I have become aware that a very experienced offshore sailor believes that yacht lifelines should include a "breaking fuse" so that these break under load and nothing more problematic breaks. For example stanchion ripping out or a persons limb gets broken due to an inadvertent entanglement.
I will use Econ 3.2mm 1x19 316 ss wire (breaking load around 856kg) for upper and intermediate lifelines on 25ft ~2 tonne yacht. 25.4mm 1.6mm wall 316 stainless tubes for the stanchions and pulpit / pushpit. I should have got 22mm.
I have done a quick web search to no result - does anyone have a web link giving more information on this concept, and also what the "breaking fuse" breaking load should ideally be for this wire and yacht size. A nylon lacing like here would be my guess - the breaking load is stated to be around 70-100kg. Seems like this information should be included in the Racing Rules of Sailing when they are next updated. I used to use 2-3mm nylon lacing and did about 6-8 overlaps of it - there must be something more definitive published somewhere?
Thanks in advance.
www.rockhardware.com.au/blue-water-static-nylon-cord-2.75mm.-black-or-colo
Select to expand quoter13 said..
Seems like this information should be included in the Racing Rules of Sailing when they are next updated.
Pretty sure the racing rules of sailing say the lifelines should at minimum be the same breaking strain through their length, including lashings.
Select to expand quotelydia said..
If you sail solo, can you leave me something in your will!
Good be upon you - I knew you would respond straight off the mark. I am well beyond sailing solo but it matters nought - I don't want to have any or another drama in any sailing trip............
Of course I should have included in the original text that I am using these Carabiners at the ends of all lifelines
www.bunnings.com.au/taskmaster-5-x-50mm-316-stainless-steel-snap-hook-2-pack_p0237922?srsltid=AfmBOorNB83F8wWmkN37jUEeSx1xqEA01BW9cMMzWPhbxyGiAVEag8Nz
With no load ratings listed on the packaging I rang Taskmaster and they advised that this Carabiner size working load limit is 100kg, breaking load limit is 200kg. These are a surprisingly low value imho - and a factor of only 2 from wll to bl is also very surprisingly low - but close to that quoted here so must be valid.
www.miamistainless.com.au/5mm-S2450-05?srsltid=AfmBOopxMPSQJ1Yj0_hubSWNTJjCqTKRhrOzLrxs6oNxNtAmkBX-uy4V
Here the wll is 1/4 the bl which is more expected.
eastmarineasia.com/products/ema-stainless-steel-316-carabiner-hook-spring-hook-without-eyelet?srsltid=AfmBOor7c8O_9RcZxFanTN_GPssqxpcCw5o8Dkibx5u7zuAMF7enarpm
Select to expand quoteJethrow said..r13 said..
Seems like this information should be included in the Racing Rules of Sailing when they are next updated.
Pretty sure the racing rules of sailing say the lifelines should at minimum be the same breaking strain through their length, including lashings.
Ok thanks I will go through them again
Yep...
3.12.6(e)
All wire, fittings, anchorage points, fixtures and lanyards
shall comprise a lifeline enclosure system which has at
all points at least the breaking strength of the required
lifeline wire.
Select to expand quoteJethrow said..
Yep...
3.12.6(e)
All wire, fittings, anchorage points, fixtures and lanyards
shall comprise a lifeline enclosure system which has at
all points at least the breaking strength of the required
lifeline wire.
Many great thanks. I have got back to Taskmaster and the most helpful bloke there advised that their 12mm Carabiner as below has a wl of 510kg and bl of 1020kg. $11.32 not $1.41 like the 5mm. I will search for an alternative but will go that 12mm path if needed.
www.bunnings.com.au/taskmaster-12-x-140mm-316-stainless-steel-snap-hook_p0237927?store=7369&gad_source=1&gclid=EAIaIQobChMIuZD-zq3KjAMVatEWBR2sSh4SEAQYASABEgKDrPD_BwE&gclsrc=aw.ds
r13 I wonder if we're talking at cross purposes here.
I think the suggestion is that it should be possible to release the lifeline tension with a knife in an emergency - which with a lashed section yes you could, this seems sensible, and I have this on my boat. As the regulations say, this should be at least as strong as the lifeline wire.
Your use of the term "breaking fuse" implies that you would want the "fuse" to break under a certain load. This would obviously be bonkers because in almost no circumstance would a swim be preferable to breaking a stanchion out or heaven forbid breaking a bone.
Thanks a lot yes agree regarding using a lashing able to be severed with a knife - I will do that. Lashing strength equivalent to the wire strength.
Select to expand quoter13 said..
Thanks a lot yes agree regarding using a lashing able to be severed with a knife - I will do that. Lashing strength equivalent to the wire strength.
Add a ceramic knife taped to a stanchion on the transom at deck level, it's much easier than trying to get a knife off your belt. Leave a long enough loop, a few inches that you can easily cut with a knife as you're most likely to be one handed/half drowned/being dragged. I was surprised that soft lashings never required redoing to keep everything tight, the normal wire turnbuckles comfortably take up any stretch that creeps in.
The other benefit is when you cut the line, the upper safety line ends up being a wire trapeze line you can stand on. The turnbuckle stops the safety line at the next stanchion, so now you have a nice big loop of wire you can stand on underwater forrard of the next stanchion.
I had the same set up across the transom as I had a post (not a stanchion really as it was removable) in the middle of the transom. The approx 2mtrs (transom) to 2.5mtrs (sidedecks) of slack gets your shoulders well above the deck when getting back on.
Select to expand quoteshaggybaxter said..r13 said..
Thanks a lot yes agree regarding using a lashing able to be severed with a knife - I will do that. Lashing strength equivalent to the wire strength.
Add a ceramic knife taped to a stanchion on the transom at deck level, it's much easier than trying to get a knife off your belt. Leave a long enough loop, a few inches that you can easily cut with a knife as you're most likely to be one handed/half drowned/being dragged. I was surprised that soft lashings never required redoing to keep everything tight, the normal wire turnbuckles comfortably take up any stretch that creeps in.
The other benefit is when you cut the line, the upper safety line ends up being a wire trapeze line you can stand on. The turnbuckle stops the safety line at the next stanchion, so now you have a nice big loop of wire you can stand on underwater forrard of the next stanchion.
I had the same set up across the transom as I had a post (not a stanchion really as it was removable) in the middle of the transom. The approx 2mtrs (transom) to 2.5mtrs (sidedecks) of slack gets your shoulders well above the deck when getting back on.
Thanks yes I will do the lashing like that and get the ceramic knife.
I'm wondering if Bunnings is the best place for safety gear like carabiners and wire. As a climber there's no way I'd trust an $11 item (probably not self locking and that's a low strength carabiner) and cheap wire / swages. The swages will be your weakest point too. Just something to think about.
Thanks. At the moment the plan is to get 6 of these; SWL (WLL) 550kg. I will get the wire from Stainless Central.
www.roadtechmarine.com.au/snap-hook-forged-formed-eye-80mm-long-8mm-dia-eye-swl-550kg/p/MXG310?gad_source=1&gbraid=0AAAAAChdn89qhq8f4WYYQGkuhe3vrlB0D&gclid=EAIaIQobChMI27Hl4ozRjAMVEt0WBR10uTsEEAQYAyABEgJZ3PD_BwE
The lifelines are not a lifting application. There are many good references on carabiners eg
www.ropelab.com.au/carabiner-specifications/
