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Admin
Administrator
USA
1662 Posts |
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RonF
Top Member
867 Posts |
Posted - 11/06/2018 : 11:33:45 AM
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quote: Originally posted by Admin
We thought you would be interested in this story about a school bus mechanic who was run over, killed by a bus in Little Rock, Arkansas. He attempted to stop the bus after the air brake released, causing the bus roll down a hill and hit him.
http://www.schoolbusfleet.com/news/731977/school-bus-mechanic-run-over-killed-by-bus?refresh=true
Hmmm. How does the air brake just release? If it doesn't have a brake interlock, and or brake interlocks for lifts, you still have to push in the button. |
US Army retired CMBT |
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partsman_ba
Administrator
United States
377 Posts |
Posted - 11/06/2018 : 12:21:35 PM
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He must not have set the PP-1(or -DC). He probably didn't choose to stop in the road, but the wheelchair lift door opened and set the interlock. When he got out and closed the door, it released the interlock. |
"Growing old is mandatory. Growing up is optional." |
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bwest
Administrator
United States
3820 Posts |
Posted - 11/07/2018 : 10:37:00 AM
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I had a friend of mine, who was a mechanic in a neighboring district, killed by a bus falling on him. The reason was that he didn't use the proper support under the axle while having the bus lifted (and wheels off) for repair. There are other factors but they are not pertinent for our conversation here. |
Bryan |
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PrestonBus
Active Member
USA
13 Posts |
Posted - 11/08/2018 : 04:33:01 AM
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Why does the term "Over-Engineering" come to mind reading this? This is the first time Im glad our buses are still all hydraulic with manual P-brakes. Condolences to his family. |
Saving the World...One school bus at a time. |
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bwest
Administrator
United States
3820 Posts |
Posted - 11/08/2018 : 05:30:58 AM
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quote: Originally posted by PrestonBus
Why does the term "Over-Engineering" come to mind reading this? This is the first time Im glad our buses are still all hydraulic with manual P-brakes. Condolences to his family.
I'm a juice brake man myself but I wouldn't say it has anything to do with "over engineering". I'd say it's human error. Not sure what he was working on but when air pressure is removed from the park chamber, the spring takes over and locks the brakes down. There should be no way for the bus to roll. |
Bryan |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 11/08/2018 : 06:06:17 AM
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Oh I see how this could very easily happen.
On at least one brand of lift bus with air brakes, if the lift door is opened enough to trigger the switch, a solenoid forces air into the rear service brakes, locking the bus in place. Newer models of that same bus engage when you flip the "lift" switch on and the bus is under a certain (low) MPH. If you are over that threshold, the brakes don't apply until you drop speed low enough.
If you have a electrical fault, accidentally flip that switch, or the door unlatches/opens enough, you go into what is essentially an uncommanded service brake application. If you fail to pull the parking valve, you can leave the seat and the bus will not move, until you remedy the fault, switch or unlatched door.
At least one brand will not allow you to release the (air) park brake if the lift door is unlatched, but it's not capable of locking down the bus if something happens while in motion (we tested it to be sure).
In any event, most certainly a tragedy. Hopefully details will be released of exactly how it happened, so we can all learn from it. |
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namao
Senior Member
Canada
89 Posts |
Posted - 11/08/2018 : 06:54:34 AM
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Feel sorry for his family. This can easily happen and this brought back a incident I had years ago when we still towed. Dad had trucks with the old sling lifts, went out to tow school bus back to shop. I was in my 20s. Backed up and touch the bus , the driver did not apply the park brake. It looked like it was on level ground but there was a slit decline. Bus starts going backwards down highway towards a intersection [75 yards], not very fast at first. I grabbed a 4x4 threw under front wheel jumps over do the same with back jumps over it jumps, try divers door and is closed and would need to get in back to open. Young guy so run to back and while bus going backwards, open rear exit door ,jumped in and stopped bus just as it got to intersection. Thinking of the incident know I could easily of tripped and been a statistic. When things go sideways sometimes,I think you do not think of the danger you put your self in and you just react to fix the problem. I am going to bring this incident up with the staff at our morning tool box meeting just to remind them things can happen fast and you need to some times just assess the situation before jumping in. WE all want to go home to our family's in the evening. Be safe. |
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RonF
Top Member
867 Posts |
Posted - 11/08/2018 : 07:37:09 AM
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quote: Originally posted by Thomasbus24
Oh I see how this could very easily happen.
On at least one brand of lift bus with air brakes, if the lift door is opened enough to trigger the switch, a solenoid forces air into the rear service brakes, locking the bus in place. Newer models of that same bus engage when you flip the "lift" switch on and the bus is under a certain (low) MPH. If you are over that threshold, the brakes don't apply until you drop speed low enough.
If you have a electrical fault, accidentally flip that switch, or the door unlatches/opens enough, you go into what is essentially an uncommanded service brake application. If you fail to pull the parking valve, you can leave the seat and the bus will not move, until you remedy the fault, switch or unlatched door.
At least one brand will not allow you to release the (air) park brake if the lift door is unlatched, but it's not capable of locking down the bus if something happens while in motion (we tested it to be sure).
In any event, most certainly a tragedy. Hopefully details will be released of exactly how it happened, so we can all learn from it.
"If you fail to pull the parking valve, you can leave the seat and the bus will not move, until you remedy the fault, switch or unlatched door."
Probably the key to this tragedy. This should remind all us in our business as to how quick something can happen. |
US Army retired CMBT |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 11/08/2018 : 08:13:05 AM
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While back I saw where someone had come up with an alarm that sounded if you took off the seatbelt without the brake being set. I think I may explore that for new purchases. |
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bfaulkner
Senior Member
168 Posts |
Posted - 11/08/2018 : 1:10:32 PM
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quote: Originally posted by Thomasbus24
While back I saw where someone had come up with an alarm that sounded if you took off the seatbelt without the brake being set. I think I may explore that for new purchases.
While yes a safety feature, I move and work on the buses quite often with no seat belt. It would drive me nuts like the bluebird no oil pressure buzzer when the key is on.
What we really need is to slow down and make sure we are doing everything right. accidents happen when in a rush. |
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1983WardFord
Top Member
USA
1395 Posts |
Posted - 11/09/2018 : 03:58:25 AM
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quote: Originally posted by bfaulkner What we really need is to slow down and make sure we are doing everything right. accidents happen when in a rush.
This.
I know it's hard with all the demands being placed on us & trying to keep the drivers and districts happy, but the few seconds to step back and assess the situation are well worth it in the end. |
Due to the current economic condition, the light at the end of the tunnel has been turned off until further notice. |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 11/09/2018 : 04:38:09 AM
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My personal truck throws a fit if me or my passenger aren't belted. It takes 3 seconds to click on a belt. 3 seconds of my life to avoid an annoyance is well worth it if it saves a life.
That said, I do agree with you both...we do need to just slow down and pay attention. |
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40ngone
Senior Member
USA
166 Posts |
Posted - 11/09/2018 : 07:22:28 AM
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Things can happen very quickly. I have found mechanics are very proud people and like to provide good, fast service.
In a busy operations, with lots of demands and pressure to keep vehicles on the road, it gets hectic. As Vehicle Maintenance Supervisor, I am constantly keeping an eye on, and reminding my mechanics to do what I think is one of the hardest things possible for most guys.
When the pressure is on, you have to slow down, be very deliberate in your actions. We all have a tendency to speed up, and I think that is what gets us in trouble.
I pray for him and his family, and hope we all take a step back try to prevent it from happening again. Remember the things that really matter.
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