How long will a bottle last?

[Monty 35]

From BATTALION 14 News & Information

BREATHING APPARATUS DRILL

As detailed in a recent post (see below) Battalion 14 recently conducted an RIC Drill. In conjunction with that drill a discussion was held regarding the use of Breathing Apparatus. As a result of that discussion the members of Fire Station 60 "B" Platoon conducted an informal in-house test of their individual Breathing Apparatus. Details of that test along with some Lessons Learned and Issues Raised follow:

OBJECT

On August 8, 2006, the members of Light Force 60, along with the Battalion 14 Command Team, suited up in their Breathing Apparatus in order to:

1. "Run out of air" in a controlled, non-emergency situation.

2. Determine the best method to "conserve" the BA air supply.

RESTRICTIONS

Members were placed into three groups as follows:

Group 1 was "on air" while exercising and was allowed to attempt controlled breathing

without manual manipulation of the BA.

Group 2 was "on air" while exercising and was allowed to attempt controlled breathing

with manual manipulation of the BA.

Group 3 was "on air" without exercising and could take any measures to conserve air

including sitting or laying down, controlled breathing and/or manual manipulation of

their BA.

RECORD KEEPING

The starting air pressure in each members air bottle was recorded and all members started at the same time. Times were recorded for all members along with the personal observations and notes of the members.

The results of the test, although certainly not entirely scientific, are significant and should be

of interest to all members:

HOW LONG DID THEY LAST?

The time of the member who ran out of air the quickest was 53 minutes. This member started with 4061 pounds and was in Group one. (Exercise/No manipulation)

The time of the member who ran out of air the slowest was *94 minutes. This member started with 4060 pounds and was in Group 2. (Exercise/Manipulation) *This is significant!

The time of the member who ran out of air the slowest in Group 3 (No exercise/Manipulation) was 88 minutes. This member started with 4495 pounds.

POUNDS PER MINUTE

The average amount of air used by members ranged from a high of 76 pounds per minute to a low of 43 pounds per minute.

AIR USED AFTER LOW AIR WARNING

The Low Air Warning Bell starts to ring when approximately 1150 pounds of air remains in the air bottle.

The average amount of air used by the member who lasted the longest before the low air warning triggered was 52.9 pounds per minute. After the Low Air Warning began that member, using manipulation of the BA and controlled breathing, was able to lower his average air usage to *26.7 pounds per minute. *This is significant.

HOW DID THEY DO IT?

The members who manipulated their BAs in order to conserve air shut their air bottles off at the bottle between breaths. The members who were able to stop the Low Air Warning Bell from ringing saved the most air. This was done by the member slowly taking a breath with one hand on the shut off. The breath was terminated by the member shutting off the air bottle.

This technique stops the Low Air Warning Bell from ringing and the resultant loss of air to the outside atmosphere. This technique is not easy and takes practice. If perfected the amount of air that can be conserved is very significant and in one case made the member's air supply last for 1 hour and 34 minutes!

WHAT DOES IT ALL MEAN?

Some of the Lessons Learned and Issues Raised include:

1. You would assume that a member who was standing still (laying down or sitting) from the start of the test would last the longest. This did not happen. The member who lasted the longest was exercising.

2. The combination of controlled breathing and manual manipulation of the BA worked the best.

3. A very significant amount of air is lost to the atmosphere when it is used to power the Low Air Warning Bell.

4. It is significantly harder to draw a breath through your facepiece when using manual manipulatinion. This is a trade-off because your air lasts longer.

5. All of the members commented that their anxiety level went up significantly at two points:

a. When the Low Air Warning Bell started to ring.

b. When they knew they were only "a breath away" from running entirely out of air.

6. The manipulation of the bypass feature did not help to coinserve air.

7. There was concern by all members that there was no "air hose" available to stick in their coat or through an opening to the exterior when out of air. This was compounded by lack of our Emergency Air Cannisters.

8. When manually manipulating the BA the visual readout is unusable. This happens when the air bottle is turned off. This another trade-off that conserves air but may raise the members anxiety level because it is impossible to determine how much air is left.

