Adjustable inline stopper?

[Skegemog]

Looking for a way to have an adjustable inline stopper on a piece of running rigging (3/8" three-strand rope) that will allow easy loosening and secure tightening.
This is for a control line that passes through a bulkhead and the idea is to be able to loosen the stopper to slide back and forth to adjust and then tighten back down so that when said control line fetches stopper against the bulkhead it jams and prevents further movement in that direction. The forces involved are not huge; it's a steering line not a sheet or halyard but I would like it to be pretty secure. While there is enough slack in the line to allow a small loop to engage with a stopper in some way the line does not have enough slack in it to allow an actual knot to be tied into it nor would I want to; neither end is free. The stopper would need to be something that could be tied around the line like a prusik knot or similar.
I thought of a way to do it with a wood toggle but would prefer using some type of knot if possible as the stopper rides along a varnished surface. Any ideas?

[Gib Etheridge]

I would consider some sort of noose knot. You could leave a noose in the free end or you could tie the noose knot with a separate bit of line.

The poacher's knot can be pulled tight enough that it is difficult but not impossible to slide, and a stopper knot at the end of the line would be a good idea in case it does.

If tied with separate line you won't be able to untie it without pliers but it can be slid off the end when you want to be rid of it.

http://www.animatedknots.com/poachers/#ScrollPoint

[Gib Etheridge]

Also, if you're concerned about the noose knot slipping you could put in a slipped half hitch (or another poacher's knot to double the friction) right behind it once you have it adjusted to where you want.

Would a jamb cleat be a better solution?

[Skegemog]

The line is an endless loop with no access to the ends and is in tension when in use, the stopper needs to be an independent entity although it can make use of a bight to engage the stopper.

[Gib Etheridge]

Then the poacher's knot(s) tied with separate bits of line. Try one, you'll see. They look good too.

Or how about a jamb cleat?

[Woxbox]

I photo would help, but if I understand right, how about a lanyard made off adjacent to the line in question, and you just toss a rolling hitch over the steering line when needed?

[Skegemog]

Don't have a relevant photo handy but it's just a line passing through a hole, here's a sketch:



I would do a wood toggle like this before adding additional lines:


but I find it hard to believe there isn't some salty old rope work solution.

[Breakaway]

How about a thick piece of rubber? You know, like a jar stopper, slit to allow it to be mounted on the line, but with a tight enough center hole that it doesn't slip under, "normal," pressure?

One of these: 1-1/16 od--3/16 center hole.



Kevin

[Skegemog]

How about a thick piece of rubber? You know, like a jar stopper, slit to allow it to be mounted on the line, but with a tight enough center hole that it doesn't slip under, "normal," pressure?

One of these: 1-1/16 od--3/16 center hole.



Kevin

thanks, but I would like a more definite lock/unlock characteristic than rubber would give me.

One thing I failed to mention is that there is the ability within this system of lines to relieve the operating tension (thus allowing the sliding of the toggle illustrated above) with an existing midshipman's hitch elsewhere in the run.

[robm]

Something like a prussik wouldn't really work, as it depends on the load on the sling to keep the knot from sliding. No load, the prussik can slide. That is how they work.

Your toggle is the best idea. Or a clam cleat to drop the rope into. Maybe have the clam cleat on a lever, that raises it up to jam the line. It will allow a small amount of slippage before it jams completely.

What is the load on this line? How much force is required? "Not much, but I want it secure" is a bit vague.

Is it supposed to limit the travel of the line, leaving it free to move unless at the limit? If so, the clam cleat won't fly.

[wizbang 13]

When I had my big boat in the rainy PNW, I had a loop of line that went past the tiller and into the cabin, where I could sit in the companionway and steer. I tried all sorts of jam cleats and toggle things. Eventually the best was a pair of small vice grips that bit both ropes together. I ground down the teeth to not fag out the line

[Woxbox]

The modern yachty solution is a rope clutch, which I presume is more expensive and more complex than what you hope to find.

So how about a slender fit kept handy on a lanyard. You just shove it in the hole to lock the line?

[lupussonic]

A Prussic hitch or Kliemhiest hitch will not move if the load isn't there. Use a smaller diameter line for the Prussic than the control line, typically 60-70% less diameter.

[Skegemog]

Is it supposed to limit the travel of the line, leaving it free to move unless at the limit? If so, the clam cleat won't fly.

