Do trains ever slide past red lights?

[driverd]

The conversation seems to have centered a lot around safety systems, but I think it's also worth bringing into the conversation that no safety system can do anything different to a driver initiated emergency brake application. Therefore, if a train, already in a slide with brake placed to emergency, triggered a TPWS OSS towards a red, the TPWS activation would make absolutely no difference to the situation. The means by which the brakes apply, any WSP (similar to ABS in car terms) activity occurs and any auto-sanding take place, will be (on all traction I'm aware of) identical, irrespective of a drive emergency brake application, a TPWS/AWS initiated one or, to the best of my understanding, an ERTMS initiated one.

In other words, if the track conditions are conducive to a slide, there isn't really any way of preventing it.

To address the OPs point, as others have stated, an unavoidable slide that results in a SPAD won't come back to the driver provided correct braking technique was used (eg: braking as appropriate for the conditions), using correct brake steps as per traction instructions and applying sand as per traction insturctions.

 

[RailwayRookie]

SPADs are classified in 5 categories, which I’ll detail another time.

I'm very interested in hearing this, please let me know when you post it.

 

[43066]

I’m surprised the Stongate incident hasn’t been mentioned yet. A good indication of how bad slides can be, caused by failure to keep sanders topped up, albeit there wasn’t actually a SPAD in this case.

Report 18/2011: Station overrun incident at Stonegate

Station overrun incident at Stonegate, East Sussex, 8 November 2010.

www.gov.uk

Shortly after 08:00 hrs on 8 November 2010, a passenger train running from London Charing Cross to Hastings failed to stop at Stonegate station in East Sussex. The train ran for a further 2.45 miles (3.94 km) with the emergency brake applied, passing the level crossing at Crowhurst Bridge before coming to a stop 3.22 miles (5.18 km) after first applying the brakes.

 

[Virgin Voyager]

Reading the trains not stopping in the right places at stations thread, made me wonder if, despite the driver on seeing a red signal, attempting to stop in good time, but the train not gripping and sliding past, maybe downhill in icy rails, (a) what sanctions - if any - would a driver face (ie can he prove it "slid") and secondly how would he get to see when the light changed, I assume he would call the signallers?

How often, if at all, does this happen?

"trains not stopping in the right places at stations thread"

Any chance you could post a link to that thread here? I've tried searching but to no avail. Thanks

 

[ComUtoR]

SPADs are classified in 5 categories, which I’ll detail another time.

How technical are you going to get ? Just the basics or all the risk ranking bits too ?

 

[Howardh]

Any chance you could post a link to that thread here? I've tried searching but to no avail. Thanks

Not Stopping in correct position

Can I ask what does this mean, train delayed by not stopping at correct position in the station?!

www.railforums.co.uk

 

[Bald Rick]

SPAD groupings:

1) Incomplete, inaccurate or ambiguous information given, or correct information given and misunderstood
2) Failure to check aspect; not looking for the signal; failure to locate signal; anticipation of signal clearing
3) Misread correct signal; viewed or responded to correct signal (read across or read through)
4) Misjudged environmental conditions or train behaviour
5) Other causes

 

[swt_passenger]

To address the OPs point, as others have stated, an unavoidable slide that results in a SPAD won't come back to the driver provided correct braking technique was used (eg: braking as appropriate for the conditions), using correct brake steps as per traction instructions and applying sand as per traction insturctions.

If the railway wanted to go further, I believe electromagnetic track brakes are the next step up?

 

[DJ_K666]

There's a guy at my model railway club who used to drive Euston/Watford DC trains and he said it had happened to him.

 

[Zamracene749]

Presumably intended for the sleepers?

Is application of fire retardant to tracks or sleepers commonplace?

I wouldn't like to say for certain, but it takes quite a lot to get the dense wood of a sleeper to ignite, otherwise steam trains would be followed by fire engines! It gets very hot over there in summer, I'd imagine it's to stop any dehydrated vegetation from catching light and causing lineside (then brush) fires. Perhaps triggered by sparks from brake blocks, hot carbon thrown out of diesel exhausts, discarded bottles, cigarettes etc.

 

[DerekC]

If the railway wanted to go further, I believe electromagnetic track brakes are the next step up?

