Semi-automated aluminothermic rail welding as a model for the future in track construction and maintenance

The global trend in mobility reflects an increase in railway usage, placing significant pressure on railway operators to both expand networks and maintain existing lines. Stakeholders must achieve a delicate balance in their use of existing welding technologies. On one hand, aluminothermic welding or thermite welding (ATW) offers a cost-effective and flexible solution but relies heavily on skilled welders, who are increasingly scarce due to a labor shortage in the railway industry. On the other hand, Flash Butt welding (FBW) provides high productivity but requires substantial capital expenditure (CAPEX) and is only financially sustainable for large-scale projects.

Addressing these challenges, PANDROL has worked on technologies to automatize key steps of the ATW process. It keeps the low CAPEX advantage of ATW and enhances the welding efficiency and performance of traditional ATW. The overarching goal is to assist railway networks and contractors in meeting their operational targets within realistic budget constraints.

Established rail markets, primarily in Western countries, face the imperative of investing in aging assets to accommodate increased traffic with enhanced efficiency. Concurrently, emerging economies, particularly in Asia, are experiencing a surge in new rail projects, with significant emphasis on metro and light rail investments. However, both scenarios confront a substantial challenge: the scarcity of skilled personnel required for railway infrastructure maintenance.

The debate regarding the most efficient on-site welding solution has persisted for years, often focusing on the comparison between Flash Butt welding and ATW welding, each having its proponents and detractors.

As a leading manufacturer of ATW welding kits and track equipment, PANDROL has anticipated the increasing demand for automation. As early as 2018, PANDROL established a mechatronics department specializing in automation and data to develop innovative tools aimed at automating ATW. The ATW welding procedure can be broken down into a sequence of sub-operations, all of which can be automated (Table: 2). This advanced welding process, branded as i+weld, equips welders with an innovative set of tools that replace the conventional manual ones. 6 technologies are used: