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Scuba Forum / General / March 2007Doubles and back plate
While I was in Curacao I saw a rig that I though was interesting. It was a stainless steel backplate with two AL80's attached. It had some kind if whing BC attached to it with straps and wrapped with bungee cord. There were two infalters one I guess for each tank and two non manifolded first stages. There seemed to be a couple trim weights on the back of the backplate and 15 pounds of lead belted to the to the front, this may have been removed and worn around the waist when actually in use. I assume that bungee cording the wing is a bad idea, especially when wearing that much weight. But two seperate first stages ? > I assume that bungee cording the wing is a bad idea, especially when > wearing that much weight. But two seperate first stages ? Yeah, it's called independent doubles... It allows you to basically have doubles, but not have to take your tanks with you since you are just using normal rental AL80s... One advantage of this setup is that you truly have an independent redundant backup... Some people claim that gas management is more difficult with this configuration, but I've never found it problematic... With such a configuration, you really don't need an octo since the second tank can serve as your backup reg for a buddy... If you have reg problem on one tank, you can just take the reg off the other tank while underwater and swap it between tanks... > While I was in Curacao I saw a rig that I though was interesting. It > was a stainless steel backplate with two AL80's attached. It had some [quoted text clipped - 6 lines] > I assume that bungee cording the wing is a bad idea, especially when > wearing that much weight. But two seperate first stages ? I'm surprised you never saw this in the NE. As Grummy said, it is independent doubles, most likely with the infamous OMS dual bladder bungee wing. It has 2 bladders for redundancy, but if you think that all the way through, it's a bad idea to have them both connected. I've also seen people put 2 single bladder wings together. The problem with independents is you have to keep switching regs, so a catastrophic loss of one tank doesn't kill you. It is not easy to change regs on back mounted tanks; but Grummy is a sidemounter so his regs are easy to get at. The lead sounds excessive for the setup. With a 3mm wetsuit, stainless plate, small canister light and dual Al80's, I don't wear any lead. > I'm surprised you never saw this in the NE. As Grummy said, it is > independent doubles, most likely with the infamous OMS dual bladder [quoted text clipped - 5 lines] > mounted tanks; but Grummy is a sidemounter so his regs are easy to get > at. The only time you should need to swap your regs around while underwater is due to a major failure of the first or second stage regulator on one of your tanks and either because of an overhead environment or decompression obligations, you cannot surface within the time left on your good tank... I once asked Dacor about this a few years ago and they said that it was recommended that you have your regs serviced if you have to swap them underwater, especially in salt water... As such, you normally wouldn't do this unless you really *had* to... Given that you are in this situation, swapping them while the tanks are on your backs are not really an option unless you are rather limber... Personally, I'm not that limber, so I would use the following procedure: ASSUMPTIONS: Left Tank has bad regulator, but more air in it, Right Tank has good regulator, but is running low on air. 1. Breathe from the RT as long as possible.. 2. As the time approaches when you need to switch tanks, remove your harness and put the tanks in front of you so that the operation will be easier to perform... 3. While still breathing from the RT, turn off the valve on the LT and remove the reg off of it... 4. Turn off the valve on the RT and take one last breath from it... 5. While holding your breath, purge the remaining air from the good reg 2nd stage on the RT... 6. Remove the good reg from the RT and put it on the left tank... 7. Turn on the valve on the LT and purge the water from the 2nd stage good reg. 8. Start breathing from the good reg on the LT. 9. Put the bad reg on the RT and possibly use whatever air remains in the RT to pressurize the bad reg to get rid of any water that got into it... As you mentioned, I tend to dive sidemount these days and as such, switching regs underwater would be a bit easier... I don't need to remove my harness and backplate to get the tanks in a position in which I can access their regulators... If I could not swap the regs with the tanks clipped into my harness, I could simply unclip them and work on them in a more accessible position... I have an inflator hose on both tanks so I guess I'm triply redundant in that matter (there's always the manual inflation method <huff-wheeze-huff>)... <grin> > The only time you should need to swap your regs around while > underwater is due to a major failure of the first or second stage > regulator on one of your tanks and either because of an overhead > environment or decompression obligations, you cannot surface within > the time left on your good tank... The fact that you even had to seriously consider this option indicates a gas management failure. > As such, you normally wouldn't do this unless you really > *had* to... Due to f.cking up gas management and not having a buddy, for example. > As you mentioned, I tend to dive sidemount these days and as such, > switching regs underwater would be a bit easier... But unless you changed your configuration, your "sidemounts", a double-sided stage bottle configuration, should be Luxfer AL80s, preferably with at least 30% HE, so the tanks would ride up under the wing instead of dangling like the pontoons of a float plane. Curtis > The fact that you even had to seriously consider this option indicates a > gas management failure. Although I've never had to swap regs underwater, I guess I like to be prepared, just in case... I figure it's better to know how to do it and not need to than the other way around... > But unless you changed your configuration, your "sidemounts", a > double-sided stage bottle configuration, should be Luxfer AL80s, > preferably with at least 30% HE, so the tanks would ride up under > the wing instead of dangling like the pontoons of a float plane. Are you talking about the time when the line connecting the snap bolts to my harness D-ring broke? I don't remember if you were on that dive with me, but it sure was funny towards the end... Why would I want 30% helium? Hell, that would mean I would have to go even deeper to get a good narc... My gas consumption would go up and as such, the narc wouldn't last as long... Kind of defeats the purpose, doesn't it? <evil-grin> On Mar 11, 10:26 pm, Grumman-581 <grumman...@DIE-SPAMMER-SCUM- gmail.com> wrote: > On Mon, 12 Mar 2007 00:05:02 GMT, "\"Magilla\"" <cavey_curtis@$$ > Although I've never had to swap regs underwater, I guess I like to be > prepared, just in case... I figure it's better to know how to do it > and not need to than the other way around... I have heard that at least one person has had a problem swapping diaphram regs in the water - when the reg was pressurized, the water slug ripped the diaphram. Some go as far as using only piston regs on stages. I would at least hold the purge button while pressurizing a diaphram with water in it. Of course, if you manage your gas properly, you'll never have to do this, but I've seen someone really experienced in diving independents get caught up in trinket recovery and come back with one empty tank (not really empty; it had water in it). > Of course, if you manage your gas properly, you'll never have to do > this, but I've seen someone really experienced in diving independents > get caught up in trinket recovery and come back with one empty tank > (not really empty; it had water in it). If I'm diving independents, it's not uncommon for me to come up with one tank that is pretty damn close to empty as long as I'm not in an overhead environment... If I know that I have 1000 psi in one tank and I had recently breathed from it, I'm not that worried about completely emptying the other tank during my ascent / deco... Well, maybe not *completely*, but enough that it gets difficult to breathe from... On Mar 11, 10:26 pm, Grumman-581 <grumman...