9. All of the participating members felt the test was beneficial and that it could definitely help them in an actual emergency situation.

CONCLUSION

Although this test was informal it yielded some basic information that was very significant and could benefit all members. It was once again agreed and graphically illustrated that each and every member who uses a Breathing Apparatus needs to develop a plan to address a situation that involves running out of air at an emergency. This plan must include having a thorough understanding of how your Breathing Apparatus functions, its' limitations and capabilities and a practical exercise that addresses running out of air in a controlled, non-emergency situation.

Interesting article - wonder what SCBA they use? I don't think it is SCOTT because they talk about bells - and my understanding is that the air for the vibralert is not vented but directed to the user. I've not tried emptying a bottle - but i'd be very surprised if I got that long. The one thing I have tried is 'skip breathing' but I didn't see any mention of that in the article. Interesting idea shutting off the valve - not something I'd think of - not sure what effect it would have either. Guess I'll have to try this sometime!

[CHIEFPHIL 90]

One drill I like to use, usally after the SCBA part of FF1 is to lower the pressure on the bottles to 500 pounds or just as soon as the low air alarm goes off. Have the FF sit down , fully geared up and breath the remainder of the bottle down till it is completly empty. The results are interesting. I mainly do this as a confidence builder for new people and to show them that if they control thier breathing how long that little bit of air will last.

We have had people last up to 45 minutes with the low air alarm going off. I have even seen a person go 20 minutes AFTER the low air alarm stopped sounding. Typically the average I have recorded has been about 15-19 minutes after the low air alarm goes start to sound.

Just passing on some of what I've witnessed.

[res6cue 67]

Um, I'm not really sure what to make of this, but overall I don't think it has any real world practical significance.

There's no mention of what manufacturer and model SCBA were used, no mention of what size bottles were used, the third group didn't even start with the same volume in the bottle and, most importantly, chances are each test subject didn't have equal lung capacity. So for them to say the test was "not entirely scientific" is to say the least, but to then say that the results are "significant" is ridiculous. If you're not going to have a practical, real world experiment where all factors are equal, there's no sense in doing it at all.

As far as turning off the bottle, c'mon now. Any Scott user knows this is a pain in the butt, having to reach back, push the knob in THEN turn it. Highly impractical during firefighting operations. By the time you turn it off, you're ready for your next breath, unless you hold your breath for a minute or so, which is not recommended. Also, what happens if the valve malfunctions and you can't turn the bottle back on? Sorry, but once my bottle is on when I'm in an IDLH environment, it STAYS on*. I would never, ever train someone to turn their bottle off at any point. If your Vibralert goes off, get the hell out, period. As far as the Vibralert venting air to the outside environment, it does not. It's a closed system where the air used to power it is diverted directly into the facepiece.

Bottom line is that the best and safest method of conserving air is to learn to control your emotions and breathing.

*The ONLY time I would consider disregarding this is if I were trapped and had absolutely no other choice in the matter and thought it would buy me a few extra minutes. Even then, I'd be leary of turning the bottle off.

Edited August 25, 2006 by res6cue

[IzzyEng4 427]

Wanna learn how to control your breathing on any SCBA, do the old 5 minute drill. Drain the air tank down to 500 psi, mask up and sit down in full gear and try to make your bottle last as long as you can. As the old story goes when your at 500 you have approximately five minute of less of stored air, depending how much air an individual needs. Learning how to control inhalation and exhalation can make you save air incase you become trapped or lost. Remember if you are moving you can go through this much air in seconds.

When I first took my Firefighter I course up here in the early 90's we were taught this more as a confidence builder on the use of an airpack. Some people only lasted 5 minutes or so, but many lasted longer I lasted 28 minuites sitting thier, concentrating onb my breathing and relaxing. One person was able to last about 37 minutes. It was a good way to learn how to control your breathing. We also later did this persforming light and strenuous work and we made a thirty miniute rate bottle last almost that long. It was a good drill just to get use to controling your bottle.