Great Western Coffee Shop

Latest information on Greater Anglia rail disruption in Norfolk and Suffolk

We are extremely sorry for the continued disruption to branch line services in Norfolk and Suffolk.

We fully appreciate that this situation is extremely frustrating and it is an absolute priority for us to get these problems resolved as soon as possible.

In the meantime, we are making sure that customers can still complete their journeys.

Please see below, the latest information on the problems as we currently understand them:

What’s going on?

Last Friday (6 December), we were asked to significantly reduce our rural branch line services by Network Rail, who were investigating signalling problems on some of our routes – looking at the impact of extreme autumn weather and leaf fall on track conditions, the components of the signalling system and the interaction of passenger trains with the signalling system.

There is also a separate investigation into an incident at a level crossing on the Norwich-Sheringham line which has led to speed restrictions at crossings on that route. This incident is currently being investigated by the Rail Accident Investigation Branch.

This has led to delays and cancellations for our customers. We are very sorry about this and we’re working round the clock with Network Rail to return services to normal.

Why are you saying its signalling issues when it seems to be just affecting your trains?

Our whole railway relies on the signalling system, which tells trains when to stop and go and controls levels crossings. Put very simply, there are sensors called “track circuits” which detect where trains are. It is essential that these track circuits are functioning correctly – picking up trains’ locations – so that signals and level crossings operate correctly.

The investigation into signalling issues is looking at the operation of some particular track circuits and the different factors involved – including track conditions, the signalling system itself and the interaction of our trains with it.

We do not know the full picture yet and it is not appropriate to rely on rumours (which are being spread by people who are not directly involved in the investigation and in many cases not even in the rail industry).

Are the new trains to blame?

You may have seen some media headlines claiming that our new Stadler trains are the sole cause of all these problems. This is categorically not true.

While our new trains had some software problems initially, these were easily fixed with an upgrade and they are returned to service.

Software problems are not the cause of the disruption that you have been experiencing since 6 December 2019.

The issue is the result of a combination of factors: track conditions, track circuits and the interaction of trains with the track circuits.

We have been working with Network Rail round the clock to find out why, examining every factor including components of the signalling system, the impact of extreme weather conditions and leaf fall, and the interaction between the signalling system and passenger trains, old and new.

The Rail Accident Investigation Branch is also investigating.

What are you doing to sort out the problems?

We are very sorry that this is taking a long time, but safety is paramount and while the investigation continues we are being extremely careful to run services more slowly, and this is leading to delays and cancellations on some of our rural branch lines in Norfolk and Suffolk.

A raft of short-term measures has been already implemented, including running extra rail head treatment trains to blast away fallen leaves, amended signalling operation on some routes and a 20mph speed restriction over level-crossings.

A team of Stadler employees has been set up and is responsible for checking train wheels on the bi-modes when they are in stations and as required, cleaning them. This is done to reduce the build-up of leaves, as well as contamination on the rails. When necessary, they clean the wheels with a pressure washer at the depot,and give them a manual scrub.

The new trains’ flange lubricators have also been temporarily deactivated. However, they do not deposit lubricant directly onto the track and this is purely a precautionary measure to help the investigation.

As soon as we, Network Rail and Stadler know more about the cause of the track circuit failures, we will recommend further long-term solutions, enabling the signalling system on these routes to detect trains consistently and accurately so that trains can run safely and on time.

Are the new trains safe and were they tested enough?

Yes – the new trains are safe. The safety performance of our new trains is in line with our existing high standard of our other train types as we operate them to industry recognised standards. They have been in operation for some time now and over many routes.

The manufacturer, Stadler, has a strong track record in safety, which is at the heart of its business. To date there are 1,900 Stadler FLIRT trains in operation in 19 countries.

Before these new trains for Greater Anglia were introduced, Stadler and Greater Anglia technicians carried out rigorous performance and safety tests, including an electromagnetic compatibility test on every single route, to see how they interact with the signalling system on the route.

Network Rail will only allow Greater Anglia to run trains on specific routes if they are satisfied that they operate safely and correctly. Each type of train also has to be signed off by the ORR before they can be put it into passenger service.

