NR Signalling in CP5

[whole diary]

[SandTEngineer]

Here is an interesting article concerning the NR^» (Network Rail - home page) signalling plans for CP5^▸ (Control Period 5 - the five year period between 2014 and 2019): http://www.therailengineer.com/2013/09/04/signalling-the-next-five-years/

[stuving]

Reading the article, I was a bit puzzled by this:

The development of automated four-barrier crossings using obstacle detector technology but without CCTV^▸ (Closed Circuit Tele Vision) monitoring is broadly completed, although there are teething problems with the performance of the LIDAR (Light Detection and Ranging) equipment that detects any objects near to the ground. It is reliability rather than safety that causes the difficulty since, if equipment fails to produce a crossing clear condition, the barriers will not raise and the crossing stays closed to road traffic.

I thought the object detection was meant to do what a signaller does: check whether all road traffic is absent before lowering the barriers which in turn clears the signals protecting the crossing. A hard failure of the OD so it always indicates something present might operate as described, but only if the barriers are down - but wouldn't such a fault prevent the barriers ever lowering?

[Super Guard]

I agree it does not read as I though.

I thought it was a "crossing clear" function, so if the barriers were down and there was an obstruction, then the signals would revert to danger and stop trains passing.

[paul7575]

AIUI^▸ (as I understand it), in the detailed operation sequence there's more than one stage of detection by different methods, initially there's a radar that checks for the absence of vehicles, if that is OK the barriers come down; and then the LIDARs (two of them set at different heights) are a second stage looking for any small objects, such as a prone child, still present after the barriers have been lowered.  Roger Ford did a piece on the problems of the latter functionality - known as Complementary Obstacle Detection(COD) - in the August Modern Railways if you can get hold of a copy.

PS

Have also found an RSSB^▸ (Rail Safety and Standards Board) paper about the thinking behind adding this COD process to the MCB^▸ (Miniature Circuit Breaker)-OD that was originally trialled without it:  http://www.rssb.co.uk/sitecollectiondocuments/pdf/reports/research/T729_rpt_final.pdf

Paul

[eightf48544]

Surely you can't do away with the CCTV^▸ (Closed Circuit Tele Vision) altogether even if the closing sequence is controlled by various detectors. If they detect an object in the way then the signaman will need to be able to see if there is an obstruction.

[stuving]

I wondered about that too, but for different reasons. I understand the idea is that if the OD says there is an object, then the crossing control believes there is an object, and CCTV^▸ (Closed Circuit Tele Vision) has no routine application. But what happens next? Call out a man in a van and wait half an hour? Phone the train driver and tell him to edge forward and have a look?

I also suspect that, for an initial period which I suspect has no fixed end point, a record will be needed for such reasons as legal liability and investigation of accidents, for which CCTV would seem to be essential. So I don't believe the "without CCTV monitoring" bit means with no CCTV installed either.

[Electric train]

Surely you can't do away with the CCTV^▸ (Closed Circuit Tele Vision) altogether even if the closing sequence is controlled by various detectors. If they detect an object in the way then the signaman will need to be able to see if there is an obstruction.

I wondered about that too, but for different reasons. I understand the idea is that if the OD says there is an object, then the crossing control believes there is an object, and CCTV has no routine application. But what happens next? Call out a man in a van and wait half an hour? Phone the train driver and tell him to edge forward and have a look?

I also suspect that, for an initial period which I suspect has no fixed end point, a record will be needed for such reasons as legal liability and investigation of accidents, for which CCTV would seem to be essential. So I don't believe the "without CCTV monitoring" bit means with no CCTV installed either.

If CCTV is installed on Level Crossings with OD it will not be installed to the same standard as CCTV at Level Crossings which rely on CCTV for safe passage of trains, ie the cameras and lighting will be to a lower standard.

Remember both CCTV and OD is there for the safe passage of trains and not for the safety of pedestrians or road users

[eightf48544]

Remember both CCTV^▸ (Closed Circuit Tele Vision) and OD is there for the safe passage of trains and not for the safety of pedestrians or road users

Not quite sure I understand the emphasis surely it is not good if the crossing operations puts pedestrians and road users in danger. Whilst a pedestrian is likely to come off worse in any incident there have been instances where a collison with a large road vehicle has cause injury to rail passengers Sudbury comes to mind.

[stuving]

Remember both CCTV^▸ (Closed Circuit Tele Vision) and OD is there for the safe passage of trains and not for the safety of pedestrians or road users

Why?

It's hard to find a simple statement of the duty of care involved in operating a level crossing, whether from the ORR^» (Office of Rail and Road formerly Office of Rail Regulation - about) or elsewhere. They refer to the Health and Safety at Work etc. Act 1974 as defining overall legal responsibility in this case. This makes a distinction between employees and others, though the responsibility is similar, and none between passengers and other users of a level crossing.

