Crows nest/cross trees 18th Century Brig

[Rick01]

I'm slowly bashing a cutter into the Australian Brig "Lady Nelson" and am currently working on the masts. Is there a formula (or set of dimensions) that set the size of of these. Side views obviously only give me the length but no clues as to widths.

 

Rick

[allanyed]

Rick

 

I do not know about Australian but they may well have followed British building guidelines at that time.  According to James Lees, for British ships, for the main and fore masts from 1670 to 1773, 15/16 inch per 3 feet in length.  For the main and fore masts from 1773 to 1794, 9/10 inch per 3 feet in length.  After that, 1 inch per 3 feet in length.  For the Mizzen, from 1670 to 1711 15/16" per 3 feet of length, from 1711 to 1719 2/3 inch per 3 feet in length, 1719 depends on rate.  Fifth rates for examples 2/3 inch per 3 feet in length, on 6th rates, 8/13" per 3 feet in length.  1773 - 6/9 " per 3 feet.   Lengths are determined in a more complex way, described in detail on page 183 in Lees Masting and Rigging. He gives formulas for the upper masts as well as spars. 

Allan

[Rick01]

Sorry Allan - badly worded request on my part. :-( I was actually asking about the crows nest/cross trees themselves. Masts are sorted and the brig was built in the UK in 1799 and then sailed to Aus in 1800.

 

Rick

[Jim Lad]

Rick,

 

Lees gives, as a rule of thumb for the topmast - trestletrees 3 3/4" for every 3 feet of mast length - crosstrees 1 2/3 the length of the trestletrees.  For the lower mast, he gives no sizes, but states that both crosstrees and trestletrees came to within an inch or two of the edge of the top.

 

I don't know if the plan on the 'Lady Nelson' web site might help - here is the link: http://www.ladynelson.org.au/ship

 

John

[Rick01]

OK now I understand it better, I read Allan's post before having my morning coffee!!! The Lady Nelson plan also helps and that together with a search of the forum for pictures of these on other brigs of the same period have pretty well solved my problem.

 

Thanks guys

 

Rick