Furling heavy weather jib on a lock
- Thread starter JL92S
- Start date
RImike
Super Anarchist
I'm not sure what type of solution you are trying to come up with, are you looking for an alternative to a Karver halyard lock or is there some wrong with it?
You will need the purchase under the furler of a 3:1 as the "system" all has to carry the working load, whatever that is and that means that generally the holding ability of the tack line is the weak point. By using a purchases the clutch/jammer holding power is doubled/tripled. Usually for a stay sail, a 3:1 is needed as that will generally get you up to the holding power of the system. It's not so much about using the winch or tension, but rather the winch to hold the tension, especially when it's nuking out and your taking water over the bow and boom, everything loads up.
On bigger boats, hydraulic rams are used to tension and hold the stay load but on smaller boats that needs to be done with mechanic purchase of the tack line.
You will need the purchase under the furler of a 3:1 as the "system" all has to carry the working load, whatever that is and that means that generally the holding ability of the tack line is the weak point. By using a purchases the clutch/jammer holding power is doubled/tripled. Usually for a stay sail, a 3:1 is needed as that will generally get you up to the holding power of the system. It's not so much about using the winch or tension, but rather the winch to hold the tension, especially when it's nuking out and your taking water over the bow and boom, everything loads up.
On bigger boats, hydraulic rams are used to tension and hold the stay load but on smaller boats that needs to be done with mechanic purchase of the tack line.
- Thread starter
- #4
Current thoughts are of using a KF5 furler with suitable Karver hanging lock, a 3:1 purchase on the deck with the tail running through a Spinlock hammer and to a deck mounted halyard winch. Wondering if anyone had experience of either the hanging lock, the installation of a 3:1 purchase with jammer or the whole setup. Alternatives are to use a 2:1 halyard and just fix the tack to the deck but looking to hear of others experiences
RImike
Super Anarchist
What size boat? Generally this setup would be for a 40' boat or so as the head stay would be either -17 or -22 rod which equated to a 5T furler storm jib set aft of the head stay in more if a IFS position. A 2:1 halyard would result in more stay sag then you think, it would most certainly need to stay on the winch while sailing to maintain stay deflection. Most if not all boats go the lock route.
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I designed and started to install a similar system on our 50' cruiser. External 6mm Dyneema halyard to an external hanging lock, Facnor FX4500 furler, 3:1 tack line to a Karver KJ jammer. Life changed while we were waiting for parts from Selden over the winter and we sold before I finished the system. So no practical experience with it on my boat, but I'd tried all the pieces on anothed boat and they worked well. I especially liked the KJ Jammer. Didn't slip like a typical clutch and no need to run a loaded line (tripping hazard) back to the winch.
- Thread starter
- #8
I don't, didn't finish it.
But I'd installed a Ubi Maior padeye socket and the structure to support it. Then the plan was to have two rings lashed to the padeye that was simply screwed into the socket when it was needed. That way the 2 rings, tack line and the 3:1 sheeve were all setup, ready to go and was simply threaded into the padeye socket, then furler attached. We wanted a fast to setup, waterproof, flush system. It was the only padeye I found that could do that for me. I could also move it between a future solent stay position and a staysail position.
https://www.ubimaioritalia.com/index.php?p=catalog&idl=5&f_type=padeye
It was thd HPBt - b and HPBt-m
Rigging plan was essentially the same as the below photo (stolen from the internet) but w/ a stripped line
But I'd installed a Ubi Maior padeye socket and the structure to support it. Then the plan was to have two rings lashed to the padeye that was simply screwed into the socket when it was needed. That way the 2 rings, tack line and the 3:1 sheeve were all setup, ready to go and was simply threaded into the padeye socket, then furler attached. We wanted a fast to setup, waterproof, flush system. It was the only padeye I found that could do that for me. I could also move it between a future solent stay position and a staysail position.
https://www.ubimaioritalia.com/index.php?p=catalog&idl=5&f_type=padeye
It was thd HPBt - b and HPBt-m
Rigging plan was essentially the same as the below photo (stolen from the internet) but w/ a stripped line
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jackolantern
Super Anarchist
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This is what Jboats has done with their J4 on the J121. Lock with a 3:1 at the deck level.
Alberta
Member
Here is my removable 3:1. I've gone through a few variations, now using a dogbone instead of the soft shackle to attach to the Ropeye deck fitting as this tack fitting is used for two different tack points so ability to switch quickly is important.
Is there only a single shackle holding both the red and blue Ronstan blocks in place? If so, do you have issues with the blocks binding and the line not running fair? Or am I just blind and there are two shackles in there?
Alberta
Member
No binding, some limited increase in friction but not an issue if tensioning under winch as I never adjusted it while the staysail is unfurled.
I actually rebuilt it recently to reduce stack height and better separate the Shocks, I’ll grab a photo this weekend.
I actually rebuilt it recently to reduce stack height and better separate the Shocks, I’ll grab a photo this weekend.
Alberta
Member
Current setup with the dog bone
Haligonian Winterr
Super Anarchist
If doing 3:1 under the furler, consider adding 3:1 or better on the aft end. It will make the jammer hold better, easier on lines, hands, winches, jammers, and can give much more luff tension.
Remember the furler should be the weakest point of the system. You never want to doubt a storm jib...
HW
Remember the furler should be the weakest point of the system. You never want to doubt a storm jib...
HW
I have two 3:1 setups to Karver Jammers mounted at the furlers on my Express 37.
The A sails off the sprit is not on a halyard lock, and the staysails are on a Karver KFH 2 lock with the same 3:1 to Karver Jammer. Jammers can be released remotely from the cockpit with trip lines. I find it a great setup for Single or double handing.
Nice Picture tDot!
The A sails off the sprit is not on a halyard lock, and the staysails are on a Karver KFH 2 lock with the same 3:1 to Karver Jammer. Jammers can be released remotely from the cockpit with trip lines. I find it a great setup for Single or double handing.
Nice Picture tDot!
Hey. You stole my photo that I stole from the internet!
Great looking boat, it looks like you've done a ton to optimize it. Looks awesome! Have you got a summary of all the work somewhere?
Not my boat, but it's probably because below that there is no access inside to be able to put the backing plate/nuts on.