@DIE-SPAMMER-SCUM- gmail.com> wrote: > Although I've never had to swap regs underwater, I guess I like to be > prepared, just in case... I figure it's better to know how to do it > and not need to than the other way around... Thinking about it after more coffee, Cindy had a deco reg blow open when it was pressurized, and we handled it by turning the valve on and off to breathe until the team 10 minutes ahead of us finished their deco and gave us one of their O2 tanks. That would be a preferred option in the CF you're thinking of (would be more difficult on back mount independents). > Thinking about it after more coffee, Cindy had a deco reg blow open > when it was pressurized, and we handled it by turning the valve on and > off to breathe until the team 10 minutes ahead of us finished their > deco and gave us one of their O2 tanks. That would be a preferred > option in the CF you're thinking of (would be more difficult on back > mount independents). Kind of depends upon the problem that you're trying to handle... Whether it is a 1st or 2nd stage problem and whether it is stuck open or stuck closed... I figure that it's nice to know that swapping regs while underwater is an option, just in case... I've had leaky second stages that were irritating enough that I had to disassemble underwater and fix... If I had been using some of the older metal 2nd stages that required tools to disassemble, that wouldn't have been an option and I would have just had to either put up with the water coming in on every breath or I would have had to abort the dive after the good tank got low... As it was, I was able to basically do my originally planned dive... It's always good to have options... Well, except for when they all suck, I guess... <grin> >>Thinking about it after more coffee, Cindy had a deco reg blow open >>when it was pressurized, and we handled it by turning the valve on and [quoted text clipped - 17 lines] > It's always good to have options... Well, except for when they all > suck, I guess... <grin> But as Al points out, there's a physics problem here: air is compressable, water is not. When you pressurize air, it absorbs the pressure surge. When you pressurize water, the water transmits all that pressure surge to those tender internal parts. Regulators are not designed to have water inside, especially in the first stage. Piston first stages and most second stages are more forgiving, but yer taking chances. esg > Regulators are not designed to have water inside, especially in the > first stage. Piston first stages and most second stages are more > forgiving, but yer taking chances. Agreed, but we're not talking about a case where you could have aborted the dive already... We're talking about a major CF where you're willing to risk damage to your regulators because the alternative is doing a quick evolutionary development of gills... Opening the purge valve and turning on the air *very* slowly should help to reduce the chances of damage from the water slug... Regardless, you're going to want to get your regs looked at after doing this... >> Regulators are not designed to have water inside, especially in the >> first stage. Piston first stages and most second stages are more >> forgiving, but yer taking chances. > Agreed, but we're not talking about a case where you could have > aborted the dive already... We're talking about a major CF where [quoted text clipped - 4 lines] > Regardless, you're going to want to get your regs looked at after > doing this... All of this goes a bit beyond my expertise, but I clearly remember people advising internal flushing of regulators with fresh water. I'm sure that salt water inside a regulator would warrant disassembly and cleaning, but I'm not sure that fresh water would be as much of a problem as indicated. While it's true that water inside the first stage would not buffer the pressure surge as much as air would, I'm not sure that either buffers it much. It's not like there's a lot of space in there to absorb the shock. I suspect that opening the valve slowly would probably be sufficient to protect the internal components of the first stage, even if the purge valve were not opened first, but I'm not going to rush right out with my expensive Scuba Pro regulators to find out. I might try it with one of my diaphragm US Divers regulators. Lee > All of this goes a bit beyond my expertise, but I clearly remember people > advising internal flushing of regulators with fresh water. I'm sure that > salt water inside a regulator would warrant disassembly and cleaning, but > I'm not sure that fresh water would be as much of a problem as indicated. I suspect that nice fresh Florida spring water would not be that bad for it... Especially after breathing a tank of dry air through it... I probably wouldn't allow it to sit around wet though... The other regulator in this scenairo already needs get serviced anyway, otherwise, you wouldn't be contemplating having to do this anyway... <grin> > While it's true that water inside the first stage would not buffer the > pressure surge as much as air would, I'm not sure that either buffers it > much. It's not like there's a lot of space in there to absorb the shock. And considering how most people just turn the valve on fully very quickly, I suspect that it builds up to 3000 psi rather quickly... At least in this scenario, the tank that you would be turning on is probably quite a bit less than 3000 psi... > I suspect that opening the valve slowly would probably be sufficient to > protect the internal components of the first stage, even if the purge valve > were not opened first, but I'm not going to rush right out with my expensive > Scuba Pro regulators to find out. I might try it with one of my diaphragm > US Divers regulators. Hmmm... Considering the fact that the 1st stage normally goes from around 3000 psi to about 175 psi, perhaps that little bit of difference with opening the purge valve might not mean much... Regardless, you're going to need to purge the water in the regulator anyway... I have to wonder if it might also be possible to keep your 1st stage oriented with the opening down that you just might not get that much water in it anyway... All in all, I hope that I never have to find out... One could definitely argue that being excessively concerned with this is equivalent to wearing a full coverage helmet and 5-point harness while driving your car to the grocery store... It's quite possible that you've had to do a couple of things wrong to get yourself into the situation where this method would be needed... All in all, it might be a useful skill to practice if you were certain that you had a regulator that would not be damaged... It would add a new level to the harassment training exercises... > And considering how most people just turn the valve on fully very > quickly, I suspect that it builds up to 3000 psi rather quickly... I seem to recall that my first tanks did, in fact, turn on quite quickly. I don't think my newest ones do, though. I'll have to check and see. > I have to wonder if it might also be possible to keep your 1st stage > oriented with the opening down that you just might not get > that much water in it anyway... I don't expect it would fill up even if you didn't. I find this discussion amusing on a somewhat different level. There's some obvious resistance to the idea of independent twins by some of the very same people that think that carrying a stage or a pony bottle is a good idea. I have a bit of trouble figuring out how the risks differ significantly. > All in all, it might be a useful skill to practice if you were certain > that you had a regulator that would not be damaged... It would add a > new level to the harassment training exercises... Agreed. One thing not already mentioned is the time it takes to do it. Personally, I think it might take me more time than I have available to turn off my gas, exhaust the pressure in one of my regulators, unscrew the DIN connection of the problem regulator, unscrew the DIN connection from the functional regulator (assuming the water in it doesn't blow it to pieces), screw the good regulator onto the full tank, turn on the valve and take a breath. Lee > I don't expect it would fill up even if you didn't. Yeah, if it had time to fill up, you've probably run out of air in your lungs by that time and the issue is probably moot... <grin> > I find this discussion amusing on a somewhat different level. There's some > obvious resistance to the idea of independent twins by some of the very same > people that think that carrying a stage or a pony bottle is a good idea. I > have a bit of trouble figuring out how the risks differ significantly. Well, let's just call it a 80 cu-ft pony then... Just the right size for Curtis... <grin> > Agreed. One thing not already mentioned is the time it takes to do it. > Personally, I think it might take me more time than I have available to turn [quoted text clipped - 3 lines] > screw the good regulator onto the full tank, turn on the valve and take a > breath. I haven't used any DIN regs before... Do they take more time to hookup than a yoke style reg? Remember though, you wouldn't be doing it quite in the order that you specified... You would turn off the gas and unhook the