A Sprit

The current "workshop"

... for the new asymmetric spinnaker turns out to not be Rocket Science. I had a bit of thick-walled aluminum tube about 6' 6" long lying around (I'll check the dimensions later). I rigged it up on the boat temporarily to see how it worked with the asymmetric with no real surprises. The interesting thing was that most of the loads appear to "push" directly back along the pole to the mounting point on the front beam, whereas I had intuitively thought that it would be "pulling" away from the end mount as the sail flies out away from the boat - just goes to show that there is nothing like a practical test.

I made up some simple brackets out of angle aluminum stock, and bolted them to the underside of the front beam. The sprit is located with a bolt through the tube and brackets.

The sprit is stabilized by 1/8 dyneema lines from the bridle mounts. I had been worried about how to keep the lines tight, but in practice the sail pulls the sprit up until they are tight, so its OK if they are loose when not in use.

It all looks a little under-engineered, but in practice has been working well and seems robust. I have flown both the symmetric and asymmetric spinnakers off the sprit in 20 knots of wind with no issues (more on that later), and was even hit on the sprit by a boat that didn't seem to know the starboard tack right-of-way rule with zero damage (he did take out the port stem/handle though, which is still awaiting repair).