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Thread: 2.2 vs 4.5

  1. #21
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    The question of tank life actually has some good info behind it.

    For steel or Al bottles, the hydrostatic test measures the bottles expansion and permanent deformation. So long as its within a specific percentage, it passes and the metal is still good. Its basically working in a well understood and easily tested property of the metal to give a go/no go test.

    For composite bottles, the failure mode is different. It is believed over time, individual fibers of the composite material will break. This is due to both sustained load and fill cycles. Each fiber breakage represents a loss of strength. The problem is how to test this 'strength' without damaging the bottle in the process. Once someone comes up with a mechanism to do a good go/no go test that is reliable, I think you'll see the service life increase. Until that point, the 15 year timeframe is a compromise to predict the longest safe usage period for a well maintained bottle. Is it perfect - nope. I am sure quite a few still good bottles get pitched each year. With that, I am sure some bad ones go too.


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    Quote Originally Posted by pvfd27 View Post
    Being able to use the 2216's at all will lessen the financial burden of replacing everything a once. It will also spread out the replacement date for the wrapped tanks.
    I feel your pain, we too had some financial constraints during the conversion. We found we could buy used bottles with 5 or more years left for less than 1/3 the cost of new, making them a better deal than new and giving us a the ability to cycle in new ones over the 5 years. We still have some of the "used" hoop wounds while everything bought new has been CF.

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    From a user standpoint... Survive Air: Poor reg useability, great buddy system. MSA:Horrible design IMHO. Poor usability overall. Not comfy, Poor visability. Scott 4.5: Great mask comfort, great buddy system, light wire frame that is comfy for extended periods 2+ hours, love the vibralert, hate the HUD for remaining air. Easy bottle change, multiple bottle options, great PASS.
    Don't know about price or maint. concerns, because our logistics dept. takes care of all that. I would guess we have over 300 bottles, but who knows. I do know that they had to take them all down for testing this winter. Don't think any failed. They get used and abused by us.

    I've used steel, ALM, and composite bottles. Please make the switch to composite. Your guys will thank you. Again my disclaimer: I don't know what the cost is for any of this stuff.

  4. #24
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    From a conditioning standpoint, if you're pretty much done by the time the alarm goes off on a 30 min. pack, you're going to really be dragging with a 45.

    Another thing to consider when switching to larger bottles is the amount of room required on the apparatus. Eight 45 min. bottles take up less space than twelve 30 min. bottles but provide the same amount of air.

  5. #25
    Forum Member MemphisE34a's Avatar
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    Two things to consider:

    #1. Although many people are voicing their opinions about the versatility of 4500 psi bottles and the fact that you can use 30, 45, or 60 minutes bottles, this is really most likely NOT the case. Yes, you have that option when you initially order, but that will be about the extent of it. There is not an SCBA on the market that I am aware of that allows you to easily interchange different rated bottles onto the same backplate and harness. The strap, linkage, or whatever is used to hold the bottle to the backplate will vary in length due to the difference in circumference of the different bottles and will not work for all 3 different sizes. Additionally, you will have the same problem carrying them on your apparatus due to the same reasons. They will not all fit in the same bracket.

    #2. Seriously consider what is gained when increasing the amount of air that you give your firefighters. IMO, to many departments (including my own) jumped into the more air is better theory without considering anything else.

    More air is only better in worst case scenario - You are alive, trapped, and inaccessible for an undetermined amount of time. However, how much more harm are you placing firefighters in by giving them more air and therefore more working time by giving them the larger bottles? More air does not mean less fatigue. I do not like 45 or 60 minute bottles for firefighting. I would go with the lighter, smaller high pressure 30 minute bottle and reduce the amount of stress involved in firefighting, not a heavier 45 or 60 minute bottle which will increase the stress and workload along with the "benefit" of more air to do it longer.
    Robert Kramer
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    Management is making sure things are done right. Leadership is doing the right thing. The fire service needs alot more leaders and a lot less managers.

    "Everyone goes home" is the mantra for the pussification of the modern, American fire service.


    Comments made are my own. They do not represent the official position or opinion of the Fire Department or the City for which I am employed. In fact, they are normally exactly the opposite.

  6. #26
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    Quote Originally Posted by MemphisE34a View Post
    #2. Seriously consider what is gained when increasing the amount of air that you give your firefighters. IMO, to many departments (including my own) jumped into the more air is better theory without considering anything else.

    More air is only better in worst case scenario - You are alive, trapped, and inaccessible for an undetermined amount of time. However, how much more harm are you placing firefighters in by giving them more air and therefore more working time by giving them the larger bottles? More air does not mean less fatigue. I do not like 45 or 60 minute bottles for firefighting. I would go with the lighter, smaller high pressure 30 minute bottle and reduce the amount of stress involved in firefighting, not a heavier 45 or 60 minute bottle which will increase the stress and workload along with the "benefit" of more air to do it longer.
    I agree wholeheartedly with #2 and the last paragraph, but I do think there are some FD's that can benefit from the versatility of multiple capacity bottles.
    Our combination FD is also a regional Haz-mat team and therefore we have a need for 60 minute cylinders. The 60 minute cylinders are also used for defensive Tower operations for the bucket personnel who will not be physically taxed. We find the Scott 4.5's, especially the wire frame older units are very easy to swap between cylinder sizes given their design. We also utilize 60 minute cylinders in or RIT packs to ensure a longer lasting air supply just in case. These benefits would not be possible with a low pressure system.

