Anchoring Fatality

[HopCar]

Big chain moving fast is scary!

 

[Comodave]

This is really too bad. A couple of quick thoughts, why did the crew stay near the capstan when the chain was running away? There is no way they could have stopped it once the brake malfunctioned. Why didn’t the captain order them away, it must have taken some bit of time for the bitter end to run out? Why didn’t the CG do a hoist if they couldn’t land? They must do rescues from smaller vessels that don’t have the room or capacity for the helo to land so I assume they have hoisting capability. Very unfortunate event.

 

[BruceK]

1. A most regrettable event.


2. On both this vessel,and another which suffered a similar event, the bitter end was shown on video able to exit the vessel. It appears the free exiting and associated whip motion creates the great danger.

3. I have always ensured the bitter end is attached or otherwise restrained from exiting the chain locker. We are not told if the bitter end was unattached. Or if it was attached, the attachment failed due t high loading (which I`d have thought could reasonably have been anticipated).


4. Should the bitter end be attached? Or is there no method of attachment likely to cope with the loading in this situation? Would a strong attachment create dangers of its own? Comment on these issues is no part of the report.


5. More knowledgeable minds than mine will apply themselves to this event, it`s causes, and possible prevention. To those members. please share your opinions.

 

[HopCar]

It occurred to me that the bolt that fell out of the brake lever was installed with the nut on top. When the nut came off it allowed the bolt to fall out. If the nut was on the bottom it could fall off but the bolt would remain in place.

 

[Bacchus]

It occurred to me that the bolt that fell out of the brake lever was installed with the nut on top. When the nut came off it allowed the bolt to fall out. If the nut was on the bottom it could fall off but the bolt would remain in place.

There is a mechanical design saying for this as a reminder to designers (really )
"DONT SCREW UP"
I've heard this stated during mechanical design reviews when questioning a potential failure point.

 

[Redhook98]

 

[HopCar]

There is a mechanical design saying for this as a reminder to designers (really )
"DONT SCREW UP"
I've heard this stated during mechanical design reviews when questioning a potential failure point.

Thanks Bacchus! I had never heard it put that way. I like it.

 

[HopCar]

Here is an idea. Have the chain pass over a wildcat connected to a centrifugal clutch. If the chain exceeds a set speed the brake pads on the clutch are thrown out into contact with a brake drum. This would happen automatically if the manual brake failed or the operator screwed up.

 

[HopCar]

Did anybody else notice that the narrator referred to a length of chain as a “shackle”? I think he meant a “shot”.

 

[psneeld]

Did anybody else notice that the narrator referred to a length of chain as a “shackle”? I think he meant a “shot”.

Maybe he learned to count by the shackles....should be the same.....


Random web note......

"A shot of anchor chain is measured either in fathoms or feet. Each shot is 15 fathoms or 90 feet long, which for all you mathematical types equals six feet per fathom. The 13 shots of anchor chain are linked by a special link called a detachable link....."

 

[kthoennes]

On that video that RedHook posted, I'm surprised those two guys stayed at the brake so long. They kept cranking the brake wheel that had obviously failed. I kept thinking, GET OUT OF THERE!

 

[Portage_Bay]

From the description of crewing and the procedures it seems to be a well run ship. The failure of the windlass brake and the chain bitter end termination are unfortunate. And the 3rd officer's decision to try to stop the chain was questionable. However there is one additional thing that could have changed the outcome. Anchoring in 34 meters of water on a ship that size with little wind or current, so little the master had to use sternway to lay out the chain, there was no reason to free drop the anchor. The chain could have been paid out by the windlass keeping things under control at all times. I say this from the persepecive of having routinely anchored in water 200+ meters depth.

 

[Comodave]

Did anybody else notice that the narrator referred to a length of chain as a “shackle”? I think he meant a “shot”.

A shackle is 90’. It is a common term in the big boats. Ever seen Below Decks? They always use shackle when anchoring.

Maybe the original design of the windlass had the screw pointing down but some crew member worked on it and put the bolt in upside down???

 

[backinblue]

A shackle is 90’. It is a common term in the big boats. Ever seen Below Decks? They always use shackle when anchoring.

Hmmmm. I watch Below Decks and always hear them say "shot". Not sure I ever heard "shackle" but I suppose they could be interchangeable.

 

[psneeld]

Gotta admit...first time I ever heard shackles used instead of shots of chain.

Pretty sure the US Navy and USCG both use shots.

Even in all my varied maritime readings never heard "shackles" but can't say it's never used.

 

[rgano]

Gotta admit...first time I ever heard shackles used instead of shots of chain.