As I'm sure you really love  this kind of legal stuff, here is the most relevant bit (there are others):

3 General duties of employers and self-employed to persons other than their employees.

(1) It shall be the duty of every employer to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that persons not in his employment who may be affected thereby are not thereby exposed to risks to their health or safety.
(2) It shall be the duty of every self-employed person to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that he and other persons (not being his employees) who may be affected thereby are not thereby exposed to risks to their health or safety.
(3) In such cases as may be prescribed, it shall be the duty of every employer and every self-employed person, in the prescribed circumstances and in the prescribed manner, to give to persons (not being his employees) who may be affected by the way in which he conducts his undertaking the prescribed information about such aspects of the way in which he conducts his undertaking as might affect their health or safety.

[ellendune]

I contend that the Obstacle Detection and/or CCTV^▸ (Closed Circuit Tele Vision) is there for protection of trains, road vehicles and pedestrians.

The protection of trains and road vehicles is mutual, since if one hits the other both are affected. 

A recent article in the railway press highlighted that the low level part of the obstacle detection, that has been causing the reliability problems is to look at a low level for a person who may be lying on the track.  The design is therefore clearly intended to protect all three.

[paul7575]

A recent article in the railway press highlighted that the low level part of the obstacle detection, that has been causing the reliability problems is to look at a low level for a person who may be lying on the track.  The design is therefore clearly intended to protect all three.

As I posted earlier (#3).  The RSSB^▸ (Rail Safety and Standards Board) link I posted explains it all too...

Paul

[stuving]

I think there are two distinct, but closely linked, issues - what the OD sensors are designed to do (and how well they do it in practice), and why such a thing (or a human) is needed, which is ultimately about the legal responsibility.

On the matter of whether CCTV^▸ (Closed Circuit Tele Vision) is going to be needed even on a CB-OD crossing, the ORR^» (Office of Rail and Road formerly Office of Rail Regulation - about)'s view is that is is, though not quite for the reasons I listed:

2.62 Equipment provided should enable the crossing to be operated manually, for example from a remote control point using CCTV. Manual operation may be necessary when a persistent obstruction is detected, when obstacle detection equipment is not in use, and for periodic monitoring of crossing usage and suitability.

One way of looking at this is to think about a case where human working an MCB^▸ (Miniature Circuit Breaker) or MCB(CCTV) crossing would make a phone call - can the OD controller do that, and what would it say?

[SandTEngineer]

If you want a really comprehensive discussion on MCB^▸ (Miniature Circuit Breaker)-OD level crossings (including a description of exactly how they work) then have a look at the 13 page thread on 'The Signalbox Forum' here: http://forum.signalbox.org/viewtopic.php?f=10&t=3467

In particular have a look at the diagrams posted on Page 7.

[TonyK]

Stepping back to the legal side for a moment, a significant part of English law relating to damage, liability for personal injury, and who owes what duty of care to whom and when, evolved out of cases involving railway accidents. The historic reasons are not a factor of railways themselves, so much as what the government likes to call "step changes" in speeds, equipment, technology, and awareness. It took mankind several millennia to get much above 20 mph, but only just over another century to pass Mach 1.

The law finds it hard to move such a speed. For this reason, any incident resulting from any use of any new technology will be judged by asking something like:
- did it happen because of the operation or failure of the technology;
- was the outcome reasonably foreseeable by the operator of the technology, or;
- would the outcome be obvious to another person looking at the situation from a purely objective viewpoint?

Over the years, the question of whether or not you owe a duty of care to a person has become of lower importance. One must consider the welfare of anyone who may be affected by your actions, something which can include the trespassing metal-thief as well as the first-class passenger, although the extent of that duty will be greater towards the latter than the former. Network Rail will have no wish to become a major part of legal history. Level crossings are the subject of enough legal argument as it is, and no-one would make a deliberate decision to introduce any new system unless it had been tested beyond all reasonable boundaries by engineers, psychologists, risk assessors - and lawyers.

I don't think that just making something fail-safe is enough. I can see a lawyer telling a court "My client would never have dreamt of climbing over a level crossing barrier, but having been stood at the closed gate for 45 minutes and seeing no train pass, something verifiable by his Google glasses, and knowing that his family were in danger on the opposite side of the tracks, he decided he had no alternative other than to take the chance, just as the delayed 18.37 came by at 100 mph". High reliability, with a plan B for exceptions, is what is needed.

And that, IMHO^▸ (in my humble opinion), is what we will get. The price of penny-pinching with any safety system can be ruinously high, and I have no doubt that the decision makers here have this firmly in mind.