Northeastwrecks once bubbled...
I always enjoy reading posts about using a 13 - 19 cu. ft. as an emergency bailout.
Its real simple: "Use it and create an emergency"
We're not talking about getting by on the minimum that you can possibly use to get to the surface, without safety stops and without returing to the upline.
A proper bailout plan should assume a couple of minutes to identify the problem, a couple more to try to rectify it while using the pony, more time to return to the upline with your buddies and enough time to make a proper ascent with safety stops.
All while breathing more heavily than usual because you are in the middle of a crisis.
Personally, I'd rather have the extra gas and not need it than need it and not have it.
If you search on the threads, you'll find a few posts calculating ascents from 120 fsw using pony's. The math is not pretty.
North east here let me post some of the math, but im going to change the depth to 130 for more even multiplication
General numbers for caluclations
Stressed SAC rate of 1.0 CFM
130 feet = 5 ata
say 2-4 minutes at 130 to figure out whats going on so and stop it or fix it 10 - 20 ft3
acent to saftey stop doing 30 fpm travel time so travel time is 4.5 mins so for gas useage will ~10 -15 ft3
and then saftey stop for 5 minutes to be safe is ~7.5 ft3
so total gas useage is 27.5 - 42.5 so really a 40 is needed if you(rough estimate) want to most certain and following that bailout at those consump[tion rates
northeast please correct me if my math is wrong