bad regulator while still breathing from the good regulator... Once it is unhooked, then you would turn off the gas and unhook the good regulator, transfer it to the other tank, and turn on the gas... Do it in the right order and you would minimize the amount of time that you would have to hold your breath... Do it in the wrong order and you better either have the breath holding ability of a freediver or be prepared for Darwin to critique your technique... > Well, let's just call it a 80 cu-ft pony then... Just the right size > for Curtis... <grin> For Curtis, you have to call it a stage bottle, but whatever you name it, it's still an independent gas supply with its own regulator. > I haven't used any DIN regs before... Do they take more time to hookup > than a yoke style reg? I think yes. In both cases, you have to bleed off excess pressure before you can remove them and both unscrew I think the DIN has more threads to unscrew and that the means for unscrewing them is less accessible. It's hard to be easier to get to than the knob on the back of an A clamp first stage. > Remember though, you wouldn't be doing it quite in the order that you > specified... You would turn off the gas and unhook the bad regulator [quoted text clipped - 5 lines] > either have the breath holding ability of a freediver or be prepared > for Darwin to critique your technique... Why would you be unattaching a good regulator if you have gas and a working regulator on the other tank? Anyway, there's a reason I chose a manifold for my twins and this discussion make it pretty clear what that reason is. I'm not sure what I'd do if I wanted to dive sidemount, but I'm willing to bet that you could figure out a way to do the same thing as my manifold does and still carry two tanks separated by your body. I know I could. Lee >>>Anyway, there's a reason I chose a manifold for my twins and this >>>discussion make it pretty clear what that reason is. I'm not sure what I'd do if I wanted to dive sidemount, but I'm willing to bet that you could figure out a way to do the same thing as my manifold does and still carry two tanks separated by your body. I know I could.<<< I've wondered if the high pressure ports could be linked with a hose to keep the pressure in two tanks balanced. They might need to be drilled out a bit first to improve the volume of air that can flow. Place an on/off valve at the regulator on each side in case the hose fails to isolate a tank. > I've wondered if the high pressure ports could be linked with a hose to > keep the pressure in two tanks balanced. They might need to be drilled out > a bit first to improve the volume of air that can flow. Place an on/off > valve at the regulator on each side in case the hose fails to isolate a > tank. I can come up with a couple of ways of doing this without trying real hard at all. Using the high pressure ports on your regulator would not achieve your goal. The port on the regulator is after the valve. If you have a regulator failure, shutting off the supply to that regulator shuts off the second regulator's access to the gas in that tank. As for a valve at either side, you don't need two. One, anywhere in the connecting hose does the trick. Once upon a time, some technical divers used a valve block to control gas from multiple sources. Its popularity didn't last long largely because you have to remember which valve accesses which gas. It does not allow you to trace the regulator you're using to the source of gas to be sure you're not about to breathe something fatal. As I recall, the system is generally credited with having killed it's inventor. That problem could have been addressed. Interestingly, the valve block system is a reasonable answer to the issue of having the same level of redundancy for all gas supplies used during a dive. At any rate, having all primary supply tanks feed to a single block could provide all the connectivity necessary no matter how the tanks are carried. Another option, perhaps simpler, would be to use the same manifold valves we now use, but with a different connection between the tanks. If the side mount tanks don't need to be able to move, the connection could be a somewhat differently shaped version of what we use with manifolded back mounted tanks. If the tanks do have to be able to move independently, then a hose would do the same job. Either way, single valve somewhere along the connection would allow the tanks to be isolated if necessary, just as it does on the more conventional back mounted twinset. My preference would be to firmly attach the valve to one of the existing valves both to keep it where I know I can find it and to reduce the number of failure points you get with a hose that might fail on both sides of a central valve. Lee > I've wondered if the high pressure ports could be linked with a hose to keep > the pressure in two tanks balanced. They might need to be drilled out a bit > first to improve the volume of air that can flow. Place an on/off valve at > the regulator on each side in case the hose fails to isolate a tank. I've seen several homemade rigs in cave country, but they all have more inherent problems than they solve, so the sidemounters have pretty much settled on independents. If you ask on cavediver.net, there are a few old sidemounters there who have tried everything and would be happy to discuss it. > I find this discussion amusing on a somewhat different level. There's some > obvious resistance to the idea of independent twins by some of the very same > people that think that carrying a stage or a pony bottle is a good idea. I > have a bit of trouble figuring out how the risks differ significantly. I'm missing something - what does carrying a stage have to do with independent doubles? How are the risks similar? >> I find this discussion amusing on a somewhat different level. There's >> some [quoted text clipped - 3 lines] >> I >> have a bit of trouble figuring out how the risks differ significantly. > I'm missing something - what does carrying a stage have to do with > independent doubles? How are the risks similar? Guess somehow burning a stage down to near zero and holding back gas (isolation manifolded) in reserve, with two first and two second stage regs in reserve, is equivalent to burning one independent double down to zero with half the back-ups. Go figure. Curtis > is equivalent to burning one independent double down to zero with half the > back-ups. Which, in all honesty, if done in very shallow water once the surface is your back-up, all deco obligations met, is a non-issue. Curtis >> is equivalent to burning one independent double down to zero with half >> the back-ups. > Which, in all honesty, if done in very shallow water once the surface > is your back-up, all deco obligations met, is a non-issue. Agreed, but I must admit, though that Grumman's method of diving independent twins is not what my learning suggests is the best way. I always thought that, when both tanks contain the same gas, the idea was to breathe one for a while, then the other, so that you know that both regulators are functioning and so that you have adequate gas to bail out safely in both tanks, all the time. Breathing one dry and then switching to the other seems, to me, to be higher risk than diving manifolded twins, but not significantly higher risk than diving one tank on your back and one carried stage style. Personally, I don't wear more than one tank without a reason for carrying the excess gas. So far, the tanks I've carried stage style have been filled with deco gas, not bottom gas. The gas on my back, the one time I have used my twins was to allow me to do an extended dive without having to worry about having enough gas to get myself and my buddy, if necessary, safely to the surface. I think that makes the gas in my tanks important enough to protect as well as practical and, for me, that means twins connected with an isolation manifold. Others may feel differently. As it happens, on that same dive, I carried deco gas for which I had no backup; but, I was carrying it as an abundance of caution, not because it was necessary for the planned dive. Had that supply failed, everybody still got to the surface safely. Lee > Agreed, but I must admit, though that Grumman's method of diving independent > twins is not what my learning suggests is the best way. My current way is basically an experiment that Curtis and I rigged up on a previous dive trip to Florida... That would be the one where I towed my boat over there... Previously, I dove banded independent doubles as back gas... Curtis and I were diving Blue Springs and no shops were open for me to get my AL80s filled, so we had to come up with a way to use my steel 72s which were full... Putting them into the bands with some filler material to make up for the smaller diameter of the tanks didn't work that