Additional measures beyond analyzing, labeling, and notox procedures to help prevent incorrect deco gas switches

[grantctobin]

This methodology is batshit.

The end.

 

[mr_v]

When you switch computer gas before performing the actual gas switch, you can ensure that you have the right PPO2 and gas for the depth. Also, depending on your computer setup, your computer may warn you when you do not select the best gas for depth. [I dive CC so 99.9% of my gas switches are either SCR or BO drills. If you’re bailing out, of course, you’ll attend to the reg first.]

If you have regs blowing up on the boats or team members not knowing the gasses that will be available on the dive, you’ve failed on the surface way before stepping on the boat or starting the dive.

Labeling, verifying regs takes less than a min.

 

[Manatee Diver]

When you switch computer gas before performing the actual gas switch, you can ensure that you have the right PPO2 and gas for the depth.

In the gas switch you should be checking the MOD and then the depth on your computer.

 

[Tracy]

If you have regs blowing up on the boats or team members not knowing the gasses that will be available on the dive, you’ve failed on the surface way before stepping on the boat or starting the dive.

I don't think I have ran a charter without at least some kind of equipment failure in years. It isn't always hoses, but regs, valve knobs, controllers, HUDs, heads. Hoses are usually the most common and it is faster to swap a reg than a hose.
That is awesome that you live in a world where gear doesn't fail. I would like to visit there someday.

 

[mr_v]

I don't think I have ran a charter without at least some kind of equipment failure in years. It isn't always hoses, but regs, valve knobs, controllers, HUDs, heads. Hoses are usually the most common and it is faster to swap a reg than a hose.
That is awesome that you live in a world where gear doesn't fail. I would like to visit there someday.

I get what you are saying. And that's why I do not think I'll ever have enough patience to own a boat charter

After observing a number of failures and discussing these failures with the equipment owners, it is painfully obvious that in most cases people came unprepared. A $10 IP gauge and two-minutes per regulator checks could have prevented most of the reg issues I've seen. Of course, there are random computer failures, but on a tech dive you should come prepared with a few extras (I've learned that lesson this summer).

Also, while I am sure that all boat owners or guides have spares, is anyone comfortable taking an unfamiliar "boat spare" on a tech dive? I know I am not.

Back to the topic in question.

- Check all your regs. SB has many thread on proper reg checks.
- Analyze all gasses and re-validate them as a team before you dive.
- Ensure that all team gasses are programmed in all your computers.
- Make sure that you, as in you, the diver, can clearly see the labels on your tanks.
- Do your gas switches the way you do them.

In my case, each reg has a gas label. If a reg goes out on me before a dive, I always have 2-3 spares with blank labels, a marker, and a gas analyzer. I will re-verify the gas, attach and label a reg. I know it is OCD and takes extra time, but that's just me.

 

[Pavao]

When you switch computer gas before performing the actual gas switch, you can ensure that you have the right PPO2 and gas for the depth.

MOD stickers display a number, which represents the depth at which the contents of the cylinder marked by said MOD sticker, is safe to breath. Your computer displays this same information, at all times, on the field designated for “depth”. When that number on the computer matches the number on the MOD sticker, you’d have ensured it’s the right gas for the depth. Follow a proven gas switch procedure from here.

Switching gas on computer is to ensure it does the decompression calculations accurately based on the actual gasses you’re breathing.

 

[SelfDiver]

This thread is great. Get some popcorn.

Color coding is right. It is cost prohibitive to do it correctly.

NASA Preferred Practices already provide for color marking rationale
https://extapps.ksc.nasa.gov/Reliability/Documents/Preferred_Practices/dfe5.pdf

Color coding of the piping systems provides accurate and immediate visual and written identification of the contents within the pipe. This will provide greater safety and lessen the chances of confusion when working within an area with numerous piping systems. The markings on the outside of the pipe show content in color code, the flow direction, pressures and name of contents (See Figure 1).

MIL-STD-1247
https://www.expresscorp.com/wp-content/uploads/2023/02/MIL-STD-1247D.pdf
Has a section (5.1.1) for marking different hoses with different colors.

Navy TABLE III. Titles and color codes for compressed gas cylinders
https://www.navyadvancement.com/assets/Docs/MIL-STD-101C.pdf
And Lawrence Berkeley National Laboratory Cylinder Size and Colour Chart Medical Applications (Praxair)
https://amo-csd.lbl.gov/downloads/Gas_Cylinder_Size_Praxair_Overview.pdf
US FDA 21CFR201.328 (Sec. 201.328) Labeling of medical gas containers
CFR - Code of Federal Regulations Title 21
The list goes on and on, but there is no rule on sport SCUBA cylinder marking.

NFPA color coding of breathing gasses highlights the issue with costs and labeling
NFPA Health Care Pipe Label Standards

Challenges associated with marking requirements
Some healthcare facilities have several floors and multiple buildings across a large campus that need medical piping. This can be hard to manage. A few common challenges that come with medical gas pipe labeling include:
Limited space: Some pipes can be small but still need clear labels.
Cost constraints: Even a small medical facility could need dozens of labels to meet NFPA requirements.
Legibility and visibility: Any printed information needs to be easily read. They can get dirty so cleanliness is essential to maintain legibility.

It is a known problem that correct marking is an economic burden, even in professional healthcare facilities.
I am not making this up. this isn't just like my opinon dude.

Infinite funds would have the tank, first stage, hose, SPG, and second stage color coordinated.
In addition, each label should include min and max depth because it is being used in a pressurized environment.

Your slate (And $1,000 Shearwater) would have each gas switch color coded as well. The pressure transmitter should be able to determine if the diver is breathing the correct/wrong tank.
If we were doing this correctly it would be unthinkable strokery to use the GREEN 1st stage+Hose+SPG+2nd stage on anything BUT the green tank at the green depth.

Human factors engineering has already designed controls for these possible mistakes. The NO TOX procedure is a cheaper workaround.

The color coding Chris is proposing only looks insane to you because you are using a warped frame of reference.

 

[mr_v]

This thread is great. Get some popcorn.

Color coding is right. It is cost prohibitive to do it correctly.

Fully agree on the cost part.

Earlier this year I came up with a few patent ideas addressing similar human factor issues in tech diving. A patent attorney who is a tech diver discouraged me from pursuing the process due to the costs combined with a lack of immediate ROI. Some responses in this thread prove that he was right.

 

[Manatee Diver]

The color coding Chris is proposing only looks insane to you because you are using a warped frame of reference.

So here is the problem, just in standard gasses you have nine different gasses.

Standard gasses:
32%
30/30
21/35
18/45
15/55
12/65
10/70

Deco only:
100%
50%

Many of the standard gasses will need two different colors one for bottom and another for deco. You are looking at over a dozen colors just for standard gasses. That is without getting into the best mix crowd.

You also need to factor in color loss at depth.

ETA: I forgot that the safe depths are also different for CCR. They typically go to the next deeper gas for their bailout.

 

[Tracy]

This thread is great. Get some popcorn.

Color coding is right. It is cost prohibitive to do it correctly.

NASA Preferred Practices already provide for color marking rationale
https://extapps.ksc.nasa.gov/Reliability/Documents/Preferred_Practices/dfe5.pdf

Surface marking is different than color coding for gases used at depth.
All of my personal and rental tanks have color coded knobs. It is for use on the surface for quickly locating tanks for a desired type. The colored knobs allow me to pick tanks from a room with 100 tanks that will work for what I need. It isn't used at depth and the colors don't tell the actual mix, just the use. It doesn't negate the use of proper analyzing, labeling, and notox procedures during a gas switch.