What determines your choice of mainsheet diameter?

Greenheart

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Here's a daft question, most of the answer to which, I probably already know, but if I haven't considered every aspect, I'll benefit from being reminded.

The first dinghy I had as a boy, came with a 10mm mainsheet, easily strong enough, but apt to hurt the childish pinkies on a long beat in a stiff breeze. I replaced it with 14mm, which looked and felt much better, and wasn't oversize for the original blocks.

I daresay race-mad weight-savers would readily use fishing line rather than nice soft thick multiplait. And I know that blocks big enough to carry 20mm line, are hefty and not much less expensive than an entire elderly GP14.

I know line with very high breaking strain won't stretch as much as may be desirable for certain applications; but for halyards and particularly, sheets, is there any non-financial, non-weight-related reason not to fit the biggest diameter lines you can find, for the great increase they bring in handling comfort?

I'm constantly surprised by the very slender lines suggested as suitable for many tough jobs in dinghies. I find 3mm and 4mm so objectionable, I've always supposed there must be a good reason for their use...but what that may be, I can't guess. :confused:
 
Ease of use and soft to my hands! I've got 14mm Ø multiplait on my mainsheet - 33' - and it's excellent. Almost certainly far too large in relation to the loads on my mainsheet but very nice to handle. Originally fitted with a fairly stiff 11/12mm Ø which was not very nice and not long enough.
 
Ease of use and soft to my hands! I've got 14mm Ø multiplait on my mainsheet - 33' - and it's excellent. Almost certainly far too large in relation to the loads on my mainsheet but very nice to handle. Originally fitted with a fairly stiff 11/12mm Ø which was not very nice and not long enough.

mine is 12 m/m with an Easy Block 3>1 or 6>1 tackle depends what string one pulls. that is fine for size on 37`
 
I find 8mm for the mainsheet and 14mm on the jibsheets is fine ( 22' boat ).

I used to crew a fiercely competetive International 14; the jib and assymetric sheets were 3-4mm, and in anything more than about Force 1 it was literally impossible to sail without gloves...

The reason being weight and windage, and sadly it's correct, does make a difference.
 
Seajet...8mm mainsheet? That must feel like a cheesewire in a gale! And 14mm for the same 22-footer's jib? Did you mean those figures the other way round, or is the mainsheet on a 6:1, or 8:1 tackle?

Maybe I've been misunderstood, here. I'm a bit of a softy and I'm hoping there's no good reason not to spend £150 on a mainsheet as thick as the fat end of my thumb. I daresay in the wacky world of International 14s, a luxurious 22mm mainsheet weighing a couple of kilos, can't be justified.

But if as I hope, I get my paws on a big old dinghy - 505/Osprey/Javelin/FD for some major modification/restoration this winter, is her performance really likely to suffer as much as the pleasure of sailing her will be increased, by a fat mainsheet?
 
Dancrane,

it's only a 109sq ft mainsail, with a 4:1, seriously never any bother at all.

As for the jibsheets, - up to 135 sq ft - I go for whole seasons without using the winches, just use cam cleats dinghy style.

I had an Osprey Mk 2, lovely boat, favourite of all the dinghies I've ever sailed by a wide margin, the 505 is OK but the Osprey is special; we sailed mine from Chichester to Cowes, using buoyancy aids as fenders ( slept ashore though ).

I wouldn't use an actually fat sheet on that, but certainly nothing like the cheesewires on the 14 - which BTW left me singularly unimpressed, £10,500 just for the hull years ago, and only a little faster than the Osprey; thing was, the Osprey handles like a thoroughbred, the 14 handled like a tea trolley with a rocket strapped to it - and you had to wear knee pads for tacking etc - as far as I could see the main requirement was to have blonde streaks in one's hair, and that's just the blokes...
 
Arthur Itis means that I have to use the biggest diameter ropes I can on my boat. Of course it's a bonus that I can get away with the cheaper end of the materials market as there's no way I need the strength of a 12 - 14mm dynema sheet or indeed halyard.

There are downsides though and I have a 12mm roller reefing pennant. Fortunately the rigger removed the core for the bit that goes round the drum (XW in Gosport if you are interested) as the sheath was strong enough to carry the roller reefing load. Other wise I'd have had to stick with the original 8mm which I could no longer grip, even with gloves.
 
Thanks, Topcat - I don't have a medical reason, but I believe I'll likewise up-size the lines I use, and enjoy the comfort.

Seajet, I recall your mention of the Osprey previously. Your account is one of several very positive testimonials that have pointed me that way.

I'm only looking at the 505 because through the winter, the boat will need to sit in the garage, and every garage I've measured is at most 510cm long! I love the Osprey's proportions, but it's about 25cm longer than the space I have to put it in...unless I prop-up one end, five feet above the ground.

I enjoy thinking of long evenings in December, with a pot-bellied stove warming the garage as I gradually bring an oldie back to perfection, ready for spring 2012. Much more pleasant work, if I can shut the freezing rain outside!

I know exactly what you mean about Int14 crews; I was regularly sailing much humbler boats near Itchenor 20 years ago, and the imperious self-satisfaction of the Int14 racing crews was obnoxious. The equivalent of BMW M3 drivers wearing hands-free kits, discussing shares and suits (I've owned BMs myself, but the clientele has always had a poisonous element!).

