Is there a good reason for not using Dyneema for shrouds on a gaff cutter?

[Andrew Craig-Bennett]

Thanks, Joe.

That really is most encouraging.

I should have written "lower static, or initial, tension, in shrouds set up on deadeyes with lanyards" - the dynamic loadings won't be so different by the time the boat is on her ear in a short cross sea - and I do enjoy sailing her on her ear, being of the very firm opinion that any old boat that cannot be sailed that way needs a rebuild. Our local waters can be relied on to produce the short cross sea!

Actually, that photo was taken in Suffolk, in the East of England - it's an anchorage in the river Deben, though it does indeed look as if it ought to be Devon.

We have a very good firm, skilled in deadeyes as well as Dyneema, in Maldon (no names, this is Spartalk!) and I'll be going to them.

I know I need to save weight - the weight of the dressed mast on the yard crane is 400 lbs!

[Joe Henderson]

Dear Andrew,

The East Coast was my next guess. I should have known really, looking at the colour of the water. I was standing on the banks of your river only last April drinking a pint with my mate. He has a rigging loft on the Deben and is the chap I was going to recommend but thought it may have been a bit far for him to travel all the way to the wilds of Devon,

If the firm you mention in Maldon starts with a capital 'TS' then you will be well served by them. (no pun intended)

We have been using CNC machined alloy deadeyes from two makers in the States and cast 316 heart shaped thinbles from, probably, China, but they all look very clumsy for the job and are like something that you would obtain from a commercial fishing shop and not at all yachty.

I don't know if you can still get Tuphnol in sheet, bar and tube form, but I reckon that if you had conventional deadeyes machined from decent sized round bar they would be perfect with minimal maintenance, and look right as well. I suggest round bar because the last time I looked the fabric was wound round like a roll of wallpaper to form the bar and so will stand the type of diametric forces better than a deadeye cut from sheet. I know that sheaves are made from sheet but those that are required to withstand high loads have to be riveted axially to keep the layers of linen together. I have seen several split.

But then again, the wrapping and containing effect of the lanyards may support the laminations in sheet components. maybe talk to the makers about the properties you need.

Do let us know how it all goes, your boat looks like an ideal candidate for - as some would have it - this type of retrograde step in the history of tension members !

Regards,
Joe Henderson.

[Bob Pingel]

Joe-

I am interested in the deadeyes you have been using. I am familiar with the ones from Precourt in Canada, and some recently developed ones from Colligo Marine. Are there others?

I agree that these don't have a salty appearance to them, but they are nicely finished in a high-tech sorta way...

Thanks,

Bob Pingel

[Joe Henderson]

Dear Bob,

In light of your post I have re-read my last one on this thread and realise that the paragraph about the deadeyes and thimbles can be mis-interpreted.

To clear up:-
The two makers we have used are Precourt and Colligo. (My apologies to Precourt, They are of course in Canada, whoops !) They are both quality products.

The cast thinbles I mention are the ones that look a bit clunky. Luckily we have a good s.s. manufacturer in Sydney and we are in the midst of sorting out some heavy stainless thinbles basd on the old British Standard specifications, crescent section steel etc.

Regards,
Joe Henderson.