Club Topsail Club

Several bloggers have asked (off-line) for more structure to our posting of pictures, which also coincides with our project documentation requirement. So, I thought I would organize the discussion by spar. We can offer our observations about the engineering of the RELIANCE from the novice standpoint, but I’ll leave the real insight to engineer bloggers amongst our group.

There were three sizes of club topsail sails in addition to a gaff topsail. To support the sail there were three club topsail yards (68’, 58’ and 48’ long) and at three club topsail clubs (57’6”, 50’ and 41’6” long). We started with fabrication of the club on our spar bench.

This bench has two sides: one for layout of the pieces and one for glue-up and varnishing. The bench is long enough to layout our longest spar – the boom (112’ long). On the glue-up side we added and shimmed a perfectly flat board so that we can space out temporary “keel-blocks” on station marks to get the correct taper for each spar.

We are attempting to fabricate prototypically correct spars with the same types of wood, scale dimensions for length, width, and depth, hollow where appropriate, the same number of internal bulkheads, and etc.

#1 Club Topsail Club:

This is a hollow spar, tapered at both ends and rectangular in cross section as shown in the sketch below.  Hollow spars offer strength and flexibility at minimum weight; attributes important to Capt. Nat and ourselves.

–          The scale spars lengths and centerlines were laid out on our layout table, stations marked along the length at perpendicular angles and distances measured off the stations (stations being points where the widths are measured in the drawings) on each side of the centerline to get the proper widths. Long battens were then used to fair the curves for the tapers. When satisfied with these drawings, the measures were transferred to our 4 rough-cut pieces (cut slightly longer and wider than required, but to correct thickness).

–          We were then able cut out and shape perfectly book-matched sides and top/ bottoms.

–          Since the sides were the “outside” dimensions, a side was laid on the keel-blocks. The walls are so thin, it fell into shape on the blocks and no clamping was required.

–          Rectangular blocks were temporarily glued to the sides to create 90 degree angles for gluing the top to the side. The top was then clamped in place.

–          While drying, bulkheads were glued in place at designated bulkhead points , which in many places differ from the stations

–          After the glue for bulkheads and top had dried the temporary blocks were removed and the bottom glued in-place

–          Liner and scotchmen were glued and fastened in position, and then the last side was glued in-place.

–          Final sanding was accomplished with a long-board to remove any imperfections, and then the spar was sealed with shellac and multiple coats of varnish.

When adding the liners and scotchmen we noted that the “as-raced” configuration differed from “as-designed.” Photos of RELIANCE during the America’s Cup races show a third liner and presumably a scotchman. This is further confirmed in the sail plan drawings. Since we are trying to build our RELIANCE in the “as-raced” configuration we elected to add the third position.

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