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Level crossing incident near Norwich new RAIB investigation

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Pakenhamtrain

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How is the TOC supposed to test their new train against the infrastructure? The infrastructure is not maintained, owned, or installed by the TOC, the ROSCO or the Rolling Stock Manufacturer. The only testing they have to conduct is for things that they can control, i.e. stopping position to account for wheelchair ramps and signal sighting,

Our new HCMTs are being tested at the moment. For the first 2500km of testing it gets carried out under a total occupation.

Every crossing the train passes over has someone from a traffic management with a stop sign. Even though the crossing is working as it should.

Part of the reason for the occupation is they dont know how it reacts with the signalling.
After it gets cleared they will allow it to play with other trains.
 
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tpjm

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Our new HCMTs are being tested at the moment. For the first 2500km of testing it gets carried out under a total occupation.

Every crossing the train passes over has someone from a traffic management with a stop sign. Even though the crossing is working as it should.

Part of the reason for the occupation is they dont know how it reacts with the signalling.
After it gets cleared they will allow it to play with other trains.
So that would be down to NR to make that distinction. Manufacturer should be saying 'we have X kit that might cause Y to happen', NR agree a special run and monitor the condition.

We did something similar with the TPE MkVa coaches. The sets don't have a TCA fitted and NR wanted to test it on a cold rail. We ran the service to SCA, left it overnight and ran it back at 0600 as the first train of the day in order to test.
 

LAX54

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The 755s when first tested, did run under Signal Exculsion zones, no other train could be in that area of testing, and also when testing on OHL, no other electric could be within about 10 miles.
 

Tio Terry

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How is the TOC supposed to test their new train against the infrastructure? The infrastructure is not maintained, owned, or installed by the TOC, the ROSCO or the Rolling Stock Manufacturer. The only testing they have to conduct is for things that they can control, i.e. stopping position to account for wheelchair ramps and signal sighting, etc.

Given that a Certificate of Compatibility will have been issued by NR for this train, I'd be looking to them to understand how they didn't spot something unique to this type of stock that could cause this type of infrastructure to not perform as predicted. Some blame also rests with the manufacturer, as their contract with the ROSCO/TOC will probably stipulate that the stock has to work within the parameters of particular routes.

That is what the Common Safety Method (or CSM-RA) is for. The Proposer of Change (TOC in this case) has to identify all the risks of the proposed change, with the help of other stakeholders (certainly NR in this case but there could be others) before they ever get to running a train in service. Obviously one of the risks revolves around the interface with the various signalling systems.
 

Edders23

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Could this just be a case of them having not tested in frost conditions and now there can be a problem which must be solvable. Frost and ice can wreak havoc with electrical circuits if you are not careful

As for apportioning blame isn't that a bit premature after all we are all human and as such with the best will in the world can we really anticipate every eventuality this sounds to me like something was overlooked so needs to be investigated and corrected . Thats trial and error not an excuse to play the blame game surely ?
 

GB

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Should be no such thing as "trial and error" with a live and fully operational railway.
 

F Great Eastern

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Thats trial and error not an excuse to play the blame game surely ?

Are you seriously advocating a safety culture of trial and error? An error related to safety could be catastrophic and no rail operator would ever employ it because it is completely irresponsible.

That's the most shocking post I've ever seen on here.
 

edwin_m

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Which is what all the 5Qxx trips are, and still are, and it seems nothing flagged up, they have also run to Lowestoft / Yarmouth / Cromer / Cambridge with no issues, until suddenly this week, maybe the profile of the wheels ?
Has rail contamination been significantly worse this week in that area? The TCA won't help if contamination is very heavy and I believe level crossing predictors detect the train in a different way from track circuits anyway.
 

HLE

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Are you seriously advocating a safety culture of trial and error? An error related to safety could be catastrophic and no rail operator would ever employ it because it is completely irresponsible.

That's the most shocking post I've ever seen on here.

To be fair I've seen worse on here. The idiotic suggestions around potential GA loans of stock from the other day is up there.
 

jayah

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So that would be down to NR to make that distinction. Manufacturer should be saying 'we have X kit that might cause Y to happen', NR agree a special run and monitor the condition.

We did something similar with the TPE MkVa coaches. The sets don't have a TCA fitted and NR wanted to test it on a cold rail. We ran the service to SCA, left it overnight and ran it back at 0600 as the first train of the day in order to test.

Sounds remarkably unsophisticated. What is a cold rail, or a very cold rail? Does it matter in push mode or pull mode? What was the dew point?

Is there not a set of defined parameters to test compliance to, or do they really try out a few random configurations once and see if anything breaks?
 

jayah

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tpjm

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Sounds remarkably unsophisticated. What is a cold rail, or a very cold rail? Does it matter in push mode or pull mode? What was the dew point?

Is there not a set of defined parameters to test compliance to, or do they really try out a few random configurations once and see if anything breaks?

I’m not an engineer so I don’t know the full details of the reasoning/test parameters. My involvement in the run was for a completely unrelated reason after it had finished the “test” leg of the journey.
 

Belperpete

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At an AHB, once the crossing has closed, then it should not re-open again until the train has been detected passing over the crossing. However, in case the track-circuit approaching the crossing briefly fails and then reoperates, e.g. due to a brief power-failure, the crossing will re-open after the track-circuit has recleared for a time. I think 3 minutes used to be standard. It sounds like this is what may have happened in this case, and NR have increased the time-to-reset values.
 

