Anchor drop failure - video

[Jon]

Anchor drop failure. Something happens around 0:57 (brake failure?) and the anchor chain starts freewheeling. Looks like no injuries. 2:07 video:

[pfredX1]

Now wait a minute. If they lost the anchor they must have dropped it. So how it is a failure to drop the anchor? Maybe they didn't drop it exactly how they wanted to, but they certainly managed to drop it. Heck they went one better and completely lost it. That's anchor dropping plus!

[kieranclay]

the breaks failed on the lowering gear. the chain is what actually holds the vessel due to the huge mass. the chain is then fastened to the bottom of the chain locker. once the breaks fail the mass of the chain hanging even if the end is on the sea floor will bull it out like that. can go much more wrong than that, ie. holes in hulls\

[aphilipmarcou]

the breaks failed on the lowering gear. the chain is what actually holds the vessel due to the huge mass. the chain is then fastened to the bottom of the chain locker. once the breaks fail the mass of the chain hanging even if the end is on the sea floor will bull it out like that. can go much more wrong than that, ie. holes in hulls\

I was there when the same thing happened in 1975 on the semi submersible oil rig "Chris Chenery" in the North Sea: the operator is only supposed to "drop" the anchor when the hoist is in gear and not just let it go and rely on the brakes only.....This was a brand new rig with 8 anchors (2 at each corner). Sleeping crew got an instant wake up.....Someone failed to read the operator's manual (

[Loose Ctrl]

My understand is that the brake is merely a holding device and not made to slow or stop a falling anchor. I've always used the motor, be it electric or hydraulic, to payout the chain in a slow and controlled manner.

[LMMasterMariner]

Sh**t happens. Combination of faulty brake and the guy who was operating that brake. As it can be seen, the guy was 'opening' the brake all the time.
(as they did on USS TARAWA, clip can be found on youtube also). Once chain start running out fast, there is no way that anyone can stop it. Loss of anchor and chain is inevitable. Have the first hand experience. Lost anchor and chain during deep water (55 meters depth) anchoring 6 years ago. Started by lowering anchor by windlass and when anchor and few shots of chain were already on the bottom, I ordered to stop the brake, disengage from the windlass and to continue by opening /closing brakes until we have final scope of 10 shots in the water. Exactly the same scenario, but brake linings were intact afterwards (didn't catch fire like in this video clip). My 'brave' crew simply ran away and didn't tighten the brakes at all and I had a lot of paperwork after that. Since that time I am not dropping anchor at all. I pay out required scope of chain cable by the windlass even in shallow waters. The whole operation lasts much, much longer than dropping anchor, but I am not going to loose anchor and chain again.

Best regards
LMMasterMariner

[Toolmaker51]

There is a phrase "The bitter end", many of you may be familiar with. That two brake operators remained at their station, until it was clear the runaway chain situation was out of control, shows dedication. Well, it comes from incidents just like this, as video depicts at about 1:44, when the final link falls into the hawsepipe. Every shipboard cable, line or chain has one included; when that end is unsecured or breaks free.

Here are related videos

One report you'll hear is the angle chain is tending [o'clock] and degree of strain. Also clear are markings on the chain to determine how much remains. BTW, just one the chain link on the aircraft carrier weigh 360 pounds plus.

They had been braking and paying out just fine, when it is clear the brake was not responding to the handwheel being released, then not at all. I'm guessing they were in a deep anchorage, or piling shots prior to heavy weather. As mentioned earlier, anchors are kind of decoration, it's the piled mass of chain that does the job.

[LMMasterMariner]

Hello Toolmaker 51,
Can't agree that anchors are just decoration, as classification societies require minimum weight of anchor for every ship. If anchor is HHP (high holding power), all classification societies allow anchor weight reduction of 25%. For example anchors on my ship (14000 TEU container carrier) are AC14 type anchors and each weighs 19.5 metric tonnes. And yes, the weight and length of paid out chain is very important. Original chain diameter on my vessel was 127 mm (5 inches). More chain you have in the water, the angle between the chain and the sea bed is smaller, which makes pulling of anchor more horizontally. Sole chain without anchor can't keep the vessel anchored. Dragged anchor several times, but it was always on the ships with Hall anchors. So far never happened to me with this AC14 type anchors. Part of technical file from class certificate attached.

Best regards
LMMasterMariner

[Jon]

Anchor drop on tug boat. 12-second video: