I prefer to use two halyards, both of them for hauling (no static line). I don't see the advantage of using a static line vs just putting the prussik around the mast, so I use the line the way a halyard is meant to be used. If both halyards are reasonably tight, it also greatly reduces the shock loading on the remaining one if one fails. If one of the halyards is internal, I'm not terribly worried about the other being external (like on the mainmast). But I don't have that option on the mizzenmast, unless I do as Danny did and have a full-length mizzen halyard made up (and drop the sail). Surely, Henri Amel had a solution to this problem? Or was he just comfortable going up on a single, external halyard? I like Paul's idea of a dyneema loop through the shackle... that takes out one failure mode, though still leaves the possibility of the rope failing (or being let go).
On the lone occasion I've had to go up a mast on a single (internal) halyard, I used a prussik-like knot as a fall arrester. It seems to be pretty safe (it can definitely take my weight dropping from the max distance I'd be before moving the knot), but if you actually need to use it, you're now stuck up there... I don't have a good solution for that. I hope the local fire department does (and I'm at the dock)! Or maybe the Coast Guard could send a helicopter? :D
Duane, thank you for the reminder about the figure-8 knot to tie onto the halyard. I shouldn't have used the phrase "clip on".
Does anyone have recommended lengths for the ballooner and utility halyards that differ from what I wrote in my first message? Should I just add a few meters to each?
SM 233 Iteration
Boston, MA, USA