Incident at Enfield Town 12/10/21

[Llama]

Not that it looks particularly likely here, but sudden and profound deterioration in rail adhesion can be brought on by the wet stuff falling from the sky, albeit usually on contaminated rails. Plus contamination can be from all sorts of sources e.g. industrial emissions - we've had adhesion incidents at Manchester Airport in the past where it was suspected that kerosene in the air contributed, and not that long ago there were station overruns on the Chat Moss line due to wood pellet dust falling from a hopper on a freight train.

But it's unlikely that low adhesion was a major factor in this incident. Obviously it should be known by now whether or not the train had a TPWS activation at the loops approaching the buffer stop due to excessive approach speed, whether the driver alleges a problem with the train or low adhesion and the driver will have undergone for-cause D&A screening, plus many other considerations of human factors and technical natures.

 

[vikingdriver]

Do these things have a combined PBC?

 

[Mcq]

Is it really necessary to suspend the whole of the line from Edmonton Green - isn't there an alternative platform at Enfield Town?

 

[richardcoughla]

Looks like the buffers did their job it could have been a lot worse!

 

[CFRAIL]

Is it really necessary to suspend the whole of the line from Edmonton Green - isn't there an alternative platform at Enfield Town?

Presumably the power is isolated if they're working in the area

 

[mr_moo]

Weather for Enfield this morning - there was no rainfall according to the met office.

UK weather map - Met Office

Our weather map shows you the latest weather and forecasts for the UK. Includes forecasts up to 5 days and observations from the last 24 hours.

www.metoffice.gov.uk

Note re the above - not trying to blame anything or anyone. Adhesion is indeed much more complex than just leaves and rainfall, but rain is certainly a factor in many cases.

 

[Llama]

Dewpoint can also be a big issue for adhesion and I'd wager that the air temperature was a few degrees higher than the rail temperature at about 8am this morning. But I'll eat my WONs if this incident turns out to be primarily due to low adhesion.

 

[Townsend Hook]

Do these things have a combined PBC?

They do.

 

[pdeaves]

Do these things have a combined PBC?

What's PBC, please?

 

[Bletchleyite]

What's PBC, please?

Power Brake Controller, i.e. a lever you (usually) pull back for power or push forward for braking.

 

[Wilts Wanderer]

If adhesion is low, could a hard brake application by the TPWS detecting overspeed at the grid result in wheels locking up and sliding?

 

[OvergroundMatt]

Looks like the buffers did their job it could have been a lot worse!

I'm not really sure this could be counted as a success. This looks more like a buffer stop fail to me. The train was launched into the air in completely uncontrolled fashion, it nearly hit a passenger area, and only good luck, rather than sound engineering, saved this from being a lot worse than it was. Had Enfield Town been fitted with a sliding friction buffer stop – recommended in by the RAIB in a number of reports now – the train would far more likely have been brought to a controlled stop.

 

[Mcq]

Thinking of the public for a minute - is the line still closed and what's required to reopen it - can anyone update on that side of the story please?

 

[Vespa]

Is there no hydraulic buffer stops on the line at all ? It could have absorbed the kinetic motion and less damage.

 

[XAM2175]

Is there no hydraulic buffer stops on the line at all ? It could have absorbed the kinetic motion and less damage.

Hydraulic stops have fallen out of favour as they're only effective at very low speeds - once the hydraulic piston is fully compressed no more energy can be absorbed and any remainder then acts on the stop in the traditional manner. The new standard is for friction-drag buffer stops which are designed to slide along the rails at a controlled rate and thus slow the train less suddenly, though with the downside of needing a longer overrun area.

 

[matt_world2004]

Didn't a class 345 overrun the buffers too at Abbey Wood. Could there be a design fault in those family of units

 

[Llama]

Sorry but that's not adhesion related it's either a train fault or the most likely driver error.

These are not units from the 60's they've got one of the most advanced wsp systems on the network.

Have a look at the Esher RAIB report and the other related ones from 2005, modern WSP systems aren't infallible. Our recent new units originally had the WSP & autosanders completely set up wrong which led to at least one station overrun in 2019 where the driver was exonerated because the unit setup meant it wouldn't be able to cope in poor adhesion.

 

[Mcq]

Presumably the power is isolated if they're working in the area

There are three platforms at the station - is it not possible to just isolate platform 2 and run a service from one of the others - the train must be well clear of the points.
This is a busy commuter branch why is there apparently little progress all day - I assume the two EMT3s shown in the Bush Hill Park Berths on OTT are line blocks.

Edited regarding progress

 

[JonathanH]

Thinking of the public for a minute - is the line still closed and what's required to reopen it - can anyone update on that side of the story please?

The train is going to have to be removed and the line restored before any passenger service can recommence.

Trains diverted to Cheshunt to reverse after Edmonton Green and peak extras cancelled.

There are three platforms at the station - is it not possible to just isolate platform 2 and run a service from one of the others - the train must be well clear of the points.

Absolutely not. They would not want passengers anywhere near Enfield Town until it is sorted out. Southbury and Enfield Chase are perfectly reasonable alternatives.

 

[Llama]

There's still a lot of human factors/non technical stuff before we can say 'it's the driver's fault' - fatigue/rostering, medical, training, equipment/distraction/miscoordination etc. for a start.

 

[GB]

There are three platforms at the station - is it not possible to just isolate platform 2 and run a service from one of the others - the train must be well clear of the points.
This is a busy commuter branch why is nothing being done all day - I assume the two EMT3s shown in the Bush Hill Park Berths on OTT are line blocks.

Isolations depends on how the overheads are set up and where the switches are. In any case this is an active recovery scene with lots of people and equipment heading that way (if not there already) and the last thing they want is to have to contend with a train service and general public.

How do you know "nothing" has been done all day? Have you attended the site or been part of the numerous conference calls and recovery plans?

 

[507 001]

There's still a lot of human factors/non technical stuff before we can say 'it's the driver's fault' - fatigue/rostering, medical, training, equipment/distraction/miscoordination etc. for a start.

Indeed! There were more people jumping to the Kirkby incident’s driver’s defence than there are here, and that was very much more obvious. He admitted being distracted at the scene!

 

[dk1]

Recovery of train has commenced but no estimate for resumption of services.

 

[Mcq]

Thank you dk1 - is there OLE damage to deal with?

 

[dk1]

Thank you dk1 - is there OLE damage to deal with?

Doesn’t appear to be. Just an isolation for the recovery team mate from what I’ve read.

 

[Bletchleyite]

A bump like this was caused to a Pendolino, I think at Liverpool Lime St, due to a fault with the design of the transition from regenerative to friction brake. As these units are newish, that is another possibility. But not for the 40 odd year old 507 at Kirkby as that braking system is well proven.

 

[Mcq]

Doesn’t appear to be. Just an isolation for the recovery team mate from what I’ve read.

Thanks dk1

 

[thomson787]

I know it's too early to tell but would a unit involved in an incident such as this be repairable, It looks as if it's held up very well.

 

[dk1]

I know it's too early to tell but would a unit involved in an incident such as this be repairable, It looks as if it's held up very well.

It will be out of service for a while but doesn’t look too severe.

 

[bassmike]

Indeed and with a passenger concourse in front of the buffers be interesting to see the risk assessment for that one that says it was fine to leave them. If there isn't anything untoward with the train braking system RAIB may well just say we've identified this risk from previous investigations and recommendations have been made to the infrastructure operator and just issue a safety digest. That would put the ball in ORR's court about what level of compliance checks they've done and what NR has previously told them about levels of compliance.

Noticed that the track was still the old-style flimsy bull-head rail with not very substantial looking stops.