The best way to rig a jackstay

[AB1707]

Hi

I have jack stays on my boat that are the correct length. I currently have tied them on at both ends using 8mm line, this has 4 lengths and then round turn and two half hitches, which I check regularly.

My question is twofold

Should I replace a shackle at the bow end?

What knot do others use?

Thank you for your replies

Adam

 

[PuffTheMagicDragon]

Sewn eye round a mooring cleat at the bows, smaller sewn eye with a captive SS triangle at the aft end. This is lashed to a shackle that is on a SS strap on deck near the front end of the cockpit. I use 6 turns of 5mm polyester braid with finishing half-hitches. The thinner line and the smooth metal allow the lashing to be fully tightened. I think that 12 thicknesses of 5mm line is ample for my 73-kilo body, even when shock-loaded.

P.S. I have not fallen overboard so far and therefore I cannot guarantee that my method will work.

P.P.S. There is a 1000 metre drop beyond my lifelines, that's why I am very careful.

 

[Sneaky Pete]

I have jackstays with a stitched loop at each end. Through this loop is a D shackle attached to the toe rail. Ensure the stitching on the loop end of the jackstay is stitched over a length of about 150mm.

 

[PuffTheMagicDragon]

I have jackstays with a stitched loop at each end. Through this loop is a D shackle attached to the toe rail. Ensure the stitching on the loop end of the jackstay is stitched over a length of about 150mm.

...AND in a contrasting colour to make any stitch failure very evident. My while(ish) lines are stitched with doubled black polyester thread.

 

[prv]

Mine have sewn loops cow-hitched onto cleats at the bow, and a kind of buckle arrangement at the aft end, secured with a shackle. They're not particularly tight - they were fitted in a hurry at the start of a trip when I realised we had a rough forecast and the existing inherited jackstays were ancient and sun-bleached, hence the off-the-shelf adjustable buckles rather than being sewn to the correct length. Medium-term I plan to replace them with wires on the cabin top to make it harder to go over the side.

Anyway, getting back to lashings (which are perfectly acceptable IMO), when I sailed on Stavros the rule for anything up in the rig that held people's weight (footropes, cranelines, etc) was "at least four turns, at least four half-hitches, and at least four tucks through the lay of the rope". This was with polyester three-strand, from memory probably about 8mm.

Pete

 

[William_H]

4 turns of an 8mm line will be very strong. Just keep an beye out for damage in the sun. But then the actual jackstays need to checked for sun damage too.
What is more important is to place the jackstays and the harness tether such that the crew can not go over the side. This might mean jackstay down the middle of the foredeck or of using the jack stay on the opposite side to waves etc. good luck olewill

 

[Graham_Wright]

Medium-term I plan to replace them with wires on the cabin top to make it harder to go over the side.

I thought wires were frowned upon because they roll underfoot?

 

[snooks]

I replaced mine with wire, lashed at each end with Dyneema, and the hitches covered in self amalgamating tape. The jackstays sit nice and flush against the corner of the deck/coachroof, only on the foredeck is it possible to step on them. But my feet are big enough and the wire thin enough that if I do stand on them there is enough of my decks shoe in contact with the deck that my foot stays where it is.

I now just leave them on all the time, rather than take them off when not on board. They cost about £65 to get made up.

 

[ghostlymoron]

They do. I wouldn't use them. If you secure the ends with a double overhand knot to a cleat base you don't need made to measure ones. Or a sewn loop/cowhitch at one end. The knot doesn't reduce strength to an unacceptable figure I've read.

I thought wires were frowned upon because they roll underfoot?

 

[michael_w]

I've got double webbing jackstays secured with sewn loops shackled onto different slots in the toerail. The leashes are attached via a large bow shackle. Quick and easy to rig and strike, so when not needed, ie: local fair weather sailing, they live out of the sun below. Also, they are not very tight. The potential loads on the jackstay rise quite dramatically the tighter they are. Ideally I'd lead them down the centreline, but pesky fittings, like the spray hood and mainsheet get in the way.

 

[KellysEye]

Our jackstays had loops at both ends which I tied to the fore and aft cleats using a bowline to tie off .

 

[snooks]

They do. I wouldn't use them. If you secure the ends with a double overhand knot to a cleat base you don't need made to measure ones. Or a sewn loop/cowhitch at one end. The knot doesn't reduce strength to an unacceptable figure I've read.

The knot might not, but UV does degrade webbing to an unacceptable figure, any fading in the colour and you have no idea how much of the strength has gone...That's just in the webbing, unless uv stable thread was used to make the loop that's probably weakend by the UV too. Ours were faded and I wasn't going to take the risk.

