Managing Steel Stage Bottles??

[ermaclob]

I have a steel 46 stage bottle. i got it a while back when i decided to give solo diving a try. back then i would sling the tank but i wasn't really into the whole keeping trim thing and would just swim with it dangling below me or on my side. it really did not matter to me. i stopped using it a little over a year ago because i never really got to into the solo diving thing. A week ago i went on a short notice trip with some friends and i only had one Al80 full and did not have time to fill my others or rent so i took the 46 and used it as part of my gas plan. I've become veeery fond of staying in trim and was unsuspectingly surprised as to how much toque that tank puts on me while im in trim. If i where to just stay still i would turn with the tank pointing down in a 45 degree angle from the horizontal position. after a few minutes it became a little more manageable but still noticeably more work then normal. i had a friend take a picture just to see how in trim i could stay

i know that some people do use steel stages for deco etc. even tho most recommend Aluminum tanks. i was wondering if there is a way to better manage this tanks and if i would need to weight my self differently to compensate?

 

[DA Aquamaster]

As you know the Faber LP 45/ OMS 46 is fairly heavy in the water at about -6 pounds full with a reg and stage kit on it. That compares to about -3 pounds for a full AL 80 or AL 72 with a reg and stage kit, or about -2 pounds for an AL 40 or AL 30.

I use LP 45s from time to time as a deco bottle, but it gets left in the cavern zone, so the time and distance I actually carry it is very short - and I prefer an AL 30 or AL 40. For stage use, I use an AL 80 or an AL 72 as steel 45s or steel 72s are just a bit too negative for effective and effortless trim (and the 45 is too gas limited to make it worth the effort as a stage).

Given the -6 pound negative buoyancy and the 3 pound differential compared to a more acceptably trimming AL 72 or AL 80, you can add a 3 pound weight to the other side of your harness to more or less split the difference and give you a little better lateral trim.

If you are diving a 3mm shorty however, I'd keep the weight in a small weight pouch so it's ditchable rather than threading it on the harness, so that you've still got the ability to swim the rig to the surface in the event of a BC/wing failure. That also makes it easy to leave off if you are not diving with the the LP 45.

In terms of mounting the tank, I'd use a shorter bolt snap on the nose and maybe lengthen the tail just a bit to level out the tank, or perhaps play with the lower band location, so it's not so a) nose low and potentially digging in the silt, and b) not angled down so sharply and adding unnecessary drag. LP 45's don't have nearly as much of the floaty tail syndrome as aluminum tanks - at least with the boot removed.

And, I'd remove the boot as one of the major killers of the Faber 45 / OMS 46 is corrosion under the boot.

 

[billgraham]

We have one of these down in Florida that we use as a safety 0-2 bottle for rebreather cave dives, and we always argue about who is going to carry the darned thing into the cavern because it weighs a ton. Most of us have come to the conclusion that aluminum tanks are better for stages/deco bottles.

 

[decompression]

I agree with DA, a small, ditch able weight pouch with 3 or 4 lbs should enable the rest to be "body language". I use the pouches from XS for threaded or the pouches from UTD which don't have to be threaded and can be moved around easier.

 

[rx7diver]

I have a steel 46 stage bottle. ... i know that some people do use steel stages for deco etc. even tho most recommend Aluminum tanks. i was wondering if there is a way to better manage this tanks and if i would need to weight my self differently to compensate?

ermaclob,

When I first began tech diving (in the mid-1990's), I purchased and used an OMS (Faber) 46 for a (slung) deco bottle. My tech instructor recommended it for the additional gas it held when filled "liberally."

I wore a drysuit and steel, manifolded doubles (PST HP 100's) with the 46 at that time. Although I was aware of the weight, or torque, of the 46, it was quite manageable without resorting to unbalanced weights. I suspect the significant weight of the steel doubles and the moveable air "bubbles" in my drysuit and wings helped in this regard; my experience probably would have been quite different had I been wearing a shorty wetsuit and a single back-mounted Al 80!

One other thing: My instructor dove with two of these deco 46's, slung bilaterally ("right-rich, left-lean," which was often taught at that time), and eventually I purchased two more 46's and dove similarly a couple of times. Of course, there was absolutely no torque from the bilaterally slug 46's.

BTW, three 46's meant one could do two deep tech dives (and two not-as-deep repetitive dives) over a weekend when using overboard oxygen and having access to an on-board compressor. For the deep tech dive, a diver would carry two 46's, each containing the same first deco gas, with the plan to breathe from only one bottle, and then finish deco using overboard oxygen. The second 46 was for contingencies. For the not-as-deep repetitive dive, the diver would carry only one--the unused 46 from the initial dive--for contingencies, with the intention of breathing only overboard oxygen for deco. Dives the second day would be carried out the same way, starting out with the two still-filled 46's. The diver would return home with an unused 46--unless something untoward had happened. (Doubles would be filled using the onboard compressor after each dive. The 46's would have been cave-filled before leaving for the trip.) I believe I described this procedure on SB before, but I wasn't able to find the old post just now when I quickly searched.

Safe Diving,

rx7diver