Track brakes are a double-edged weapon! There are two kinds - electromagnetic friction brakes (like on a tram) which literally grab the railhead when energised. They work very well at low speed, but would probably destroy the track and themselves if applied at high speed because of the heat generated. There are also electromagnetic induction brakes which work by inducing eddy currents in the rail - Deutsche Bahn uses them on its high speed trains. However they are very expensive, make the bogie design a lot more complicated and heat the rail up considerably, to the point where the rail can overheat if several trains in succession use them.
s
RSSB has found that "Double Variable Rate Sanders" are a very good way of improving braking performance in low adhesion conditions. There is information available here, but you may need an RSSB login:

https://www.rssb.co.uk/what-we-do/k...esign-radically-improves-low-adhesion-braking

Here's the important part:

Sander configurations and variable rate sanders​

Our research has provided compelling evidence that double variable rate sanders (DVRS) can help end the need for autumn timetables, and allow reliable braking in low adhesion conditions all year round.

Earlier research had identified the potential safety benefits of using multiple sanders on rolling stock. We followed this up with on-track testing of different sander configurations, using a modern multiple unit in various adhesion conditions.

Fixed rate sanders (constant sand delivery rate) and variable rate sanders (sand delivery rate varies with train speed) were tested, together with using them at one and two axles. Using a pair of variable rate sanders (at two axles), which became known as double variable rate sanders (DVRS), was found to improve stopping distances on a four-car train by around 50 per cent compared to single axle fixed-rate sanders. They provided assured 6%g braking performance, even in very low adhesion conditions.

Drivers, operators, engineers, suppliers and RSSB then worked together to install DVRS on Class 323 trains. West Midland Trains drivers also carried out a limited number of controlled in-service trials of DVRS during the late autumn period in 2019, adopting harder and later braking than their autumn driving policy. This showed that, with DVRS, it is possible to drive safely in autumn without adopting a seasonal braking strategy.

Our research was a key enabler for Rail Delivery Group’s DVRS national business case. Following completion of the business case, the entire Class 323 EMU fleet is to be fitted with DVRS, once it is reunited with Northern Trains.

There is also a webinar here:

https://www.rssb.co.uk/what-we-do/k...e-variable-rate-sanders-an-in-service-success

I don't know what has happened to this initiative, but I surmise that DfT has declined to fund any kind of retrofit programme.

 

[Bald Rick]

DVRS is being fitted to two fleets currently. It’s not cheap. in defence of DfT, they haven’t been asked to fit anything else.

 

[norbitonflyer]

It was the bit about points being 'unlocked' I was taking issue with.

The interlocking prevents points being moved when the signal protecting them is showing a proceed aspect. They can only be moved when the signal is red.

 

[DerekC]

DVRS is being fitted to two fleets currently. It’s not cheap. in defence of DfT, they haven’t been asked to fit anything else.

Which fleets, as a matter of interest?

 

[The Puddock]

The interlocking prevents points being moved when the signal protecting them is showing a proceed aspect. They can only be moved when the signal is red.

Well no, that’s what route locking/back locking and track circuit deadlocking are for.

 

[LAX54]

Just to add, trains sliding on leaves / ice etc, is not just a UK 'thing' .... all railways suffer from it.

 

[ComUtoR]

SPAD groupings:

5) Other causes

Group 5 is :
Signaller communication human error, Signaller operating error, Uncategorised driver error

 

[Bald Rick]

Which fleets, as a matter of interest?

Northern’s 323s, and one in Scotland that I can’t remember.

 

[hexagon789]

and one in Scotland that I can’t remember.

The HSTs?

 

[Speed43125]

The HSTs?

http://live.ezezine.com/ezine/archives/759/759-2023.11.20.09.55.archive.txt

DVRS fitment programmes are now in place for Northern Class 323 EMUs, ScotRail’s 34 Class 170 DMUs plus SWR Class 158 and 159 units. The Rail Safety & Standards Board, funder of the research programme which developed DVRS, tells me that it will be a required feature in future new train procurement.

== Doublepost prevention - post automatically merged: 27 Nov 2023 ==

There was a reference to the possible fitment of DVRS to the HST fleet in the minutes of a Scotrail board meeting back in March, but I've not found anything to suggest this is going ahead.