Runaway vehicle at Queen Street

[matchmaker]

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-22526116

Rail worker hurt near Glasgow Queen Street by runaway vehicle

A worker was seriously injured when a runaway maintenance vehicle crashed into scaffolding near Glasgow Queen Street Station, it has emerged.

The Rail Accident Investigation Branch (RAIB) said it was looking into the "serious incident", which happened on the station's high level, on 21 April.

The vehicle, which is fitted with wheels for road and rail, ran away as it was being transferred to the tracks.

It ran for 1.6km before hitting buffers at the end of the station's platform.

The RAIB said no-one was onboard the mobile elevating working platform (MEWP) when it ran away at about 00:30 at the Keppochhill road-rail access point.

'Inadequate brakes'

The watchdog said: "However, while passing through the tunnel, the MEWP struck some scaffolding which was being erected as part of the planned engineering work and a person working on this scaffolding was seriously injured.

"Other members of staff working on the track were able to move clear of the runaway vehicle because they either heard its approach or were warned by mobile telephone."

(read more)

Could have been much,much worse, but still very bad!

 

[John Webb]

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-22526116

Could have been much,much worse, but still very bad!

May I point out that this is a "Current Investigation" - the formal RAIB Report will not be published until the investigation is finished. (The RAIB usually mention some of the factors involved in any incident to explain why they are investigating it.)

 

[Zoidberg]

May I point out that this is a "Current Investigation" - the formal RAIB Report will not be published until the investigation is finished. (The RAIB usually mention some of the factors involved in any incident to explain why they are investigating it.)

Indeed, and on that basis maybe better if the OP amends the thread title.

The RAIB document is at http://www.raib.gov.uk/publications/current_investigations_register/130421_glasgow_queen_st.cfm

Extract

The RAIB is investigating a serious accident caused when a road-rail maintenance vehicle ran away and struck scaffolding in a tunnel near Glasgow Queen Street High Level station on Sunday 21 April 2013.

The maintenance vehicle was a mobile elevating working platform (MEWP) that was equipped with both rubber wheels for road running and steel rail wheels for operation on the railway. It was intended to be used for engineering work on a section of track which was under possession (temporarily closed to normal train services).

 

[dysonsphere]

Having read the report as posted today the more worrying fact is that brake issues were found on other vehicles. This makes you wonder how long this has been going on.

 

[fsmr]

I don't know about the rail equipped version, but I operate the normal diesel engine factory /construction version of these MEWP booms and they have hydraulic drive to the wheels which means that as soon as the direction control valve is released (which is all via dead mans controls), the machine stops instantly even on a slope due to the hydraulic oil flow shutting off preventing it running away so no further brakes on the machine are required.

In the rail converted version, if its like 360 wheeled excavators etc I have observed on the track, the road wheels drive the rail flanged steel wheels but only once in the rail position where the pneumatic tyres can contact the flanged rail wheel. On these machines though, the pic shows that the tyres are actually outside the gauge of the track and only contact the drum bolted on the outside of the rail wheel once the rail wheel is lowered fully and comes back in to the tyres, thus in the pic, the MEWP is actually just sitting on free wheeling rail wheels when it transfers from road to rail until it is then raised relying on what little brakes are on the rail wheels assuming reading the brief report that there are additional brakes on the rail wheels. and was not to the correct position and therefore hadn't made contact with the rail wheels, so it was relying on the rail brakes rather than the normal hydraulic drive and these brakes were unable to hold on the gradient.

Lucky it wasn't worse in the tunnel.
Of course normally, these machines (all the ones I have driven) also have an audible alarm on the move but as the machine itself was stationary, that wouldn't have been active.

 

[Darren R]

Wasn't there a similar incident in similar circumstances at Bradford Interchange last year? I seem to remember initial investigations found that to have been a brake issue.

 

[wilsontown]

I also recall one where the operator was injured after the road/rail machine he was in crashed into the back of a loaded pipe train. That was also something to do with the machine being in "unbraked condition", if I recall correctly...

