On the T6N tramway project in Lyon, Pandrol supplied Nabla Evolution®️ fastening systems for 15,700 sleepers, representing around 10km of single track. This system offers electrical insulation of over 9 kOhm and high performance, particularly for tight radius layouts. It guarantees excellent track gauge stability and optimised component life. Nabla Evolution stops also enable precise track adjustment in 1.25mm increments. Moreover, the Nabla Evolution®️ system offers homogenous tightening of the clips thanks to its patented contact tightening technology. The Nabla Evolution system is suitable for all types of track, from grass to asphalt.It increases insulation and offers a wide range of stiffnesses and vibration mitigation, which is key in this busy, city centre context.
The tram rails are grooved steel – standard grade R200 and R260 for straight lines, and hard grade R290 and R320 for turns. With a large number of aluminothermic welds to be completed, we decided to use two key tools from our i+weld range to maximise quality, safety and productivity on this project – AutoSeal® moulds and the High Flow Preheater (HFP) 36V.
AutoSeal® moulds streamline the welding process by removing the need for luting – sealing moulds to rail ends with paste or sand to avoid metal leaks. Instead, a built-in strip expands during the pre-heating phase to create a tight seal between the mould and the rail. As well as saving time, using AutoSeal® on the T6 line extension is reducing waste and resulting in a much more comfortable, less stressful process for welders.
The HFP 36V – which only uses propane and is significantly safer and more cost-effective than traditional oxy-propane equipment – is being used for preheating on the project. This is resulting in significant benefits, with welders reporting that the automated process takes half the time of traditional methods and is easier and more comfortable to use. Tests have also shown clear improvements in accuracy and uniformity, with better heat distribution in the ends of the rails.