Boat is a performance cruiser, 40' LOA, P=47'5", E=17'0", laminate main with four full battens, one season old, always carefully flaked.
PO installed a Harken Lazy Jack kit. Two-part cascade, with three legs on each side. I think it's a PITA, but Mrs. T-M vigorously disagrees. Ok, it's kinda nice to have when short-handed, especially in a blow. OTOH, battens hang up in it when we're hoisting, battens sometimes hang up in it off the wind, interferes with proper flaking, the zippers in the sail cover are a PITA, it's a PITA to adjust, weight aloft, windage, chafing and the bitter end is too short to bring all the parts forward. Plus the lines need replacing anyway. I'd like to downsize the line from 1/4", plus be able to easily bring the entire mess forward along the boom and mast. We'd pull it into position just before dousing and re-stow it before putting on the sail cover.
Here's what I'm thinking, and want to bounce off folks here:
I'm leaning toward HMPE single-braid. New England Ropes STS, because somebody I know can give me a break on NER. I figure that a Brummel splice is going to be easier than double braid eye splice with the skinnier line. Plus less weight aloft and windage. Does that make sense?
The top of the old one is a pair of 6' wire pendants, each fixed to the mast, with a small bullet block on the end. I'm thinking about replacing the wire with 5 mm = 5/16" (right?) STS. The plan is a pair of 29mm air blocks shackled to the existing eye strap on the mast, leading down to a clam cleat (?) just above the gooseneck. The pad eye on the mast is 35' above the gooseneck, so I figure 35' + 6' + some extra = 42' (right?).
The other two parts are currently 1/4" double braid. The upper pair each has a bullet block spliced to one end, and an eye splice terminating in an eye strap on its respective side of the boom. It passes through the block at the end of the pendant, and the block end supports the lower part. The lower parts are made from a single line. It has an eye splice dead ended with eye strap on the middle port side of the boom It passes up and through the block on the end of the port upper part, then back down to an eye strap fairlead under the boom, back up the starboard side to the upper part, then down to a cheek block and cleat. I think I can go to 3mm = 1/8" STS for those two parts. I'm dithering as to whether to make the lower part in two separate pieces, each dead ended to the boom, or to keep it in one piece for adjustability. I also am a tiny bit concerned about the stamped eye straps chafing at the splices (is it really a problem? what to do about it?).
Yeah, I know, TL;DR. If it's too unclear, I'll try to do a drawing.
To summarize, the questions are:
Is single braid HMPE the right stuff? Are 3 mm and 5 mm, respectively, going to be the right size, or should I move up? Are clam cleats the right thing to use in this application? Do I still need to adjust the lowest part, since I can adjust the top?