I have two thin areas (where the wire is) on the whole of my foredeck where I have to take a little bit of caution if I step there, I haven't had them roll under my feet yet.

 

[johnalison]

It partly depends on the boat. Our old Sadler 29 had wire, which caused a lot of trouble to rafters crossing in the dark, though I never achieved a broken limb.

I currently have webbing with rings sewn to the ends, lashed to fixings on the toerail. More of a problem is finding the right path to allow easy access to the foredeck. I have settled for a line outside the rigging but a friend with a different model has a better line inside the cap shrouds.

 

[Giblets]

I replaced mine with wire, lashed at each end with Dyneema, and the hitches covered in self amalgamating tape. The jackstays sit nice and flush against the corner of the deck/coachroof, only on the foredeck is it possible to step on them. But my feet are big enough and the wire thin enough that if I do stand on them there is enough of my decks shoe in contact with the deck that my foot stays where it is.

I now just leave them on all the time, rather than take them off when not on board. They cost about £65 to get made up.

Out of interest, Graham, did you use plastic covered wire?

 

[estarzinger]

Hi
jack stays . . . . have tied them on at both ends using 8mm line, this has 4 lengths and then round turn and two half hitches.

Should I replace a shackle at the bow end? Your lashings are strong enough. No reason to replace them with shackles unless you want to.

What knot do others use? a bowline or a buntline hitch are most common for terminating a lashing. But your round turn and two half hitch is satisfactory.


Adam

Ensure the stitching on the loop end of the jackstay is stitched over a length of about 150mm.
It turns out to be quite difficult to sew a full strength (to ISAF specification) loop in webbing. The difficulty is that the stitching is not all evenly loaded - it is highly loaded away from the loop where you have a two ply to one ply webbing transition and less loaded near the loop where you have two plys of webbing sharing the load. The net is that the key is to get a lot of stitching strength within the first 50mm, NOT to have a long amount of stitching (which will just progressively peel up as the load is transferred to it). I have done a lot of testing on this, which you can see at http://www.bethandevans.com/load.htm if you are interested.

....

 

[Phoenix of Hamble]

Also, they are not very tight. The potential loads on the jackstay rise quite dramatically the tighter they are.

I was intrigued by this comment... intuitively, it would be snatch loads that bothered me, and hence a tight jackstay would be preferable, as a falling body would have less distance to build up momentum... but I'm basing that on nothing other than gut feel, so was keen to understand where your thinking came from?

 

[estarzinger]

The potential loads on the jackstay rise quite dramatically the tighter they are.

I was intrigued by this comment... intuitively, it would be snatch loads that bothered me, and hence a tight jackstay would be preferable, as a falling body would have less distance to build up momentum... but I'm basing that on nothing other than gut feel, so was keen to understand where your thinking came from?

It is basic engineering/trigonometry. The more acute the angle the higher the leverage (force multiplier). If the load is right in line with the jackline (eg pulling right aft) there is no leverage and the load on the tether and jackline are the same. Whereas if the jackline is very very tight and the tether is pulling at 90 degrees to it the leverage is very high and the load on the jackline is a big multiple of the load on the tether. Remember you use this leverage to warp a boat in . . . you pull at 90 degrees to a tight mooring line and you can a lot of leverage and put a much higher pull force on that mooring line and can pull quite a big vessel in against wind.

 

[snooks]

Out of interest, Graham, did you use plastic covered wire?

Nope, bare wire, like you get for standing rigging. I don't like the idea of it corroding away without me knowing about it

 

[blackbeard]

On my little boat, the jackstays ran along the side deck, such that, if you slipped, you could go over the side and finish up either being towed alongside the boat, or else suspended below deck level but above the water (depending on whether you went under or over the lifelines). Neither position is ideal, as you probably wouldn't be able to regain the deck. It seems that this arrangement is fairly common. (Yes I know you are supposed to use the windward jackstay, but that doesn't guarantee you will stay on deck.)

I have therefore installed a pair of jackstays which run either side of the coachroof, are thus higher up and can be used with a shorter tether, and give a sporting chance that you will still be on deck after your tumble.

As for what they are made of, I care not provided they are not rotten. I'm a bit anti shackle on the grounds that a. they will keep off watch crew awake with their rattling against the deck when in use, and b. if a shackle is about to fail or come unscrewed it's less obvious than a lashing about to come undone and c. shackles are moderately pricey if they are the nice ones that come with an indication of safe working load, and if they don't I don't trust them.

 

[AB1707]

Thank you everyone for all your knowledge and expertise.

Safe sailing

Adam