the shape of a backplate ?

so i've decided that i'm about ready to move away from the jacket style BC and into a backplate and wing. in my research it seems that the vast majority of backplates have the same shape, then i stumbled across this guy:



source: Designing your own SCUBA Backplate

the shape of this plate seems logical to me in that, outside of the scuba world, it makes a lot more since to sit a cylinder between two bent v's instead of up atop an inverted u. thing is, though, i can't find a major manufacturer actually producing a "double-v" shaped plate.

i'm just curious about more of the "why" for backplate shape and if i'm missing something regarding the "double-v" vs. "inverted u" shape of a scuba backplate.

thanks in advance.

it likely costs more to make those additional bends, and either a STA or a wing such as the HOG that has stays to work with singles does the same thing. Not sure it is any "better"..... switch it to doubles, and you have achieved nothing...

Now, in regards to unique shape - Freedom Plate........

How about the Kydex backplates from Deep Sea Supply?

I think no one make the double V band because there are already simpler solutions out there 1) STA 2)wing with STA pillow to stablize the tank. If you use one of these, which is most likely, then with double V or not, it makes no difference.

To me, more important things are: 1)how steep the band is? this controls how far away the tank is from your back. 2)the bolt holes locations on the plate, this control how high (or low) the tank(s) will sit.

Years ago I remember seeing plates like that from a company in Australia. I do not remember the name. Currently, the only plate I know of is the reverse profile Golem Gear plate.

Nearly all my backplates are from DSS. The only exception is an al plate that i dont use much. The dss does not have a sta so to speek but it does have pads on the straps to contend with when you switch from single to doubles. for singles divers and dedicated doubles rigs this is a moot point.

jallen013:

so i've decided that i'm about ready to move away from the jacket style BC and into a backplate and wing. in my research it seems that the vast majority of backplates have the same shape, then i stumbled across this guy:

View attachment 149342

source: Designing your own SCUBA Backplate

the shape of this plate seems logical to me in that, outside of the scuba world, it makes a lot more since to sit a cylinder between two bent v's instead of up atop an inverted u. thing is, though, i can't find a major manufacturer actually producing a "double-v" shaped plate.

i'm just curious about more of the "why" for backplate shape and if i'm missing something regarding the "double-v" vs. "inverted u" shape of a scuba backplate.

thanks in advance.

Click to expand...

The shape is suited for doubles which sit on either side of the channel. Plates of that type require a BC (wing) with built in roll control or a single tank adapter (STA) because they are meant for doubles, not singles. Thus the Freedom Plate and other plates without the inverted channel that were designed for single tank usage.

VDH singles plate:



Freedom Plate beside a Hammerhead (doubles) plate:



Oxy singles plate:




Several (of many) vintage plates:







N

For single tank plates, a flat plate using a wing with a built in STA keeps the tank close to you and reduces roll. For doubles. where can you place channel weights and the wing nuts? Looks like a solution looking for a problem to solve at your expense.

jallen013:

the shape of this plate seems logical to me in that, outside of the scuba world, it makes a lot more since to sit a cylinder between two bent v's instead of up atop an inverted u. thing is, though, i can't find a major manufacturer actually producing a "double-v" shaped plate.

i'm just curious about more of the "why" for backplate shape and if i'm missing something regarding the "double-v" vs. "inverted u" shape of a scuba backplate.

Click to expand...

Thanks for the interest in my designs.

The main thing you must consider is that the first metal backplates in the form that is common today were made specifically for use with twin tanks. There is an article around from the guy who supposedly created the first metal backplate from an old road sign describing how and why he created the design, basically to improve the stability of his double tank rig when cave diving over the simple harness they were using beforehand. (There used to be a PDF of this article on the Dive Rite web site, but I can't find it now.) Bolting a single tank adapter (the clue is in the name!) to the backplate to allow it to also be used with single tanks came later.

However, for exclusive use with a single tank, the inverted centre channel works really well. The main benefits gained are; simplicity (eliminating the STA, bolts, wingnuts etc) and that the tank sits closer to your back. Consider this comparison:



The tank sits about an inch closer to your back compared to a standard backplate/STA combination.

The main disadvantage is that a backplate with an inverted centre channel can't be used with twin tanks using bolts, so if you dive both single tanks and twinsets you need two backplates, which gets away from the multi-purpose concept of a backplate a bit. (Personally I have four plates in regular use - single tank steel, single tank aluminium, twin tank steel, twin tank aluminium - so I'm not the one to ask. )

There is a bit more background about the design on my page about my first single tank plate (from 2003): H-Plate

The only manufacturers that currently produce backplates like this that I am aware of are Golem (mentioned before, though I think they intend their plate more for use with rebreathers?) and Halcyon, with their new Traveller BC (with a plastic backplate), though several wing manufacturers (Deep Sea Supply, Oxycheq for two) make wings that don't require a separate STA. And there is nothing wrong with a backplate and STA combination in any case.

Note I'm not a manufacturer, just a hobbyist - and I made these largely for the pleasure of creating and diving my own designs. I'm also not really concerned with cost - just making something as optimally functional as possible.

I'd also mention that I don't claim that this is my original idea - there have been plastic backpacks that achieve the same end around for decades as other posters have mentioned, and before I started making my own plates there were other (now defunct) manufacturers making metal plates with inverted channels - Black Art from Australia were one, and Portland Oceaneering from the UK another.

Cheers,
Huw

awap:

For single tank plates, a flat plate using a wing with a built in STA keeps the tank close to you and reduces role. For doubles. where can you place channel weights and the wing nuts? Looks like a solution looking for a problem to solve at your expense.

Click to expand...

I wouldn't go quite that far. These plates were designed to do away with the single tank adapter before wings with built-in STAs became the norm. Some wings still require the use of an STA, Halcyon, Dive Rite, and DRIS come to mind. For example, the Golem reverse dog bone backplate would make a good travel plate with a Halcyon wing.

As far as flat plates go they don't seem to be very popular, the only ones I have ever heard of is the Jet plate, the fabric plates from Zeagle and Oxycheq and now the one from VDH.