Looking for triple manifold

[Jim Lapenta]

Acustomer of ours is looking for a triple manifold to put together 3 40 cu ft tanks to use for swiftwater recovery/rescue operations. He wants to carry as much air as possible in the lowest profile. I suggested dual 72's but he wants even slimmer than that. I remember Mike Nelson's triples and have seen others talked about on the board. If any one has any info please PM me. He wants a manifold to use with a single first stage and second only. Does not use an octo and as small a wing as possible. I have also suggested going sidemount but that would require the use of two regs which he does not want.

 

[fishb0y]

Hope he is looking to spend a pretty penny

 

[Nemrod]

Triples will not be slimmer than steel 72s on a narrow doubles manifold. Independent double 72s can be made very narrow. In any case there are no triple manifolds being made today and to my knowledge, the main player, the Nemrod Triple was realy intended for LP tanks. I have one brand new and it is not for sale--sorry. They usually run well over 300 dollars if you can find one--new. It is 1/2 pipe thread so bushigs are needed and it cannot really be used at 3,000 psi--well--maybe.

The USD triple manifolds are even more rare and I know little about them.

This USD set is clearly low pressure and similar to the Nemrod set ups. The Nemrod could be set up with different connector pipes of different lengths to change C/C measurements for different tank sizes.

No modern tanks are really suitable for a triple set up.

Here is a suggestion, have Victor make a set of triple bands for aluminum 40s. Connetc the right tank and center tank with a vintage style single outlet manifold (Sherwood is OK for 3,000 psi) and then use a K valve on the left tank. This way you have 2/3 gas for the dive and 1/3 reserve. This set up will require a custom harness as triples will not fit on a backplate.

Modern dive equipment aside from being made of plastic and being unreliable is awfully boring.

N

 

[Nemrod]

Nemrod Triple set up probably for steel LP 30s compared to a vintage USD doubles manifold as used on 38s/45s/50s and 72s.

Note, 1/2 pipe thread on Nemrod and 3/4 straight on the USD. Both are clearly low pressure service with the fat O rings.

Notice O rings on the Nemrod spreader tubes.
N

 

[DA Aquamaster]

I bought a set of two US Divers stickered Luxfer 30 cu ft tanks with a USD double manifold with a single outlet (for a K-valve). It includes a rubber piece in the center to keep them properly spaced when attached to a BC or backplate. It is designed to be held in place with a cam band on a normal BC but would also work with a cam band on a single tank adapter and backplate.

The manifold would work with a pair of Luxfer 40's as well (about 5" longer than a 30). That would give 80 cu ft in a pair of closely spaced (about 1" apart) low profile 5" diameter tanks - a package about 11 inches wide and 5 inches deep.

I use them separately for deco bottles and the manifold is consequently still in nearly new condition in storage. If he is willing to pay what it is worth, I'd be willing to find it in storage and sell it.

I do know what your customer is looking for. US Divers also marketed a 3 tank angle formed verion of this manifold with a single K-valve outlet in the mid-late 1970's as a simplified version of their UDS-1 system. They were sold with triple 30's but 40's would work as well and that would make 120 cu ft possible with a unit about 6" wider - if he could find one.

A UDS-1 system would possibly fit the bill as well, although they were a little different in layout and hose arrangement. The Going Under Dive Center had a new old stock UDS-1 4 or 5 years ago and may be in the mood to sell it if hey still have it.

Back in the day I used a Watergill AT-Pac with a fairing when diving in tailraces below hydro electric dams. It looks a little bulky but the fairing did actually help reduce drag and would accommodate a single AL 80 or steel 72. It would also work with any tank the same diameter as an AL 80. I still have it around here somewhere as well along with a still serviceable AT-Pac.

 

[Nemrod]

OBTW, there is a Nemrod set with triple 72s for sale--maybe --from Scuba4life on the VDH forum.
N

 

[james croft]

Not to change the subject, but scuba diving should not be used in swift water rescue.
Anything faster than about 2 knots is dangerous and you will lose a diver or two (or three). Not sure what the customer defines as swiftwater but what I call swiftwater is not for scuba. Big difference between a little current and swiftwater IMHO.

 

[fishb0y]

Looks like he was looking to trade...

I have a friend who may have a USD triple manifold. He hasn't found it yet, buy I've got faith.

 

[John C. Ratliff]

I have a bit of an alternative to Nemrod's answer. It is one I have contemplated for myself, but I already have too many tanks and combinations. The original Aqualung concept from Cousteau contained, within the USA patent (#2,485,039, October 18, 1949), the idea of a triple tank setup, with the third tank used as a reserve, just an Nemrod said above. But under the Cousteau system, the third tank was mounted upside-down, with the valve on the bottom. If you look at the photos of the Cousteau triple tank setups, you will see this valve at the bottom.

That gives you an option for your diver. You can purchase the triple tank setup with a standard double tank valve (two posts for regulators would be better for balance, and give you a center position). Purchase two sets of double tank bands for the system, and it would be good to purchase a valve protector for the upside-down cylinder. Simply mount them in this fashon, with the double tank bands offset for the third tank (either above or below the other bands).

This triple tank system could then be set up on a backplate, with a BC if you want, or on a BC single-tank hoopup. That would take care of the BC connection.

Now, the tricky part. Since there is no connection (yet) between the doubles and the single tank, you could connect instead the regulators. This would require a second first stage on the reserve cylinder, and that would then hook into the primary first stage via a LP hose. This would require a female end on both sides of the hose. But that could be accomplished by placing a AMF Voit Swimaster MR-12 Seat - 2nd Stage Poppet (Item #28, Part Number B20210A) between two regular LP hoses (part #25 on the Titan); this particular seat is reversible, and both sides will connect the male end of a LP hose.

In this way, you would have a single scuba unit with two first stages, one a primary for breathing off and one a "feeder" first stage which would feed air from the reserve cylinder into the primary first stage. Both regulators could have available LP and HP ports for monitoring primary rig and reserve cylinder pressures, if desired. Here is the diagram for the AMF Titan regulator, which contained this same part:

The way the Cousteau system worked, as described in their patent:

The third cyclinder C serves as a reserve; the gas contained init being available for the diver when he feels that the supply of gas contained in the two cylinders A and B is close to being exhausted. The capacity of this third cylinder is sufficiently large to supply sufficient air to the diver to enable him to rise to the surface sufficiently slowly. The diver can thus dispense with any instruments for measuring the pressure in the two cylinders A andB. The air is withdrown from the reserve cylinders C through a pipe O. Pipes N and O are providid with (valves) K and L respectively, which operated by the diver. While two cylinders A and B have been shown for the normal supply of air to the diver, only one could be utilized instead...

This would not act quite the same as the Cousteau system, as they transferred the HP air from the reserve cylinder into the other two cylinders, and this created quite a sound that the team divers could all hear, so they knew when a diver went onto the reserve cylinder. In this method, the pressurization would already be there in the first stages. The reserve cylinder would be initially turned on, to check for leaks and pressurize the system, then shut off to function as the reserver cylinder (but the regulator would remain pressurized, since the air would go to that first stage from the other regulator). When breathhing resistance was felt, then the third cylinder valve could be turned on. If the valve you use between the twin cylinders is a "J" reserve valve, with a 500 psi spring, it could also retain 500 psi in the outside cylinder on the other side, as an additional reserve (using a pull-rod, of course), and it would need to be reverse-mounted as described here:

http://vintagescuba.proboards2.com/index.cgi?board=instruction&action=display&thread=1160451692

These types of cylinders are available in Al or steel, and the one I was looking at was the OMS Diving cylinders. They had a twin 45 available with double tank bands, but they are not currently advertising the double tank bands. Whatever type of cylinder you get, manufacturing double bands, or even a triple band system, would not be difficult for a machine shop. Here is OMS's specifications on their cylinders:

http://www.omsdive.com/cyl_spec.html

Now, saying all of this, you would have a very unique system, one which the diver would need to train on and use in pool and then in open water on training dives to become used to its features. Without further instruction, this could be a system which someone not familiar with could abuse, misuse, and get into trouble with. So this is my disclaimer, that you must build and use this at your own risk.

SeaRat

 

[John C. Ratliff]

Not to change the subject, but scuba diving should not be used in swift water rescue.
Anything faster than about 2 knots is dangerous and you will lose a diver or two (or three). Not sure what the customer defines as swiftwater but what I call swiftwater is not for scuba. Big difference between a little current and swiftwater IMHO.

James,

I understand where you are coming from on swift-water rescue, but I tend to disagree. Today's divers are so equipment-laden that their streamlining is shot, and they cannot function easily in any greater than 2 knots of current. But swimmers can, as with just a wet suit on, you can swim against a two-know current (I used to do this all the time in the North Umpqua River for fitness--swimming against the rapids). But there are times when SCUBA is appropriate, such as crossing under a heavy current (where the current goes over the diver, but there is little current below) to get to a survivor. This can be done without scuba, but not quite so easily as with scuba.

Where SCUBA is more appropriate is when a Whitewater SAR team arrives quickly, and there is an apparent drowning victim. Here, finding the victim very quickly is extremely important, as it is possible to revive a hypothermic drowning victim up to an hour after the event, without brain damage (the colder the water, the better the survival rate for these victims--it's called "cold water near-drowning; see: http://scuba-doc.com/hypoth.htm). This would occur in a river pool below the rapids, or in the case where the victim was trapped underwater by the current. SCUBA would be imparitive to a successful recovery effort, and hopefully lead to reviving the victim.

I have a reference, Tim J. Setnicka's Wilderness Search and Rescue, Appalachian Mountain Club: Boston, 1980, which has a whole chapter on "Whitewater SAR, beginning on page 441. I got it just after my work in the Pararescue Section when I was with the 304th Aeorspace Rescue and Recovery Squadron in Portland, Oregon in the mid-1970s.

SeaRat