View Full Version : Lift bags
jsteedley
08-22-2005, 09:22 AM
I'm not really familiar with lift bags. :oops: I know that lift bags come in pound ratings. This is the question, how many and what pound lift bags would it take to lift a vehicle that weighs around 8,600 lbs, maybe 2 or 3 feet off of a river bottom. :-D
I'm not really familiar with lift bags. :oops: I know that lift bags come in pound ratings. This is the question, how many and what pound lift bags would it take to lift a vehicle that weighs around 8,600 lbs, maybe 2 or 3 feet off of a river bottom. :-D
I would use a tow truck for that kind of recovery. :-D
I'm not really familiar with lift bags. :oops: I know that lift bags come in pound ratings. This is the question, how many and what pound lift bags would it take to lift a vehicle that weighs around 8,600 lbs, maybe 2 or 3 feet off of a river bottom. :-D
Would this vehicle be long and yellow, and perhaps in Blue ridge Lake?
Dave
irdiver
08-22-2005, 10:46 AM
I'm not really familiar with lift bags. :oops: I know that lift bags come in pound ratings. This is the question, how many and what pound lift bags would it take to lift a vehicle that weighs around 8,600 lbs, maybe 2 or 3 feet off of a river bottom. :-D
well the math says... based on the vehicle being 50 cubic feet if completely crunched into a solid mass, it displaces 3120 pounds of freshwater, so if it weighs 8600 pounds then you need a lift bag capable of 5480 pounds. of course this is just a guestimate, but it gives you an idea what you are dealing with. hope this helps!
Genesis
08-22-2005, 11:00 AM
Don't drop it on you :-D
normblitch
08-22-2005, 12:09 PM
I'm not really familiar with lift bags. :oops: I know that lift bags come in pound ratings. This is the question, how many and what pound lift bags would it take to lift a vehicle that weighs around 8,600 lbs, maybe 2 or 3 feet off of a river bottom. :-D
well the math says... based on the vehicle being 50 cubic feet if completely crunched into a solid mass, it displaces 3120 pounds of freshwater, so if it weighs 8600 pounds then you need a lift bag capable of 5480 pounds. of course this is just a guestimate, but it gives you an idea what you are dealing with. hope this helps!
PLUS a fudge factor to account for bottom suction...been there, done that...got 'er done!
Norm
jammer
08-22-2005, 12:51 PM
(2) 3,000Lbs lift bags should do it.
jsteedley
08-23-2005, 04:16 PM
Guys:
thanks a lot for the input and I will try not to drop that darned thing on me. The vehicle is actually an Avalanche, no pun intended. I contacted an insurance company to see if they needed help locating the avalanche which was last seen floating down the river, but have not heard back from the insurance company.
The helpfulness and responses make me proud to be a cave diver. I have strayed from cave for a while with black water diving and hope to get back to some cave diving soon.
dive safely,
jody
Spd 135
08-23-2005, 09:13 PM
I do a lot of this. If there is a heavy current, a lift bag will get you in trouble. It has a lot of drag and when the truck starts up it will be out of control. You also want pillow bags and not open bottom bags. When open bottom bags hit the surface they can lose air and buoyancy. Also, you need training in them to use them safely. Best way to do it is to find the truck, mark it with a small lift bag and then swim back with a long rope. Take one end of the rope and tie it to a bumper or attachment point. Make sure it floats. Get a large float ball and attach a wrecker's hook and cable to it. Tie the float ball to the floating rope. This will allow you to pull the cable to you using the truck for an anchor point so you will not exhaust youself trying to get it to you. In dirty water you will know when the cable is above you because the rope you are pulling will be straight up. Take a tow strap and hook it to a towing point on the vehicle. Surface and take the hook down and then shackle the hook to the strap. This maintains a solid attachment because the hook can come lose. Chain is hard to handle underwater so tow straps work well. Surface and have the wrecker operator start pulling. Leave your bag on in case something breaks. If you have coms you can stay until the cable tightens and the vehicle starts to move. When the vehicle starts moving get out of the water. Hope this can help and keep you safe. Also, don't be in the water when the vehicle starts to surface because gasoline is no longer held by the ambient water pressure. Gas can damage your equipment and you. Mark from Louisiana (diverecoveries@charter.net)
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