Soldadura exotérmica ferroviaria en Metro Praga

October 23, 2025 | Prague Metro

During the week of October 22–23, 2025, the KLK Weld team carried out a series of rail connections at the Prague Metro facilities (Czech Republic), specifically at the Depo Hostivař yard. These tests, performed using our exothermic welding processes, are part of the ongoing technical approval and product validation program that Prague Metro is conducting for its electrical connection and rail grounding systems.

Project Details at Prague Metro

The work carried out at Depo Hostivař had a dual purpose: to serve as a test installation for technical evaluation and as a hands-on training session for local supervisors. During the session, several types of rail connections were performed:

RR Connections (rail-to-rail) using direct welding.
ELPA Connections (indirect), applied on the rail head.
Electrical resistance measurements to verify joint quality.
Preheating and conditioning of molds and rail surfaces prior to ignition.

The results of these tests were highly satisfactory, confirming the reliability of the KLK Weld system for critical railway applications. Moreover, this practical trial marks a key step toward the official approval of the KLK Weld exothermic welding process by the Prague Metro.

Full Rail Connection Process | KLKweld | Prague Metro Nov. 2025

Expansion in Central Europe

This project adds to three other installations recently completed by KLK in the Central European region: two in the Czech Republic and one in Slovakia. All of them are part of a strategic plan aimed at achieving technical validation by the Czech and Slovak Railways, strengthening KLK’s position as a leading provider of exothermic welding solutions for the European rail sector.

The continuation of these tests and collaborations underscores KLK’s commitment to innovation, technical training, and the ongoing improvement of electrical processes in railway infrastructure.

What Is Exothermic Rail Welding? Still Not Completely Clear?

No worries, we’ve got you covered. Exothermic welding is a process that permanently joins conductive materials—such as copper or steel—through a controlled exothermic reaction. In the railway environment, this system ensures safe, durable, and highly conductive electrical connections, essential for track continuity and system protection.

The process requires no external power source, operates fully autonomously, and is used for both signal bonding connections and rail grounding applications. The graphite molds, welding charges, and accessories designed by KLK guarantee precise, safe execution fully compliant with the most demanding international standards.

Benefits of KLK Weld for Railway Infrastructure

Permanent connections with low electrical resistance.
Increased safety during operation — no external power required.
Superior performance under extreme weather conditions.
Compatible with multiple rail profiles and conductor sizes.
Reduced maintenance and extended track service life.

DO YOU KNOW THE DIFFERENCE BETWEEN “RAIL-TO-RAIL” AND “RAIL-TO-CABLE” EXOTHERMIC WELDING?

Frequently Asked Questions

What’s the difference between a direct and an indirect weld?

A direct weld joins the cable or connector directly to the rail, while an indirect weld (ELPA type) uses an intermediate support. Both ensure electrical continuity, but the choice depends on the type of installation or environment.

Are KLK Weld joints approved in Europe?

They are currently in the validation phase across several European countries. The tests carried out with the Prague Metro, Czech Railways, and Slovak Railways are part of this process and have shown positive results.

Can I request a demonstration or training session?

Yes. KLK offers both in-person and online technical training on exothermic welding processes, safety, and best practices for railway connections.

Conclusion

The KLK Weld project at Prague Metro reflects the progress and consolidation of our technology within European railway systems. Collaborations like this are key to continuously improving the safety, efficiency, and reliability of electrical transport infrastructure.

So, why choose KLK Weld?…

With over 60 years of experience developing grounding and aluminothermic welding solutions, KLK is a recognized leader in innovation across the electrical and industrial sectors. Our systems meet the strictest international standards and are implemented in railway projects throughout Europe, Latin America, and the Middle East.

We also provide technical training and direct support for installers, engineering firms, and maintenance departments, ensuring proper on-site application of our products.

Want more information or a technical demonstration?

Contact our technical team here