A drag issue : to bungee wings or not to bungee

[Garth]

haha. we'll see. What type of wing do you have? I need probably 50lb lift or so for double 120s. Which one would you suggest? I would like to get a dual inflation wing. To be honest I could care less if its bungee or not but I would like it to be smaller than my OMS wing.

 

[LiteHedded]

I use a 55 pound explorer. It's pretty much perfect for the diving I do

 

[Tortuga68]

Get a room you two

If memory serves, it was 240ish..
DanV

So 8ATA and it was the bungees that prevented the wings inflating?

What was actually happening, was the OPV opening?

 

[Tortuga68]

I use a 55 pound explorer. It's pretty much perfect for the diving I do

55#? lol

Don't you know you only need 18# lift to dive doubles

Are you sure you're not overweighted?

 

[cool_hardware52]

So 8ATA and it was the bungees that prevented the wings inflating?

Please explain why ambient pressure would have any effect on wing inflation if the inflation gas is ~150 psi (IP) above ambient.

What was actually happening, was the OPV opening?

If you constrain a wing by any means, including bungees the OPV will vent when the internal pressure exceeds the ambient by about 2.5 psi.

Tobin

 

[Tortuga68]

So was the problem the bungees or the OPV?

Please explain why ambient pressure would have any effect on wing inflation if the inflation gas is ~150 psi (IP) above ambient

Please explain why bungees would have any effect on wing inflation if the inflation gas is ~150 psi (IP) above ambient

And can you also tell litehedded how much lift he needs

 

[PfcAJ]

Litehedded dives lp104s and lp108s, often with multiple stages and deco bottles.

You would sink like a rock with an 18lb wing, guy.

 

[Tortuga68]

Litehedded dives lp104s and lp108s, often with multiple stages and deco bottles.

You would sink like a rock with an 18lb wing, guy

AFAIK noone makes an 18# doubles wing anyway. Or a 30# one. Yet every time the amount of lift I should be using comes up, those two numbers get mentioned

So, let's do the numbers - how much lift does LH actually need?

 

[Gombessa]

Please explain why bungees would have any effect on wing inflation if the inflation gas is ~150 psi (IP) above ambient

I'm guessing the simple explanation is that the bungees are able to constrain more than 2.5psi (the pressure at which the OPV vents) and much less than the ~150psi of the regulator?

 

[danvolker]

Get a room you two




So 8ATA and it was the bungees that prevented the wings inflating?

What was actually happening, was the OPV opening?

As Tobin pointed out, the opv let's go pretty easily...restrictive bungees destroyed the required lift these wings needed to deliver.

Of course once you discover that it could be in the
50's at 240 feet and deeper, any sensible diver would decide a wetsuit would be a huge mistake for the dive....these guys had lots of weight to neutralize the 7 mil suits they wore, which were like paper at 240....with no wetsuit buoyancy, no protection from 55 degree water, and pretty soon, leg muscles that could not kick hard enough to lift much of anything off the bottom.
They should have thought about the wetsuit issue. They should have thought about the heavy steels...they should have thought about why they might not want to chance using bungees, considering the choices they had already made, would make huge lift capability CRITICALLY IMPORTANT.
Well , Elkins had only about 87 dives, so maybe it would be hard to imagine that he could have the knowledge and thought process to have avoided the bad choices. Maybe if his peers told him how foolish this whole plan was, maybe he would have a shot....no one told him how wrong all these things were...and he was with a tech instructor....

DanV