Pretty sure the US Navy and USCG both use shots.

Even in all my varied maritime readings never heard "shackles" but can't say it's never used.

Yes, we used "shot" in Uncle Sam's Navy.

 

[HopCar]

According to Google, shackle can mean the same thing as shot. In my fifty years selling chain I had never heard that term.

 

[psneeld]

According to Google, shackle can mean the same thing as shot. In my fifty years selling chain I had never heard that term.

Probably no one at Google either but they watched the same video.

 

[kthoennes]

I'm not even sure "shackle" makes sense in that context. Who would connect lengths or segments of anchor chain together with shackles?

 

[psneeld]

Read post #11, vessels that load "shots of stud link chain"

 

[Comodave]

I'm not even sure "shackle" makes sense in that context. Who would connect lengths or segments of anchor chain together with shackles?

The chain isn’t connected together it is just a measurement term. Like fathom, foot, yard etc. maybe it started out that way but no longer.

 

[Comodave]

1 shackle = a length of cable or chain equal to 15 fathoms (90 feet or 27.432 meter). “3 shackles in the water” means that a ship has passed 3 shackles (of anchor chain) into the water. For a given depth under the ship you want to have 3 to 5 times that lenght of chain on the bottom of the sea.

 

[psneeld]

More commonly in the USA known as "shots of chain"... they are connected by shackles which for some reason the guy in the video uses "shackles" when many here have just heard of "shots" and that is the term of 90 foot length of chain sold.

And yes there are commonly sold in 90 foot lengths. They are shackled together.

 

[BruceK]

There are knowledgeable posters on the thread but no one is dealing with bitter end attachment ,yes or no, and/or attachment failure. I know the brake failing is the proximate cause, but further upstream lies attachment/attachment failure.

Anyone see it as worth addressing?

 

[psneeld]

Pretty sure at the size of the ships we are looking at here and bigger, runaway anchor chains often do break loose.

 

[RT Firefly]

Greetings,
Mr. BK. I don't know if, given the tonnage of the anchor and chain AND it's inertia, if there would be anything strong enough on the ship to attach it to. Might be better to stand back and let everything go rather than tearing out a bulkhead or worse.


Just speculating here.

 

[Peter B]

True. Not likely even a decent length of fairly stretchy hawse cable would hold it without something tearing out..? All the same it might be preferable for it not to be steel chain whipping around as it disappears over board..?

However, having watched and filmed the anchor drop of the cruise boat we were on, near an Island in the Vanuatu group, (Pacific Sun, for those interested - now sold to a Chinese owner), I was filled with fascinated horror at the clouds of rusty dust that enveloped the whole foredeck. It looked like they just "let 'er rip", so not surprised at the failure of the windlass brake or whatever it was that failed in the vessel involved. The forces involved in stopping that sort of run-out must be tremendous..?

 

[BruceK]

Appreciate the comments on bitter end attachment and failure potential. If chain and attachments are proportionate,in runaway, our little boats could suffer similar events,hopefully without similar consequence due to diminished proportions. Our Muir windlass,popular here, has chain brake/clutch and motorized payout (and retrieve).
I remember a sewerage fatberg removal team here lost control of the 12000psi clearing hose jet, they could not get away fast enough. Very wise.

 

[rgano]

There are knowledgeable posters on the thread but no one is dealing with bitter end attachment ,yes or no, and/or attachment failure. I know the brake failing is the proximate cause, but further upstream lies attachment/attachment failure.

Anyone see it as worth addressing?

My own feeling about how to secure the bitter ends of the all-chain rodes on both my former trawler and my smaller Pilot is that I do not want chunks of my boat being ripped out of the anchor locker due to the chain being attached to the boat with the idea that the attachment would stop the runaway and hold the boat in place (think a heavy blow or current and a runaway). I consider that the attachment should be a cuttable fiber and of sufficient length to allow the bitter end to clear the bow roller and of sufficient strength to prevent the casual loss of the chain in a light load situation.

 

[Wayfarer]

I've never experienced it myself, but I've worked with a couple of folks that have had the brake fail and the chain run away. In both instances the chain was fastened to the ship sufficiently that it stayed attached, and didn't do any significant damage. No idea if all of our ships are set up that way or not. I've known of a few ships that have lost their anchors and chains, but I'm not clear on the circumstances.

They always taught us in school that the chain was connected to the ship via a 'weak link' so that it would detach if the force was great enough. That way it didn't pull the entire ship out through the spillpipe, causing us to turn inside out and disgorge all of our personal affects into the sea.