Chain Stopper Installation Questions

[mitiempo]

Originally Posted by Charlie

I think you can get it in Sidney at West Marine

West Marine is gone from Sidney and Victoria. They have only one store left in Canada and it is going soon.

I agree with Stumble that Starboard - or Walmart cutting boards - are a bad choice.

The best option is G10 or fiberglass epoxied to the deck.

[Scout 30]

What do the experts think about PVC board?

[mitiempo]

Originally Posted by Scout 30

What do the experts think about PVC board?

Same as Starboard, it's a poor choice.

[UNCIVILIZED]

Guys, this isn’t an attempt to criticize people’s gear, material choices, or ground tackle installation designs. But given that it’s both a boat safety issue, & a human safety issue, I’ll lay out some of the facts on gear, & the elements of good system design. In efforts to up the safety factor, & ease of operation of these critical ground tackle components.

Firstly, for a boat of that size, 41’, as well as windage & weight. Or for any vessel of enough size to be using both windlasses & chain stoppers, you want the largest, strongest, most well thought out gear & systems which you can find/design. Almost regardless of cost.
As one item fails, it’s mountings fail, or it’s operation fails; then both the vessel & lives are now on the line.
Those of everyone onboard, & those both; as well as the folks downwind of you, & whom may attempt to come to your aid.


Also, the gear needs to be dirt simple to be operate; instinctively, simply, on a pitch black night, with numb hands, in the rain, by a half awake crewman who just stumbled out of their bunk. One who’s new to the boat, & her gear, to boot.


So in this application, my leanings are towards a chain stopper which is Much, much bigger. As in, with at least twice the hardware’s footprint size. And which is made out of stouter materials than thin, stamped sheet metal. Like the one by Windline.


Plus, it needs to be able to be released AND simultaneously reset (within seconds), without getting your hands anywhere near the chain while doing so (SIC).
And doing so, Absolutely should not involve the removal of Fast Pins, along with the gates held in place by them, which secure the chain. For then, in order to re-secure the chain, you have to physically pin the chain in place, re-install the gate, & try & slide the Fast Pin into place.

Not a task to attempt, when it involves a moving, bucking piece of chain, on a wildly bucking foredeck… likely in the dark. And when the load upon the piece of chain in question is measured in tons.
At least, that is, if you want to keep all of your digits.
Nor do you want to have to stick your fingers into the unit in order to lift up the locking plate which holds the chain in place.

Rather, what you want, is 2+ chain stoppers in series, between the roller & the windlass. Which are each operated by a 6” (minimum) lanyard. Which, when pulled, pivots the stopper’s gate vertically, on it’s hinge pin. Thus, allowing the chain to then be eased out via the windlass. And then once the chain has been adjusted, you simply release the lanyard, in order to secure things.

So, yes, chain stoppers also need to be designed to hold the full breaking strength of the chain & then some. Ditto on everything used to connect them to the boat, including that section of the boat itself.
And, yes, on the described style of chain stopper, the hinge pin on such can (& likely should) still be a Fast Pin.


Maxwell, Lewmar, ABI (now defunct) & some others used to make them. And with some digging, I’m sure that such units are findable. That, or it’s easy enough to have such made; or OEM ones modified to meet such descriptions/criteria.

And, as stated, you want at least 2 of them on the ground tackle installation, in case you do have to pull out the Fast Pin on one of them. Thus rendering it temporarily inoperable. So that you still have at least one working chain stopper in place. Until the seas calm enough for you to reassemble the one now in pieces.

One other test (key bit of math) which should be done on all components of one’s ground tackle, is to calculate the strength of their fasteners, under a worst case loading scenario. In order to see what kinds of loads the gear can truly hold. Safely. Chain stoppers included, especially.


Regarding the supporting material for such hardware, skipgundlach's installation is pretty much on the right track. And if there’s any question as to the suitability of the material for the task, quite simply, look up it’s technical specifications. Whether via the manufacturer’s website, such as for King Starboard King StarBoard® | King Plastic Corporation
Or more generally, via Online Materials Information Resource - MatWeb for most items & materials used in building/for projects, which are in common use.

And think though the application with an eye towards common sense.
Given the (tiny) footprint size of the chain stopper in question, the point loads on it’s edges, & fasteners are going to be Very high. Especially given the size of the vessel, & the loads on it’s chain at times.
Which WILL Fully be borne by the stopper under various circumstances. So EVERYTHING connected with the chain stopper & ground tackle, needs to be designed with this in mind.

So if you take the load of a ton or three, generated by the chain, & concentrate it along the edge of the stopper, & or it’s bolts. As will inevitably happen at times. Then the material which you’re using as a deck riser block/backing plate, needs to be able to handle these loads. Repeatedly, without issue: As shock loads, mind you, for they Will be such. Without question.


Which, if you look up the properties of many of the “lighter duty” proposed materials, it should be pretty clear that they’re not up for the task. Nor will even thinner gauge stainless plate be.