Belperpete

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Is there not a set of defined parameters to test compliance to.......?
Unfortunately, once you get beyond the simplistic explanations, track-circuit theory rapidly becomes a very black art. Whether or not a given track-circuit detects a given train depends on a whole raft of variables, most of which are site-specific and weather-dependent. Getting any individual track-circuit to work correctly is a compromise between getting it to detect every train, and not showing occupied when it shouldn't. As well as the track-circuit specific conditions, it also depends on the dynamic rail to rail resistance of the moving train, which will vary depending on loading, speed, worn rail profile, worn wheel profile, springing, hunting, rail gauge, railhead contamination, and so on. The train interacts with the track-circuit, and the two have to be considered together. The idea that there is a set of parameters that you can simply check a train against is simplistic, to say the least.

As part of the approvals process, the infrastructure owner is required to identify the different types of train detection system the train will traverse, and their operational parameters. This incident does suggest to me that not enough was known about these predictor circuits to determine how they would perform with this new type of train. This may perhaps be because they were bought-in proprietary items, that NR has little in-house expertise with.
 

twpsaesneg

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My previous understanding was that unless either the strike out treadle / axle counter had been activated, or the crossing had timed out, the barriers on an AHB could not raise.

I can understand the role of these predictor units in delaying strike in for a slow moving train to keep crossing down time to a minimum, but why the need to change the strike out? Also, in the event of a failure or a spurious reading, shouldn't the system fail safe and revert to the old form of operation?

Can any signalling bods explain in simple language for a non-signalling engineer please? :)
 

trebor79

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Yes, something very odd indeed about that level crossing incident. Regardless of any issue with the train activating track circuits (or not), I can't understand how a system would fail such that the barriers raised before the train passed.
Comment in another forum that some S&T people were working at the location at the time. According to that poster, they said none of the relays activated as the train approached. Someone then raised the possibility of the work they were doing havinf caused the fault. OP hastily clarified and said they hadn't actually been doing any work, but were merely present.
2 things stand out:
1. If they weren't actually working on the equipment, how come they were close enough to know which relays did or did not actuate, and why would they have been noting that anyway?
2. If none of the relays activated, how did the crossing barriers lower in the first place?

It wouldn't be the first time something has inadvertently gone wrong whilst working on S&T stuff on a live railway.
 

w0033944

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My previous understanding was that unless either the strike out treadle / axle counter had been activated, or the crossing had timed out, the barriers on an AHB could not raise.

I can understand the role of these predictor units in delaying strike in for a slow moving train to keep crossing down time to a minimum, but why the need to change the strike out? Also, in the event of a failure or a spurious reading, shouldn't the system fail safe and revert to the old form of operation?

Can any signalling bods explain in simple language for a non-signalling engineer please? :)
I was wondering precisely the same thing! We've had friends here today, one of whom is an enthusiast and expert on local railways during the mid-20th century, and I'd said to him that I doubted the predictors could have been the cause of this incident for the reasons you mention.
 

alxndr

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Comment in another forum that some S&T people were working at the location at the time. According to that poster, they said none of the relays activated as the train approached. Someone then raised the possibility of the work they were doing havinf caused the fault. OP hastily clarified and said they hadn't actually been doing any work, but were merely present.
2 things stand out:
1. If they weren't actually working on the equipment, how come they were close enough to know which relays did or did not actuate, and why would they have been noting that anyway?
2. If none of the relays activated, how did the crossing barriers lower in the first place?

It wouldn't be the first time something has inadvertently gone wrong whilst working on S&T stuff on a live railway.

I don't know anything of the particulars of this instance beyond what is posted in this thread and by the RAIB, but I can say that relays can make an audible clunk when changing state, so the chattering of several relays could well be conspicuous by its absence even if you weren't paying attention for it. That said, you're quite right that the crossing would never go down at all without at least some relays changing state.
 

GB

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S&T or Pway were not at Norwich Rd crossing when this incident occurred. S&T were at another crossing during a separate incident last week.
 

arb

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I noticed people in several people in orange jackets with a 'stop' road sign at Waterbeach level crossing this morning. Interesting given that Greater Anglia are terminating all of the Norwich to Cambridge services at Ely, short of Waterbeach.
 

ashkeba

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I noticed people in several people in orange jackets with a 'stop' road sign at Waterbeach level crossing this morning. Interesting given that Greater Anglia are terminating all of the Norwich to Cambridge services at Ely, short of Waterbeach.
Two possibilities are that GA is moving the 755s parked at Cambridge for some reason or that the 379s have been to the same wheel lathe and someone suspects that. Or it may be something else.
 

hwl

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Two possibilities are that GA is moving the 755s parked at Cambridge for some reason or that the 379s have been to the same wheel lathe and someone suspects that. Or it may be something else.
The other stock doesn't appear to have problems so NR probably sent the staff to the crossing but GA did't tell them no 755 going through the crossing.
 

trebor79

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The other stock doesn't appear to have problems so NR probably sent the staff to the crossing but GA did't tell them no 755 going through the crossing.
Err, presumably they'd have needed to tell NR they wanted to terminate at Ely instead of Cambridge?
 

Class 170101

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I noticed people in several people in orange jackets with a 'stop' road sign at Waterbeach level crossing this morning. Interesting given that Greater Anglia are terminating all of the Norwich to Cambridge services at Ely, short of Waterbeach.

Surely the 'Orangemen' would just put the crossing into manual and lower the barriers themselves?
 

MikeWM

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Possibly the Orange ppl at Waterbeach are a red herring - when I passed through this morning they were quite a number of them working on the platform extensions.

While waiting at Ely this morning a 755 ex-Norwich terminated in platform 3 (it had destination advertised as 'Cambridge' but announced as terminating at Ely). After a few minutes it drew forward slightly and slowly (back in the Norwich direction) about a carriage length while someone on the platform was looking down at the wheels or similar. Then my (late!) train arrived and I didn't see what if anything happened next.
 
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