You mentioned about a fortnight ago, that the Osprey didn't strike you as a good bet for singlehanding, even if the sails were carefully set up so as to allow a slab-reefing main and roller-jib/genoa. Quite a few reports I've read describe the boat as a very thrilling singlehander, but by no means impossible. I've no inclination towards racing, but I adore the speed aboard a well-bred race boat, and the fun of breakfasting at Paignton then being in Weymouth for late lunch, is an appealing idea. Any thoughts you can pass on, I'll be grateful for. :)
 
Topcat,

very good point about arthritis; as it strikes a lot of people, I can't help thinking there's a gap in the market for kit such as you have adapted.

Dancrane,

I did singlehand my Osprey, but only up to about F3.

With a small mainsail off something else I don't see why one shouldn't be quite adventurous, with a long tiller extension Contender style ( had one of those too, not oversmitten but maybe I didn't give it a fair try ).

A non-racing but reasonable main with a well sorted simple reefing system may be the way to go.

One snag the boat does have is that she can turn turtle, ( no more than most boats ) so I had a plastic milk bottle at the masthead, though I'm sure something more elegant could be arranged if doing it a lot.

The Mk 2 with the aft deck is the one to go for; looks great, and you can keep beer in the locker !

I found a jockey wheel was necessary for the launching trolley, you can do without but much easier with.

Osprey1.jpg


Dancrane,

just remembered something which will make you smile; I found the Itchenor 14 lot might be red hot on racing, but didn't know simple nav' marks...we were usually blinded by spray, and I remember on one occasion I just saw a buoy I recognised flash past, on the wrong side...a buoy I recognised...I just had time to yell " Err ! " when we piled straight onto the Winner, it was like concrete and we were lucky not to be injured; the owner started jibbering 'my board ! My board !' Due to the cost of the thing...

Not so funny, our fancy jib was stolen during one week, notably mains with numbers were left; then I was amazed at leaving sails like that in a common loft...
 
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Fun story, cheers Seajet. Great picture, too. Makes me want one, more than ever!

Given the very real constriction of my garage space, d'you suppose rigging up webbing straps beneath three or four of the roofing beams, to support the Osprey hull longways at approximately a 20 degree angle (so that I can close and lock the door!) will allow me to work on it, without overstraining her? I'm not thinking I'll actually climb in, while she's hanging up.

I'm imagining the hull will be all ply, basically sound, and I'd be careful to equalise the amount of weight on each piece of webbing. Obviously when weather permits, the 17'6" length can lie on the floor and point out of the door.

If you've any good advice on problems Ospreys suffer from, which might make a cheap one into a false bargain, I'd benefit from reading it. I'm happy to take time redecking, renewing all the lines and deck gear, standing rigging, even foils/centreboard case if necessary, but I'm wary of critical structural repairs which might upset hull-lines that need to be just right.

Some great Osprey footage here: http://www.youtube.com/watch?v=TIn0nA3f5tw

...and how didn't I find the following, earlier?!! This gent starts rowing his Osprey along with SWMBO and the kiddie, then offloads the family and singlehands! Great stuff, slightly ominously set to Mozart's Requiem, if I recognise it correctly: http://www.youtube.com/watch?v=uF4L7rwseek
 
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Just realised that the footage from Lake Diefenbaker taken last winter, was of a GRP Osprey; I thought only the new ones were made that way. Very appealing to my woodworking inabilities - I'm fine with bookshelves and breadboards, even a bit of cabin cornicing carpentry, but stuff that needs a real shipwright's judgement finds me way out of my depth.

Any idea how many of each construction method were built?
 
I realise now I've probably answered re. hoisting an Osprey on the wrong thread, must be some confused readers !

I don't think it would do any harm using something like a webbing sling, and another or something half way along.

My boat was 902, Mk2 by Westerlys of Cornwall; I'm no genius at woodwork, but she didn't present any problems.

I can't remember the actual method of getting that slight 'clinker' effect, but it certainly stiffens the boat; personally I wouldn't touch a grp one, old big grp dinghies seem to be very heavy, and you'd lose the aesthetic beauty which gives so much pride of ownership - get an up-together boat & add a decent cover, and only touch-up varnishing should be required, but you know that.

May I suggest another boat which may suit your needs; how about a Scorpion ?

I had one of those too, very seaworthy, fun to sail, and a better proposition singlehanded; it'd fit your garage too !

Another gorgeous looking boat...Compare it to the GP behind in this shot !
FreeBird-1.jpg
 
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Agreed, the Scorpion is a very lovely looking boat, and a good little performer too...PY106? And handier proportions.

It probably says sad things about my ego and self-confidence, but I'm strangely attracted to the bigger dinghies. If only some examples of the Flying Dutchman class weren't as rarely seen as the old ghost ship itself, I'd be trying to work out how to shoehorn a 19' 10" hull into our 16' garage!

I think long-entrenched memories of eleven and twelve footers that denied one much comfort, and over-reacted to wavelets, and lagged far behind bigger brethren, has made me fixated on the larger boats, even if I need to set them up with reefable sails for singlehanding in a breeze.

Many thanks for thoughts on GRP. The example on the lake in Canada looked good, if elderly, to me, but I know what you mean about older boats being heavier than necessary. And I'm a big fan of unpainted wood decking, coppery-red with many coats of carefully-applied varnish...I can see I'm going to enjoy every season with whichever boat I decide on.

(SWMBO has just suggested that my search for the biggest dinghy I can find, sounds like it may relate psychologically, to my desire for the thickest guage of mainsheet... Hmm...next time we go to the cliffs at Worth Matravers, I must take a whole bottle of Cognac... :D)
 
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