Alice Monk
RSSB
I first joined RSSB in 2010 as part of my DPS placement year from the Loughborough University Ergonomics course and re-joined the company after graduating in 2012. I am now a Senior Human Factors Specialist at RSSB and have worked on a variety of projects including ERTMS, axle end inspections, suicide prevention, the rule book and compliance with speed restrictions
RSSB research project T774: research in to the effects of human factors in axle inspection developed human factors guidance related to Ultrasonic Axle Testing (UAT) (RSSB, 2014). This guidance included good practice on the task of axle end re-assembly. The guidance on axle end re-assembly made up a small part of the report and was therefore not easily accessible. Following a number of National Incident Reports (NIRs) of bearing failures attributable to re-assembly errors, RSSB were tasked with reviewing the guidance with managers and staff involved in the re-assembly process. The aim of this was to promote and support the application of axle end re-assembly error management strategies by industry and refine the guidance where necessary. The focus of the project was the maintenance operator task but also the context in which the task was undertaken, for example, the working environment, equipment, procedures, and design mitigation strategies.
The data for this project were collected from site visits. Site visits included a selection of depot and overhaul sites, geographical locations and operations. The final sample included five depot visits and two overhaul sites. The data collected at each site were: background information about the site (e.g. units worked on, operations and number of staff completing the re-assembly), observations of staff completing the task, good practice examples of the task, understanding of underlying issues, potential errors that could be made in axle end re-assembly tasks, and feedback on the original T774 human factors guidance. The information collected from the site visits were used to amend the T774 human factors guidance which was reviewed during a workshop with representatives from the locations visited and again during a meeting with senior managers to produce the final project output.
There were several themes that were identified during the site visits which included how to ensure that: the correct tools and bolts are selected, the correct torque is applied, and the axle end re-assembly is checked and signed off. For example, there were two approaches to signing off the axle end re-assembly and that is to have a sign-off sheet for the task as a whole or for sub tasks. There are strengths and weaknesses in both these approaches. For example, whole task sign-off takes less time but is less thorough and more difficult to trace axle ends/tasks to individuals. However, the sub-task sign-off is time consuming and can lead to signature fatigue (where signatures are completed at the end of the day as part of a routine rather than as each sub task is completed). At certain sites, there was a second person who signed the axle off as complete. The sign-off of tasks or sub tasks need to be completed at the time of the assembly rather than at the end of the day or shift as this significantly reduces their effectiveness.
This paper has given a brief overview of a range of findings from the site visits but the detailed information can be found in the final project report (RSSB, 2017).
Human error and human reliability , Maintenance, engineering and track work
