ECDuck Modifications After The EC - Roller ReefingBy Scott Widmier #104 "Half and Half" (2es 1eo 7ea 2ad 23ar)
I had a very successful test-sail of ECduck with a new roller standing lug rig. Let me first go into rig details, then describe the test sail, and finally conclude with future plans.
For the mast, I used the very first mast I ever made which happened to be perfect length at 12'8". For the boom, I bent some new 1" EMT so it would fit the existing mast step, slipped a PVC pipe over it, and made a roller drum to fit the forward end of this pipe. The sail is skinnier than lug sails I have made in the past and taller than I wanted but that was the only way to get the 82 square feet I wanted and stay within the physical constraints. The first of these was not wanting to big an angle on the mainsheet by having an overly long boom. Naturally, I can't attach the mainsheet where the PVC pipe is so have to attach it to the end of the boom. Too big of an angle and you don't have good control over the boom so this limited me to 7'6" foot.
The 7'6" head of the sail does have a peak on it, in other words, it is not parallel with the boom like John Wrights roller lug. I wanted this for the mechanical advantage it provides in helping to stretch the luff of the sail for better windward work. This means that when the sail is all rolled up I will still have a small lateen shaped sail. Will have to use a sailtie on the last bit when lowering the sail. The luff of the sail is 11 foot long. I made the sail out of white polytarp I had in the shop using the factory seam for luff and boom and white duck tape on the other sides with grommets for the head. Should last two seasons at least.
I tested this rig out on Lake Allatoona this past Saturday with the wind not exactly stable but with gusts up to 15+mph. First I noticed a gratifying turn of speed off the wind. Second, the lower aspect rig seemed to eliminate most of the bow plow I had experienced in gusts. More testing is needed before this is conclusive. The upwind performance was hard to gauge thanks to the unstable wind but the roller setup on the sail really allowed me to tension the luff well which is generally the cause of poor upwind performance of lugs. Overall, I was very pleased and will continue to work on it.
What didn't work so well was the deck stepped boom which initially had nothing holding it down against the upward pull of the roller sail. I added a downhaul but this put a kink in the bend of the boom. The roller drum and deck-mounted pulley for the line didn't line up properly resulting in the line getting fouled if I didn't almost hand feed it in. The boom was also a bit low for my taste though, given the ability to roll up a bit of sail, this wasn't a huge problem.
I am in the process of modifying this rig and am almost ready to test. I cut the bend off the boom and mounted it to the mast using a sliding gooseneck I had on another boat. This way I can use the full sail in light winds and roll it up raising the sail a bit for comfort in more wind. I limited vertical swing on the gooseneck so it won't traverse far enough to knock the reefing drum on the mast. The roller drum is closer (3") to the mast which will help keep the boom level and made it easy to mount a pulley on the mast for the furling line.
I am so enamored with this sail design that I may try it out on my self-designed 12' speedster Knot Yacht. That boat had a truly heroic 18' stayed mast with Flying Junior main and jib. It was a bit much to rig though the boat's speed was gratifying. The main and jib went to our Sea Scouts to equip a Flying Junior they were given (much rather have the sail get kids into sailing than to experiment with it) so Knot Yacht lacks a sail and I lack enthusiasm with the stayed marconi rig. What I am going to do is use the roller standing lug rig described above in combination with a jib sail to equip Knot Yacht. The sail area for the Flying Junior rig is 100 square feet so, add a 20 square foot jib, and I am at parity!