tank position, why not like firefighters

[Blacthorn]

Yes you can use a full face mask with traditional tanks, the 1st stage is the same.

As for reg recovery, while at first thought it would seem that this would be a major problem with the valve down approach the more I think about it, the more it seems that this would actually be easier in a worse case situation. The initial thought I had was that with a long hose, and with with valve downward that reg if you lost it completely would be so far away from you that it would be very difficult to find. But again you run into the idea of it is easier to reach the 1st stage with the valve downward, then upward, so if you do lose the reg, it should be easier to reach down, find the 1st stage and pull the reg upward with the hose, than to reach behind your head and do the same.

Either way, this comes down to if you want to try it, go for it, and see what you think. But there is a good argument that it has been tried before and discarded for general use. Just like solo diving or any other of the different tacts we take in this sport, do what feels best to you. Its your life you need to save, and its your gear you need to take care of. If you are diving with a buddy, you might just want to mention that the tank is upside down before you dive, don't want your buddy to freak out and try to turn on your nose by accident.

 

[Bigcape]

Yes you can use a full face mask with traditional tanks, the 1st stage is the same.

If you are diving with a buddy, you might just want to mention that the tank is upside down before you dive, don't want your buddy to freak out and try to turn on your nose by accident.

So are all full face mask configurations done with an inverted tank configuration?

 

[Bryan]

So are all full face mask configurations done with an inverted tank configuration?

Not all of them. I dive an AGA/Divator full face mask, but use my tank valve-up.

While any SCUBA tank can be used with a full face mask, if you bought Divator tanks, hoses, and gauges (pictured earlier), they come inverted.

 

[boulderjohn]

It's been a good many years since I was a fire fighter and had to enter a burning buildng with an air pack, so I won't comment on this comparison, but I think I can offer some insight into the basic concept of change.

I was a staff developer in a large school district, and my job was trying to get teachers to adopt new instructional strategies in place of the ones they had been using for years. Our department leaders had a philosophy with which I disagreed vehemently. They wanted to make sure we staff developers weren't perceived as a threat, so they wanted us to validate what these teachers had been doing in the past first, figuring that we should first get on their good side. "What you have been doing for years is great, but we have something we think will be better" was the theory.

Later research in adult learning agreed with me that this approach is doomed failure. People won't change what they are doing unless you convince them that it is important to do so. Telling them that they are already doing a great job pretty much eliminates any possibility that they will try something new. I had my best success by helping people see that the newer processes were significantly better for students, making them realize that continuing with their old practices was doing a disservice to their students.

For a slight (but important) digression, let me offer the term QWERTY. This is the name of the keyboard configuration nearly everyone posting to this board is using--look at the upper left row. When typewriters were first invented, those clunky machines tended to jam if keys were pressed too quickly in succession. The QWERTY configuration was intentionally designed to be inefficient, to keep people from typing too fast. Today we have no such problem, and there is a much better keyboard design available. People who have been trained on it can type much faster than people with a QWERTY configuration. All logic says we should change, so why don't we? With all the QWERTY's around, with all the training manuals, etc. in place, the change would be monumental. Where would people trained in the new keyboard find one to use? Why would people manufacture keyboards no one has used? People therefore decide that the QWERTY system is fast enough for them, and they don't think the benefits of conversion are worth the effort.

It seems to me that we have a parallel situation. Is the upside down system better? I don't know. It appears to me, though, that if it is better than the existing system, most people would say that the existing system is good enough--why make all kinds of expensive changes for a marginal benefit? You would have to convince people that the improvement is really monumental and worth the effort and expense.

 

[SparticleBrane]

I tried a DVORAK keyboard but I'm so used to a QWERTY that it was practically impossible for me to change.
Then again I have no need to change--I frequently type 100-120+ wpm.

 

[boulderjohn]

I tried a DVORAK keyboard but I'm so used to a QWERTY that it was practically impossible for me to change.
Then again I have no need to change--I frequently type 100-120+ wpm.

I think that's my point.

You see no reason to change, and making the change will require a substantial effort. The DVORAK keyboard is almost certainly better, but you would never make that change for the reasons you offer. I use the QWERTY myself for similar reasons, although if I could type at your speed, I would be three years younger.

For me to change to an upside down scuba configuration would require me to invest in all new equipment. It would require the dive boats I use to adapt new techniques, etc. If the upside down configuration is better, I would have to be convinced that it is worth it to make the change. I doubt if that is going to happen.