    Lastly the smaller size of the 4500 psi 30 min. cylinders was the real benefit on the firefighting side. In the "old days" guys had to doff their packs in the training smoke maze and drag them through, now most can easily negotiate the tubes, holes and obstacles wearing the SCBA as intended. This of course doesn't mean they aren't put into a tougher maze to ensure they can complete reduced profile maneuvers.

  7. #27
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    Quote Originally Posted by MemphisE34a View Post
    Two things to consider:

    #1. Although many people are voicing their opinions about the versatility of 4500 psi bottles and the fact that you can use 30, 45, or 60 minutes bottles, this is really most likely NOT the case. Yes, you have that option when you initially order, but that will be about the extent of it. There is not an SCBA on the market that I am aware of that allows you to easily interchange different rated bottles onto the same backplate and harness. The strap, linkage, or whatever is used to hold the bottle to the backplate will vary in length due to the difference in circumference of the different bottles and will not work for all 3 different sizes. Additionally, you will have the same problem carrying them on your apparatus due to the same reasons. They will not all fit in the same bracket.

    ...

    smaller high pressure 30 minute bottle and reduce the amount of stress involved in firefighting, not a heavier 45 or 60 minute bottle which will increase the stress and workload along with the "benefit" of more air to do it longer.
    You need to get a better brand of SCBA. Takes 2 seconds to adjust the locking strap on a Scott AP or NxG going from one cylinder capacity/size to another.

    Weight of a Scott 30min is 9.4lb (2216psi or 4500psi); 45min 4500psi is 13.6lb Thats not particualily significant when gives you twice the effective usable air.

  8. #28
    Forum Member MemphisE34a's Avatar
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    Quote Originally Posted by neiowa View Post

    Weight of a Scott 30min is 9.4lb (2216psi or 4500psi); 45min 4500psi is 13.6lb Thats not particualily significant when gives you twice the effective usable air.
    Like I said, many people jump straight to the automatic, more air has to be better theory.

    Twice the useable air could be the problem, not the answer.
    Robert Kramer
    cell #901-494-9437

    Management is making sure things are done right. Leadership is doing the right thing. The fire service needs alot more leaders and a lot less managers.

    "Everyone goes home" is the mantra for the pussification of the modern, American fire service.


    Comments made are my own. They do not represent the official position or opinion of the Fire Department or the City for which I am employed. In fact, they are normally exactly the opposite.

  9. #29
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    The point is the lack of usable air is the problem. The additional 4lb is not a problem. Buy leather boots and get rid of the rubbers.

  10. #30
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    Quote Originally Posted by MemphisE34a View Post
    Like I said, many people jump straight to the automatic, more air has to be better theory.

    Twice the useable air could be the problem, not the answer.
    A major factor is how a department operates. If you take a department that has a guideline that you rehab after 2 30-minute bottles and a department that rehabs after 1 45-minute bottle, who's using more air?

    If you are a department that rehabs after a single 30-minute bottle, I'd venture to say you're an anomoly.

  11. #31
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    Quote Originally Posted by neiowa View Post
    The point is the lack of usable air is the problem. The additional 4lb is not a problem. Buy leather boots and get rid of the rubbers.
    Why would you pay for more expensive boots if weight and stress is not a problem?
    Robert Kramer
    cell #901-494-9437

    Management is making sure things are done right. Leadership is doing the right thing. The fire service needs alot more leaders and a lot less managers.

    "Everyone goes home" is the mantra for the pussification of the modern, American fire service.


    Comments made are my own. They do not represent the official position or opinion of the Fire Department or the City for which I am employed. In fact, they are normally exactly the opposite.

  12. #32
    Forum Member MemphisE34a's Avatar
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    Quote Originally Posted by Catch22 View Post
    A major factor is how a department operates. If you take a department that has a guideline that you rehab after 2 30-minute bottles and a department that rehabs after 1 45-minute bottle, who's using more air?

    If you are a department that rehabs after a single 30-minute bottle, I'd venture to say you're an anomoly.
    Agreed, but how many departments do you think are out there that have maintained a (2) bottle rule even though they have increased the air supply in those bottles.

    Also, even a quick bottle change will give you a little bit of a break.

    No one has to agree, but I think small, high pressure 30 minute bottles are the best way for firefighting.
    Robert Kramer
    cell #901-494-9437

    Management is making sure things are done right. Leadership is doing the right thing. The fire service needs alot more leaders and a lot less managers.

    "Everyone goes home" is the mantra for the pussification of the modern, American fire service.


    Comments made are my own. They do not represent the official position or opinion of the Fire Department or the City for which I am employed. In fact, they are normally exactly the opposite.

  13. #33
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    It's not always how long you can work before you are "done" but how long before you need to take a quick break so you can keep going for a good while. A 30 min bottle puts you in this situation. Get in, do you work, come out, take a breath while you get a change, reevaluate what's going on and talk to the boss, then go back to work. When you put those small breaks in guys will last longer in case you NEED to go on a little more.

    We recently went to Scotts with 30min bottles replacing MSAs with 2216 bottles. They're also great on an OSHA ladder or other tight spaces.
    I may speak gibberish, but I don't talk s***! -- Dropkick Murphys

  14. #34
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    Quote Originally Posted by MemphisE34a View Post
    Agreed, but how many departments do you think are out there that have maintained a (2) bottle rule even though they have increased the air supply in those bottles.

    Also, even a quick bottle change will give you a little bit of a break.

    No one has to agree, but I think small, high pressure 30 minute bottles are the best way for firefighting.
    You know those two-bottle FD's using 45 min. packs, too, eh? I have seen a couple that do that, but for the most part they're few and far between around here.

    It seems to be based a lot on the operation of the department in question. Both packs have their pros and cons. But I think we both agree, it's something you have to think about before jumping in head first.

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