 

[fsmr]

Bit more detail on the Scotsman article
http://www.scotsman.com/news/transport/glasgow-queen-street-worker-hurt-by-runaway-train-1-2927962

Quite a gradient, under remote control on the transfer, and rolled to a stop before the buffers, I did think the pic showed no damage to the MEWP consistent with hitting the buffers

Investigators found the vehicle’s brakes were inadequate for the 1:45 gradient of the line through the tunnel into the station, which is steep in rail terms. The road-to-rail transfer was also not carried out correctly.

The Raib report said such vehicles had brakes effective only up to 1:29 gradients.

The vehicle, which did not have anyone on board, rolled for one mile from Keppochhill, north of the station, stopping before the buffers in the station

 

[PaxVobiscum]

Surely a 1:45 gradient is less steep than a 1:29?

In other words, the brakes should have held it as they were specified up to a steeper gradient than the 1:45 down to Queen Street (is that figure correct?)*, but for reason or reasons still to be determined, didn't do so. That is my understanding of the RAIB comments so far.

The Scotsman report reads to me as if the writer didn't understand this.

Or have I got it wrong?

*EDIT:http://canmore.rcahms.gov.uk/en/site/103559/details/glasgow+cowlairs+incline+railway+tunnel/ says Cowlairs tunnels is 1:46. Near enough.

Only the N end of the tunnel is still as built in 1842; the S end was cut back in 1878-80. A double-track tunnel on a 1-in-46 gradient with a single ventilation point, it starts just W of Pinkston Road, Springburn.

 

[fsmr]

Surely a 1:45 gradient is less steep than a 1:29?

In other words, the brakes should have held it as they were specified up to a steeper gradient than the 1:45 down to Queen Street (is that figure correct?)*, but for reason or reasons still to be determined, didn't do so. That is my understanding of the RAIB comments so far.

The Scotsman report reads to me as if the writer didn't understand this.

Or have I got it wrong?

*EDIT:http://canmore.rcahms.gov.uk/en/site/103559/details/glasgow+cowlairs+incline+railway+tunnel/ says Cowlairs tunnels is 1:46. Near enough.

Yeh I thought that to I cant imagine the gradient there being 1:29 though, that's very steep even the Lickeys only 1 in 37.7 in which case a design of brakes set for worst case 1:29 would sound fairly reasonable unless there was some sort of initial steeper access siding that set it off moving
I am sure it will all come out in the wash in a years time RAIB will be needing more staff now, another incident in Nottingham today

 

[dysonsphere]

Surely a 1:45 gradient is less steep than a 1:29?

In other words, the brakes should have held it as they were specified up to a steeper gradient than the 1:45 down to Queen Street (is that figure correct?)*, but for reason or reasons still to be determined, didn't do so. That is my understanding of the RAIB comments so far.

Thats is what I thought I think someone is mixing their facts up.

 

[steverailer]

Most of these 'brake failures' are not at all. The rail axles on alot of these MEWP's have no brakes on them, they use the brakes of the road wheels which are in contact with the rail wheels.

It seems alot of these runaways are caused by incorrect procedure when on/off tracking.

Have heard rumours that they will have to be modified at some point so the rail axles have their own brakes.

 

[DarloRich]

Most of these 'brake failures' are not at all. The rail axles on alot of these MEWP's have no brakes on them, they use the brakes of the road wheels which are in contact with the rail wheels.

It seems alot of these runaways are caused by incorrect procedure when on/off tracking.

Have heard rumours that they will have to be modified at some point so the rail axles have their own brakes.

As steverailer says a lot of these events are caused by failures in the on tracking procedure.

From what i understand road wheel braked OTP is no longer allowed. (Well either not allowed or in the process of being outlawed) Rail wheel braking must also be present. I do not know enough about standards etc but i wonder if these changes were prompted by accidents such as this?


I would also imagine these machines will be banned, temporarily, from the railway until the outcome of this investigation is known