One possible solution to pumping/dewatering is an installed eductor.
Do you have a link (with specs) to one that is roughly the size for one of our sailboats?
On some of the powerboats I was involved in we set up the main dewatering pump (AC) to also be able to be used as a fire pump.....always surprised not to see it more often
Good thought to add, although firefighting is a whole big topics that deserves its own article, but about which I know very little.
Splices . . . strength
There have been several splice tests (by several of the mfg's) on spectra single braid but none that I am aware of on spectra double braid. It is easy to lower the strength of these splices - by not using a long enough burry, by a sloppy 'lock' in the Brummel, by using to small a bend radius, etc). NER is conducting some tests right now, related to this article, on both the lock stitched and Brummel splices (I think in both single braid and double braid)
"who is your audience"?
more thorough and illustrated explanation of system design and usage, and less on sewing.
Why not just state that they should be built from spectra?
I completely agree about halyards and hoisting, but the notion of cutting away the lifelines potentially puts the rescuer at risk as well. And on boats with SS lifelines it's not happening anyway.
I suggest you break this thread into four threads, .
For Jacklines and Tethers, the initial audience was actually racers (the topics were proposed to me by the US Sailing OSR group). But they seem relevant to cruisers.
What specifically do you want to see in more detail on the design? Since boat deck layouts are so different I find it hard to see how to get more specific.
I am honestly not sure about pure spectra jacklines, for shock loading issues. They are allowed by the OSR's. What do others think about the need for some amount of elasticity in the jacklines?
The sewing perhaps should be a 'sidebar', but its there because #1 a lot of the sewing I have seen is clearly inadequate, and #2 a couple people have said that its impossible to sew spectra cord strongly, which is wrong, the way I have described is only one way, but is how North does it.
Even on SS lifelines, I like lashing terminations at least on the aft end. Agree there is a bit of a 'safety trade-off' when cutting them, but cutting them will reduce by almost 50% the distance and time required to get the MOB back on board, which has been a real struggle in most of the incidents I know the details of. I would be curious to hear other opinions on this dropping the life lines vs not?
I did not want to start 4 threads, and I am fine plowing thru combined ideas, but if someone else wants to break one or more topic out into separate thread(s) that's fine.