The company was founded in in Switzerland by Emil Haefely, an inventor who played a decisive role in the development of the electrotechnical industry at beginning of the th century. With the patent of the OIP Condenser type bushing in by Emil Haefely, the company became a pioneer in Oil type bushings. Trench France is part of the Trench & HSP Bushing group belonging to Siemens with locations in France (Trench France), Germany (HSP) and China (THVS). This close cooperation for innovation and design is supported by Siemens process and manufacturing know how. In , the Trench Group decided for Trench France to focus specifically on bushings by making extensive manufacturing investments and improving all customer relevant processes.

Trench and the companies forming the Trench Group have always been front runners in all three fields of the business. With the patent on Oil impregnated paper condenser type bushings in , Emil Haefele laid the foundation for the Trench Bushing business. In Instrument transformers the Trench Group is a technology leader since years, when in Italy the first paper oil Instrument transformers were produced. And Tony Trench, the founder of the Trench Group was a real pioneer developing Air core reactors in the early s.

In Trench Austria was established by Alois Esslinger, an electrical engineer known beyond the borders of Austria. The former name of the company until was Spezielektra Esslinger KG. From the very beginning, one focus area of the company was the development and production of reactors for electrical power system. The use of glass fiber reinforced plastic as part of the insulation of reactors was revolutionary in the s . Trench Austria gained significant international reputation in the s when supplying high current and high voltage test reactors for leadin test laboratories like KEMA in Arnheim/The Netherlands. In Spezielektra was merged with Trench Electric Toronto/Canada. This was also the starting point for the foundation of the Trench Group. Today Trench Austria in Leonding near Linz produces reactor/coil products for medium and high voltage electrical systems, both in dry type as well as oil immersed technology and is one of the worldwide leading companies in this special area of the electrical industry.

For more than years, Trench has supplied air core reactors to the electric power industry. Founded by Tony Trench in , Trench Canada has demonstrated versatility, confirmed capability and compliance with the most stringent quality standards to ensure that Trench maintains a worldwide leader for coil products. Located in Scarborough, Ontario, Trench has proven the effectiveness of vertically integrated operations in the manufacturing of air core reactors. Significant investments in the factory layout and process optimization over recent years makes Trench Canada a reliable partner for customers.

The company was founded in in Switzerland by Emil Haefely, an inventor who played a decisive role in the development of the electrotechnical industry at beginning of the th century. With the patent of the OIP Condenser type bushing in by Emil Haefely, the company became a pioneer in Oil type bushings. Trench France is part of the Trench & HSP Bushing group belonging to Siemens with locations in France (Trench France), Germany (HSP) and China (THVS). This close cooperation for innovation and design is supported by Siemens process and manufacturing know how. In , the Trench Group decided for Trench France to focus specifically on bushings by making extensive manufacturing investments and improving all customer relevant processes.