Pandrol Advanced Welding,
Tyne and Wear Metro, Newcastle, United Kingdom
With work already underway, Pandrol approached GPX and suggested that its new Advanced welding process would provide a particularly effective solution to help meet the time challenges of the Nexus project. Having looked at the process in detail and having carried out a risk assessment that showed a reduced level of risk, GPX and Nexus agreed that Pandrol Advanced should be used for the remainder of the project. Pandrol Advanced brings together innovations at every step of the welding process to save time and improve safety, ergonomics and weld quality. A small team of welders working on the Nexus project were trained over two days by Pandrol and then
supervised on site while they cast their first welds using the new process. Aluminothermic welding traditionally involves luting – sealing moulds to rail ends with paste or sand to avoid metal leaks. With Pandrol Advanced, the luting process is replaced by AutoSeal, the world’s first self-sealing mould. AutoSeal comes with a built-in insulation joint that expands during pre-heating to create a tight seal when fitted onto the rail. This brings five key benefits: • It saves time – at least five minutes per weld, as sealing the mould is automatic and there is no need for the luting procedure. • It makes sealing more reliable – especially in cold weather and tight spaces. • It reduces the defect rate – by facilitating moisture evacuation during the preheat. • It is environmentally friendly – reducing plastic waste and saving the energy needed to transport traditional luting material. • It promotes the welder’s health and wellbeing – with less time spent kneeling and reduced stress. The self-sealing mould proved extremely popular with welders working on the Nexus project. ‘It’s quick, simple and saves time kneeling down on the track,’ explained Shane Jennings, one of the welding team. ‘The weld is clean and lines are defined, with no blemishes. Collar formation is spot-on every time.’ Rather than the large CJ2 crucible, the Pandrol Advanced process uses the smaller, CJ1 one-shot
The Autoseal Mould
Startwel electronic ignition system
The Tyne and Wear Metro in north east England is a light rail network that covers over 48 miles and serves a total of 60 stations. Owned and operated by Nexus, it serves as the rapid transit system linking South Tyneside and Sunderland with Gateshead, Newcastle, North Tyneside and Newcastle Airport. As part of renewing rail in a tunnel on the metro system, Nexus needed 140 aluminothermic welds to be completed in a tight timescale. Possession times were short, with access to the track from 1am to 4am, Sunday to Thursday. Railway contractor GPX Engineering was appointed to deliver the welding services, including inspection and certification. Teams of welders began work using the Pandrol PLA one-shot crucible welding process.
Pandrol Solution
Great Western Star Summer 2021
47