Also, if you really want a delineation as to how to scrutinize things. Take King Starboard for example, & look at it’s HDT, & Izod impact resistance numbers. Or, for that matter, it’s Tensile Strength.
On any, or, all of these, it falls short, for use In this application. As, frankly, so do most non-reinforced hardwoods. Given the load concentrations generated by a chain stopper.

The above is also easy to determine by asking yourself the common sense question; “If this material is subject to a repeated, multi-ton shock loads, concentrated in a small area/along lines of high compression, will it fracture”?

The answer to such is obvious; as is whether or not to use it for such an application.


Plus, if anyone thinks that such questions/criteria are extreme, here’s a real world example:
I was cooking at a friend’s house, & took over my Wok & Chinese Cleaver. And the first solid whack of my Cleaver on their plastic HDPE cutting board, it split into 3 pieces. While my Maple one at home had survived thousands of such strikes, with nary a scratch.

It’s food for thought; the above dissertation, I mean. No pun intended

[thinwater]

Note that this stopper is NOT rated for the chain strength (only 5500 pounds) and probably has a WLL of about 1200 pounds. Without a snubber, I reached this during testing (load cell) in an open anchorage in 30 knots with a 34' catamaran. Storm loads would have been over 2 tons. Perhaps your boat is larger too? And can your roller take that beating?

I would NOT trust this as a rode anchor, only as a backup to a snubber.

As for all the discussion of wood and HDPE, we're arguing over ~ $3 and safe function for a $75 piece of hardware. Of the materials suggested, ONLY GRP can be permanently epoxy bonded to contribute to horizontal sheer. Seems obvious.

[darylat8750]

When I first saw the proposed stopper I thought it must be for a 20 foot boat.
Uncivilized said it better than I could. The chain stopper and mount needs to be able to withstand the weight of your boat acting like a big hammer on the chain.

I would add to the discussion about Starboard or cutting board. The issue is not just compressibility during installation but "flow" or "creep" during extended loading. If you test in a vice for 2 min. you will get one value but if you leave it loaded for a week you would be able to compress it more.

[UNCIVILIZED]

Originally Posted by thinwater

Note that this stopper is NOT rated for the chain strength (only 5500 pounds) and probably has a WLL of about 1200 pounds.
Without a snubber, I reached this during testing (load cell) in an open anchorage in 30 knots with a 34' catamaran. Storm loads would have been over 2 tons. Perhaps your boat is larger too? And can your roller take that beating?

If that's as strong as it truly is, & I believe you, ergo my earlier dissertation, then said piece of gear has no place on a 13m, 9t+ vessel. Period

I would NOT trust this as a rode anchor, only as a backup to a snubber.

As for all the discussion of wood and HDPE, we're arguing over ~ $3 and safe function for a $75 piece of hardware. Of the materials suggested, ONLY GRP can be permanently epoxy bonded to contribute to horizontal sheer. Seems obvious.

Yeah, I too have trouble seeing much "wisdom" in cheaping out on a critical piece of hardware, & or, any supporting components of such a Key system.

And out of courtesy initially, plus in keeping OT, at first, I didn't want to say anything. But to me, that piece of gear does not align with the word Skookum as I understand it to mean.

[thinwater]

https://www.anchordockingdirect.com/...chain-stopper/

Anchorlift™ Chain Stopper for chain 7mm to 10mm 1/4" - 3/8"
Works with your anchor rollers to take the tension off the windlass by locking the chain. Handles 7 - 10 mm (1/4 - 3/8") chain. Included a convenient foot tab for safe and easy operation. Mounted with 4 screw holes to increase breaking strength. Made in mirror polished stainless steel.
Breaking Load: 2500 kgs (5,500 lbs.)
Fits Chain Size: 7-10 mm (1/4" - 3/8")



This is just barely strong enough for 1/4" grade 30.


1/4" G43 = 7750#
5/16" G30 = 7600#

3/8" G30 = 11000#
3/8" G43 = 16000#

I can see that it could be useful when dropping and recovering on some boats. But a snubber is still needed.

[mitiempo]

Originally Posted by thinwater

https://www.anchordockingdirect.com/...chain-stopper/

Anchorlift™ Chain Stopper for chain 7mm to 10mm 1/4" - 3/8"
Works with your anchor rollers to take the tension off the windlass by locking the chain. Handles 7 - 10 mm (1/4 - 3/8") chain. Included a convenient foot tab for safe and easy operation. Mounted with 4 screw holes to increase breaking strength. Made in mirror polished stainless steel.
Breaking Load: 2500 kgs (5,500 lbs.)
Fits Chain Size: 7-10 mm (1/4" - 3/8")



This is just barely strong enough for 1/4" grade 30.


1/4" G43 = 7750#
5/16" G30 = 7600#

3/8" G30 = 11000#
3/8" G43 = 16000#

I can see that it could be useful when dropping and recovering on some boats. But a snubber is still needed.

What stopper do you suggest?

[uncle stinkybob]

Are we talking about the same thing? I thought the OP was talking about a chain lock to secure the anchor in the bow roller and take the holding pressure off the windlass, not lock the chain while on the hook. For that I use a Mantus double bridle with a Mantus chain hook, chafe guards, run through port and starboard chocks and looped through both bow cleats.

[Stumble]

Originally Posted by Marqus

I get the fact that bolt heads or nuts will dig in deeper as you tighten up more. Not good.

In the case of the OP, there are no bolt heads/nuts in contact with the starboard pad. The anchor stopper has a base plate, say 2" by 2", and this base plate sits on top of the starboard pad.

So Greg you're saying that when the bolt heads on top of the anchor stopper are tightened, the 1/2" starboard pad under the stopper's base plate will respond by becoming thinner and expanding in size, so you would see its horizontal dimensions increase measurably ?

Pretty much. HDPE suffers from what's called cold forming, basically any preassure applied will cause it to flow away from the preassure point over time. Think of it as clay. If you hit it hard enough with your hand you can break a knuckle, press on it and it easily deforms. Obviously HDPE is a little more rigid than clay but the principle applies.

In reality people don't wind up retightening the bolts and their backing plate is just loose, which combined with the thermal expansion allows the bolt to wall or around in the fiberglass, expanding the holes or cracking the deck in short order. Almost immediatly these people then post asking if they can fix a rotten core by injecting CPES into their deck, or if they really have to cut out the rot.

All to save a couple of bucks on G10, which is really the right way to do it. I would have to look, but I think I just paid $15 for a 12"x12"x.25" piece of G10 to use as new backing plates for my A-Cat rudders.

[Jim Cate]

As for all the discussion of wood and HDPE, we're arguing over ~ $3 and safe function for a $75 piece of hardware. Of the materials suggested, ONLY GRP can be permanently epoxy bonded to contribute to horizontal sheer. Seems obvious.
_

Are you quite sure about this bonding issue? I'd think that one could bond a chunk of 6061 Al quite securely, and that it would make a fine mounting pad or backing plate. I've used such before without problems, although an isolating gasket between s/s and the alloy is a good idea.

Jim

[UNCIVILIZED]

Originally Posted by mitiempo

What stopper do you suggest?

You might try giving the Port Townsend Foundry a call Port Townsend Foundry in Washington as if they don't have them, they likely can make'em. That, or make customized parts to fit the bodies of another brand of solid chain stopper bodies, like Maxwell for instance. Winch Accessories
And Maxwell, may in fact, have some of the older styles around, or know who does. As there are many dozens of companies which make windlasses, & the accessories to go with.

Plus, if not new, then there are literally hundreds (or thousands) of used gear chandleries around, which have such gear. Usually it just is a matter of tracking down the right curmudgeon who knows what sort of gear a proper sailor is after.

On top of which, of course, there are literally pages & pages of such retailers to be found online & in periodicals. And properly made, such gear doesn't wear out quickly. As typically, it's fairly massive (as in overbuilt), & until recently, the prefered materials were chromed bronze & the like.
Including uber-sized fasteners, as well as moving parts.

So between those qualities, & the bits which I mentioned before... If you're up for perusing older, more nautical, seaside cities & towns, you'll likely have good luck. And such spots are to be found in any port of consequence, regardless of country or state. Be it; live, via phone, word of mouth, periodical, bulletin board, & or the internet.

Also, some of the newer, toe/foot activated designs may work well also. They'd be worth looking into. Albeit, with either style, watch yourself, as chain can jump when released (sideways, & or vertically), even when it doesn't appear to be under much, if any sort of load.

[Paul L]

I'm not usually a fan of Lewmar gear, but their chain stopper is pretty beefy and reasonably priced. It also fits into tighter spaces.

[UNCIVILIZED]

Originally Posted by Jim Cate

Are you quite sure about this bonding issue? I'd think that one could bond a chunk of 6061 Al quite securely, and that it would make a fine mounting pad or backing plate. I've used such before without problems, although an isolating gasket between s/s and the alloy is a good idea.

Jim

Below decks I know that you'd be fine bonding aluminum to GRP, having done it with winch backing plates even on Maxi's. And, done right, for the most part, it should work topsides too. But you'd have to be a bit more anal about the prep.
Plus you'd have to keep up a bit more fanatically with coatings, & ensuring that the high strain load cycles, & thermal expansion differentials don't allow water to get in between the aluminum & the deck. Which, of course, would throw a wrench into everything.

But before composites got advanced, say 3 decades ago+/-, they used to glue the aluminum crash tubs in race cars together. The ones which protect the drivers, when the car disintegrates at 200mph.
As the adheisve bonding was stronger than any other method.

Still, as with most things on a boat, it's the cyclical loadings which eat things up. And even 2ndary composite to composite bonds, have crap for strength, & flex life, as compared to primary composite bonds.
As, for example,. Some of the stories of the top end race boats, & their "structural bonds" becoming "not so structural", during the "Queen's Birthday Storm", in the Sidney-Hobart, are quite, ah, disturbing.