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  1. #41
    Forum Member FIREMECH1's Avatar
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    Quote Originally Posted by oper77 View Post
    However, I am confused with your process, spring brakes, the spring holds the s-cam to engage brakes, right? and the air then pulls the S-cam against the spring. That way when you lose air, it defaults to engaging brakes to prevent run aways.

    The air lock for the front end seems interesting, never seen it. How well does it work? Is it worth adding it as a feature on a new spec?
    The spring brake and service brake are two different systems in the same brake can.

    The spring brake is activated when there is no air charge in the chamber to release the pressure of the spring. Meaning the brakes are applied. To release the S-cam/brakes, air pressure is applied to overcome the spring pressure and release the brakes. With the spring brakes released (air pressure applied to the spring brake only), and you have a failure in the air supply, the spring will start engaging the S-cam/brakes as the air pressure decreases. This is the safety valve to stop the vehicle.

    The service brake also has a spring in it. However, this is a return spring against a diaphragm. With no air pressure, the brakes are released by the pressure of the return spring against the diaphragm. Apply pressure and it over rides the return spring pressure to apply the brakes.

    This is a decent overview of air brakes: http://www.newbiedriver.com/abcsupda...rbrakes101.htm

    As for the front air brake lock, it depends on your local surroundings and needs. I think it is a good idea, but I wouldn't say it should be mandatory equipment either.

    FM1
    Last edited by FIREMECH1; 10-04-2011 at 11:15 AM.
    I'm the one Fire and Rescue calls, when they need to be Rescued.

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  2. #42
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    Quote Originally Posted by FIREMECH1 View Post
    The spring brake and service brake are two different systems in the same brake can.

    The spring brake is activated when there is no air charge in the chamber to release the pressure of the spring. Meaning the brakes are applied. To release the S-cam/brakes, air pressure is applied to overcome the spring pressure and release the brakes. With the spring brakes released (air pressure applied to the spring brake only), and you have a failure in the air supply, the spring will start engaging the S-cam/brakes as the air pressure decreases. This is the safety valve to stop the vehicle.

    The service brake also has a spring in it. However, this is a return spring against a diaphragm. With no air pressure, the brakes are released by the pressure of the return spring against the diaphragm. Apply pressure and it over rides the return spring pressure to apply the brakes.

    This is a decent overview of air brakes: http://www.newbiedriver.com/abcsupda...rbrakes101.htm

    As for the front air brake lock, it depends on your local surroundings and needs. I think it is a good idea, but I wouldn't say it should be mandatory equipment either.

    FM1
    Sweet! got it, thanks.

  3. #43
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    Quote Originally Posted by donethat View Post
    NFPA 1901 Standard For Automotive Fire Apparatus requires that wheel chocks be supplied with the truck and be mounted before the truck is put in service.

    Might be a reason for that!
    Stating that is nice. Short of spending $50 to buy the document, can you provide a location for where that is stated. I have scrolled through the document, and I am not seeing it yet.

    just a curiosity thing

  4. #44
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    Quote Originally Posted by oper77 View Post
    Stating that is nice. Short of spending $50 to buy the document, can you provide a location for where that is stated. I have scrolled through the document, and I am not seeing it yet.

    just a curiosity thing
    NFPA 1901:

    For Pumpers:
    5.8.3* Miscellaneous Equipment. The following additional equipment shall be carried on the apparatus:
    (17) Two or more wheel chocks, mounted in readily accessible locations, that together will hold the apparatus, when loaded to its GVWR or GCWR, on a hard surface with a 20 percent grade with the transmission in neutral and the parking brake released

    For Aerials:
    8.8.2 (23) same text
    For Quints:
    9.8.3(21) same text
    For tankers:
    7.7.3.1(13)


    Without looking at every single category, I'm betting the reoccurring theme is that if it has wheels, 1901 says it needs chocks.

  5. #45
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    Nice! Thanks

  6. #46
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    Quote Originally Posted by RFDACM02 View Post

    Two or more wheel chocks, mounted in readily accessible locations, that together will hold the apparatus, when loaded to its GVWR or GCWR, on a hard surface with a 20 percent grade with the transmission in neutral and the parking brake released
    This I find interesting now that I reread it. Both chocks together must be capable of holding the apparatus. How often do two chocks mounted on the same side get placed to hold the apparatus in only one direction? Even when parking on a grade, most of the time I've seen chocks on both sides, indicating they're being placed to comply with a policy vs. placed for maximum effectiveness. It seems that maybe one chock may not be enough to hold the apparatus as intended? Does anyone have a policy that says place both in one direction for inclines?

  7. #47
    MembersZone Subscriber sdff1520's Avatar
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    Place one in each direction so that when you drive away you are forced to move them and don't accidentally leave them behind....

  8. #48
    Forum Member CaptOldTimer's Avatar
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    When we ran tractor drawn aerial's, we had four wheel chocks. Two for the tractor duels. One chock on each side of the wheel, both right and left.
    Stay Safe and Well Out There....