well... As we were walking along the boardwalk to the entry point, one of my tanks fell out of the bands... With the spare parts that I had on hand, eventually we came up with a sandwiched wing between aluminum and stainless steel backplates in addition to rigging the various tanks that I had with me as stages in somewhat of a sidemount configuration... As it turned out, I kind of liked it and decided to give it a try for awhile... So far, I haven't seen that much of a need to go back to back gas except for some inconveniences on getting through hatchways on the Spiegel Grove... I probably need to get a smaller wing though... The 75 lb one that I have tends to fold upwards even with the additional backplate sandwiching it... > I always thought that, when both tanks contain the same gas, the > idea was to breathe one for a while, then the other, so that you > know that both regulators are functioning and so that you have > adequate gas to bail out safely in both tanks, all the time. Correct... And that is what I normally do... If I suspect that the dive is not going to be long enough to use both tanks, I will probably use one more than the other so that I completely empty it prior to getting back on the boat... That way, the second dive probably just requires one additional tank instead of two... > Breathing one dry and then switching to the other seems, to me, to > be higher risk than diving manifolded twins, but not significantly > higher risk than diving one tank on your back and one carried > stage style. If you are going to do it that way, you don't breathe it dry before switching... You leave enough in it to surface in case you have a problem with the 2nd tank... If I'm in an overhead environment, I'm switching tanks enough that I doubt that there is seldom more than a couple hundred psi difference between the two tanks... If I have a clear shot to the surface, I'm a bit less concerned about them being equal (other than them affecting my lateral ballast)... > Personally, I don't wear more than one tank without a reason for carrying > the excess gas. So far, the tanks I've carried stage style have been filled [quoted text clipped - 4 lines] > protect as well as practical and, for me, that means twins connected with an > isolation manifold. Procedures for diving with a buddy are different than when you dive solo... Just as diving in open water vs an overhead environment... In open water, I'm usually satisfied with having 300 psi in each tank when I surface... One tank might even be less... Hell, look at how many dives we did "way back when" with just a J-valve and no SPG... Although I might do that these days in open water, I don't think I would do it in caves like we used to do... As I've said before -- sometimes, Darwin is asleep... > My current way is basically an experiment that Curtis and I rigged up on a > previous dive trip to Florida... I remember. I wish though that, if you're going to dive sidemount, you'd put together a real sidemount rig. It hurts my eyes to look at that thing you use now. >> I always thought that, when both tanks contain the same gas, the > > idea was to breathe one for a while, then the other, so that you [quoted text clipped - 6 lines] > the boat... That way, the second dive probably just requires one > additional tank instead of two... Then I misunderstood something somewhere and withdraw my comment. > Procedures for diving with a buddy are different than when you dive > solo... True, but with or without a buddy, I will still only wear twins when there's a good reason. Curtis actually likes his better than a single. I don't. When there's a good enough reason to take the gas with me, there's a good enough reason for me to protect it as much as is practical. YMMV. > open water, I'm usually satisfied with having 300 psi in each tank when I > surface... One tank might even be less... Hell, look at how many dives we > did "way back when" with just a J-valve and no SPG... Although I might do > that these days in open water, I don't think I would do it in caves like > we used to do... As I've said before -- sometimes, Darwin is asleep... As one that ran out of gas at the back of a cave, while diving alone, I can assure you that Darwin sometimes sleeps . . . or plays favorites, or something. Whatever the reason, once is enough. Lee > I remember. I wish though that, if you're going to dive sidemount, you'd > put together a real sidemount rig. It hurts my eyes to look at that thing > you use now. I'm still trying to decide if I *really* like it... I guess I'm kinda slow to make a decision... <grin> > True, but with or without a buddy, I will still only wear twins when there's > a good reason. Curtis actually likes his better than a single. I don't. > When there's a good enough reason to take the gas with me, there's a good > enough reason for me to protect it as much as is practical. YMMV. Stay down longer, go deeper, get a better narc... What other reasons could you possibly want? <evil-grin> > As one that ran out of gas at the back of a cave, while diving alone, I can > assure you that Darwin sometimes sleeps . . . or plays favorites, or > something. Whatever the reason, once is enough. Following the 'exit' line the wrong way in a cave got my attention... Finally finding a piece of PVC pipe with a markered arrow drawn on it pointing the *other* way... Well, at least I was running a manifolded set of doubles back then... OK, it was the yoke type non-isolation manifold that US Divers made back then which slipped over normal valves... Yeah, Darwin sleeps... Trust me... > Stay down longer, go deeper, get a better narc... What other reasons could > you possibly want? <evil-grin> Deeper for longer is one reason, not two and the only one that applies to me. Narcosis has never been something I find particularly desirable. I prefer alcohol or other drugs on the surface, preferably relaxing on my boat or patio. > Following the 'exit' line the wrong way in a cave got my attention... I imagine it did. What was that you were saying about narcosis? Lee > I imagine it did. What was that you were saying about narcosis? Can't blame that one on narcosis... The best I remember, it was perhaps 40-50 ft deep at the most... It was more a case of there being a line into the cave and following it... At some point, I left the line to check out a side area... Explored around there for awhile and then came back to the line... By that time, I had forgotten which way I had come from and ended up following the line the wrong way... The line traversed an area that was fairly open, so I'm thinking that during my exploration, I had come back under the line and then back up on the other side of it without realizing it... Back then, we didn't necessarily have jump reels... The line that was in the cave was a permanent one, not one that we put there... > Can't blame that one on narcosis... The best I remember, it was > perhaps 40-50 ft deep at the most... It was more a case of there being > a line into the cave and following it... At some point, I left the > line to check out a side area... Explored around there for awhile and > then came back to the line... By that time, I had forgotten which way > I had come from and ended up following the line the wrong way... Must be inherent narcosis. It's probably something related to eating cocktail weenies cooked over an unregulated gas burner on a stainless reserve activator rod. > The line traversed an area that was fairly open, so I'm thinking that > during my exploration, I had come back under the line and then back up > on the other side of it without realizing it... Back then, we didn't > necessarily have jump reels... The line that was in the cave was a > permanent one, not one that we put there... I'm going to tell on myself with this, but I was quite surprised when I realized that most discussions about the risks of cave diving were talking about caves with permanent lines laid by someone else. I've always worried about losing my way in a cave system, finding that I no longer knew which way was out and not being able to sort it out before running out of gas. My concern, however, was always focused on systems where the only line to the surface was the one I brought with me. Before I want into the first cave, or cavern, for that matter, I was quite aware that the way out is probably not up, that silt can quite easily reduce visibility to zero in a heartbeat and that, if you don't plan for it, it can be a lot easier to find your way into a multi passage cave system than to find your way back out. Frankly, it seems to me that the death of someone who loses track of the way out of a cave, who can't figure it out before drowning, is nothing more than a bit of chlorine in the gene pool, Darwin working as intended. It's a problem for all those more responsible divers that want to retain their