Keelen Whiteley, Supply Chain Manager at Davis Wagon Services, John Hall, Managing Di-rector at Davis Wagon Services, and Josh Jordan-Boddey from Knorr-Bremse © Knorr-Bremse

Derailment Detector set to make a significant impact on freight train safety.

Knorr-Bremse Derailment Detector EDT101, fitted to Davis Wagon Service’s UK freight wagons, has been awarded runner-up in the Sustainability and Safety category at the Rail Freight Group Awards.

The derailment detector recognises when a vehicle has derailed and immediately instigates an emergency brake application. The first deployment in the UK is now underway.

The railways of the UK have a proud record regarding safety; it is front and centre of operations and planning and is undoubtedly never taken for granted. The determination to improve rail safety for both passenger and freight operators is a continuous process.

Despite this, the freight sector continues to see vehicle derailments. A derailed wagon will sustain damage, and any delay in bringing a train to a halt once even a minor derailment has occurred can result in other wagons leaving the rails and sustaining damage. The railway infrastructure may be destroyed for a significant distance.

The power of modern locomotives means that a driver may not immediately notice a derailment. The distance travelled by a derailed train before it is finally brought to a stop could put other services, members of the public and non-rail infrastructure at risk. These events can also damage the goods being transported, interrupt business and cause reputational harm to the railway, the freight operator, and the final customer. Occasionally, around the world, derailments have led to significant incidents which have required the mass deployment of emergency services to ensure that people and property are safe.

Responding to this challenge, Knorr-Bremse has developed a derailment detector that can recognise the sudden change to a vehicle’s ride in a derailment and immediately vent the main air brake pipe, ensuring a rapid, complete emergency brake application.

Fitting the Knorr-Bremse EDT101 Derailment Detector to a Drax Wagon © Knorr-Bremse. Used with permission.
Fitting the Knorr-Bremse EDT101 Derailment Detector to a Drax Wagon © Knorr-Bremse. Used with permission.

How it works

The Knorr-Bremse EDT101 Derailment Detector is a highly secure system that can be fitted easily to any new freight wagon and retrofitted to those already in service; once activated, a driver or crew member walking along the stopped train can quickly spot which unit has been triggered. It is a passive, pneumatic/mechanical unit and does not need an external power supply. In addition, because the units operate as a closed system, wagons carrying the detectors can work with those yet to be fitted, meaning that an operator is not constrained in the marshalling and operation of vehicles during a roll-out programme.

Easily fitted to new freight wagons and retrofitted to those already in service.

From the outset Knorr-Bremse has worked to ensure the installation and operation of the units are quick and straightforward, encouraging take-up across the freight sector. Before fitment on a vehicle, a vibration and resonance test is carried out by Knorr-Bremse to determine the correct installation position and sensitivity of the EDT for the type of wagon involved. The bespoke parameters are then used to set up the EDT101 units to ensure they respond only when a derailment may have occurred and not when the train passes over a section of infrastructure that merely causes some rough riding. Installation is a simple process involving fitting a new bracket and a connection to the EDT unit’s brake pipe; activation requires only opening the stopcock to connect the device to the brake pipe.

Identifying the derailed wagon or axel

In the event of a derailment, the valve reacts to the abnormal vertical movements and opens the brake pipe, which initiates emergency braking. At the same time, a red indicator device pops out of the EDT housing, ensuring that once the train has stopped, the driver or a crew member can quickly identify the derailed wagon or axle even if the vehicle has re-railed itself, which can happen following an initial derailment. Following activation, the system will also reset itself automatically, and if it is safe, the vehicle can then be moved to clear the line to a better place for recovery or continue running on its way if this is deemed acceptable. However, the indicator will continue to show until the EDT101’s indicator is reset by hand, enabling further checks to be carried out even if the vehicle has remained in service to the end of its journey.

Whilst the parameters will vary slightly for each wagon type, the EDT101 is typically activated when a vertical acceleration of 11.5g is detected, and the units are designed to work within the expected pressure range of train air brakes. Their operating temperature of between -40° and +70°C means there are no challenges for their use in the UK, whilst the low overall weight of just 1.6 kilograms for the bracket and stopcock and 2.8 kilograms of the derailment detector itself ensures that fitment has no real impact on the weight of the vehicles themselves. The EDT101 meets International Union of Railways (UIC) standards and has been subjected to rigorous testing; it has been proven reliable, and with reaction times measured in milliseconds, the unit is expected to make a significant difference to train safety.

Keelen Whiteley, Supply Chain Manager at Davis Wagon Services, John Hall, Managing Di-rector at Davis Wagon Services, and Josh Jordan-Boddey from Knorr-Bremse © Knorr-Bremse
Keelen Whiteley, Supply Chain Manager at Davis Wagon Services, John Hall, Managing Director at Davis Wagon Services, and Josh Jordan-Boddey from Knorr-Bremse © Knorr-Bremse. Used with permission

The first deployment of a freight wagon rail detector in the UK

The first deployment in the UK began in May 2023 following a decision by UK power generator Drax Power Ltd. to fit the EDT101 units to its existing fleet of 225 high-capacity wagons manufactured by British firm WH Davis and on the additional 30 vehicles it has now ordered to boost capacity; this is the first time a derailment detector product has been fitted onto freight wagons in the UK. Drax is proud of its use of rail to transport biomass from the port in Liverpool and the Port of Tyne to its power station in North Yorkshire. Ensuring the services run reliably and safely is a significant priority. Each train can carry sufficient biomass for Drax to generate enough reliable renewable electricity to supply around 800 UK homes for a year, so the loss of a train or even a single wagon due to an incident would have a significant impact; installation of the EDT101 units will give another layer of protection and safety.

With the cost of providing rail services and maintaining the existing infrastructure currently under intense scrutiny, the proven effectiveness and simplicity of the Knorr-Bremse EDT101 can significantly impact rail freight services across the UK.

Wagon maintainer Davis Wagon Services is also proud to have fitted the EDT101 detectors to the fleet; whilst it is already achieving very high levels of reliability for the vehicles, this project is an exciting step, as DWS Managing Director John Hall explains, “It is a fantastic achievement for Davis Wagon Services to be the first company in the UK to have installed these derailment detectors. As soon as we presented this project to Drax, they recognised the benefits and could see that this would add safety to the network. Knorr-Bremse has fully supported us; they have been there for testing, development, and installation.”

For Knorr-Bremse, this first deployment of the derailment detector was also an important step; as Freight Business Manager Joshua Jordan-Boddey notes, “We at Knorr-Bremse are happy to be working in collaboration with Davis Wagon Services alongside Drax to bring innovation to the UK freight market. The derailment detector is a perfect example of what we bring to the sector to improve safety and performance in the industry.”

The wider freight community has also welcomed the project; Maggie Simpson OBE, Director General of the Rail Freight Group, comments, “The operation of freight services safely and reliably is vital for the industry and their role in the UK supply chain. The availability of a simple, fit, easy-to-fit and use device is a significant step. I am delighted to see the collaboration between the three businesses, enabling the first deployment of the derailment detectors. Whilst we all hope they will never be needed, it is reassuring to know that the drive for ever higher levels of safety is continuing to make a real difference for our network.”


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