 

[Cfdsmokeater]

Tell me about that "search line" you mentioned. When we run rescue scenarios, we make the standard search pattern for owner casualties, or follow the hose to find the firefighter. So I am intrigued in a new way to try.

FD

Most of our engines have a "Clorox" type bottles stuffed with synthetic line. Loaded just like a rope bag. beaner off the top is connected somewhere outside and the bottle is carried by the search team (usually when search is done without a hose team --or single search team.)

Rescue trucks have a more commercial system. Some equipment manufactures sell "pre packaged kits." These usually consist of a "main" line that is deployed lets say down a hallway. One fireman stays in the hallway while the others clip an individual small search line bag and proceed into individual rooms. Personally, nice idea in theory but takes alot of man power.

I have seen "rope light" search line. Novel idea but I don't see our dept. buying it anytime soon.

http://www.rocknrescue.com/acatalog/Rescue_Catalog_Escape___Search_Bags_24.html

 

[vjb.knife]

It has been done... hasn't caught on...

I dove this original version of the Diviator back in the mid 1970's and I still consider it to be the best thing going.

It did not "catch on" for 2 reasons - 1. it was very expensive compared to other standard gear of the time and 2. the tanks operated at 4500 psi which was standard in Europe but in the US the top fill available at most shops was 3500 psi.

Interspiro is in process of having the newest version of the Divator system approved for use in the USA at this time and hopefully it will be ready this Spring. The latest version will use carbon fiber tanks and hopefully be as nice as the original one shown above. If it is I will get one without doubt, as the monetary factor is no big deal now.

 

[in_cavediver]

Frankly, I think isolating would go from difficult, to near impossible. If I were going to go to the trouble of inverting, changing all my hoses, and doing something "different", I'd just sidemount.

I gotta agree with Perrone here. If you have mobility issues, carrying two 'single' tanks has to be a lot easier to do than them doubled up. (think multiple trips). Also, if your going to do dives that need doubles and you have these issues, you should have the skills to handle the independent nature of sidemounted tanks.

I'd hate to think of setting my rig (dbl 104's) down on the manifold/valves. I'd hate even more to think of the 'cage' required to do it. Just smacks of entanglement hazard.

 

[in_cavediver]

1: Air rises underwater... (note your BC)... so it would make sense that if you're low air and need to accend... having what air remains in your tank near the valve (I assume we all asscend head up)... is, in my opinion... a "good thing"... (but then... I don't know... does air in a hollow sealed container like a cylinder actually rise??? hummm... not good at physics... may not be a relevant arguement... SOUNDS GOOD THOUGH!!)

It sounds good but since the tank is pressurized, air flows out the hole, wherever it is.

2: The issue of pressure dynamics (without reinventing the entire wheel) would indicate that the first stage should be on a relative level with the 2nd...

Again, this is false. The first stage takes tank pressure - up to 3000 and steps it down to 120-150psi. A 4ft difference is 2psi. Not significant for functionality. (and even could be adjusted out to match). Its the 2nd stage that takes it to ambient and that position can be important.

3: I do "Midwest muck diving"... if I do a butt-plant on the bottom (... hey, it happens)... I don't want muck jammed in my first stage...

4: I'm not overly concerned with valve stems snapping off... its more likely, I would think, loading and unloading the tanks into your vehicle for trasport... or sitting around the shop... and, in those situations... a snapped valve in either configuration would have the same basic result... degree of trauma relative to the initial pressure load inside the tank. However... in my previous post I mentioned the issue of finding the hoses if dropped. I think this is a VALID point... I don't know what all kinds of regulator systems firefighters use... but what I've seen is full face masks... strapped on. Don't see a lot of em' in scuba... just a reg with teeth on one end and a hose on the other...

5: "Reaching your valve" seems, to me... a bit like a bogus argument... that's what we've got buddies and buddy checks for. Re-designing a tank because we forgot fundimental diving skills *seems* like a bit of overkill to me...

I agree, protecting the reg/valve is important. Remember, an SCBA pack weighs 10-15lbs (if I read prior posts correctly), my 104's weigh over 100lbs. A lot more energy to be concerned with. Also remember we attach regs right on the post and they are soft metal.

I can see the problem of reaching valves and do acknowledge it. I will also grant it more of an issue in tec than rec. I just think that for those people who are concerned with reaching thier valves, there are better solutions than inverting a tank if the standard method doesn't work.