Stadler engineers conduct regular routine exams of the Greater Anglia new trains to ensure that the required safety standards are maintained.

Are these new trains too sophisticated for old British infrastructure?

The new trains made by Stadler have been subject to industry standard safety checks and authorisation before they were permitted to enter passenger service. They are also inspected as part of planned routine exams to ensure the required safety standards are maintained

Why is it that other operators on the same lines, old trains and freight trains are still allowed to operate normally unaffected by the signalling problems?

Network Rail is responsible for prioritising which trains run on our network. Some of our services have been cancelled to allow extra rail head treatment trains to run on our routes. Others have been affected as the investigation is looking at how our passenger trains, both new and old are interacting with the tracks.

When is this going to end and the train service get back to normal?

But we are working closely with Network Rail to get the service back to normal as quickly as possible – we are planning for a full service on Monday on all routes except Norwich to Sheringham and Ipswich to Peterborough.

Can I get compensation?

Yes you may be eligible for delay repay compensation if your journey has been delayed by 15 minutes or more.

Why have you sent your old trains back before the new ones are ready?

We haven’t. We still have nine of our old diesel trains in service.

Replacing every single old train on our network with brand new trains is a very complex project, which has involved careful planning over several years and many different contingencies.

It is not possible to entirely predict the results of safety and performance tests, when we check how the trains interact with the infrastructure, such as signals and points - which is why we drew up these different contingencies, which included worst case scenarios.

We have more new trains in our fleet than the number we have returned.

As we continue to increase the number of new trains in service, we will have a wider pool of back-up trains should faults occur.

Ultimately, our fleet of new trains will be larger than our old fleet was. 

I am surprised this was not noticed earlier. I was staying in Norwich July and August and the 755 units were out all the time on driver training.

If IUIC the problem relates to the interaction of track circuits, leaves on the line, and new trains. 

This recent period is the first time all these things have come together so I am not surprised it was not noticed earlier. 

There are 1900 FLIRT trains in operation in 19 countries (according to the the GA website quote above). Have the problems been observed elsewhere or is this unique to NR for some reason? ... type of track circuit for example.

There are 1900 FLIRT trains in operation in 19 countries (according to the the GA website quote above). Have the problems been observed elsewhere or is this unique to NR for some reason? ... type of track circuit for example.

An unwanted side effect of some forms of rail contamination, and indeed possible from some forms of low adhesion remedial treatments such as those involving sand, is a failure of the train to activate a track circuit. These incidents occur when the conductivity of the wheel / rail interface is insufficient for the track circuit to detect the presence of a train. Such failures, known as Wrong Side Track Circuit Failures (WSTCF), have the potential for safety related incidents with severe consequences such as train collisions, or failure of other signalling related equipment to operate level crossing barriers for example.

Much research into this phenomenon was undertaken by BR in the late 1980s / early 1990s following the introduction of new diesel multiple units which were causing more WSTCFs than the units they replaced. It was noted that low voltage DC track circuits were particularly vulnerable to problems where modern diesel multiple units with good riding bogies and disc brakes operated. A range of solutions were found for the most common cause of WSTCF; rust film on the rail. However, such solutions are not always effective for other causes of WSTCF such as dry leaf film and excessive applications of friction improvers such as TG60, Traction Gel or sand. As a result, the railway suffers a number of WSTCFs every year.

The first priority is to identify vulnerable locations so that mitigation measures may be implemented. Such locations do not necessarily coincide with low adhesion locations identified for traction or braking problems, as track circuit failures can occur at locations where trains normally do not need to accelerate or brake. It is also rare to have both adhesion and track circuit problems at the same time since poor adhesion requires damp conditions, while poor track circuit performance requires dry conditions.

I think we'll just have to let the investigating team, with all the data they have available, get on with working this one out.

Since the incident, Network Rail has modified the settings of this and similar level crossings on the line to reduce the chance of a repeat of this incident.

Our investigation will identify the sequence of events which led to the incident. It will also consider:

•   the design, implementation and operation of the predictor system, including any effects of rail head contamination due to fallen leaves
•   the design of relevant elements of the class 755 train and the process for accepting it for use on this route
•   any underlying factors.

