Project number: 2022-STN-022

Update of Assessment of Conformity of Engineering Change to Rail Vehicles to include software and cyber security considerations

Standard sets out the industry-agreed process to verify that engineering changes meet the relevant requirements.

This will help industry to manage engineering change and avoid cyber security and software incidents

Mark Oakley
Professional Head of Rolling Stock

The challenge

Even small changes to a rail vehicle can sometimes lead to unexpected problems, both for the vehicle and the systems with which it interacts.

For example, when a train monitoring device was upgraded, the new design inadvertently allowed a member of the public to access it using a mobile phone.

There have been other cases just like this, where software updates for trains caused them to operate incorrectly.

Take the train runaway at Bawtry. A safety feature was unintentionally reversed because the organisation overhauling the brake system component was not aware of a previous safety modification.

Another incident, the Llangennech derailment, meanwhile, was attributed to management and maintenance of safety-critical components.

What we did

RSSB has previously published two technical notes: TN2306 Issue 1 and TN2312 Issue 1. The aspects of these documents that are directly relevant to RIS-2700-RST have been included as new appendices.

New guidance has been drafted in response to the Bawtry runaway. It clarifies the role of assurance schemes such as RISAS and how engineering change should be managed. Likewise, in response to the Llangennech incident, there is now new guidance on maintaining safety-critical components.

There were plans to update the guidance in RIS-2700-RST with an explanation of the roles of entities in charge of maintenance and railway undertakings during engineering change. However, following a consultation, it was agreed that these topics would be better covered in a new guidance note, GMGN2697.

Benefits delivered

RIS-2700-RST ensures that rail vehicles consistently meet the safety and design requirements that are set out in vehicle design standards.

RSSB expects that the clear explanations and guidance in RIS-2700-RST will reduce costs and improve safety and reliability by:

reducing the need for discussion and agreement between different parties on the suitable application of the requirements
helping the industry to manage the risk of breaches and cyberattacks, providing benefit to the reliability and operation performance of the railway
supporting the industry to better manage engineering change to software and the maintenance of safety-critical components.

We have estimated that these improvements could bring the industry more than £100k in benefits over five years.