Yes, exactly

[Skegemog]

Eventually the best was a pair of small vice grips that bit both ropes together.

I am afraid visegrips would scratch the bejesus out of the varnish just under this line

[Skegemog]

The modern yachty solution is a rope clutch, which I presume is more expensive and more complex than what you hope to find.

So how about a slender fit kept handy on a lanyard. You just shove it in the hole to lock the line?

rope clutch wouldn't work nor a fid, again this is a stop ON the line to limit its travel

[lupussonic]

What sort of load will the stopper see?

[Skegemog]

What sort of load will the stopper see?

the load is pretty low, less than 15 lbs

[Skegemog]

here is a revised drawing hopefully clarifying things

[robm]

Maybe there is another spot in the system where you can install a travel limit? Does this limit the travel of a tiller?

[Skegemog]

Maybe there is another spot in the system where you can install a travel limit? Does this limit the travel of a tiller?

It's an endless loop that goes from one 3:1 tackle between transom and port side of rudder all the way forward to a block at the stem and back aft to another 3:1 tackle between transom and starboard side of rudder. The line is used to steer with, the stop (actually stops) will limit the travel of the rudder to ~90 degrees. Currently the rudder is free to pivot 180 degrees which is problematic when backing down due to leverage exerted on rudder by water flow. The wooden toggle(s) I drew should work fine but I would rather not have a hard toggle knocking around and if there is an all line solution I would like to know what that it is.

[Garret]

Doesn't this last drawing kinda spell it out? Make a 1" diameter cylinder with a hole barely big enough for the line, cut it in half lengthwise, put it on the line & do a whipping around it to hold it tight. Could even cut a couple of grooves to hold the whipping.

[Gib Etheridge]

Just because I happen to be such an obnoxious bugger I'm going to recommend the noose knot again. It seems to me that it fits the bill exactly. If you pull it up nice and tight it will be a very effective stopper that you can still slide with some effort and will not scratch anything. It doesn't need to have more than 1/2" of tail at each end so it's not going to foul anything, and it looks good.

So There!

[robm]

A toggle like a tent adjuster, which is what Skegemog showed in one sketch, is dead simple to build and install. Make it out of rubber so it won't mar anything. A piece of truck mudflap. It won't be pretty, but it would work.

Getting the noose just right for tightness could be harder than it looks. Overload it and it will slip.

[Skegemog]

Doesn't this last drawing kinda spell it out? Make a 1" diameter cylinder with a hole barely big enough for the line, cut it in half lengthwise, put it on the line & do a whipping around it to hold it tight. Could even cut a couple of grooves to hold the whipping.

How do you go from sliding to fixed and back?

[Garret]

How do you go from sliding to fixed and back?

Didn't see that it had to do that. Modify to have screws that can be tightened/loosened?

[Skegemog]

Just because I happen to be such an obnoxious bugger I'm going to recommend the noose knot again. It seems to me that it fits the bill exactly. If you pull it up nice and tight it will be a very effective stopper that you can still slide with some effort and will not scratch anything. It doesn't need to have more than 1/2" of tail at each end so it's not going to foul anything, and it looks good.

So There!

Having a hard time imagining how this would work in practice, relying on just enough constriction to hold it in place while leaving enough slip to adjust it when necessary? sounds like a huge PIA

[Skegemog]

Didn't see that it had to do that. Modify to have screws that can be tightened/loosened?

it needs to be simple with one hand operation, no tools.

[Gib Etheridge]

Having a hard time imagining how this would work in practice, relying on just enough constriction to hold it in place while leaving enough slip to adjust it when necessary? sounds like a huge PIA

That's why I would consider using two. Each could be easy enough to move individually while the two together would be immovable.

[Skegemog]

That's why I would consider using two. Each could be easy enough to move individually while the two together would be immovable.

I see what you are saying, will give it a try

[Gib Etheridge]

Won't work with one hand though?

[Skegemog]

Won't work with one hand though?

Actually I think it would, one knot at a time

[robm]

Two nooses would do it. They would be easier to move one handed than the tent toggle.

[Gib Etheridge]

If you find that you don't like the noose knots robm's suggestion that you put limiters somewhere else is a good one. Snubbers going from the transom to the rudder port and starboard would work very well.

[Garret]

How about something like this? Could be made from wood of course: