Home-made chain stopper

[Barnacle Bill]

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I've just managed to make a chain-stopper which fits unto my bow roller. Image 1: chain being pulled in, with chain-stopper rattling on top of the chain, image 2: chain-stopper down and holding the weight.

The idea is, I'm still strong enough to pull up the anchor by hand, and you can recover most of the chain with no effort anyway. But when you're lifting the anchor plus maybe 10 metres of chain it's nice to be able to pull two-handed, leaning back with your weight, then pause and have some ratchet device 'take the strain', to allow you to change your grip on the chain.

I think this may work, though I haven't tried it in a real situation yet.

The two pieces of scrap stainless steel were free, and I paid a guy 5 euro to weld them together.

 

[rogerthebodger]

I made the same type of chain stopper and it works well. Useful when you have a combined chain and rope warp when changing from the rope drum to the chain gypsy on the windass.

 

[Bajansailor]

BB, it might be worthwhile withdrawing for inspection those two rust stained fastenings on the port side of your roller assembly?

 

[Poignard]

BB, it might be worthwhile withdrawing for inspection those two rust stained fastenings on the port side of your roller assembly?

It could be a bit awkward suddenly finding one's anchor is connected to the masthead via the forestay

 

[Neeves]

Your chain stopper relies on the integrity of the bow roller assembly. In the worst case scenario any tension is on the bow roller. The bow roller holds the forestay and presumably was designed like that (to take the forestay tension). Was it designed to take the possible tension imposed by the anchor?

If you have a Samson post or a couple of bow cleats it might be worth considering a short strop attached to 'another' strong point, Samson post, cleats with a simple claw or chain hook that you can use if rode tension is high. The claw can be easily released, knife, I'm not sure how you quickly release a chain stopper without introducing some slack - you need to pull the rode forward of the chain stopper (not so easy if you are waiting for hip or knee replacements ).

A common time to have high rode tension is on retrieval when your 'new gen' anchor has set deeply, the chain is vertical and you are waiting for the seabed to release the fluke - a MoBo goes past at the wrong time, throwing up a big wash, and suddenly you have a snatch load of many hundreds kgs (one of the disadvantages of modern anchors ) - I've measured it.

Otherwise a great idea.

Jonathan

 

[Poignard]

Reading the first post again I see that BB is only suggesting using the stopper to temporarily hold the chain when hauling it in and that's fine. Eric Hiscock recommends this in his "Cruising Under Sail".

When lying to the anchor the load should of course be taken by a sampson post, or bitts; with a nylon spring.

 

[GHA]

Nice.

Made one similar but welded to steel deck further back, yet to test in anger but testing it made a huge difference pulling up the chain by hand. Been there before with a bust windlass..

And as poignard mentioned, yours changes and increases the force direction on the roller so good idea to be a bit aware when using it.

 

[Neeves]

Having measured snatch loads on a rode the largest loads are likely to occur on retreival when the rode is almost, or is, vertical and the anchor is so well embedded patience is needed for it to release. This action might be conducted in chop, from wind, or as mentioned the wash of a passing Mono. There will be no snubber, there will be no catenary - just a tight chain - suddenly further tensioned when chop lifts the bow.

in this situation a short strop with a claw (as they are easy to drop onto a link) or a hook will take the tension of the bow roller and chain lock (unless it protrudes excessively) and onto a dedicated strong point.

Those with good memories will recall this was, possibly, the mechanism described of the first 'bendy shank' saga in the lagoon at Venice when an anchor shank bent, according to the owner, on retrieval.

Jonathan

 

[rogerthebodger]

This is my chain locks hinged on a mooring post welded to my bow fitting.

The blue cover is my windlass and the line next to it is my chain hook line the attaches to a heavy just bollard bolted through the main deck steel framework.


This below shows the bow fitting and mooring/towing bollard during fitting out. Windlass not fitted yet

 

[Barnacle Bill]

... BB is only suggesting using the stopper to temporarily hold the chain when hauling it in and that's fine. Eric Hiscock recommends this in his "Cruising Under Sail".

Yes exactly, I use my cleats at the bows to take the load when anchored. Chain stopper will be removed.

And yes - when breaking the anchor out of the mud, just secure the shortened chain to the cleat and wait (pulling on it just cushions the movement of the boat).

 

[BabaYaga]

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I've just managed to make a chain-stopper which fits unto my bow roller. Image 1: chain being pulled in, with chain-stopper rattling on top of the chain, image 2: chain-stopper down and holding the weight.

The idea is, I'm still strong enough to pull up the anchor by hand, and you can recover most of the chain with no effort anyway. But when you're lifting the anchor plus maybe 10 metres of chain it's nice to be able to pull two-handed, leaning back with your weight, then pause and have some ratchet device 'take the strain', to allow you to change your grip on the chain.

I think this may work, though I haven't tried it in a real situation yet.

The two pieces of scrap stainless steel were free, and I paid a guy 5 euro to weld them together.

I found your project very inspiring, I am thinking about arranging something along the same lines for my own anchor roller.
Apart from the final lifting of chain and anchor, I think it could also quite useful when hauling in chain in windy conditions (or put differently, hauling the boat up to where the anchor is). In those situations, the boat will often be 'tacking' a bit and at the end of each 'leg' the strain increases significantly. That would be a right moment to park the chain in the stopper and catch you breath.
Two questions:
1) The angle between the chain line and the stopper appears to be rather shallow. Are you confident it will be able to 'cut in' between the horisontal links to get a grip?
2) It seems as if the stopper, when gripping the chain, is resting on and applying force to the roller flanges (presumably nylon or delrin). No risk of them getting deformed?

 

[Barnacle Bill]

1) The angle between the chain line and the stopper appears to be rather shallow. Are you confident it will be able to 'cut in' between the horisontal links to get a grip?

