how does an anchor break its shank?

riverdiver
20th July 2008, 18:28
We have found 5 anchors that have their shanks broken this year while diving the St. Clair River in Michigan. Is this from getting pulled to tight into the hawsepipe, or the ship droping the anchor and getting turned in the strong current of the river and snapping it ?
Thanks Ed

Tony Breach
20th July 2008, 20:59
Are the anchors identical &/or do the have identity of manufacturers still legible as may be a forging problem.

Tony

non descript
20th July 2008, 21:04
I wish I knew.... (Jester)

riverdiver
21st July 2008, 02:46
No, Tony all are different sizes and weights.

lakercapt
21st July 2008, 03:00
Where about in the river did you find them???

gdynia
21st July 2008, 03:26
Ed

The 2 photos you have posted look like the anchors have been deliberately cut as the breaks are too clean

riverdiver
21st July 2008, 03:36
Where about in the river did you find them???

On the bottom !

gdynia
21st July 2008, 03:37
Ed

Probally just dumped we have picked up alot of anchors like these in the past

Chouan
21st July 2008, 08:14
When I was on Havdrott's "Havjarl" we had an anchor which broke its shank in the Gulf. It too was a clean break, rather like those that you have shown. We started dragging some time after testing our engines after some work had been done one afternoon. Not immediately afterwards, but after about an hour. The dragging was almost imperceptible ar first, but then became more obvious. The Old Man took a lot of convincing that we were dragging, having been disturbed from his afternoon nap, and was then, of course, annoyed that I hadn't called him sooner once he was on the bridge!
When we got the "anchor" up, all there was was the shackle and a couple of yards of shaft, with a clean break at the end.

jimmys
21st July 2008, 09:12
Ground tackle gets an awful pounding. The only time we really see it is when it is flaked out in the dock for survey. There is a lot of problems with it, it just wears out if there is a lot of use.

I was on a steam VLCC in the gulf when we lost two anchors along with their chains. One after another.I was in the engine room for emergency movements. It was not very nice.

regards
jimmys

Dave Woods
21st July 2008, 10:43
We have found 5 anchors that have their shanks broken this year while diving the St. Clair River in Michigan. Is this from getting pulled to tight into the hawsepipe, or the ship droping the anchor and getting turned in the strong current of the river and snapping it ?
Thanks Ed

A couple of years ago we were recovering old telegraph cable in the North Sea prior to a Gas Pipe line installation. We were dragging a C&W de-trenching grapnel with 2 metre flukes at approximately 1 KPH on a 50 tonne wire and the instrumentation showed we had a tow pull of 15 tonne. Suddenly the tension instantaneously rose to more than 100 tonne, and fell off to almost zero. The result is attached! The ROV was put down to try and lasso the fluke, which it did, and it was recovered it to deck quite easily. The only explanation was a change of sea bed conditions.

Best regards

Dave.

andysk
21st July 2008, 17:27
...... Suddenly the tension instantaneously rose to more than 100 tonne, and fell off to almost zero. The result is attached! .....

That's scary - I'm glad I wasn't anywhere in reach of the wire end as the tension came off !

lakercapt
21st July 2008, 22:43
On the bottom !

Course .
Sillly me where else would an anchor be.
Rephrase my initial question.
Which part of the river or location???
Anchored many times in the river but did not lose an achor or cut cables either

non descript
21st July 2008, 22:51
It seems that metal in the shank suffers a unique fatigue, and if and when the ship receives orders to proceed to a port that requires both anchors to be available, the molecules somehow get to hear of this, and then, not unlike the old galley radio, they work in unison to achieve the clean break that we have seen….In technical terms it is referred to a Stress Fracture, because the molecules in the metal apparently get very upset (stressed out) when they hear the news… One such example is located here (http://www.shipsnostalgia.com/gallery/showphoto.php/photo/57329/ppuser/3912)

JamesM
30th July 2008, 13:03
riverdiver,
Never mind all the theorising ----- get the bloody things "weighed-in" at the local scrap yard and earn yourself some extra dosh. Steel is £280 per tonne in the UK, so I'm sure it will be similar where you are. Get moving, 'cause the first round's on you.(Pint)
JamesM

Jeffers
30th July 2008, 14:04
Never mind the various theories.....can some-one please change the title of this thread to "break" not "brake"!!! it annoys me every time I see it, it sounds like it's asking a completely different question.