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--------------B4214BB591563D0E6D33705D Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Pierre.Morell@cs*.un*.ed* wrote: > I would appreciate a reference (or specific hints) as to deploying a > fixed (attached to wreck) 50 lb lift bag. Specifically, any rules of thumb as > to size (strength) and length of the line (deployed from reel or spool) as a > function of the variables which include - at the least - depth and current. You need some scope, but not much. About 1/3 more than your max *possible* depthseems about right. This is the complete opposite of anchor lines, where you neeed 3 times the depth or more. When the bag gets to the top, KEEP THE TENSION!. If you let it get all floppy, the bag can collapse as a wave goes over. By keeping the tension, when the big waves go over the bag just goes under. > Also, how is the line controlled as it is released from the reel so that it > does not run off the reel? - or jerk out of your hand? How is the line > attached to the wreck? I always use a Jersey reel, so things are a little different. Most of the time I just drop it and let itunwind itself. You can hold lightly onto the handles, and the new Aquaexplorer reel that I just bought has handles that rotate! As far as running off the reel, you need to have more line than your depth, plus a bit. I always attach the line to the spindle of the reel by splicing a loop (not an option for you), or with a round turn and two half hitches. I only saw a regular reel being deployed as an upline once. We were down in Virginia Beach, the mate had not tied in at all. Wave height was a staggering 1-2' - considered snotty by the DM. The grapple hook of course came out of the wreck. The most experienced diver in the group blew the bag, on his penetration reel. It looked to me like he was taking care to meter the line out using his glove for friction. I don't have to do that with my Jersey reel, which I carefully hand wind on. But hey, gloves are cheap. I assume he was doing that to limit the speed, and reduce the likelihood of a bird's nest. If the reel had jammed, then it probably would have been jerked from his hand. Three of us surfaced on that one line - not ideal. The nylon line is very thin and difficult to hang on. But it worked. And when an anchor comes out, generally the boat is downstream of you - it was an easy swim for us. > Finally, is there a rule of thumb about when you have > to discard the idea of a fixed deployment and assume you will have to come up > and decompress while drifting. Now there's a difficult question. Thinking about it, a drift hang is presumably going to be fatal -you are going to be well out of sight before you surface. I would say you should probably keep trying. You also have the option of just tying to the wreck, and going up on the reel, if you have a big problem with the bag. Not ideal, but it works except in really rough sees. If you are completely off the wreck, you try tying it to your weight belt. You would have to hold on to your line tight once you ascend - you will presumably be positively buoyant. In a similar situation once (see Freediver brings gas) I dropped my Jersey reel in the hope that it would snag on the wreck. It in fact tangled on the shot line, which was ideal. On your last 300-500 psi, you are probably better off getting to the surface. If you can make it to the boat quickly, then submerge saying you need gas. Borrow some from anyone else who is decompressing, until they bring some to you. That all assumes that you can get back below the surface within seven minutes. If not, its onto the boat and 100% O2. > This is all in the context of emergency only (I have done quite a few > wreck dives without an emergency so the bulky Jersey reel/biodegradable line > is not a desirable option for me). A scenario of interest is offshore North > Carolina at 100 feet with a 2 knot current. I looked through related threads > in the list aand several wreck diving books but could not put together an > answer to these questions. I thank any respondents for their time and > apologize for what may be too elementary a question for this forum. The only stupid question is one that is not asked. Please practice this procedure until you could do it blindfolded and drunk Wrolf Wrolf's Wreck: http://www.concentric.net/~Wrolf Wrolf's Net.Wreck: http://www.concentric.net/~Wrolf/netmgmt.shtml --------------B4214BB591563D0E6D33705D Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit <HTML> Pierre.Morell@cs*.un*.ed* wrote: <BLOCKQUOTE TYPE=CITE> I would appreciate a reference (or specific hints) as to deploying a <BR>fixed (attached to wreck) 50 lb lift bag. Specifically, any rules of thumb as <BR>to size (strength) and length of the line (deployed from reel or spool) as a <BR>function of the variables which include - at the least - depth and current.