HomeGeneral InterestInnovation in level crossings

Innovation in level crossings

Issue 195 of Rail Engineer (March/April 2022) included an article written by Paul Darlington describing efforts to make level crossings safer. This described the situation with gated or barrier crossings, manually operated barrier crossings with obstacle detection, automatic half barriers (AHB), automatic barrier crossings locally monitored (ABCL), automatic open crossings (AOCL), and open road crossings. The article looked at the risk assessment procedures for all of these and the factors that must be taken into account.

As a follow up to this, a talk given recently to the IRSE London & SE section, described some of the technical and communication innovations that are being trialled or introduced as part of the overall safety improvement initiative.

Level crossings remain one of the 12 priority risk areas in the UK. They are where the operational railway comes into contact with the general public who are not train travellers. It is a salutary statement that the public can at times be capable of doing unwise and risky things that can result in injury or even death. However, the public have to be given accurate guidance, sometimes even training, to avoid the biggest risks and nowhere is this truer than when obeying the instructions relating to level crossings.

There are many types of crossings covering main roads, minor roads, private roads (sometimes called occupation or accommodation crossings) and footpaths. All have their own risks and many varieties of crossing equipment plus associated signage are in existence. Some of this is very good, others are less than optimum and there is rarely a situation where one size fits all. Around 5,600 crossings still exist on Britain’s railways even after 1,250 having been closed since 2009. Seventy-five percent of those remaining require the user to make the decision as to whether it is safe to cross. There has thankfully been a 37% reduction in accident rates since 2009.

To put this all into perspective, Angela Adams, principal engineer for level crossing technology and Darren Witts, the principal engineer, principles & standards, both from Network Rail, explained the work being undertaken.

Risks and messaging

A constant consideration of level crossing standards and operation is always active. Four main areas of study and improvement are ongoing: risk management; technology and innovations; competence management; and education and enforcement.

In all of these, many external changing factors are happening, including increases in both road and rail traffic; more congestion pockets on both road and rail; changes in population density; and changes to public attitudes.

All of these can affect level crossing types and the ever-present possibility that a particular crossing may need to be upgraded to another type if greater usage rates and possible congestion is occurring.

Signage comes in for a lot of criticism both for road and foot crossings. It is often unclear as to when and how the crossing controller (usually the signaller for that section of line) should be contacted.

There exist multiple signs as to what the user is required to do, which often cannot be read until very close to. Network Rail has worked closely with the Department for Transport (DfT), ORR, RSSB and others on the development of a new more consistent suite of signs. More use is made of pictures/symbols and to help people who struggle with the English language. This was trialled by human factor experts around three years ago at a test site in Cannock, and deployment elsewhere is commencing with individual DfT authorisation for each site until the new signs are prescribed in legislation. The new signs are much larger than the previous ones and, in time, Welsh language signs will need to be produced, necessitating two sets of signs in that province.

Private road and foot crossings

Recent accident reports have given prominence to the relatively high risk that user worked crossings represent. Often, there is only signage to advise the user as to when it is safe to cross but increasingly the use of Miniature Stop Lights (MSL) gives a greater confidence.

Overlay MSL solutions which operate independently of the signalling system have been developed to provide a lower cost solution with minimal site-specific design. Approaching 200 of these have been commissioned and each can be deployed for a reasonable cost of between £120,000 and £150,000 per crossing. Currently approved systems are Ebigate 200 using axle counters and VaMoS using axle counter based wheel detection.

Systems under development include: Covtech, which is a Radar based audible warning device; Meerkat, which is radar based; and Wavetrain, based on acoustic sensing.

There is also a need to make MSLs much more visible and the latest design has a 200mm lens as against the existing 70mm. The larger lights can replace the existing without too much difficulty and users can expect to see these gradually installed over the coming years.

Interfacing to the signalling system

There are situations which the overlay MSL is not designed to cater for. One of these is where a signal exists within a strike-in area that could lead to a prolonged red light at the crossing if the train stops at a red signal. The Flex interfaced overlay MSL has been developed to provide a limited interface to the signalling system in such circumstances. Where a signal exists within a commensurate distance from where the crossing is located, then the MSL can be activated once the signal is showing a proceed aspect, delayed as necessary to ensure the train does not arrive too soon.

A further constraint is where a station exists within the strike-in area. It would be no good displaying the red MSL if the train is scheduled to stop at the station as this would also lead to prolonged red warnings. Thus, there exists a need to differentiate between non-stopping and stopping trains. The traditional means of achieving this is by the signaller or a control system (with knowledge of the timetable) selecting the required mode for each train.

