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#20448
Calculators on the blue toolbar
LatitudeAdjustment - 1/26/2013 6:43 AM
Category: Training
Replies: 8

Greg, I just found your "Lift Bag Size/Volume Calculator", what we really need is a "How much does that thing on the bottom really weigh?" calculator :)

Back in the 70’s our dive club tried to raise an anchor with five 55 gallon drums, they were not enough. As long as the boat was moving they stayed near the surface but the Captain was affraid when he slowed in the inlet it would dig in so we cut it loose just outside the Beach Haven inlet. Someone is going to find it and go nuts trying to tie it to one of the wrecks :)

Anyone else got an idea for another calculator or fooled around with a historical site? ie, I think a local NJ dive shop or diveboat has been seeding old coins on the Spanish Wreck to build up travel to the site.
#51828
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Greg - 1/26/2013 10:33 AM
Any calculator suggestions that would help divers, send them my way. Provide the idea, and any links that support the calculations and data so I can research more.
#6537
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MonkeyDiver - 1/26/2013 12:29 PM
The dry weight of an object is reduced to the wet weight by figuring out the object’s volume, multiplying that times the weight of water displaced by the object, and then subtracting that from the dry weight. It appears that Greg’s calculator does that calculation without disclosing that information when interring the object’s volume.
#6537
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MonkeyDiver - 1/26/2013 12:53 PM
Just modify the calculator to display the "wet weight" which it already calculates.
#6537
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MonkeyDiver - 1/26/2013 1:29 PM
Just checked Greg’s lift calculator again, and it does already display the "wet weight". Works great and no changes needed. Not clear how big the anchor was or how the 55 gallon drums were being used in the comment above. Were they used at depth as a lifting device or just on the surface as a lift platform?
#12175
Eric_R - 1/27/2013 9:51 AM
Maybe these will work.
lift bags

around
#12175
Eric_R - 1/27/2013 10:11 AM
Greg, I’ll let you clean up my mess.lol
There’s always cheap lift bags laying around .
#51828
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Greg - 1/27/2013 10:53 AM
Latitude started the forum topic, so he can delete your duplicate responses, plus this one.
#20448
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LatitudeAdjustment - 1/27/2013 11:32 AM
From MonkeyDiver: Just checked Greg’s lift calculator again, and it does already display the "wet weight". Works great and no changes needed. Not clear how big the anchor was or how the 55 gallon drums were being used in the comment above. Were they used at depth as a lifting device or just on the surface as a lift platform?...


Somewhere I have pictures of that anchor draped in chain, we spent weeks removing the chain, wished I’d saved a link. Someone had made a guesstimate at how much the anchor weighed, so much for things lookinging 25% bigger underwater :(

The drums had eye bolts welded on and were lashed to the anchor and then filled thru the bung hole. Once the anchor was pulled from the sand it rose to the surface until one drum surfaced, then stopped. The bungs were replaced but too much of the anchor hung down to clear the inlet. One drum did break loose and it looked like a WWII sub movie in reverse with the depth charge jumping out of the water!

In hind sight once the anchor was free of the sand we should have layed it back down and tied the drums to float it horizonally but we hadn’t made provisions to let the air out of the drums from the up end :(