    Always remembering 9-11-2001 and 343+ Brothers

  9. #49
    Forum Member GTRider245's Avatar
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    This is really not that hard..

    NFPA (as illustrated), manufacterer guidelines, department SOP/SOG, industry standard, etc. all point to putting wheel chocks on the ground. It takes 5 seconds to place and pick them up. I will take that 5 seconds to ensure that I am not on the stand somewhere trying to jusftify my complacency, because that's all it is.

    And by the way, our aerials have the front tires touching the ground in most routine operations. Those are the wheels that get chocked. For those of you unfortunate enough to have to worry about it, do you not place jack pins either? Afterall, you shouldn't need them right?
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    Quote Originally Posted by Rescue101 View Post
    I don't mind fire rolling over my head. I just don't like it rolling UNDER my a**.

  10. #50
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    Quote Originally Posted by GTRider245 View Post
    This is really not that hard..

    NFPA (as illustrated), manufacterer guidelines, department SOP/SOG, industry standard, etc. all point to putting wheel chocks on the ground. It takes 5 seconds to place and pick them up. I will take that 5 seconds to ensure that I am not on the stand somewhere trying to jusftify my complacency, because that's all it is.

    And by the way, our aerials have the front tires touching the ground in most routine operations. Those are the wheels that get chocked. For those of you unfortunate enough to have to worry about it, do you not place jack pins either? Afterall, you shouldn't need them right?
    Like I said better than half a dozen times. I always chock tires, Im just saying the point and purpose has gone away with the re-invention of the new airbrakes.

    Additionally, just because your aerials tires are all on the ground, doesnt mean they all are.

    Finally, not all manufactures require or even have pins on jacks. E-One aerials dont have a way to pin, because cross jacks are engineered in a way that you dont need to pin them. There are no pin holes, there are no pins. It is not laziness, you just cant pin them if you wanted to. Also, its strange, all this steel, and these hydraulics, and you have to put your life on 4 steel pins. Are you going to tell me steel doesnt fatigue and eventually fail?

    Again with the re-invention of the hydraulic piston, there is a fail safe to it.

    Listen, for all you who are missing the point. This forum topic was about Sutphen claiming to be faster set up and deploy a tower than E-One, who is known to be the fastest. We were mainly pointing out the the garbage in the video, and showing there was no comparison. Showing the tower operators on the right truck, seemed uneducated with what they were doing, and showed an unequal comparison due to doning the helmet, and also chocking the wheel; what wasnt done on the Sutphen. Then the question was brought, do you really need to chock the wheels of an aerial that is on outriggers, and what is the point. Then we were talking about what fail-safe wheel chocks were replacing, and it got into roll away apparatus. Well, you cannot have a 70klb piece of steel not on wheels "roll away" due to it being on outriggers. Then we discussed air brakes failing, and how the new style air brakes actually work, and what their fail safe is.

    Chock wheels. I chock wheels. Chock every wheel on the fleet, hell, have a service piece come around to all the scenes with a truck load of wheel chocks and chock every wheel, inner and outer duallies, front and back of the wheel. Who cares.

    Just the point of chock tires, that are off the ground, due to outriggers seems STUPID.

  11. #51
    Forum Member Bones42's Avatar
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    Quote Originally Posted by firepundit View Post
    ...Glad I don't have to work a fire ground with you.
    Me too.
    "This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?

  12. #52
    Forum Member Bones42's Avatar
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    Quote Originally Posted by donethat View Post
    NFPA 1901 Standard For Automotive Fire Apparatus requires that wheel chocks be supplied with the truck and be mounted before the truck is put in service.

    Might be a reason for that!
    not to be a *****....but....does NFPA state they should be used....or simply supplied?

    and do we all still agree that NFPA stands for...

    Not
    For
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    Application
    "This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?

  13. #53
    Forum Member GTRider245's Avatar
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    Quote Originally Posted by oper77 View Post
    Finally, not all manufactures require or even have pins on jacks. E-One aerials dont have a way to pin, because cross jacks are engineered in a way that you dont need to pin them. There are no pin holes, there are no pins. It is not laziness, you just cant pin them if you wanted to. Also, its strange, all this steel, and these hydraulics, and you have to put your life on 4 steel pins. Are you going to tell me steel doesnt fatigue and eventually fail?
    You are preaching to the choir. I drive a E-One platform every third day. That's why I said those unfortunate enough to have to use jack pins.
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    Quote Originally Posted by Rescue101 View Post
    I don't mind fire rolling over my head. I just don't like it rolling UNDER my a**.

  14. #54
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    Default To Chock or not to Chock.

