top of page

Technical Authoring

Rail vehicle maintenance documentation is the 'bread & butter' of train maintenance activities; it's crucial to the safe and reliable operation of the railway. The vehicle maintenance plan should detail all preventative and corrective maintenance activities applicable to a specific train fleet. It should be used by maintenance staff on a day-to-day basis to ensure these activities are carried out correctly, safely and to the required standard.


RIS-2004-RST - Rail Vehicle Maintenance sets out the requirements for the provision of documentation for the maintenance of rail vehicles. This is a high level document designed to cover a large variety of rail vehicles operating on UK railways; therefore it is written using fairly broad terminology. Although compliance to RIS-2004-RST and its supporting documentation is imperative; compliance alone will not prevent misinterpretation, human factor errors or accidents.

When creating or amending rail vehicle maintenance documentation it's vital to have a good balance of academic and practical knowledge. Essentially, maintenance documentation should portray what to do, how to do it and (often forgotten) how NOT to do it. A purely academic, matter of fact or contractual style of maintenance document (often provided by OEM's) can leave a lot of room for misinterpretation thus increasing the likelihood of errors. Therefore it's important for all maintenance documentation to be written in such a way that complex elements are expressed in a simple, straight forward, easy to understand manner - without over-simplifying. A balance that’s much easier said than done!

There is an art to presenting information in technical procedures; like art, it will never be perfect and it should continually evolve. It's important to understand how each document will be used, who will be using it and how frequently the task is performed. Pictures, diagrams, simplified schematics etc. can all be used to help the end user understand how to perform the task; particularly if the task doesn't form part of routine maintenance. Information presented in tables or charts can help the end user quickly & easily determine complex pass/fail criteria without having to trawl through lines & lines of text to find the information they are looking for.

Trevally Engineering has a lot of experience when it comes to technical authoring specific to rail vehicles. Lead Engineer, Andrew has written a vast amount of rail vehicle maintenance / modification documentation for a variety of different fleet types. Andrew was apprentice trained so understands the needs of the end user. However, has worked in office based / consultancy positions for the last 10 years where he has gained a deep understanding of the applicable industry standards.

Techncial authoring services include:

  • Amendment of Maintenance Documentation (VMI, VOI & COI)

  • Creation of New Maintnenace Documentation

  • Modification / Repair Instructions

  • User Manuals

  • Rescue & Recovery Manuals

  • Training Course Content.

Case Studies

New Train Fleet - Vehicle Maintenance Instruction (VMI) Re-Write

The customer informed that their new train manufacturer had supplied a suite of Vehicle Maintenance Instructions (VMI's) that were suited to ‘DC’ depots only. The customer intended to maintain the new fleet at both ‘AC’ & ‘DC’ depot facilities. All 160 vehicle maintenance instructions were re-written to include the relevant information to enable the trains to be safely maintained at both AC & DC depots.


Particular attention was given to the train safety status of each instruction to reduce the risk of injury to maintenance personnel. During this work a number other technical and non-technical changes were made to address outcomes from locally raised non-conformances and National Incident Reports.

New Train Fleet - Rescue/Recovery Procedures

Following an operational incident involving a failed train the customer requested that their train recovery procedures (used by Operations staff) be improved. The knowledge base required to deal with serious service affecting failures involving a brand new train fleet was limited amongst Operations staff therefore a robust, easy-to-use set of train recovery procedures needed to be in place to deal with future incidents effectively.


Trevally engineering worked closely with the train manufacturer and operator to scrutinise the new procedures and conducted a number of working reviews to mimic each failure scenario. The aim of this was to help Operations staff recover failed trains in a timely and safe manner.

Brake Control Unit (BCU/CCU) - COI

The customer informed that a modern like-for-like Brake Control Unit (A.K.A. Code Conversion Unit) had been introduced onto two very similar train fleets. An overhaul instruction had not been provided by the OEM therefore an overhaul & test instruction needed writing along with the associated engineering change documentation to justify the scope.

The customer provided a spare BCU/CCU so that the overhaul & testing documentation could be fully developed and approved for use by the ROSCO's (the owners of the two train fleets).

bottom of page