ability to dive in caves, but it's not exactly an undeserved outcome. Glad you survived. Even more glad I survived my OOA in a cave by myself mistake. Lee > Stay down longer, go deeper, get a better narc... What other reasons could > you possibly want? Two out of three anyways. More gas in a balanced configuration. Same with a stage, more time and / or a bigger reserve, not in my case to increase penetration. I don't view "narc" as something desirable. Curtis > I don't view "narc" as something desirable. Well, I don't dive in water cold enough to keep my beer cold, so I have to be willing to get by with just a good narc... OK, I guess I *could* carry a cooler full of ice and beer with me during the dive, but for some reason, that just seems a bit wrong... Well, unless it was a stainless steel cooler, of course... <grin> > I remember. I wish though that, if you're going to dive sidemount, you'd > put together a real sidemount rig. It hurts my eyes to look at that thing > you use now. Awh, 'ell, at least I'm not using duct tape and beer cans to hold my back gas together... Hmmm... Come to think of it, if Curtis and I had had a couple rolls of duct tape that day, we probably could have made the steel 72s fit my existing bands... Which part of my exist rig pains you the most? The fact that the wing is so big that it folds up above me when it's not full? I probably need to do something about that... Probably get a smaller wing like the one you were wearing last time... What's it's size? On Mar 13, 12:04 am, Grumman-581 <grumman...@DIE-SPAMMER-SCUM- gmail.com> wrote: > Which part of my exist rig pains you the most? The fact that the wing > is so big that it folds up above me when it's not full? I probably need > to do something about that... Probably get a smaller wing like the one > you were wearing last time... What's it's size? Why reinvent the wheel? The next time you're in FL, stop at Bill Rennaker's place in Luraville (www.sidemount.com)and have a chat. Not only do they know what works, they have it hanging on the wall for sale. With steel tanks, you still need some lift. I think most of the sidemounters are using a DR Rec wing and an inner tube to hold it down. Also look at the Armadillo from Curt Bowen. > Why reinvent the wheel? Probably because I prefer something that I've created over something commercially available... Flexibility in changing it to suit my own needs is probably one of the main things that I like... I figure that I need to get Scott to design me a stainless steel front plate to protect me from those mankiller stingrays... <grin> > With steel tanks, you still need some lift. I think most of the > sidemounters are using a DR Rec wing and an inner tube to hold it > down. Something just strikes me wrong about using an inner tube as part of my dive gear... Well, unless it's held in place by duct tape and beer cans... I've considered trying using a horsecollar BC with a sidemount configuration... Theres still at least one company that makes one and the quality of materials and workmanship appears to be as good as the top of the line 1000 denier wings... Since the BC would be on your front and with minimal air in it, actually more likely wrapped around your sides, you wouldn't have the problem with the sides of it folding upwards like I've had with my current configuration... Unfortunately, it's been too many years since I've dove with one to really remember any especially irritating features about them... Damn, must be another Alzheimer's Moment... > Probably because I prefer something that I've created over something > commercially available... Flexibility in changing it to suit my own > needs is probably one of the main things that I like... I figure that > I need to get Scott to design me a stainless steel front plate to > protect me from those mankiller stingrays... <grin> It's still worth a stop. It doesn't hurt to see what others are doing, and they have some custom made little parts and such that facilitate putting your own rig together. > I've considered trying using a horsecollar BC with a sidemount > configuration... Theres still at least one company that makes one and [quoted text clipped - 6 lines] > any especially irritating features about them... Damn, must be another > Alzheimer's Moment... I've seen several setups based on stripped down jacket BC's. >> I remember. I wish though that, if you're going to dive sidemount, you'd >> put together a real sidemount rig. It hurts my eyes to look at that [quoted text clipped - 4 lines] > couple rolls of duct tape that day, we probably could have made the steel > 72s fit my existing bands... If you had waited for me to arrive, you would have had your duct tape. Some lives in my dive bag (yellow) and some lives in my vehicles (gray). With all the stuff you had in your truck, particularly when pulling your boat, what the hell were you doing without duct tape. > Which part of my exist rig pains you the most? The fact that the wing is > so big that it folds up above me when it's not full? I > probably need to do something about that... Probably get a smaller wing > like the one you were wearing last time... What's it's > size? I don't know which of my wings you've seen. It was probably the 27 lb Halcyon wing. My 18lb wing won't float my gear in fresh water. I bought and used my 50 lb doubles wing for the first time after the last time we dove together. I'm not sure what bothers me most about your rig except that the parts don't seem to work together as well as they should. I'll have to get out my video tape of MJK's Dreamchasers dive to be sure, but I think the sidemount rigs the Mexican cave divers wore held the tanks more in line with the body and that their wings went under the tanks, between the tank and the body, rather than over the tanks like yours does. That would seem to keep your vertical profile smaller which, after all, is the point of sidemount in the first place. Lee > If you had waited for me to arrive, you would have had your duct tape. Some > lives in my dive bag (yellow) and some lives in my vehicles (gray). With > all the stuff you had in your truck, particularly when pulling your boat, > what the hell were you doing without duct tape. I know it might be a bit surprising coming from a person from the South, but pretty much the only thing I used duct tape for is actual duct work in the attic... Unfortunately, I didn't bring everything that I might need for an impromptu gear reconfiguration... I *thought* that I was ok and if I had been able to refill my AL80s, Curtis and I wouldn't have had to attempt this endeavor, but all in all, it turned out ok... At the very least, we got some good laughs out of it that evening at Lowes when we were building the pseudo-sidemount rig... > I don't know which of my wings you've seen. It was probably the 27 lb > Halcyon wing. Yeah, I seem to remember an "H" on it, so it was probably the Halcyon wing... > I'm not sure what bothers me most about your rig except that the parts don't > seem to work together as well as they should. I'll have to get out my video [quoted text clipped - 4 lines] > profile smaller which, after all, is the point of sidemount in the first > place. On thing that I do notice with mine is that when I'm getting in an enclosed area, I can feel / hear the portions of the wing that is folded up scraping across whatever is above me... With tanks in the same scenario, it would be a thud, perhaps followed soon thereafter with me being wedged in... I guess you could kind of consider it something like the metal rod curb feelers that you used to see on cars many years ago... <grin> All in all, I suspect you're right though... I need to work on that configuration a bit... > Awh, 'ell, at least I'm not using duct tape and beer cans to hold my back > gas together... Hmmm... Come to think of it, if Curtis and I had had a > couple rolls of duct tape that day, we probably could have made the steel > 72s fit my existing bands... They make an adapter for that, I know who has some for you. > They make an adapter for that, I know who has some for you. Perhaps, but we were working with what we had on hand... If I had had a couple of rolls of duct tape with me, I suspect that it would have been used too... Hell, I'm pretty sure I had the empty beer cans... > They make an adapter for that, I know who has some for you. Did I keep them or did you? > My current way is basically an experiment that Curtis and I rigged up Correct that a bit. I don't want any blame, er, credit on that one. Showed you somewhat how to tie on a stage, your bands had issues, and how to keep the wing from "tacoing". Temporary set-up, not intended to be a permanent solution. AL80 stages a handle differently from old 72s, and are a totally different animal from large steels. And, your hose issues are foreign to my usages.....hell, the concept is