This is expensive to provide as it involves modifications to systems outside of the level crossing and the supporting infrastructure is rarely already in place. This is an area where solutions are being investigated. One possible answer is to adapt the overlay MSL so that it can be used to interface with a speed measuring system that determines whether an approaching train is on the braking curve for a station stop. Ways of achieving this could be based on measuring the time between two detection points but more likely is to use speed measuring axle counter heads.

Power operated gate opener

A big problem with user worked crossings is getting people to follow the correct procedure in opening both gates before crossing and then closing them afterwards. To help users get it right, power operated gate openers (POGOs) have been developed and undergone a number of modifications as lessons have been learned. On approaching the crossing, the new signage will include instructions on how to operate the gate opener. This will be activated by a prominent yellow button. If the crossing is equipped with MSLs and a red light is showing, the gates will not open.

Level crossing power supplies

Many crossings are in remote locations and, with the increasing use of protective measures, providing a power supply for these from the national grid can be a problem. Finding the optimum alternative is being investigated. The VaMoS crossing at Acle Marsh on the Norwich Yarmouth line uses photo voltaic cells in conjunction with fuel cells. With the large bird population in the area, droppings on to the solar panels can impact on the electrical efficiency and this has to be a consideration. A good downpour of rain usually helps.

The use of fuel cells, whereby hydrogen is fed into plates on one side of the cell and oxygen into the other, can provide additional electrical energy to top up any solar or wind generators and thus maintain the battery charge.

Public road crossings

While many measures have been taken over the years to improve the safety of crossings on public roads, investigations continue in how to overcome the persistence of public misuse.

One such development is to improve the visibility of booms. The existing specification for boom lighting is 25 years old and was designed primarily for illuminating booms at night. Daytime lighting was not considered important but, in an age where new cars have their headlights on throughout the day, similar considerations are being given to other road infrastructure including level crossing booms.

Network Rail has worked with optical experts to develop a new specification for boom lamps with a brightness of between 30 and 50 candela. A prototype has been trialled in non-operational environments under different lighting conditions. Further development is underway and operational trial sites will be selected shortly.

Extending the length of booms to help deter motorists from weaving round a half barrier crossing is another initiative. A prototype extension has been developed as a lightweight plastic retrofit addition to existing booms. It is attached with a hinged and tethered arrangement to mitigate any potential increase to the trapping risk. This is ongoing work and operational trial sites will be selected shortly.

Engineers will be familiar with the ABCL crossings (automatic barriers controlled locally), whereby a train driver receives a white light to indicate the crossing has activated correctly and he/she can proceed without stopping, unlike an open crossing. ABCLs remain subject to pedestrian misuse and thus another initiative is to equip such crossings with full barriers and obstacle detection. These will remain locally monitored thus becoming AFBCL. This solution has been commissioned at three sites in Scotland which are being monitored for a trial period, but is already being written into standards to make it more widely available.

Other considerations

The reliability of barrier machines is generally good but there is always room for improvement. Combating climate change and extreme weather is now a requirement for many engineering disciplines so a more environmentally robust machine, which can be remotely monitored and equipped with telemetry-led maintenance routines, is something the supply chain will be encouraged to develop. A reduction in ‘No Fault Found’ instances will be part of this exercise.

Telephone communication between the crossing user and the signaller is required when the associated instruction informs the user to call and is often a vital element in enabling safe operation. A working party is looking at the next generation of technology to see if improvements can be made.

The use of video analytics on CCTV monitored crossings whereby AI (artificial intelligence) can detect and highlight a person on the monitor screen is another investigation for the future.

Rail Engineer will keep an eye on all of the developments described and will provide updates in due course.

Clive Kessell
Clive Kessellhttp://therailengineer.com
SPECIALIST AREAS Signalling and telecommunications, traffic management, digital railway Clive Kessell joined British Rail as an Engineering Student in 1961 and graduated via a thin sandwich course in Electrical Engineering from City University, London. He has been involved in railway telecommunications and signalling for his whole working life. He made telecommunications his primary expertise and became responsible for the roll out of Cab Secure Radio and the National Radio Network during the 1970s. He became Telecommunications Engineer for the Southern Region in 1979 and for all of BR in 1984. Appointed Director, Engineering of BR Telecommunications in 1990, Clive moved to Racal in 1995 with privatisation and became Director, Engineering Services for Racal Fieldforce in 1999. He left mainstream employment in 2001 but still offers consultancy services to the rail industry through Centuria Comrail Ltd. Clive has also been heavily involved with various railway industry bodies. He was President of the Institution of Railway Signal Engineers (IRSE) in 1999/2000 and Chairman of the Railway Engineers Forum (REF) from 2003 to 2007. He continues as a member of the IRSE International Technical Committee and is also a Liveryman of the Worshipful Company of Information Technologists. A chartered engineer, Clive has presented many technical papers over the past 30 years and his wide experience has allowed him to write on a wide range of topics for Rail Engineer since 2007.

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