blocks and tackle

[straipach]

Hi folks im rigging a 32ft gaff cutter,[for the first time] and im having bother finding anything that can help me work out bolck sizes[purchases] how many ?
amount of cordage,that sort of thing. no winches .
if anyone has this knowlage floating around in thir heads i would appreciate the help,
or anyone no any web sight where i might find this info .
dont sugest john leather after reading the other post.
thanks for reading hope you can help

 

[Mirelle]

Some reference texts:

Old books (not too hard to find, though)

Sailing Seamanship and Yacht Design - Uffa Fox (block list for Lexia)

A Manual for Small Yachts - Graham and Tew (block list and rigging list for 10 tonner)

Cruising under Sail - Eric Hiscock - rigging chapters

Yacht Architecture - Dixon Kemp - 11th edn ed. Linton Hope (advanced...)

Modern Books

Hand Reef and Steer - Tom Cunliffe

And, yes, Gaff Rig by John Leather, who is not a bad man, or a bad designer - he just irritated a lot of us!

 

[Peterduck]

Some basic "rules": [a] keep everything as simple as you can; gaff rig is complex enough without making it more so. I initially made the throat halyards on my ketch "Swallow" with too many parts in the purchase. This made it hard to get the gaff down again. I found that single block with becket at the hounds and a single block on the throat was enough. have your blocks big enough so that the rope reeves through them easily. Blocks are usually designated by sheave diameter, and sheaves should be at least 5 rope diameters. Usually, if the rope will go through the swallow of the block easily then the sheave diameter will be OK.
Swallow had a motley assortment of blocks when I bought her, being parish-rigged. [The polypropylene rope turned to dust in my hands.] I acquired some offcuts of jarrah and elm and made most of the blocks which she now wears. They are of the outside-wire-stropped style, which I found surprisingly easy to make.
How big a rope? Well, I used 1/2" diameter for halyards and sheets, mainly to give a good thickness to hold on to. For topping lifts and other less used ropes I used 3/8". For strength, the 3/8" is quite adequate for all purposes.
Peter.

 

[straipach]

Thanks a lot Peter, what size of a boat is swallow ?
what kind of sail area .got any pictues,
1/2inch single purchase on the throat,was that right?
what kind of rope are you using.


dont want much do i. thanks again
Andy
and thanks Mirelle for the refferance book names

 

[Peterduck]

Swallow is a 36ft gaff ketch, about 10 tons displacement. I have pictures, but haven't worked out how to post them here. Yes, a single purchase is enough. Bock systems are like gears; you can put energy through the system one way and it's easy. Try putting it through the other way and it's nigh on impossible! The greater the "gearing effect", the worse it is. I'm using 3 strand laid polyester rope. I was told that I would find it hard on my hands, and that I should use braided rope [this was from the plastic boat racers, you'll understand], but I couldn't see braided rope being appropriate for a 1917 boat. I haven't found it hard on my hands. The Boy Racers may have been of the school that thinks that manual labour is a Spaniard!
Peter.

 

[straipach]

thanks again Peter
like you i have no digital camera and would'nt know what to do with it anyway.
half inch three strand all round, ill have to order a couple of miles
of it then.iv'e orderd acouple of books from that list hopefully they'll
throw some light on the situation
all the best
Andy