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Schoolbusdude
Active Member
10 Posts |
 Posted - 12/10/2012 : 2:37:34 PM
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I was recently talking with a friend of mine who works in mass transit about some roll-away incidents that I read about on SBF, and he said that many urban mass transit coaches are equipped with what is called a Hill Holder--it's essentially a momentary electro-pneumatic version of a parking brake. However, the only difference is that the hill holder uses less air than the regular parking brake (and thus less wear and tear on the air compressor), and the momentary control (press and hold a sprung toggle switch to engage, let go to disengage) makes it easier to control.
As I said, the feature is common on many urban mass transit coaches, but I want to know--have any school buses been so equipped? Should they? |
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Thomasbus24
Administrator
USA
4547 Posts |
Posted - 12/12/2012 : 03:07:57 AM
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Since air brakes don't use air to apply the parking brake, only to release the parking brake, you've been misinformed about this hill holder thing saving on air compressors.
I see no need for such things, that is what the park brake is there for, use it. I do however like the concept elsewhere on this site of an alarm that sounds if the driver unbuckles the seatbelt without setting the brake. Makes a better reminder than the bus rolling into someone/something. |
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bus724
Top Member
USA
1609 Posts |
Posted - 12/12/2012 : 05:21:12 AM
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I know a lot of transit buses have interlock systems that automatically apply the parking brake and cut out the throttle when the exit door is open, when the wheelchair lift is being used, etc. They use those instead of having the driver set the brake and go into neutral at every stop, since most transit stops are done more quickly than in the school bus world.
As with anything, it's easy to become overdependent on a feature like that. I've heard of incidents like a driver leaving the bus to grab a coffee while on a layover after unloading at a stop, forgetting to set the brake because the interlock was holding the bus, and having it start to roll when they reached through the driver's window from outside to close the door. |
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Hill Holders?