foreign to me. As Al said, a trip to Luraville would be more productive. Curtis >> I'm missing something - what does carrying a stage have to do with >> independent doubles? How are the risks similar? > Guess somehow burning a stage down to near zero and holding back gas > (isolation manifolded) in reserve, with two first and two second stage > regs in reserve, is equivalent to burning one independent double down to > zero with half the back-ups. Go figure. Ever see anyone carry a stage under their arm with only one tank and one regulator on their back? Someone you dive with fairly frequently, perhaps? Ever see or hear of anyone breathing from their stage at the end of the dive instead of the beginning, say someone that dives in caves? Is the stage any less an independent gas supply because it's under the arm? Is the gas in that stage tank any more or less exposed to problems than Grumman's independent twin because you call it a stage instead of a sidemount? Lee >> Guess somehow burning a stage down to near zero and holding back gas >> (isolation manifolded) in reserve, with two first and two second stage >> regs in reserve, is equivalent to burning one independent double down to >> zero with half the back-ups. Go figure. > Ever see anyone carry a stage under their arm with only one tank and one > regulator on their back? Someone you dive with fairly frequently, > perhaps? Yeah, you telling me you screw up your gas management too? > Ever see or hear of anyone breathing from their stage at the end of the > dive instead of the beginning, say someone that dives in caves? Deco bottles, yes. Otherwise, I'm more familiar with either burning the stage first, or breathing part then dropping it, depending on the dive. Still, where are you leading? > Is the stage any less an independent gas supply because it's under the > arm? Still off on a tangent? > Is the gas in that stage tank any more or less exposed to problems than > Grumman's independent twin because you call it a stage instead of a > sidemount? Actually, yes. Where his tanks "ride" is different. > Agreed, but I must admit, though that Grumman's method of diving > independent twins is not what my learning suggests is the best way. I [quoted text clipped - 5 lines] > but not significantly higher risk than diving one tank on your back and > one carried stage style. Gas management is the issue once again. (And you're right about breathing down both in that scenario.) But, don't think Grummy said that was his SOP, he commented about taking one down late in the dive. My comment was simply that if you're thinking about the reg switches then you've already got three strikes. 1) gas mismanagement 2) reg malfunction 3) buddy issue You're getting too focused on configurations to catch what's being said about gas management. The manifold takes care of the equal usage issue, but require more attention to proper filling. Independent supplies in any configuration require more attention to gas usage. You're making the waters murky by concentrating on the word "stage". > Personally, I don't wear more than one tank without a reason for carrying > the excess gas. So far, the tanks I've carried stage style have been [quoted text clipped - 8 lines] > necessary for the planned dive. Had that supply failed, everybody still > got to the surface safely. Obviously we agree in this area, (or at least you're willing to humor me). Curtis > don't think Grummy said that was his SOP, he commented about taking > one down late in the dive. My comment was simply that if you're > thinking about the reg switches then you've already got three strikes. The way that I figure it, when you've reached the point where you need to contemplate a reg switch, you've already had quite a few things go wrong... Let's say that you're following the rule of thirds... You use 1/3rd of your gas getting into the cave then you have a problem with one reg... At that point, you've got 2/3rds gas left in both tanks, but since one reg is dead, you've only got 1/3rd in the tank with the good reg... At this point, because of the whatever reason (swimming against the flow, difficulty getting through an opening that has partially collapsed, silting causing you to swim slower, or losing contact with the line and having to search for it), you realize that there is no way that the remaining 1/3rd of you gas is going to get you out of the cave... You also realize that you haven't screwed up so bad that the 1/3rd in the tank with the bad reg also wouldn't get you out... All you need to do is come up with a way to use the air in the tank with the bad reg... Being able to swap the good reg to the tank that had the bad reg on it is a solution... Given that the other choice at this point is learning how to breathe water, I figure it's defintely a *better* solution... But yeah, if you've gotten to this point, a lot of other things have had to go seriously wrong for you that day... > The way that I figure it, when you've reached the point where you need > to contemplate a reg switch, you've already had quite a few things go [quoted text clipped - 3 lines] > but since one reg is dead, you've only got 1/3rd in the tank with the > good reg... You mean you only have 1/3 left in the tank with the good reg. Al, Magilla and I all still have 2/3 in tanks with a good reg. We have to have two regulator failures to get where you are after only one . . . assuming we're managing our gas the same way. > At this point, because of the whatever reason (swimming > against the flow, difficulty getting through an opening that has [quoted text clipped - 10 lines] > point, a lot of other things have had to go seriously wrong for you > that day... On this, I certainly agree. Consider though, that a manifolded twinset requires at least one more thing to go wrong before you're in the same situation than independent twins do. With our configuration, assuming only two bottles, our backup regulator is already attached to our remaining gas supply. Yours isn't. Used properly, that gas management Curtis keeps referring to, your configuration can work just fine, but to be as safe as our configuration makes us, you have to manage your gas so that either tank can get you, and your buddy if you have one, to the surface, if you loose access to the other tank. That means you can't use as much of your gas as we can without increasing risk. Being able to swap regulators underwater without drowning, if you can do it, helps, but the risk is still higher. Lee > You mean you only have 1/3 left in the tank with the good reg. Al, Magilla > and I all still have 2/3 in tanks with a good reg. We have to have two > regulator failures to get where you are after only one . . . assuming we're > managing our gas the same way. Actually, if you have two regulator failures, you are in the same place I would be with two regulator failures -- trying to breathe water... We talk about preparing for regulator failures, but quite frankly, I suspect that a complete failure of the regulator is a rather uncommon occurrence... Yeah, I've had to disassemble a 2nd stage underwater to get it to quick breathing wet, but if it had been my only 2nd stage, I could have put up with it... How many people around here have actually experienced a complete regulator failure? Maybe we should seperate that further into complete 1st stage vs complete 2nd stage failures... Let's not consider regulator freeze ups since we don't dive in conditions where our water turns solid... <grin> > On this, I certainly agree. Consider though, that a manifolded twinset > requires at least one more thing to go wrong before you're in the same > situation than independent twins do. With our configuration, assuming only > two bottles, our backup regulator is already attached to our remaining gas > supply. Yours isn't. Correct... I choose to go with a system where my main gas and any stages are all configured exactly the same... I'm quite aware that it is a compromise, but I'm willing to take the *slightly* higher risk for what I preceive to be certain benefits (e.g. being able to use standard rental tanks when I go somewhere instead of having to bring my tanks with me)... I've heard it argued that with a manifold, there's a couple more O-rings and as such potential failure points... Yeah, the potential is extremely remote, but it's there... In the even of a neck seal O-ring from one tank, a manifolded set will lose all the air from that tank and part of the air from the other tank until the diver can get it isolated... With an independent setup (sidemounts or independent back gas), you just lose the gas from the problem tank... > Used properly, that gas management Curtis keeps referring to, your > configuration can work just fine, but to be as safe as our configuration [quoted text clipped - 3 lines] > increasing risk. Being able to swap regulators