Norton-on-Tees SPAD

[Tomnick]

The RAIB have released their report (here) into a SPAD at Norton-on-Tees earlier this year - I thought one or two members here might be interested in (and possibly surprised by) the findings!

Signal NW36 passed at danger at Norton-on-Tees West, 16 January 2013

Description of the incident

At about 07:45 hrs on Wednesday 16 January 2013, train 1A60, the 06:45 hrs Grand Central Railway service from Sunderland to London King’s Cross, passed signal NW36 at danger at Norton-on-Tees West and passed over a level crossing adjacent to Norton-on-Tees West signal box. The barriers were still raised and the crossing was open to road traffic. The Norton-on-Tees West signaller saw that two cars, one in each direction, had stopped at the level crossing as train 1A60 was passing over it. The train should have stopped at signal NW36. The driver of train 1A60 was unaware that he had passed the signal at danger and the train continued on its journey. It was not stopped until it reached Bowesfield, around 3.5 miles (5.6 km) beyond Norton-on-Tees West. There were no other trains in the area at the time of the incident, so there was no risk of a collision
between trains.... (read more - PDF format)

 

[O L Leigh]

I thought one or two members here might be interested in (and possibly surprised by) the findings!

At the risk of being controversial, no not really. There's nothing startling in the report. I'm not even particularly sure why it's being touted for discussion.

I drive mostly under Track Circuit Block (TCB) regulations using colour light signals but also under Absolute Block (AB) regulations using a mixture of semaphore and colour light signals and, in common with Norton-on-Tees, areas with fixed distant signals. You know what the risks are, where you need to concentrate and what you should be looking for.

I agree that there are issues with regard to reading semaphore signals and that reducing the areas covered by semaphore signals means that drivers will are perhaps less used to seeing them, but anyone in the industry who stops and thinks about it for even a minute will realise this.

O L Leigh

 

[Tomnick]

It was the suggestion that - admittedly referring more to a previous incident locally - there had been some misunderstanding of the meaning of a stop signal mounted on the same post as a distant signal that struck me the most, but also the rather bizarre (and unoffical) method of signalling. I find it quite enlightening, in the spirit of mutual improvement, to see how a simple concept to a Signalman is open to misunderstanding and confusion by some of our driving colleagues. I'm sure the reverse is often true too, which is why it's such a shame that there's very little opportunity to see how the other side work nowadays .

 

[O L Leigh]

I don't think that was the RAIB's conclusion. There were a number of factors at play, not limited to the non-standard bell code (which only exacerbated the overrun and was not contributory to the SPAD itself). There were local conditions affecting signal sighting, the driver's previous experiences of the route and an assumption about the status and meaning of the signals seen. It seems more likely that the driver gave greater emphasis to the associated distant signal than the stop signal for some reason. Such factors are causal to many SPADs.

O L Leigh

 

[Tomnick]

That's the interesting part for me, trying to understand the factors behind an otherwise straightforward SPAD. I'm also not sure that I could receive a string of fourteen bells and just pull off for a train that's arrived unexpectedly without managing to interpret that bell signal!

 

[Lockwood]

As a total outsider, I'd have thought that an "Oh poop" bell code would be simpler, either banging out 1-1-1-1-1-1-1-1-1-1-1-1, a simple repeating pattern like 1-2-1-2-1-2 or a continual mash like 10; something that is easy to mash out and recognise that the 4-5-5.

 

[BravoGolfMike]

Sometimes when you read about a SPAD you think how on earth did that happen. Sometimes you read about one and you think woah that could have easily been me - and hopefully learn from it. (Which is why SPAD details are published locally.) To me this one falls into the latter category. Driving over a portion of line you are less familiar with, in the early morning and on signals that you might be unfamiliar with.

It was dark so there would have probably been no sighting of the signal arms. The driver saw a yellow light but obviously missed the red above it. Lights in AB areas are very dim and it is worth remembering that in a TCB area the red is positioned closest to the driver (on a signal on a stick it is the bottom aspect, if the signal is on the deck it is the upper light. However, in AB when you have a stop above a distant then the distant is closest to the driver hence the reacting on the yellow.

Should the SPAD have happened? No, of course not. But it is a classic "Domino" scenario: take out a domino and the SPAD would not have happened ie:

Had there not been problems that morning the train would have gone booked route and the SPAD would not have happened.

If the signal was cleared the SPAD would not have happened

If it was light, the driver would have seen the stop arm.

If it was the booked route, the driver would have been more familiar with the signal.

If it was a colour light signal, the driver would have not seen a yellow.

Very unfortunate incident and I sincerely hope the driver is back driving as this one could have happened to any one of us.

 

[Tomnick]

That's my point really - I think, as a Signalman, it's helpful to understand why these incidents, which might look like no more than a silly mistake on the surface, really happen - so that we can perhaps all work together to avoid leading each other into unnecessary traps!

As a total outsider, I'd have thought that an "Oh poop" bell code would be simpler, either banging out 1-1-1-1-1-1-1-1-1-1-1-1, a simple repeating pattern like 1-2-1-2-1-2 or a continual mash like 10; something that is easy to mash out and recognise that the 4-5-5.

There are quite a few emergency bell signals with different meanings (6 consecutive beats being probably the best known - 'obstruction danger'), so it does need to be possible to quickly and reliably distinguish between them. Once you're used to listening to bell signals, 4-5-5 is probably more recognisable than 10 consecutive beats - I find that it's more about the rhythm than (mis)counting individual beats.

 

[edwin_m]

It is stated that the driver was aware of the red light, the meaning just didn't register. The driver was accustomed to seeing a very similar set of signals nearby when not diverted from the usual route, but with the stop signal almost always "off" as that box is normally switched out.

 

[Lockwood]

There are quite a few emergency bell signals with different meanings (6 consecutive beats being probably the best known - 'obstruction danger'), so it does need to be possible to quickly and reliably distinguish between them. Once you're used to listening to bell signals, 4-5-5 is probably more recognisable than 10 consecutive beats - I find that it's more about the rhythm than (mis)counting individual beats.

That makes sense. Phones being more common now that back in the telegraph days, I was of a mindset of "General emergency bellcode - and I'll call your box in a minute to explain why I did that"

 

[edwin_m]

The action to be taken on different emergency bell codes is different so it is important that the signaller receiving one can act immediately without having to wait for an explanation.

6 is "Obstruction Danger" meaning stop anything going towards the box sending it.

4-5-5 is "Train running away on right line" meaning a train is approaching that might not stop, so do what you can to divert it or move anything else out of harm's way.

There are (or at least were) several others, for example "train passed without tail lamp" which requires the train in question to be checked but also trains in the other direction to be stopped in case the part carrying the tail lamp has derailed foul of the other track. Usually it just means the lamp has gone out, fallen off or been missed by the signaller sending the code.

Perhaps the most scary is "train divided", which is accompanied by a special hand signal to tell the driver to do whatever he can to keep ahead of the rear portion. Fortunately since continuous brakes became universal these are pretty much part of history.

 

[Southern Dvr]

I haven't read the report yet.

Could an emergency broadcast not have been made on the NRN?

The sooner GSMR goes live across the UK the better.