Noob question: Small triples or doubles?

[spectrum]

Just remember that some shops will insist on charging per cylinder to fill and you will be looking at 3X per year on VIP. And all that to provide 1 typical dive per fill.

The low & broad CG is attractive.

Pete

 

[5ata]

That is only a relatively recent way of thinking.

Small doubles and triples were used in the past for their low profile and better balanced. A pair of thin doubles with just a harness is IMHO the most comfortable rig available.

It does add a few very minor points of failure, but vintage regulator had very few points of failure. They are simpler with less parts and very few connections or O-rings. A DA Aqua Master is a two stage regulator with no O-rings at all (only the tank to regulator connection), also no LP hose to fail.

Redundancy is more of an issue in a overhead environment (either hard overhead or deco).

With todays current dive gear - What would the recommendation be then for low profile tanks with appropriate valves, etc. I dive Poseidon Regs with DIN and yoke adapter. I would prefer DIN on the manifold since I like the simplicity of DIN versus Yoke valves.

 

[JahJahwarrior]

Spectrum brings up a good point about doubles or triples--most shops will charge you per tank, so $12 per fill instead of $4, for about 80 cubic feet of gas either way. Also, $90 for hydro every 5 years, as well as $50 for vip every year, compared to $30 and $15ish. Moreover, you'll pay maybe $100 per tank, for a total of $300, compared to $140 a tank, and you'll need a triple manifold, which might cost $300 or more, if you can find one. For doubles, $50 for hydro, $30ish for vip, $8 a fill, and a manifold, for about $200, and two tanks for about $240.

If you go doubles, I'd say get something more like 50-60 cubic feet, that way you have more gas than an 80.


The only other thing is if you want to do multiple dives. I have two alu 100s, if you only have 80-120 cubic feet of gas with you, you'll need to get a fill each dive, or buy two setups......that is alot of money.

Lastly, vacation. Pain to carry your rig with you, pain to change so much to dive with a single tank.

 

[Thalassamania]

What would you recommend for a manifold to work with these? From what I can determine, triple manifolds are virtually non-existent - I'm trying to distribute the tanks weight across my back instead of right in the center as well as being lower in profile across the back. How would a pair of double 40's work? I want something as streamlined as possible. What about BC? Wings? I know nothing about tech dive gear and this appears to fall into that category.

Any recommendations on this would be great.

With a set of double S30s and your lung volume you can pass on the drag inducing BCD or Wings. Find an old Fenzy if you feel that you need a life vest, but as long as you're not wearing rubber the BC function is irrelevant.

 

[5ata]

With a set of double S30s and your lung volume you can pass on the drag inducing BCD or Wings. Find an old Fenzy if you feel that you need a life vest, but as long as you're not wearing rubber the BC function is irrelevant.

I'm thinking probably a set of Double 40's since doing triple 30's will be difficult to find a triple manifold for. If I could get my hands on a pair of Poseidon dual 10 liter bottles would be sweet, but I figure the dual 40's will be sufficient and will be easier on my back due to more even distributed weight bearing.

Recommendations on manifold/valve setup/manufacturers?

 

[Luis H]

With todays current dive gear - What would the recommendation be then for low profile tanks with appropriate valves, etc. I dive Poseidon Regs with DIN and yoke adapter. I would prefer DIN on the manifold since I like the simplicity of DIN versus Yoke valves.

I would keep it to doubles. A triple manifold will be very hard to locate (although I do know a shop that has a NOS set of triple 30's for sell, but they are aluminum from the 1980).

The complexity mentioned by Pete and JahJahwarrior are real. I did have to point to all my LDS that my twin 40 are the same volume and less pressure than an AL 80. They only charge for the fill now. I do my own VIP and I only worry about hydro's once every 5 years.

Aluminum (or possibly steel) twin 50's are great, but they tend to be short and about 6.9 inches in diameter (same as a steel 72). I like them a lot, but it seems that you would prefer twin 40's.

With twin tanks you have relatively large variety of manifold selection. You can use many modern or vintage manifolds (they can easily be purchased on eBay).

The center to center distance may not be design for narrow tanks, but you can still use it with custom bands, which are easy to have made. Custom bands are available from a couple of sources. I don't have the information handy, but in vintage web sites many divers have used them (the "Sea Hunt" section of ScubaBoard, VintageDoubleHose.com, VintageScubaSupply.com).

When using doubles I do use a traditional horse collar for a BC, just because I like the low profile and simplicity of a basic harness, not back pack or back plate.

Oh, and switching from singles to doubles is easy. When traveling, of course I use an AL80. At home I never use an AL80, I normally use steel 72's.

 

[Izze]

I'm thinking probably a set of Double 40's since doing triple 30's will be difficult to find a triple manifold for. If I could get my hands on a pair of Poseidon dual 10 liter bottles would be sweet, but I figure the dual 40's will be sufficient and will be easier on my back due to more even distributed weight bearing.

Recommendations on manifold/valve setup/manufacturers?

Just a minor thing but a 10 litre tank is about the same size as an 80'. The poseidon tanks you're looking for (I assume) are the 4 litre ones. They're quite common in Sweden and are usually advertised as AGA 324 (300 bar, 2*4 litre)

 

[5ata]

Just a minor thing but a 10 litre tank is about the same size as an 80'. The poseidon tanks you're looking for (I assume) are the 4 litre ones. They're quite common in Sweden and are usually advertised as AGA 324 (300 bar, 2*4 litre)

Oops - my bad on that..

 

[Luis H]

I'm thinking probably a set of Double 40's since doing triple 30's will be difficult to find a triple manifold for. If I could get my hands on a pair of Poseidon dual 10 liter bottles would be sweet, but I figure the dual 40's will be sufficient and will be easier on my back due to more even distributed weight bearing.

Recommendations on manifold/valve setup/manufacturers?

Yeah... this is what you are looking for. And no they are not for sale.
IMHO they are by far the most comfortable set of tanks, but this are not DOT cylinders.

I haven't used this tanks in a couple of decades. I hope to have them re-hydroed soon, but to fill them I will have to trans-fill from another cylinder. I will probably won't get to 200Bar (close to 3000 psi), but I don't need that much air (they are 50 cu ft each).

The valves are DIN and since I am not using Poseidon regulators (I still have them) anymore, that is another issue I will have to deal with. In general I prefer a yoke connection.

A harness like that with no back pack or back plate is very comfortable even with minimal or no wetsuit. The center is open so nothing presses on your backbone and the center of gravity can't get any closer to you.

 

[Luis H]

Just a minor thing but a 10 litre tank is about the same size as an 80'. The poseidon tanks you're looking for (I assume) are the 4 litre ones. They're quite common in Sweden and are usually advertised as AGA 324 (300 bar, 2*4 litre)

I would love to have a modern set, but I dough that they are available with DOT stamps for export to the US.