History of the Thermit© welding technology. The invention of the century
On January 1, 1919, Th. Goldschmidt AG, Essen, together with the Berlin-Hagen battery factory, founded the subsidiary company Elektro-Thermit GmbH in Berlin, Tempelhof. Thus, there was a combination of many years of knowledge and experience in the field of welding. From the very beginning, the new company proved to be extremely successful and contributed to the further breakthrough of the Thermit© welding.
A prerequisite for this was the aluminothermic welding method invented by Professor Hans Goldschmidt and patented in 1895. He managed to turn the chemical reaction of metal oxide with aluminium powder into a common industrial application. Thus, the aluminothermy, known since the time of N. N. Beketov, discovered by him in 1859, was given to the service of technical progress by the merits of Mr. G. Goldshmidt. On March 13, 1895, the Goldschmidt company in Essen received the Kaiser patent number 96317 titled "Method for production of metals or their alloys."
Soon enough, Professor Goldschmidt found out that the incredibly high energy released during the reaction of metal oxide with aluminium powder could be used to weld massive metal parts. Thus, since the beginning of the 20th century, there were first attempts to weld rail tracks by the Goldschmidt method, and already in 1928, the first rails were, with technical and commercial success, welded on the German Railways.
After the Second World War, almost all railway companies began to use the Thermit© method of welding, which brought the companies of Thermit® group such a rapid breakthrough to the world stage. Thanks to high-speed SmW welding technology developed in 1955, it became possible to substantially shorten the duration of Thermit© welding, which contributed to an increase in economic efficiency of this method. Another step forward occurred in 1972 after the method of high-speed welding was improved and put into operation as the SkV technology, the standard welding method for German Railways and other railway companies. Also, the companies of the Thermit® group, with the use of electric welding, began to restore the geometry of already laid and worn rails, and to improve their performance. The technology of submerged arc welding with the ELLIRA® method was used quite often. This technology was developed in accordance with the requirements of the railway companies for ETEKA 5® welding method – and, accordingly, with RIFLEX®. In addition, special grinding equipment was used to restore the profile of the rail surface. This successful approach led to the fact that the quality of the new rails also improved thanks to this technology, which, in turn, ensured smooth running and long-term operation.
It is worth noting that the companies of Thermit® group were engaged in development and improvement of not only the very method of Thermit© welding, but also manufacturing of necessary tools, units, and devices. Examples include hydraulic grapple (1970), automatic crucible plug (1982), or EURO crucible for single use (1998).
In addition to Thermit© welding, the company developed novelties in other fields that were also related to the railway infrastructure. So, in 1970, the insulating MT joint bars were put on the market. Since then, those and other designs of insulating joint bars, like other products and services, have complemented the diverse range of the Group services.
Already before the First World War, the method of Thermit© welding, developed by the Thermit® companies was used worldwide by their numerous affiliates. Thanks to newly created enterprises, as well as equity participation, the Group became a global player. Its presence is worth noting in countries like Italy (1950), India (1951), Brazil (1952), Austria (1952), England (1958), the USA (1967), Australia (1986), Czech Republic (1993), and Hungary (1995). In 1999, Thermit® Group separated from its parent company Goldschmidt AG and passed under the management of Erben Dr. Karl Goldschmidt GmbH, Essen.
Elektro-Thermit GmbH & Co. KG, which has had its headquarters in Halle (on the Saale River) since 2015, became the most important support of the Goldschmidt Group a century later. At the production site in Halle, the main production site of Goldschmidt Thermit Group is now located.