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When a vertical understanding of the railways makes a difference

When a vertical understanding of the railways makes a difference

Data interaction across the wheel/rail interface

Tags: Infrastructure Traction and Rolling Stock Value - Increased Digital Value - Increased Performance Value - Innovation Value - Optimised Cost Value - Reduced Risk

The size and complexity of rail system means that developing new technological innovation can be difficult. Issues around electrical interference, system incompatibility, or even the mis-transmission of electrical signals.

Which is why companies involved in the development of new products need to understand the complexities of the system – or work with an engineering company that does.

At Unipart Rail we understand system complexities. We work right across the network on traction & rolling stock, signalling & traffic management, and infrastructure – meaning that we have a huge pool of engineering experience that delivers excellent innovation and understanding of complex systems. Our dedicated engineering teams have decades of experience that supports this.

An example of this is TPWSfour, which combines the TPWS (Train Protection and Warning System) and AWS (Automated Warning System) into one control unit. The system is train-borne, but has constant communication with the signalling system through a system of infrastructure magnets (for the AWS) and Transmitter (“TPWS Loops”) that communicate the status of the signals to the on-board system.

The system constantly monitors and protects the train by ensuring than if the driver passes through a Red signal, or is travelling faster than the speed limit, a SPAD (Signals Passed at Danger) or OSS (Over Speed System) stops the train automatically if the driver doesn’t apply the brakes. The latest TPWSfour Control units are now SIL 1 approved and have an optional serial bus data to allow the train system to monitor parameters including the state of the inputs and outputs in the TPWSfour without the use of the older style hardwired outputs. The TPWS / AWS system has been designed, tested and installed in trains worldwide, and are fully compatible for all vehicles from Steam Trains to the latest ETCS enabled Trains.

But there are situations that can interfere with this smooth running process – situations that can only be avoided if they are designed into your system with expert engineers who have a wide understanding of the railways, and years of experience in designing safety critical systems.

Our TPWS / AWS, TCA systems have been designed to be robust to the challenges of the environment, for example

  • The high currents used by the traction motors causing electromagnetic fields.
  • Poor cable screening and installations on train.
  • Infrastructure components degrading or failing.
  • Rail contamination i.e. leaf residue on the rail head.
  • Reduced electrical conductivity for the track circuits.
  • Bogie movement and gauging.
  • Shock and vibration.
  • Wheel slip and braking.

Unipart has developed a monitoring system which can be installed in the train to continuously monitor the parameters from the TPWS and the track mounted components such as TPWS loop output frequency and AWS magnet signal. This data is mapped by location and time to allow degradation of performance to be spotted and rectified before this impacts the train operation.

Just another example of technological innovation across the wheel/rail interface from Unipart Rail.



Increased Innovation, Improved Performance, Reduced Risk, Optimised Cost, Increased Digital

About this author
Dave Tilmouth

Head of Marketing Communications

I'm Head of Marketing Communications for Unipart Rail, so I get to be involved in lots of exciting stuff across Traction & Rolling Stock, Infrastructure and road traffic. My colleagues know me as someone who has a perspective on everything, as well as being a bit of an extrovert!


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