</BLOCKQUOTE> You need some scope, but not much. About 1/3 more than your max *possible* depthseems about right. This is the complete opposite of anchor lines, where you neeed 3 times <BR>the depth or more. <P>When the bag gets to the top, KEEP THE TENSION!. If you let it get all floppy, the bag can <BR>collapse as a wave goes over. By keeping the tension, when the big waves go over the bag just <BR>goes under. <BLOCKQUOTE TYPE=CITE>Also, how is the line controlled as it is released from the reel so that it <BR>does not run off the reel? - or jerk out of your hand? How is the line <BR>attached to the wreck?</BLOCKQUOTE> I always use a Jersey reel, so things are a little different. Most of the time I just drop it and let itunwind itself. You can hold lightly onto the handles, and the new Aquaexplorer reel that I just <BR>bought has handles that rotate! <P>As far as running off the reel, you need to have more line than your depth, plus a bit. I always <BR>attach the line to the spindle of the reel by splicing a loop (not an option for you), <BR>or with a round turn and two half hitches. <P>I only saw a regular reel being deployed as an upline once. We were down in Virginia Beach, <BR>the mate had not tied in at all. Wave height was a staggering 1-2' - considered snotty by the <BR>DM. The grapple hook of course came out of the wreck. The most experienced diver in the <BR>group blew the bag, on his penetration reel. <P>It looked to me like he was taking care to meter the line out using his glove for friction. I don't have <BR>to do that with my Jersey reel, which I carefully hand wind on. But hey, gloves are cheap. I assume <BR>he was doing that to limit the speed, and reduce the likelihood of a bird's nest. If the reel had jammed, <BR>then it probably would have been jerked from his hand. <P>Three of us surfaced on that one line - not ideal. The nylon line is very thin and difficult to hang on. <BR>But it worked. And when an anchor comes out, generally the boat is downstream of you - it was an <BR>easy swim for us. <BLOCKQUOTE TYPE=CITE>Finally, is there a rule of thumb about when you have <BR>to discard the idea of a fixed deployment and assume you will have to come up <BR>and decompress while drifting.</BLOCKQUOTE> Now there's a difficult question. Thinking about it, a drift hang is presumably going to be fatal -you are going to be well out of sight before you surface. I would say you should probably <BR>keep trying. <P>You also have the option of just tying to the wreck, and going up on the reel, if you have <BR>a big problem with the bag. Not ideal, but it works except in really rough sees. <P>If you are completely off the wreck, you try tying it to your weight belt. You would have to hold on to your line <BR>tight once you ascend - you will presumably be positively buoyant. In a similar situation <BR>once (see <A HREF="http://www.concentric.net/~Wrolf/freediver.html">Freediver brings gas</A>) I dropped my Jersey reel in the hope that it would snag <BR>on the wreck. It in fact tangled on the shot line, which was ideal. <P>On your last 300-500 psi, you are probably better off getting to the surface. If you can make it to the boat <BR>quickly, then submerge saying you need gas. Borrow some from anyone else who is decompressing, until <BR>they bring some to you. <P>That all assumes that you can get back below the surface within seven minutes. If not, its onto the boat <BR>and 100% O2. <BLOCKQUOTE TYPE=CITE> This is all in the context of emergency only (I have done quite a few <BR>wreck dives without an emergency so the bulky Jersey reel/biodegradable line <BR>is not a desirable option for me). A scenario of interest is offshore North <BR>Carolina at 100 feet with a 2 knot current. I looked through related threads <BR>in the list aand several wreck diving books but could not put together an <BR>answer to these questions. I thank any respondents for their time and <BR>apologize for what may be too elementary a question for this forum.</BLOCKQUOTE> The only stupid question is one that is not asked. <P>Please practice this procedure until you could do it blindfolded and drunk <P> <BR>Wrolf <P>Wrolf's Wreck: <A HREF="http://www.concentric.net/~Wrolf">http://www.concentric.net/~Wrolf</A> <BR>Wrolf's Net.Wreck: <A HREF="http://www.concentric.net/~Wrolf/netmgmt.shtml">http://www.concentric.net/ ~Wrolf/netmgmt.shtml</A> <BR> </HTML> --------------B4214BB591563D0E6D33705D-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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