Original Merlin sail plan

31/07/2009 08:48:13
Measurement Man
Merlin sail number 36 is trying to get certified following her stunning overhaul by Chris Barlow, and the new owner would like to rig her to the original 1946 25ft sail plan if possible.

None of the documents that I have give full enough details for us to re-create the other rig dimensions (foot, jib luff and perp, etc). I know that the main foot was really short, but just how short is a mystery to me. Dimensions following the reduction to 22'6" are available, but I haven't come across the original measurements.

Does anyone have such info? it would be really interesting to read..

Many thanks,


31/07/2009 08:57:54
Chris M
I've linked the well known photo of 175 being sailed by two pairs of legs and not much else! This must be the origional sail plan and the foot of the main finishes almosty exactly halfway along the stern deck.

Not a precise measurement of course, but surely close enough to get a reasonably authentic looking sail.

31/07/2009 09:32:27
I belive Dick Batt has no 16, Gently. What rig is on that at present?

I guess the problem is many early boats would have cut their masts down to 22' 6" at the time, so not many left (if any)

31/07/2009 12:21:51
Intelligence Officer.
If you look at almost any of the old pictures, the known is 14'long which gives you a scale alowing for angle of the boat to the picture gives you a further scale and this should get you to within experiemental accuracy.
Though wasn't it the same formula with 100sq ft at 25' to 110 sq ft at 20'? or something like that?

31/07/2009 13:25:58
Gently is now with Chris Barlow for restoration but has the shorter rig.
Chris has however put a 25ft mast on Iska (6) for which he has some original cotton sails which could be measured.
The modern MacNamara sails put on 36 are good and make her hard to beat, but old style would be nicer with that mast and its original diamond rigging.

31/07/2009 13:30:09
Picture of Iska with tall rig at Baltic Wharf in April this year

31/07/2009 13:51:56
Perhaps this may help. Garry R sent me a photocopy of the Merlin review in Yachting Monthly (I think) from 1946. It had all the plans.

31/07/2009 13:52:35
This picture has dimensions of sails...

31/07/2009 14:51:38
Measurement Man
If there were knighthoods for such things, you would for sure be Sir Magnus Smith by now...

Thanks very much Mags.


31/07/2009 14:54:08
Measurement Man
Interesting to see that the mainsail luff is 22'5", presumably leaving 2'7" to the lower band from the sheerline to make the 25ft mast?


31/07/2009 14:56:16
Great news to hear that Gently is being restored!!!

31/07/2009 17:42:32
Here's a link to the restoration photos of 36 and there's one of her sailing with one of Chris's original cotton sails - love the sail colour!

31/07/2009 18:17:58
Garry R
Well done Mags - spot on.  GGGGGGGG  - if anyone ever needs measurements for an original Rocket design I have got a cotton sail from one so I could measure it.  As Secret Water's (111) mast was cut even shorter than the 22'6" to 21'6" (I wonder if it was broken) this set fit perfectly.  I am hoping to use them at Roadford at the CVRDA event and more importantly should I ever manage to pick up a Rocket mast I can use them on Gannet (252) as well.

31/07/2009 18:22:51
Garry R
If anyone would like the original article you can mail me your home address and I can send a photocopy.  I hope I don't get inundated - if I do then I suppose I could send them for distribution with a magazine.

01/08/2009 10:11:12
Robert Harris
Hi Garry
I also have a copy of the origional June 1946 Yachting World introduction of what the magazine called the '14ft Restricted Class'. This includes the construction rules and a dimensioned drawing of the rig.

The measured sail are was 100 sq ft - later increased to a max. of 110 sq ft. when mast heights were lowered. The mast height is not given but I believe it was 25ft. The mainsail measured area was 70sq ft, luff 22ft 3ft, foot 6ft 3ins. The foresail area was 30sq ft, luff 13ft 6ins, diagonal 4ft 6ins.

The article also includes the lines of 'Merlin' and detailed sketches of various aspects of her design.

01/08/2009 16:05:08
chris B
I have a copy of the 1947 yearbook with rules. The jist of it for the rig is
Weight of mast must be not less than 18lbs bare wood. It's C of G not less than 10ft above sheerline. Mast may rotate a total angle of 100degrees. boom and mast must passs through 5" diam circle (ex. fittings)
sail area is total 100sq ft ht of sail plan not to exceed 25'. ht of foretrianglenot to exceed 16'. Lower band not to be less than 27" above gunwale
Area= LxF over 2.
area due to curve of leach is not included in measurement, but width half height must not exceed half foot plus 1'9"
no batten to exceed 3'
Mainsails which are not triangular are to be measured in accordance with YRA rules for the measurement of sail area.
Calculated areas to be legibly stamped in figures at least 1" high on port side of main and jib
Spinny. no part of the foot to be more than 14' from headboardand no part of width to exceed 8ft . pole 5ft max.
sheeting around the forestay or jib luff is not allowed.
spinny halyard block must be below the foretriangle.
Rule 9 All sails are to be made of cotton.

The drawing I have gives the mainsail luff as 22'3" foot 6'3" which does roughly correspond to the 1946 sail I have although it has inevitably shrunk a bit. Jib is 13'6" by 4' 6". these measurements do work out to 70 and 30 sq ft - close enough.

Things were different eh?

But it does interest me that a couple of modern sails have been made for the old taller rig that clearly don't follow these rules and are clearly too tall to follow the modern rules as well. How can these be legal?
Our current rules say either modern rules or the rules when the boat was first certified not Pick 'n Mix measurements and rules. So there's a little challenge for the measurement man!

I'll photo some of the plans and rules I have and try and put them on the photo gallery.

01/08/2009 16:31:13
chris B
I see there is a photo of the original sail plan and measurements in the Gallery; follow vintage etc. 
I have some photos of Gently as she is today I can upload. Can someone tell me how? thanks.

01/08/2009 19:50:24
Garry R
Chris - I send all the photos to Mags and he then can create a Gently gallery.  Good point regarding sail plans following class rules.


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