Over the last few days I installed the “auto trapeze system.” This system automatically switches the attachment point for the trapeze line from just above the shroud-to-mast attachment point (for upwind work), to just just above the spinnaker halyard exit block (for wire reaching). This eliminates various manual trapeze adjusters (dual trapezes, earwigs) and makes for another thing I don’t need to think about when racing.
I used a kit sold by Ryan Nelson of Rogue Rigging (roguerigging.com). His kit comes complete with all the fittings and fasteners you need, as well as all lines precut and prespliced. You reuse your old trap lines. Ryan includes a full set of instructions.
The first step is to attach an eyestrap above the spinnaker exit block with 3/16″ SST pop rivets supplied in the kit. Hint: Use a #11 drill bit (NOT 3/16″) to drill the holes. The number 11 is slightly larger than 3/16″ and makes the right size clearance holes for 3/16″ rivets (as well as #10 machine screws).
The line spliced into the eyestrap is about 12″ long and is spliced onto a low friction ferrule thru which the spinnaker halyard passes. Between the eyestrap and the ferrule, is another ferrule to which two trapeze support lines are spliced. This makes a 2:1 purchase that shifts the trapeze attachment point, depending on whether the spinnaker is up or down.
Next attach two tangs for the lower attachment line, just above where the shrouds attach to the mast. The tangs are thru-bolted with a #10 machine screw and nylock nut, supplied in the kit. Again, a #11 drill bit provides the right clearance hole. Cut off the excess bolt with your tool of choice (I used a Dremel tool) and file or sand smooth.
Next tie or splice your trapeze lines to the “dog bones” attached to the upper and lower support lines (one continuous line actually, looped around the dog bone for adjustment purposes). In the photo below the line leading to the left is the trapeze line; the lines leading to the right are two sections of the support line; one part leading to the lower support point (shrouds – upwind) and the other part to the 2:1 ferrule adjuster (spin halyard exit block – wire reaching). I spent a fair amount of time finding the right spot for the dog bone. Its kind of an interesting/complicated exercise in geometry. A good starting point is to have more or lees equal tension on the two legs of the adjustment line, when the spinnaker halyard is down and the trapeze line is parallel to the mast. Once the correct position for the adjuster lines is established, the legs are stitched together to prevent them from “walking” on the dog bone.
Here is the adjuster with the spinnaker halyard down. The trapeze line load is taken by the lower support line (attached at shrouds); the upper support line is slack.
Here is the adjuster with the spinnaker halyard up. The trapeze is raised about 6″ and the load is taken by the upper support line (spin halyard exit block). The lower support line is slack.
This is a pretty cool system. Wish I’d invented it. Thanks to Ryan for making a great kit, and to Howie Hamlin for walking me through the setup, and to Doug Dommermouth for helping me get the mast down so I could do the install.