steve


Posted: 06/02/2007 22:18:46
By: Steve ex3019
Hi Adam,
This is the same as the item I bought a few months ago for £12 including postage. Power is 8 to 1. It is about 7 inches long and the adjustment available is about 4 inches. I had to refurbish it at a cost of a further £12 for a set of sheaves (there were several of the old ones with chips off the edges - they go brittle with age) and some 4mm pre-stretched cord, so it would be worth checking with the seller that the sheaves are undamaged. The idea is to hang it upside down under the deck. The string can be led down then aft to a jambing cleat (or cleats if you want to adjust it from both sides of the boat). I have had to glue a couple of mounting blocks to the deck reinforcement and beams below and forward of the mast gate to avoid having to cut into the main deck cross beam.
Have fun. Peter


Posted: 07/02/2007 12:22:27
By: Peter 2789
I have a muscle box for ram on 2988; it does not work anything like as nicely as the lever on 1620, which presents no resistance to being let off.


Posted: 08/02/2007 15:01:49
By: Rod & Jo

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