About Volker Rail
Since entering the construction market in 1935 VolkerRail has become one of the UK’s leading multi-disciplinary railway infrastructure contractors, with over 70 years of experience in both the heavy and light rail infrastructure sectors.
VolkerRail has a successful track record of delivering projects on the UK’s national rail network, working with Network Rail and London Underground, as well as most of the light rail and tram organisations in the UK. They are also one of a few companies to hold a Railway Safety Case and train operator’s license – enabling them to operate plant on mainline railways.
ESUK had an enquiry from Volker Rail, Doncaster to discuss arc flash and how to manage the risk of arc flash. Paul Hopton, ESUK Principal Electrical Consultant attended a meeting with some of Volker Rail’s Senior Managers, Engineers and Health and Safety Professionals in Doncaster. This initial consultation was free of charge and Paul took the meeting through the characteristics of arc flash and how the hazard could be minimised and mitigated.
Volker Rail came back with an enquiry about a project they were doing for Network Rail in the North West. Network Rail had experienced a serious arc flash incident and they wanted to be sure that the project had considered arc flash risk. The project involved upgrading a number of HV and LV switchboards, some in existing switchrooms and some delivered as packaged sub-stations. Network Rail had a particular concern with the 11kV switchboards which had pressure relief panels to the rear, which in the event of an arc flash could release arc flash products to the rear of the switchboards where maintenance personnel could be working.
Electrical Safety UK Ltd proposed three key activities:
deliver arc flash awareness and practical arc flash risk assessment training to Volker staff and contractors
Carry out arc flash incident energy and arc flash boundary calculations on the new switchboards
Carry out task-based arc flash risk assessments on the switchboards to determine if arc flash PPE should be worn and what level of PPE should be worn
The proposal was fixed price and required the work to be done in a compressed timescale as the project was already partially completed. The project was completed in 3 months, on time and to budget.
ESUK agreed the scope and strategy with Volker Rail management in Doncaster. ESUK’s standard Windows-based software tool, EasyPower® was used to model the electrical systems that were being modified as part of the project.
ESUK carried out the discovery phase of the work, gathering information on the distribution system from Volker Rail’s design documentation and Network Rail’s records. Fault level information was provided by Volker Rail.
Site visits were carried out at the sub-stations that were being modified and at Portakabin in York where the packaged sub-stations were being manufactured. Task-based risk assessments were carried out during the site visits. These risk assessments considered the design of the switchgear, the installation, buildings, environment, maintenance history and the tasks that were likely to be carried out on and around the switchgear. For each task, the likelihood and severity of any potential arc flash was assessed using Volker Rail’s risk tolerance criteria.
Incident energy analysis was then carried out and arc flash boundary distance calculations were completed. Arc flash equipment labels were dispatched to the site once the design was approved by Volker Rail. Arc flash PPE guidance was included in the report as was guidance on equipment risk assessment. Finally, electrical personnel on-site received site-specific arc flash awareness training and task-based risk assessment training. Electrical Safety UK recently applied for and received accreditation for these training courses from City and Guilds.