Footer Anchor

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Re: Footer Anchor

by hausen » August 2, 2011, 10:53 am

Larry wrote:To be accurate, and have a large enough anchor, wouldn't the correct weight be calculated on the loaded weight? Just a thought.
The "one pound of anchor for each ton of ship" rule of thumb is a handy way for a layperson to estimate the weight of an anchor that might be on a ship. It is not the way that naval architects / engineers decide the size of an anchor to put on a vessel; actually do take loaded displacement into consideration when choosing an anchor.

The rule of thumb is just an expression of a coincidence; it just so happens that things roughly work out that way, and that is a consequence of physics and the conversion rate between arbitrary units of measure (tons and pounds).

Re: Footer Anchor

by bigboat » August 2, 2011, 10:38 am

Another thing that people seem to overlook is the part played by the anchor chain itself. There is a substantial amount of weight in all that chain and it plays a major role in the process.

Re: Footer Anchor

by Randy S » August 2, 2011, 2:43 am

Lets not forget that the weight is not the sole force in anchoring - the flukes are designed to grab the bottom and dig in.

Re: Footer Anchor

by Guest » August 1, 2011, 4:05 am

Larry wrote:To be accurate, and have a large enough anchor, wouldn't the correct weight be calculated on the loaded weight? Just a thought.
Yes, you would think so.

Re: Footer Anchor

by Larry » July 31, 2011, 11:09 pm

To be accurate, and have a large enough anchor, wouldn't the correct weight be calculated on the loaded weight? Just a thought.

Re: Footer Anchor

by hausen » July 30, 2011, 10:41 am

Brent wrote:The Gott's weight is 35592 tons.
That's her gross tonnage, which confusingly enough is a measure of her internal volume, not a measure of her weight.

Re: Footer Anchor

by Brent » July 30, 2011, 7:13 am

The Gott's weight is 35592 tons. Rule of thumb the anchor should be about 35500 pounds or about 17.7 tons. This is gust a way of estimating anchor weight and I am sure that some are more and some are less.

Re: Footer Anchor

by hausen » July 30, 2011, 12:19 am

Guest wrote:
Brent wrote:The normal rule of thumb is 1 pound per ton of ship.
Using that equation, a footer would weigh in at 45 million pounds.
I was under the impression that a footer's lightship weight / displacement was something like 20,000 - 25,000 tons. Using the 1 pound of anchor for 1 ton of ship equivalency yields a 20,000 to 25,000 lb or a 10 to 12.5 ton anchor.

Re: Footer Anchor

by newbie » July 29, 2011, 3:10 pm

Awesome, Thanks guys. That puts things in perspective. Pictures of that retrieval would be awesome! how did you guys manage to lift it, a crane barge or bags? How many anchors do you think are sitting on the bottom? (not from wrecks)

Re: Footer Anchor

by Guest » July 29, 2011, 1:14 pm

Pete in Holland wrote:In the early 80's, I worked with a salvage crew in Alpena. A 1000'er dropped its anchor and 640 feet of chain in the waters off Stoneport. We were given the task of retrieving it.

I remember being told it was a 9 ton anchor. Chain links were made from 2-3/8" round stock.

Somewhere I have photos of that whole recovery expedition. Pretty exciting for a college kid at the time.
If you find the pictures of that, please share! Would love to see them.

Re: Footer Anchor

by Pete in Holland » July 29, 2011, 11:04 am

In the early 80's, I worked with a salvage crew in Alpena. A 1000'er dropped its anchor and 640 feet of chain in the waters off Stoneport. We were given the task of retrieving it.

I remember being told it was a 9 ton anchor. Chain links were made from 2-3/8" round stock.

Somewhere I have photos of that whole recovery expedition. Pretty exciting for a college kid at the time.

Re: Footer Anchor

by Guest » July 29, 2011, 2:03 am

Brent wrote:The normal rule of thumb is 1 pound per ton of ship.
Using that equation, a footer would weigh in at 45 million pounds.
Sounds a tad high for an empty boat, and about 1/4 of what a loaded footer will weigh. Do they use that equation figuring loaded, or empty?

Re: Footer Anchor

by Brent » July 28, 2011, 9:15 pm

The normal rule of thumb is 1 pound per ton of ship.

Re: Footer Anchor

by Hermie Phillips » July 28, 2011, 7:51 am

A spare anchor for the Gott or Speer layed on the dock at the Soo Warehouse for many years. It was stamped 22500 lbs.

Re: Footer Anchor

by Guest » July 28, 2011, 2:32 am

newbie wrote:I was wondering if anyone knows the weight of an anchor of a 1000 footer? (assuming they carry the largest anchors) they all look big.
I had heard 13,000 pounds.

Footer Anchor

by newbie » July 27, 2011, 10:37 pm

I was wondering if anyone knows the weight of an anchor of a 1000 footer? (assuming they carry the largest anchors) they all look big.

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