Question for PSV drivers

[Bob696]

As some of you may have seen on the news there was a fatal accident last week in dudley. A driver lost control of a bus on a steepish hill, carreared into a parked car, killed a pedestrian, went straight through a concrete lamppost and then damaged a row of 4 terraced houses to such an extent that it looks very likely they will be demolished.

I was talking to an eyewitness today who said that after hitting (side swipe) the car the driver leaped out of the cab to leave the bus to wend its merry path of destruction.

My question is, what fault could cause a driver to bail risking life and limb (20-30mph?)?

The driver was taken to hospital and treated for cuts n bruises. There was one passenger who lept from the bus after it burst into flames (ruptured a gas main in the houses) and legged it. He still hasnt been traced !

[Bush Tucker Man]

I was talking to an eyewitness today who said that after hitting (side swipe) the car the driver leaped out of the cab to leave the bus to wend its merry path of destruction.

My question is, what fault could cause a driver to bail risking life and limb (20-30mph?)?

Is it this case??

No 'loyalty' to his passengers??, that seems odd?

'Old Fart' mode selected;
In WW2 (& even now) pilots stayed with the planes for as long as possible to avoid built-up areas.


You still sometimes hear about drivers who give their lives to save others...
Ie; There was a case in Halifax a few years ago where a 8x4 tipper ran out of control & the driver stayed with it (sadly dying, as did people on the street), but he at least tried to steer it for as long as possible

Not the most pleasent of reading, but the driver must have been 'old school'??

[Bob696]

Yeap. Thats the crash.

[Drift]

Having been a bus driver for 18 years before moving to a nice cumffy office job in our area head office, I cant think of anything other than the complete failing of the air system (brakes) that would warrant me to jump from a bus at 20 MPH  :?
The guy who jumped off must have been standing next to the driver when it happened, otherwise he wouldn't have made it off before the crash.
Which leads me to another question.
If as I mentioned the air system could have possibly gave up causing no brakes then the doors are air operated on 80% of buses and there would /should have been enough air in the system to keep these shut (emergency measure, to stop kiddies falling out if doors fail)
They would have had to force the doors open.
t doesn't take much, but at 20MPH heading to a house it would be difficult.

Leads me to believe the bus was stolen     and they had the doors open and weren't used to the vehicle and straight forward crashed it.
Most likley wrong but a good theory  :lol:
Ste

[Sider]

Having been a bus driver for 18 years before moving to a nice cumffy office job in our area head office, I cant think of anything other than the complete failing of the air system (brakes) that would warrant me to jump from a bus at 20 MPH  :?
The guy who jumped off must have been standing next to the driver when it happened, otherwise he wouldn't have made it off before the crash.
Which leads me to another question.
If as I mentioned the air system could have possibly gave up causing no brakes then the doors are air operated on 80% of buses and there would /should have been enough air in the system to keep these shut (emergency measure, to stop kiddies falling out if doors fail)
They would have had to force the doors open.
t doesn't take much, but at 20MPH heading to a house it would be difficult.

Leads me to believe the bus was stolen     and they had the doors open and weren't used to the vehicle and straight forward crashed it.
Most likley wrong but a good theory  :lol:
Ste

There is one but with your 1st theory. Air brakes are vacuum operated. If for any reason the tanks or lines blow up, the brakes go into emergency mode, slowly stopping the vehicle, and once stopped, applying the parking brakes. The air in the tanks does not apply the brakes, it keeps the brakes from working, until you force the air out with the brake pedal.

[Bob696]

Bus wasn't stolen I am afraid. Also there is no indication that the passenger jumped from the moving bus.
Aparently only the center 2 properties will have to be demolished now. Should be interesting as it will turn the 2 outer properties from end terraces into detached  :P

[Drift]

Having been a bus driver for 18 years before moving to a nice cumffy office job in our area head office, I cant think of anything other than the complete failing of the air system (brakes) that would warrant me to jump from a bus at 20 MPH  :?
The guy who jumped off must have been standing next to the driver when it happened, otherwise he wouldn't have made it off before the crash.
Which leads me to another question.
If as I mentioned the air system could have possibly gave up causing no brakes then the doors are air operated on 80% of buses and there would /should have been enough air in the system to keep these shut (emergency measure, to stop kiddies falling out if doors fail)
They would have had to force the doors open.
t doesn't take much, but at 20MPH heading to a house it would be difficult.

Leads me to believe the bus was stolen     and they had the doors open and weren't used to the vehicle and straight forward crashed it.
Most likley wrong but a good theory  :lol:
Ste

There is one but with your 1st theory. Air brakes are vacuum operated. If for any reason the tanks or lines blow up, the brakes go into emergency mode, slowly stopping the vehicle, and once stopped, applying the parking brakes. The air in the tanks does not apply the brakes, it keeps the brakes from working, until you force the air out with the brake pedal.

Now there a point
Ive know on slightly older buses you can empty the air out of he system with as few as eight full brake depresions. (Its happened to me :shock: )
Only other two options are brake fade or just plain old bad driving, which looks the likely cause :?
Ste

[BrumLee]

There is one but with your 1st theory. Air brakes are vacuum operated. If for any reason the tanks or lines blow up, the brakes go into emergency mode, slowly stopping the vehicle, and once stopped, applying the parking brakes. The air in the tanks does not apply the brakes, it keeps the brakes from working, until you force the air out with the brake pedal.

Not sure where you got your information about how air braking systems work  :shock:

I could bore you with how air brake systems work, but roughly the handbrake works on a spring in the brake chamber. When the air is released from the chamber through a quick release valve the spring takes over and forces the brake on. If there was air failure then the spring brake would have come on automatically.

You can have a foot valve failure, but I've never know full loss of footbrake (although drivers tell you there was when they've hit something) Air brakes work on pressure (8 to 12 bar) and not a vacuum. Foot valves have dual circuit porting, so if one cicuit fails you still get brakes but increased pedal travel. If all else fails pull the handbrake lever on as this works the spring system.



Fat spring is park brake, next chamber is air chamber to force park spring for park brake off and final chamber is for foot brake application

This bus had just been mot'd so I suspect it was down to speed and driver panicing

[Sider]

Ok, slight misconception on my behalf. I have to say that the way you explained it is much more understandable (and probably correct) than the way my fitter explained it to me.

However, when one of my air tanks blew out, my lorry came to a stop, with reasonable degree of control. It was a tad sudden, but I didn't leave any screech marks, although I was doing 56 mph at the time. Scary, since I was in lane 2 (3 if you count the slip road) of the M25, around junction 15

[BrumLee]

The way it happened to you would be the case in most experiences, but the warning devices (either light, buzzer or gauge) would let you know there was loss of air. The compressor would try and maintain pressure, but if loss is greater than output the spring brakes would come on gradually. If you had applied the secondary or park brake the brakes would have locked on quicker, so you did the correct way of a controlled stop  8)    (count that as a credit to a good driver).

Taking this into account its difficult to understand why a driver would jump from a cab fearing the vehicle was in danger of not stopping. The only reason it wouldn't stop is if there is a driver error, or worse, no driver  :shock:

[Sider]

Believe me, there was no time for warnings. All of a sudden I heard this almighty bang, and all I could do was close my eyes and pray :D

More than a good driver, I'd say it was a good amount of sheer luck.

[ian_s]

or the driver wasnt really driving. hence why the 'passenger' has scarperd

[mmgemini]

There is one but with your 1st theory. Air brakes are vacuum operated. If for any reason the tanks or lines blow up, the brakes go into emergency mode, slowly stopping the vehicle, and once stopped, applying the parking brakes. The air in the tanks does not apply the brakes, it keeps the brakes from working, until you force the air out with the brake pedal.

Not sure where you got your information about how air braking systems work  :shock:

I could bore you with how air brake systems work, but roughly the handbrake works on a spring in the brake chamber. When the air is released from the chamber through a quick release valve the spring takes over and forces the brake on. If there was air failure then the spring brake would have come on automatically.

You can have a foot valve failure, but I've never know full loss of footbrake (although drivers tell you there was when they've hit something) Air brakes work on pressure (8 to 12 bar) and not a vacuum. Foot valves have dual circuit porting, so if one cicuit fails you still get brakes but increased pedal travel. If all else fails pull the handbrake lever on as this works the spring system.



Fat spring is park brake, next chamber is air chamber to force park spring for park brake off and final chamber is for foot brake application

This bus had just been mot'd so I suspect it was down to speed and driver panicing

The foot brake works in exactly the same way as the handbrake.
There is a [well was in my time] 3/4 AF bolt head theat up screwed in or out [again I can'rt remember] to release the brakes to allow the disabled vehicle to be towed.

How many ports are on the footbrake valve  :roll:

[BrumLee]

The foot brake works in exactly the same way as the handbrake.
There is a [well was in my time] 3/4 AF bolt head theat up screwed in or out [again I can'rt remember] to release the brakes to allow the disabled vehicle to be towed.

How many ports are on the footbrake valve  :roll:

Handbrake and footbrake circuits work completely different  :roll:  Footbrake works on air pressure (8 to 12 bar max and 6 to 8 bar on trailers) and handbrake (park brake) works on spring pressure when the air is exhausted from the chamber. If the handbrake worked on air pressure and the pressure dropped the vehicle would roll away, very safe indeed  :roll:  :shock: Wouldn't want to drive any truck or bus that uses your braking system  :shock:

As for ports on a foot valve, depends on the make of valve (i.e. Haldex, Wabco, etc..) What significance has ports on the footbrake valve got to do with the handbrake?  :?

[mmgemini]

The foot brake works in exactly the same way as the handbrake.
There is a [well was in my time] 3/4 AF bolt head theat up screwed in or out [again I can'rt remember] to release the brakes to allow the disabled vehicle to be towed.

How many ports are on the footbrake valve  :roll:

Handbrake and footbrake circuits work completely different  :roll:  Footbrake works on air pressure (8 to 12 bar max and 6 to 8 bar on trailers) and handbrake (park brake) works on spring pressure when the air is exhausted from the chamber. If the handbrake worked on air pressure and the pressure dropped the vehicle would roll away, very safe indeed  :roll:  :shock: Wouldn't want to drive any truck or bus that uses your braking system  :shock:

As for ports on a foot valve, depends on the make of valve (i.e. Haldex, Wabco, etc..) What significance has ports on the footbrake valve got to do with the handbrake?  :?

Sorry Lee you're reading me wrong or I'm not explaining correctly.
The way I understand it ALL air brake systems work the same.
The air pulls the spring off and no air stops the vehicle.

A much better system than any car or Land Rover

[Drift]

I know moving a bus around the yard many many years ago and I was only crawling and pumped the brakes a couple of times and the thing wouldnt stop the pedal went to the floor and bump hit the wall, horrible feeling being that helpless  :roll:
Not much damage but learnt my lesson to build up the air pressure when you get into a fresh vehicle :oops:
It had gauges and a light no buzzer, it was an old Atlatean  

[gtomo2]

Quick way to comfirm brake system just empty your air out when parked up then start the truck drop the park brake and try and pull away you will find the brakes are locked on till the air pressure is up to the correct pressure before it releases the brakes

[Dave_]

Iv been on the buses for about 3 years now, i had the power steering fail on me the other day!  Try driving an 11 ton double decker round a corner with no steering :oops:   needless to say i took out a lamp post and a traffic island :shock:

[thermidorthelobster]

Given the driver sits right at the bottom at the front, with many tonnes of bus behind him and a thin slice of metal and glass in front of him, if he knows the bus is likely to be impacting with something very solid at about driver height, would that be enough for the self-preservation instinct to kick in?  To be fair, if bus hits immovable object then the driver's going to come out of it much worse than the passengers surely?

[BrumLee]

Given the driver sits right at the bottom at the front, with many tonnes of bus behind him and a thin slice of metal and glass in front of him, if he knows the bus is likely to be impacting with something very solid at about driver height, would that be enough for the self-preservation instinct to kick in?  To be fair, if bus hits immovable object then the driver's going to come out of it much worse than the passengers surely?

He hit enough things that wouldn't have caused him too much harm before the single decker hit the houses, one of them been a pedestrian that died. I think the order was as follows: kerb. parked car, pedestrian, lamp post, garden wall, house. He may have missed a few of these if he used the steering wheel.

I remember quite a few years ago a fire engine had a sudden fault with the diff that locked one rear wheel and caused the appliance to veer into a house. All the firemen were un-harmed even though the appilance had imbedded itself that far into the house it was left there for over a week because it was the only structural part of the house  :shock:

Cabs are fairly strong now and offer a good deal of protection. I've seen a few where you would think the driver had been killed but fortunatly that wasn't the case.

[Drift]

I agree with Lee, Ive seem many buses with the fronts smashed in after hitting buildings ect and the drivers have walked away, but unfortunately Ive seen a few where the driver hasn't been so lucky.

It all depends on the incident and other variables.

[BrumLee]

I agree with Lee, Ive seem many buses with the fronts smashed in after hitting buildings ect and the drivers have walked away, but unfortunately Ive seen a few where the driver hasn't been so lucky.

It all depends on the incident and other variables.

As they say "when your number's up".

I'll see if I can find the picture I took of a Renault Premium cab that was 8" deep on the n/s and the o/s had folded 90 degrees as it wrapped round the side of a stationary trailer, hitting it at 56mph. The steering wheel had been cut in half to remove the presumed dead driver. On further asking the driver had survived, suffering two broken legs, albeit the one leg had his foot where his knee should have been and his knee-cap was poking through his groin (made my eyes water too).

[Drift]

I agree with Lee, Ive seem many buses with the fronts smashed in after hitting buildings ect and the drivers have walked away, but unfortunately Ive seen a few where the driver hasn't been so lucky.

It all depends on the incident and other variables.

As they say "when your number's up".

I'll see if I can find the picture I took of a Renault Premium cab that was 8" deep on the n/s and the o/s had folded 90 degrees as it wrapped round the side of a stationary trailer, hitting it at 56mph. The steering wheel had been cut in half to remove the presumed dead driver. On further asking the driver had survived, suffering two broken legs, albeit the one leg had his foot where his knee should have been and his knee-cap was poking through his groin (made my eyes water too).

 :shock:  :shock:  ouch
A mate in one of our Garages was thrown through the Sceen on his bus about 4 months ago, reckons he will be back at work in a few more months if the DVLA think his medical tests are ok as he went into a coma, that was a nasty one :(

[greasemonkey]

This one still confuses me though as already discussed surely if the brakes fail they come on applied by the springs failing this the hand brake has a secondary position to apply all the brakes at once rather than just the rears and then well have already talked about the steering why not just steer until it came to a stop
i think the driver [!Expletive Deleted!] his pants and abandoned a moving vehicle without any regard to the safety and lives of his passengers and other people i think they shoud throw the book at him
i would never ever abandon my wagon unless i knew i would be damaged by say a bridge support and even then as i have done before i would steer it off the road and it a ditch (took two recovery wagons lol one for the unit and one to keep the trailer upright) the good news is the cyclist who turned right infront of me without looking lived allbeit with slight brain damage
just my two pence worth (Hi Drifty)
Steve

[Terranger]

Can't say i'm mechanically minded, even though I drive the things, but we've got Brohms brakes fitted which won't let you move til the air's up, and you press a plunger.
Probably it was an old bus, as i can't see a new one travelling on after losing air.
As for the driver, a long while ago, in Stirling, a driver who had days experience on a double decker, was on a school run and got disorientated, so he took a road he recognised, forgetting he was on a larger bus, and slammed into a bridge.
After the reality of what he'd done sunk in, he ran off thinking he'd killed all the kids upstairs, and they found him 3-5 miles away from the accident site.