When I'm pulling the chain in, it's angled upwards to where I'm standing (first picture shows this roughly). The when you stop and let the chain back an inch, the stopper seems to catch quite readily. Mind you, I'm doing this by hand and watching it - so I can easily lift the chain a bit to get a better angle. Once a link is caught it is pretty secure. I'll get a better idea of this when I'm using for real.

I forgot to add that the ends of the chain stopper are curved down slightly, in the manner of a claw, to help it to slip further onto the chain and catch a link. This is visible (just) in the pictures.

2) It seems as if the stopper, when gripping the chain, is resting on and applying force to the roller flanges (presumably nylon or delrin). No risk of them getting deformed?

My rollers are flanked by vertical stainless steel plates, and the chain stopper is hinged on a fairly robust steel pin that runs through all three plates. It will be pushed down onto the roller, but not much compared to what the roller is used to. So there's no obvious weakness as long as the load isn't too great. The stopper itself is fairly thin, maybe too thin, but the load on it is 'upwards' towards the hinge, i.e. not at right-angles to the steel plate, so I'm hoping it won't bend. But again, I'll learn more about that when I start using it.

 

[BabaYaga]

Thanks for your replies!

 

[Neeves]

B Bill, The design indicated in the image and the way you use it seems, with no disrespect intended, to be very simple and fool proof (simplicity being ideal ). It does not look much different to Roger's - great minds think alike. You obviously have no intent on overly loading it. In the pictures your chain seems very high off the deck, I assume that's because you hand retrieve? Thanks for sharing.

Jonathan

 

[Barnacle Bill]

I assume that's because you hand retrieve?

Yes - pulling the chain up at an angle, standing back a bit from the bows.

 

[Neeves]

There is something satisfying standing on the bow power washing the mud off a chain as it is retrieved using a foot switch for the windlass

I admire your love of hand retrieval. anything that saves on gym fees (like washing you own car or cutting the grass) I can admire but you need too many hands to hand retrieve and wash down simultaneously. I have thought of having a brush integrated with a hose nozzle fitted to our bow roller to make cleaning more efficient - but not got round to putting ideas into practice. We have muds that at first glance could be tractor sump oil (and smell surprisingly similar).

Jonathan

 

[BabaYaga]

In the design process for a chain stopper integrated into my anchor roller fitting, I have now reached the mock-up stage. Today's testing went surprisingly well, in that the stopper willingly caught and released the chain without the need for any modifications.
In the finished item, the 6mm plywood of the mock-up will be replaced by a piece of stainless steel plate of similar thickness. The hinge links will be welded to the plate edges and beefed up a bit (only 2mm here).
Is there something I would need to consider before putting the welder to work? Any comments are most welcome.

 

[Neeves]

In the design process for a chain stopper integrated into my anchor roller fitting, I have now reached the mock-up stage. Today's testing went surprisingly well, in that the stopper willingly caught and released the chain without the need for any modifications.
In the finished item, the 6mm plywood of the mock-up will be replaced by a piece of stainless steel plate of similar thickness. The hinge links will be welded to the plate edges and beefed up a bit (only 2mm here).
Is there something I would need to consider before putting the welder to work? Any comments are most welcome.

Your bow roller is a hefty bit of kit, really good, I'm envious. . The chain stopper is made, to be made, from much thinner plate. In the extreme you might rely on your chain stopper to hold the yacht under arduous conditions. Bending the chain stopper is not going to damage the integrity of the existing bow roller - but I wonder, as you are going to some trouble with the design, why not make the chain stopper from steel plate similar in thickness to the bow roller itself. The greatest loads will occur when you retrieve think many hundreds of kgs, the anchor is still engaged (and holding well) you might need to lock of the chain mid retreival and then you will be at short scope, you will have no snubber attached and no catenary. My example is really worst case scenario and I hope never happens - but is there any reason not to beef up the chain stopper bracket? (I appreciate you have made half the bracket already with the flange, bent end plates - but you did ask ). I might also widen the entry, just the entry, to the slot in the plate that actually forms the chain lock - to make it easier to engage the link. I might also attach some sort of handle to allow you to lift and disengage the chain lock. I'm not sure but I might not fancy putting my fingers in there to lift it.

Jonathan

 

[penfold]

In the design process for a chain stopper integrated into my anchor roller fitting, I have now reached the mock-up stage. Today's testing went surprisingly well, in that the stopper willingly caught and released the chain without the need for any modifications.
In the finished item, the 6mm plywood of the mock-up will be replaced by a piece of stainless steel plate of similar thickness. The hinge links will be welded to the plate edges and beefed up a bit (only 2mm here).
Is there something I would need to consider before putting the welder to work? Any comments are most welcome.

What do the rubber doorstops(if that is what they are) do?

 

[BabaYaga]

Thank you for the feedback.

The risk of the 6mm stopper plate bending under heavy load is certainly a concern. I am however a bit reluctant to increase the general thickness of the plate, as I fear that might impair the stopper's ability to grip and release the chain. (The gap between two horisontal links is limited and the geometry changes quickly as the stopper plate lifts).
If beefing up the plate to resist bending is necessary, I suppose the best way would be to ask the welder to put a reinforcing piece of steel (like a ridge) across the upper part.
The welded on links that connect the plate to the pivot point will, as mentioned, be made thicker, maybe 4mm. (There is not so much force on them, as the load from the locked chain is more or less at right angles to the plate).
Here are some further data for assessment of the loads involved:
The chain is standard 8mm, the unsupported span between the cheeks of the bow fitting is 50mm and the boat has a displacement of 4 tons.

Yes, indeed rubber doorstops. They keep the shank of the anchor central in the fitting when parked and (I believe) reduce some noise.