Our investigation is independent of any investigation by the railway industry, the Office of Rail and Road.

We will publish our findings, including any recommendations to improve safety, at the conclusion of our investigation. This report will be available on our website.

I was thinking about the investigation by the railway - NR/GA/Stadler - when I wrote that, but the RAIB are also investigating, specifically, the incident at Norwich Road crossing. They have said:

So we should get to find out what happened and why, perhaps with a lot of detail.

A possibly stupid question - I have a basic understanding of how track circuits work - but could this problem be eliminated by replacing the 'traditional' TCs with axle counters? And, if so, what would be the time & cost of doing so on the routes over which the Stadler trains run?

'Not the new trains' fault' says Greater Anglia after rail chaos
PUBLISHED: 10:37 17 December 2019 | UPDATED: 11:22 17 December 2019  Paul Geater

The new trains introduced on Greater Anglia's rural routes were not the cause of the signalling problems that have plunged services into chaos over the last few weeks, the company said today.

Their engineers have been working with Network Rail since signalling problems first hit services at the end of November.

They are now satisfied that the signalling problems only affect the Norwich to Sheringham line in Norfolk - and that all trains that use that line, old diesel units and freight trains travelling to North Walsham - have been affected by it.

There have been no problems with signalling on any other lines in the region, and Greater Anglia is now trying to reintroduce normal services on all of these.

However the problems of the last three weeks have delayed the commissioning of new trains and training of drivers, so it will be a few days before a normal service is introduced everywhere.

And the Ipswich to Peterborough service could remain suspended until early in the new year because it has not been possible to carry out route testing with the new trains.

Greater Anglia officials had to introduce speed restrictions and extra tests on the new trains because they were the one new factor that had been introduced into services before the problems became apparent - officials say if there had been a problem with them it would have been irresponsible to run them normally without making changes for safety reasons.

A spokesman for Greater Anglia said: "We are very sorry for the major disruption to services on our regional lines recently. These delays and cancellations were not due to the performance or design of our new trains. We were unable to run our normal train service due to signalling issues.

"We are now able to operate the normal timetable on our rural branch lines again, except for the Norwich to Sheringham line, so the majority of services have been reintroduced.

Confirms then that the level crossing sequence was correctly initiated, cancelled when the train appeared to reach the inner, second train coming strike-in point, and then reinitiated again when it reached the strike-out point for the wrong direction running.  That looks like an infrastructure and not a train issue to me.

Level-crossing predictor
With automatic level crossings, the disadvantage of a fixed strike-in point is that the actual warning time given to the user may vary significantly according to the speed of the train. To overcome this issue, a level-crossing predictor was first introduced between Norwich and Cromer when the line was resignalled in 2000. The GETS Harmon HXP-3 uses audio frequency track circuits to detect an approaching train, and the rate of change of the inductance of the rails is used to determine its speed and hence calculate the trigger moment to provide a constant warning time for each train. Another similar product is the Siemens Automation Wayguard WESTex GCP4000.

Train arrival prediction systems to dependably predict the time of a train’s arrival at a level crossing have been available for some time, but performance is variable and not consistent enough to provide ‘safe to cross’ information. The Network Rail strategy is to continue to develop a means of accurately and consistently predicting the arrival of trains at crossings that overcomes the limitations of current systems.

Investigating the interlocking of highway road traffic lights with the signalling system at areas where drivers running red lights is a known problem, or at high volume road junctions near to level crossings, is under way.

Hmm. The point I was making was that the crossing appears to have had its initial strike-in operate correctly (barriers down and road lights operating).  At some point the strike-in was lost and the sequence cancelled (barriers raise and road lights extinghuish).  It then re-initiated around the wrong direction strike-out point. I never mentioned treadles to back up that operation, its entirely reliant on track circuit operation.

INFORMED SOURCES e-Preview February 2020

Crossings modified for Class 755 operation

Last month’s Modern Railways reported that the Rail Accident Investigation Branch (RAIB) was investigating a very, very near miss at an Automatic Half Barrier (AHB) level crossing on the Norwich-Sheringham line.

 Here’s the RAIB description of what happened.

“At about 19:53 hours on Sunday 24 November 2019, a 4-coach class 755 passenger train, operating the 19:45 Norwich to Sheringham service, was approaching Norwich Road automatic half barrier level crossing, to the north-east of Norwich.  The crossing barriers were in the lowered position until the train, travelling at about 45 mph (72 km/h), was about 200 metres from the crossing.  The barriers then lifted, the level crossing warning lights went out and cars began to cross the railway.  The train driver applied the train’s emergency brake and sounded its warning horn, but the train was unable to stop before reaching the crossing.  No road vehicles were struck but a car passed in front of the train around a quarter of a second before the train went over the crossing”.

After privatisation, one of Railtrack’s priorities was to obtain low cost signalling, suitable for replacing manually controlled mechanical boxes and crossings.  In November 1997, two pilot schemes were let, one of which was the Norwich-Sheringham route.

Harmon of the USA would provide the single processor interlocking and other hardware.  The contract was let through its recently acquired subsidiary Vaughan Systems of Ware, now renamed Vaughan Harmon Systems Ltd.  Three existing automatic crossings would be modernised and three others automated.

With automatic level crossings, the disadvantage of a fixed ‘strike-in’ point, where the train is detected starting the crossing closure sequence, is that the warning time given to the user may be longer than necessary for slow trains.

Harmon’s predictor uses track circuits to detect an approaching train and determines its speed.  The speed is used to calculate the ‘strike in’ point to provide a constant warning time. 

Harmon’s predictor system was fitted to the six AHB between Norwich and Cromer and entered service in 2000.  According to ORR, there has not been any previous accident history on the crossing in the 20 years since the predictor system entered service.

What seems to have happened is that the track circuit lost detection of the approaching Class 755.  The crossing assumed the train had left the section and opened the gates. 

RAIB has identified two key issues for its investigation.

These are the design, implementation and operation of the predictor system, including any effects of rail head contamination due to fallen leaves, plus the design of ‘relevant elements of the Class 755 train and the process for accepting it for use on this route’.

After the incident Network Rail immediately put the barriers under local control and imposed a 20 mile/h Emergency Speed Restriction.  This accounted for much of the service disruption.  The extended running times meant that there was insufficient time to run to Sheringham and pick up the return timetable.  Trains were therefore turned back at Cromer.

It was also decided to fit treadles as a backup to the predictor track circuit at the six AHBs.  This is a reversion to British Rail practice which combined track circuit and treadles.

Norwich Road, Great Plumstead and Rackheath Road crossings had been equipped just over a week after the issue emerged.  The closed period for the gates has also been extended to 98 seconds.  The other three AHB crossings on the route were fitted early in January.

Other routes were also affected by loss of detection of Class 755 multiple units during leaf fall.  The leaf fall period officially ended on 18 December, but testing was still needed to check that Class 755s were being detected correctly on track circuited lines.

In the column I describe the recovery process, which was assisted by some of Network Rail’s ‘intelligent infrastructure’.  By the start of the New Year the infrastructure was fully available with no restrictions on Class 755 operation.  The only exceptions were the 20 mile/h ESR at the three AHBs pending fitment of treadles.

Now we wait for the RAIB report.

Summary

On 24 November 2019, the barriers at Norwich Road level crossing, near New Rackheath, Norfolk, lifted as a passenger train from Norwich to Sheringham was approaching. Two road vehicles crossed the railway in front of the train, which reached the crossing less than half a second after the second road vehicle was clear.

The investigation found that there was contamination of the railhead in the area caused by leaf-fall and atmospheric conditions. This contamination had not been removed because there were no railhead treatment trains on the Norwich to Sheringham line at weekends. The narrow band on which trains? wheels were running on the contaminated railhead, which was a consequence of the introduction of new trains, left the wheel-rail interface vulnerable to a poor electrical contact in the event of contamination. This caused the level crossing equipment to misinterpret the position of the train, and consequently it opened the crossing to road traffic while the train was closely approaching.
 
RAIB has made three recommendations addressed to Network Rail regarding the planning of autumn railhead treatment, guidance on the introduction of new trains and the configuration control of signalling equipment. RAIB also identified two learning points concerning the investigation of incidents and the signalling design process.