underwater without drowning, > if you can do it, helps, but the risk is still higher. Although I haven't tried it underwater, I've done it above water, allowing for a few more seconds than I think it would probably take to purge and such... Of course, being above water, I don't truly have the pressure (no pun intended) on me to do it right the first time like I would in a real emergency situation, but I managed to complete it without needing to fake my own drowning death... <grin> On the other hand, one could put some air in their BC and breath from there while doing the changeover... At worst, you're so positively buoyant that you're pinned to the overhead... I've had been pinned to the overhead at Blue Springs enough time even while being extremely negatively buoyant that such a position is practically second nature to me... > Actually, if you have two regulator failures, you are in the same > place I would be with two regulator failures -- trying to breathe > water... True, but we're not in the same place after only one. > We talk about preparing for regulator failures, but quite frankly, I > suspect that a complete failure of the regulator is a rather uncommon > occurrence... It's never happened to me, but I know someone it did happen to. The regulator was serviced by a shop that was too cheap to buy their shop manual from Scuba Pro, so they made a copy of a preliminary one. It had a mistake that resulted in a part, something to do with the high pressure side, being installed upside down. The friend's regulator stopped working at depth. > I've heard it argued that with a manifold, there's a couple more > O-rings and as such potential failure points... More than a couple. There's 4 where my manifold connects to the valves and several more in the isolation valve. > Yeah, the potential is extremely remote, but it's there... In the event of > a neck seal O-ring > from one tank, a manifolded set will lose all the air from that tank > and part of the air from the other tank until the diver can get it > isolated... With an independent setup (sidemounts or independent back > gas), you just lose the gas from the problem tank... I won't loose much before I can get the isolation valve closed. If that was something I was worried about, it's simply enough to chut the valve at the beginning of the dive, providing me with independent twins, but retaining the option of reconnecting them. Any way I look at it, the manifolded twins are more versatile. > On the other hand, one could put some air in their BC and breath from > there while > doing the changeover... If you're going to put enough in there to do much good, better have something anchored to the bottom to hold on to. > At worst, you're so positively buoyant that you're pinned to the > overhead... If there is an overhead. Lee > If there is an overhead. If there is not an overhead, then I probably wouldn't be getting into that situation anyway... With an open water dive, if I lose a reg on a tank, I'm probably going to abort the dive at that point unless I want to consider an emergency ascent to the surface as my alternate air supply... With a shallow reef dive in Florida, I might continue with just a single tank and reg and just plan on surfacing towards the end of the tank with the good reg... There's no reason to worry about switching regs on a dive like that... A bit more bottom time is not worth the potential of having to get the reg serviced after switching it underwater... <snip> Hey Lee... Found a photo of a new ATV for you... http://www.dpchallenge.com/image.php?IMAGE_ID=474454 > Hey Lee... Found a photo of a new ATV for you... > http://www.dpchallenge.com/image.php?IMAGE_ID=474454 That's a beauty alright. Full tracks are pretty in my part of the state, but the number of them is beginning to diminish as more and more areas only allow vehicles with pneumatic tires. The tracks are perceived as being too destructive which, unlike a lot of what Florida's conservation people do, may actually be true. Still, when they're all gone, it will be the end of an era. > Gas management is the issue once again. (And you're right about > breathing down both in that scenario.) But, don't think Grummy said that [quoted text clipped - 13 lines] > require more attention to gas usage. You're making the waters murky by > concentrating on the word "stage". Thanks Curtis. I was in the middle of writing essentially the same thing. >> Ever see anyone carry a stage under their arm with only one tank and one >> regulator on their back? Someone you dive with fairly frequently, >> perhaps? > Yeah, you telling me you screw up your gas management too? Nope. It's there as a precaution. You telling me you don't prepare for problems too? >> Ever see or hear of anyone breathing from their stage at the end of the >> dive instead of the beginning, say someone that dives in caves? > Deco bottles, yes. Otherwise, I'm more familiar with either burning > the stage first, or breathing part then dropping it, depending on the > dive. Still, where are you leading? Nowhere. I arrived. The point was that the stage tank has all the same risks as Grumman's independent twins. While you change that risk by breathing the stage first, anyone the breathes it last, and actually needs it to dive his plan, has the same risk that Grumman does. Whether you call it a stage or an independent twin, or anything else, the effect, and the risks, are the same. >> Is the gas in that stage tank any more or less exposed to problems than >> Grumman's independent twin because you call it a stage instead of a >> sidemount? > > Actually, yes. Where his tanks "ride" is different. Which changes the exposure to problems how? > You're getting too focused on configurations to catch what's being said > about gas management. You're getting too focused on gas management to catch what's being said about configurations. You, I, all sane divers, plan and equip to handle postential gas management failures. The jury's out on whether Grumman is sane or not, but denying the risk while planning for it isn't particularly consistent thinking either. > The manifold takes care of the equal usage issue, but require more > attention to proper filling. Independent supplies in any configuration > require more attention to gas usage. You're making the waters murky by > concentrating on the word "stage". Quite the opposite. I've been very specific in stating that it does not matter what you call the tanks. Independent twins, stages, or deco bottles are all the same. If not connected to other tanks and regulators, the reisks are the same. I'm the one that has said, several times, that the name is not what defines the risk. > Obviously we agree in this area, (or at least you're willing to humor > me). Both, actually. I don't choose to emulate Grumman's configuration choices, but I understand them and recognize that they are not all that big a risk by themselves. Granted the risk changes dramatically depending on how he manages his gas while diving that configuration, but this discussion is about configurations, not about all the other aspects of diving, whether DIR, Stroke, stroke or Grumman. Lee >> Yeah, you telling me you screw up your gas management too? > > Nope. It's there as a precaution. You telling me you don't prepare for > problems too? Was wondering why your configuration had to do with the price of tea in China. You were obviously leading up to some point, but I still don't know why. You plan on needing to do regulator switches underwater? >>> Ever see or hear of anyone breathing from their stage at the end of the >>> dive instead of the beginning, say someone that dives in caves? [quoted text clipped - 4 lines] > > Nowhere. I arrived. Must have been a different location. >> Actually, yes. Where his tanks "ride" is different. > > Which changes the exposure to problems how? "CLANG" > You're getting too focused on gas management to catch what's being said > about configurations. Well, that way I can control what I'm trying to express without being sidetracked into a big pissing match. With that, time to play with another thread. > You plan on needing to do regulator switches underwater? It's not so much that you plan on needing to do it, but rather knowing how to do it just in case it is ever necessary... I didn't plan on having to land my aircraft off-airport in an emergency, but I know how to do it, just in case... > With that, time to play with another thread. Awh, 'ell... This is has stayed diving related for way too long... We need to do something to change that... So, what type of holster is best to use when diving independent back mount vs manifolded back mount vs independent sidemounts? <grin> > Was wondering why your configuration had to do with the price of tea in > China. You were obviously leading up to some point, but I still don't > know why. You plan on needing to do regulator switches underwater? Not leading anywhere, just commenting that others accept the same kind of configuration risk that they are criticizing Grumman for, only with stages instead of tanks on the back. The only point is that any independent gas supply, with only one regulator carries the same kind of risk. As for doing regulator switches underwater, only if I have to, but I'm Eagle Scout. I believe in being prepared. Lee > Not leading anywhere, just commenting that others accept the same kind of > configuration risk that they are criticizing Grumman for Then you're missing what the "criticisms" were, and you're locked on to a non-existent target. The comments are totally out of place when attached to snips of my posts. > The comments are totally out of place when attached to snips of my > posts. Guess you're right. Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is to isolation manifold their deco and other stages. > Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is to > isolation manifold their deco and other stages. Well, Curtis could probably get away with manifolded LP-120s as sidemounts / stages in addition to back gas, but us more normal sized folks don't quite have that option... <grin> > Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is > to isolation manifold their deco and other stages. Have some more fun at my expense. I think I've outgrown this newsgroup. >> Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is >> to isolation manifold their deco and other stages. > > Have some more fun at my expense. > > I think I've outgrown this newsgroup. I think you've closed your mind to contrasting views. > I think I've outgrown this newsgroup. Awh, just loosen your belt a bit and stay around awhile... Greg will be back in awhile and we can go back to picking on him again... <grin> >> I think I've outgrown this newsgroup. > > Awh, just loosen your belt a bit and stay around awhile... Greg will > be back in awhile and we can go back to picking on him again... <grin> Yeah, right. Said it before, here for fun, when it ceases to be fun, why bother? I do suppose you already knew your rig needed refining? When a friend insists on "bitch slapping" me for giving a straight-forward opinion, including insulting me for being DIR, (which has little or nothing to do with these comments), kind of makes me feel like I am wasting time here. Talk about over-analysis. Lee Bell >>> "Still, the same people that would criticize his configuration, as he uses it, decline to accept the fact that part of their configuration is exposed in precisely the same manner." Because some facts only exist in your opinions. Fact is, TRIM & GAS MANAGEMENT vs REG SWAPPING comments were the only ones made. NO OTHER ISSUE WAS DISCUSSED, COMMENTED ON, or "criticized" by me. Any additional assumptions tagged on to me are merely a distraction. What you declare is the subject is not the subject I am bound to participate in. Scoring an imaginary point on another unmanned court is irrelevant. How this brings up humourous ideas in one's head I haven't a clue. If being "closed minded" means I do not entertain every crazy idea that comes along, so be it.......funny how the same people get irritated by the anti-gun nut's ideas, the closed-minded Hypocrites. <ducking & running> Anyways, this "discussion" has run its course in my eyes also. A mutual STFU is in order. Curtis > I do suppose you already knew your rig needed refining? Of course... It works well enough, but is just not quite right yet... Perhaps I'll get tired of it and go back to back gas independent twins one of these days... Perhaps I'll put the HP-120s for back gas and save the AL80s or steel-72s for stages for when I finally get a chance to do the Oriskany... > When a friend insists on "bitch slapping" me for giving a > straight-forward opinion, including insulting me for being DIR, (which has > little or nothing to do with these comments), kind of makes me feel like I > am wasting time here. Awh 'ell... If you can't be ribbed for being DIR, what can you be ribbed about? Being a concrete block abuser? <grin> > Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is to > isolation manifold their deco and other stages. WTF? You're totally fixated on the stage - take a step back and look at the whole picture. Backmounted manifolded doubles and stages is not a DIR thing; it's what is taught by every US agency. The DIR folks might manage the gas a little differently, but you're nowhere near a discussion of that. >> Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is >> to >> isolation manifold their deco and other stages. > WTF? > You're totally fixated on the stage - take a step back and look at the > whole picture. In a discussion of the risks of an independent tank, what else would you expect. That's the topic. OK, so Grumman breathes his stage tank first and his primary supply second. You breathe your stage tank first and your primary second. See some significant difference there? Me neither, as I originally said. Did you, perhaps, miss the part where I mentioned my twins are connected by an isolation manifold? Lee > >> Sorry everyone. I failed to realize that, unlike Grumman, the DIR way is > >> to [quoted text clipped - 5 lines] > primary second. See some significant difference there? Me neither, as I > originally said. There is a significant difference in the configuration of the primary supply, and it changes everything from a risk management point of view. Like I said, you have to look at the whole thing. Sometimes I don't touch the primary supply. This discussion has run its course. The gear is all checked out, the batteries are charged, and it's all in the truck. I'm headed for FL cave country in a few hours. Y'all play nice for a few days. al > There is a significant difference in the configuration of the primary > supply . . . Nobody said differently. The point was that the risk to the secondary supply is the same, and it is. His aren't manifolded. Yours isn't manifolded. If you need that gas, the issues are the same. Still, the same people that would criticize his configuration, as he uses it, decline to accept the fact that part of their configuration is exposed in precisely the same manner. > Like I said, you have to look at the whole thing. Sometimes I > don't touch the primary supply. Sometimes he doesn't either. > This discussion has run its course. The gear is all checked out, the > batteries are charged, and it's all in the truck. I'm headed for FL > cave country in a few hours. Y'all play nice for a few days. Have a fun, safe time. Personally, I'm headed to Dallas. All things considered, I'd rather be going with you . . . with my isolation manifolded twinset. 8^) Lee > I'm missing something - what does carrying a stage have to do with > independent doubles? How are the risks similar? The stage is an independent bottle. Furthermore, it is part of your gas plan, right? The only difference between a stage and an independent bottle is that one is on your back and the other is hanging under your arm. The similarity is even more clear in Grumman's case since both of his tanks are hanging under his arms very much stage style. Lee > The stage is an independent bottle. Furthermore, it is part of your gas > plan, right? The only difference between a stage and an independent bottle > is that one is on your back and the other is hanging under your arm. The > similarity is even more clear in Grumman's case since both of his tanks are > hanging under his arms very much stage style. If I am carrying a stage or a deco bottle, I am in manifolded doubles, so whatever happens to the stage, I still have lots of gas with regulator redundancy which allows me to access all of the gas on my back even if one regulator goes bad. My plans are such that if a stage goes bad on the way out, I still have more than enough gas on my back to get out or to the next stage drop. I also have a buddy who has lots of gas. Nothing is perfect, and the wrong combination of failures can still kill you (like the guy who died a couple of weeks ago under the ice when both of his first stages froze open). With independent doubles, that is your main gas supply. There is no built-in redundancy that allows seamless access to all of your gas in the event of a regulator failure. What would you rather do, reach back and close off one side, or do Grummy's take-a-deep-breath-and-change- regulator CF, and then still have only the gas left in one tank? Properly managing the gas takes some real discipline, which I have seen the "king" of independents in the NE blow. It sounds easy, but it is so easy to make a mistake, especially below 100' with some task loading and no helium. Remember, "If you can't completely explain it in one sentence, it won't work underwater". |
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