We have completed construction of our topsail yard, save for a few open questions about rigging:
a. How was the splice eye of the eye luff rope kept in place at the top of the yard?
b. How was the foot of the yard attached to the topmast, if at all?
c. How was the double scotchman rigged?
We’ll get to these questions in our rigging phase, but in the meantime more research…
The yard was a 68′ long Oregon pine (Douglass fir) spar, rectangular in cross section except at the very tips where it was cylindrical. At maximum cross-section it is 13 5/8″ x 10″ but this tapers to 4 1/2″ at the ends. Bottom 36′ of the yard lies alongside the topmast, while the top 32′ extends beyond. Three yards (and clubs) were constructed. #1 spars were the longest and #3’s the smallest. These #1, 2 and 3 spars would have decreasingly smaller sails bent to them. In addition, there appears to have been a gaff topsail. From records we have seen that 6 sails were made for each sized sail over the course of the campaign.
Unlike the club topsail club where the sides run the full width, the top and bottom on the yard run the full width and we can only surmise that was purposely done because of different directions of bending moments for each spar. The yard has 3″ thick tops and bottoms and 1 3/8″ thick sides. (The smaller club has 1 1/8″ thick top/ bottom and 7/8″ thick sides.)
Again unlike the club, the yard’s top and bottom are tapered from 3″ thick mid-yard to 2 1/4″ thick at the ends, and are “guttered” 1″ deep the entire length, creating a top and bottom that are in effect “c” channel beams which are strong but lighter. This tapering and guttering (routing) must have taken very significant weight out of this 68′ spar.
For now we have settled on the 24″ double scotchman since the approval date for that drawing is much later than the topsail yard approval date, but the hand written note on the yard drawing for a 14″ single scotchman is curious, and we also know that the topmast/ topsail rig did collapse during cup trials which may have caused changes.
I also just had an exciting telephone conversation with Claas van de Linde who has done wonderful research on all things Herreshoff. Among many interesting tidbits, he told me that HM Co. bought Reliance’s wooden spars from a Boston firm (our local lore has HM Co. building everything!)
We built our yard the way HM Co./ Boston firm would have, as a hollow rectangular spar of Oregon pine. We inserted scale 1 1/8″ thick bulkheads at the appropriate locations, guttered a scale 1″ deep trough in the top and bottom and tapered these pieces from scale 3″ to scale 2 1/4″ at the ends. The result is an amazingly light and strong yard. I enclose pictures showing progress at each step: