Wrightbus with throttle stuck open?

[pompeyfan]

A few months ago I recall reading about a serious accident in which a Wrightbus NBFL had its throttle stuck open. Was there any follow up to the story and what caused it to jam open, and wether anyone was given the blame?

 

[CatfordCat]

inconclusive.

driver found not guilty - no conclusive proof he was at fault. no conclusive proof bus was defective.

evening standard report here

 

[gazthomas]

In the report linked it showed an LT bus crashing?

 

[BestWestern]

That's interesting. Are the footbrake, handbrake or Neutral gear selection button disabled when the throttle is open on one of those? The driver does appear to eventually attempt to select neutral (I assume that's what he's reaching for on his right hand side), but clearly without success.

 

[the101]

A few months ago I recall reading about a serious accident in which a Wrightbus NBFL had its throttle stuck open. Was there any follow up to the story and what caused it to jam open, and wether anyone was given the blame?

Claims of the throttle stuck open or the brakes failed are sadly common when buses are involved in accidents. It may happen very, very occasionally, particularly on buses with air-operated throttles in very cold weather when there is moisture in the system somewhere, but in about 99% of claims of this nature by drivers it is, sadly, an attempt to shift the blame from themselves.

 

[pompeyfan]

Looking at the video again, and having driven a Wright Streetlite (which I assume are similar in terms of operation and cab layout) I can confirm that selecting neutral would usually put the bus in neutral, even if the throttle was open. However from the video he doesn't appear to attempt to select it, the button is to the right of the steering wheel, it's a simple 3 button DNR set up. When he turns to the right he appears to try and isolate the bus using the master switch, which is down the right hand side.

Presumably he suffered from rabbits in the headlights syndrome. I also find it hard to believe that the power of the bus was stronger then the operation of the disc brakes. Usually they can stop on a sixpence, if the driver so wanted to. This is why I asked if there was any further follow up as it doesn't add up to me.

 

[Carlisle]

That's interesting. Are the footbrake, handbrake or Neutral gear selection button disabled when the throttle is open on one of those? The driver does appear to eventually attempt to select neutral (I assume that's what he's reaching for on his right hand side), but clearly without success.

I'm surprised the rear platform conductor didn't attempt to intervene in some way once it was clear their driver had totally lost control

 

[BestWestern]

Looking at the video again, and having driven a Wright Streetlite (which I assume are similar in terms of operation and cab layout) I can confirm that selecting neutral would usually put the bus in neutral, even if the throttle was open. However from the video he doesn't appear to attempt to select it, the button is to the right of the steering wheel, it's a simple 3 button DNR set up. When he turns to the right he appears to try and isolate the bus using the master switch, which is down the right hand side.

Presumably he suffered from rabbits in the headlights syndrome. I also find it hard to believe that the power of the bus was stronger then the operation of the disc brakes. Usually they can stop on a sixpence, if the driver so wanted to. This is why I asked if there was any further follow up as it doesn't add up to me.

Certainly strange. I'd have thought the master switch would have shut the bus down, I'd also agree that the brakes should easily have overriden the drivetrain, or at the very least significantly reduced the speed of the bus. Presumably the engine off switch should also have functioned as normal. Of course nobody can really know, but short of some kind of catastrophic electrical malfunction which simultaneously jammed the throttle and rendered everything else inoperative, it is certainly perplexing to consider what happened here!

 

[the101]

Looking at the video again, and having driven a Wright Streetlite (which I assume are similar in terms of operation and cab layout) I can confirm that selecting neutral would usually put the bus in neutral, even if the throttle was open. However from the video he doesn't appear to attempt to select it, the button is to the right of the steering wheel, it's a simple 3 button DNR set up. When he turns to the right he appears to try and isolate the bus using the master switch, which is down the right hand side.

Presumably he suffered from rabbits in the headlights syndrome. I also find it hard to believe that the power of the bus was stronger then the operation of the disc brakes. Usually they can stop on a sixpence, if the driver so wanted to. This is why I asked if there was any further follow up as it doesn't add up to me.

A StreetLite will be capable of putting a lot less torque to the drive wheels than a New Routemaster, which has an electric motor as its form of propulsion and is thus capable of delivering a huge amount of power from zero revs if required (and permitted by the bus's control system). However, it is still true that in an emergency situation a full application of the footbrake will be more powerful than the electric motor.

I agree that there is more to this than 'the bus wouldn't respond', as is being claimed.

Regarding the suggestion of the brakes being disabled when the accelerator is applied(!)... I very much doubt that method of configuration would be permitted in any vehicle by governing and certifying bodies.

 

[Busaholic]

I'm surprised the rear platform conductor didn't attempt to intervene in some way once it was clear their driver had totally lost control

Reports at the time said the female passenger assistant shouted a warning to passengers to brace themselves: her job was to remain on or near that open rear platform. It was very fortunate that the bus didn't collide with the car it almost took out as it went across the red light at the bottom of Sloane Street, where it should have turned left.

It should also be noted that after the initial experiment with a few buses on route 38 using drivers as passenger assistants (aka conductors) the p.a.s were recruited as such on the open job market, so few if any would have bus driving experience.

Reading between the lines, it sounds like the driver hadn't had the requisite type training.

 

[Temple Meads]

I wonder how well all this speculation would've gone down on this forum had a train driver been involved....

 

[90019]

I'd also agree that the brakes should easily have overriden the drivetrain, or at the very least significantly reduced the speed of the bus.

Any vehicle with brakes that cannot overcome a wide open throttle shouldn't be on the road, in my opinion*.
See also: Toyota accelerator pedal recall.




*Obviously brakes can fade, which is an entirely different matter.

 

[pompeyfan]

I wonder how well all this speculation would've gone down on this forum had a train driver been involved....

Us bus drivers aren't as important

But on a serious note, the investigation was inconclusive. There's no pedal telemetry to download, no OBDR to check, but there are questions which still need answering. If something like this had happened on the railway then the data would have been there....

 

[Tetchytyke]

Unless you can prove what pedal he was pushing, there's no way of getting a conclusive outcome. You can guess what happened- I think most people will guess one way- but it's only a guess.

But even if there was a conclusive outcome, that doesn't mean the driver would be punished. There was a Sunderland driver who killed two people because he pushed the accelerator instead of the brake on a Dennis Dart and he was acquitted of all charges back in 1999.

 

[pompeyfan]

Which is why it surprises me that there is not now some sort of F1 style telemetry stored somewhere with footbrake pressure %, throttle pressure %, handbrake etc. like OTDR, but for buses... I suppose the cost outweighs the usefulness as usually CCTV is adequate.