    Quote Originally Posted by RFDACM02 View Post
    This I find interesting now that I reread it. Both chocks together must be capable of holding the apparatus. How often do two chocks mounted on the same side get placed to hold the apparatus in only one direction? Even when parking on a grade, most of the time I've seen chocks on both sides, indicating they're being placed to comply with a policy vs. placed for maximum effectiveness. It seems that maybe one chock may not be enough to hold the apparatus as intended? Does anyone have a policy that says place both in one direction for inclines?
    Chief Looking back on the original instructions of an OEM, Most of then state the chocks should be placed on the down grade side of the wheels -axles when working on a grade, so in monday morning quarterbacking one unit with 4-chocks should have all 4-chocks on the down grade side of the apparatus axles.

    BTW I will be up your way in November or December, I stop in and say hello to all if time allows.

  15. #55
    Forum Member SCOOBY14B's Avatar
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    I'm always amused how 99% of the topics get derailed in forums and the subject is changed and no one notices.

  16. #56
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    Quote Originally Posted by Skysthelimit View Post
    Chief Looking back on the original instructions of an OEM, Most of then state the chocks should be placed on the down grade side of the wheels -axles when working on a grade
    This of course is the only way that makes sense. As I said, if you look around, when you see chocks out, they're most often on both sides of the wheel vs. two in the same direction, unless the slope is so obvious people really are worried.
    Quote Originally Posted by Skysthelimit View Post
    BTW I will be up your way in November or December, I stop in and say hello to all if time allows.
    That'd be great. Let me know I might be able to meet you somewhere if your not to close, I'm gonna be "light duty" for a bit with a shoulder surgery next week. Course as everyone is so quick to remind me, most of my job seems to be pretty light in the duty category and holding a radio mic isn't bad one handed.

  17. #57
    Forum Member Rescue101's Avatar
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    Quote Originally Posted by oper77 View Post
    Stating that is nice. Short of spending $50 to buy the document, can you provide a location for where that is stated. I have scrolled through the document, and I am not seeing it yet.

    just a curiosity thing
    I'm not going to go thru my desk full of paper to justify what I'm gonna say. we are a licensed Repair facility in the State of Maine,do vehicle forensics with MSP, and run a Towing and recovery service. The following statement of facts apply: Auto adjusters..........DON'T. Spring brakes/anchorloks,what ever you care to call them........FAIL and NOT always catastrophically. Chocks are MANDATED here by both MY company and FD Sog's. Front brake locking I believe is now mandated on all new aerial trucks. It's simply an electrically operated solenoid that applies/retains pressure to the front brake "cans". Our 09 Smeal has it on it. Easy way to remember how an air brake works: when you push the yellow release button,air pressure compresses a big coil spring in the far end of the brake can and holds it there.In NORMAL braking,air pressure pushes on a diaphram in the LOWER end of the can and overcomes a smaller spring, jacking the S cam to apply pressure to the shoes/rotor caliper to effect the stopping process. In EMERGENCY(air loss)or parking,the air pressure holding the BIG parking brake spring is removed which causes the spring to apply the brake(S cam) just as normal braking would do but faster, Hence the name"Spring brake" T.C.

  18. #58
    Forum Member Rescue101's Avatar
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    Quote Originally Posted by GTRider245 View Post
    You are preaching to the choir. I drive a E-One platform every third day. That's why I said those unfortunate enough to have to use jack pins.
    Our Smeal has pins. Has the same hyd safety valves the E-ones have.If you DON'T have hyd. pressure,nothing moves.The pins are a redundant safety and I don't mind that when my happy a** is many feet off the ground. T.C.

  19. #59
    Forum Member Rescue101's Avatar
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    Quote Originally Posted by GTRider245 View Post
    This is really not that hard..

    NFPA (as illustrated), manufacterer guidelines, department SOP/SOG, industry standard, etc. all point to putting wheel chocks on the ground. It takes 5 seconds to place and pick them up. I will take that 5 seconds to ensure that I am not on the stand somewhere trying to jusftify my complacency, because that's all it is.

    And by the way, our aerials have the front tires touching the ground in most routine operations. Those are the wheels that get chocked. For those of you unfortunate enough to have to worry about it, do you not place jack pins either? Afterall, you shouldn't need them right?
    You were taught RIGHT. The Smeal operators manual says you chock whichever wheels are on the ground. Which COULD be front or rear depending on Setup. It ain't Rocket science even though some try to make it that way. A Chock full of AIR never worked yet. T.c.

  20. #60
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    Quote Originally Posted by oper77 View Post
    the re-invention of the new airbrakes.

    with the re-invention of the hydraulic piston, there is a fail safe to it.

    There is nothing new about the way modern air brakes work. They have been working the same basic way since George Westinghouse invented them.

    There is also nothing new about hydraulic pistons. The reason some manufacturers supply pinnable outriggers is due to the fact that holding valves all leak to some minor degree. Maybe only a drop every few minutes but, they do leak a little. Consequently, if you set the aerial up for an extended period of time, the jack will move a little. Even on an E-One.

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