• bushings in operation all over the world

Trench & HSP Group – Ready to be your bushing partner

The Trench & HSP Group is one of the largest bushing manufacturers in the world. It operates bushing factories in Germany, France and China. From these factories comes a wide range of bushing products for Power Transformers, Gas Insulated Substations, Breakers, Generators, Buildings, Test Equipment, Rail Road Systems and other special applications. The patent of Emile Haefely for Oil impregnated paper (OIP) condenser type bushings in 1937 was the basis for the success in the bushing market.
Success story

World's first 1,100 kV HVDC valve bushings in RIP technology

The most powerful HVDC transformer in the world has recently successfully passed its test phase in Nuremberg, Germany. The transformer will enable low-loss high-voltage direct-current (HVDC) power transmission over a record distance of 3,284 kilometers with a transmission capacity of twelve gigawatts.

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Trench together with HSP - a pioneer for dry type bushings – is one of the leading Bushing manufacturers in the world with a very broad portfolio.


Trench and HSP Bushings are available in a wide variety of internal insulation technologies including

  • Oil Impregnated Paper (OIP)
  • Resin Impregnated Paper (RIP)
  • Resin Impregnated Synthetics (RIS)
  • Resin Impregnated Fiberglass (RIG) and
  • SF6  gas.

They are available with a variety of external insulation materials including porcelains in brown or grey; Epoxy-resin for indoor applications; and, Silicone Rubber compounds for heavy pollution or high seismic areas.


A bushing is an electrical engineering component that insulates a high-voltage conductor passing through a metal enclosure or a building. Bushings are needed on:

  • Transformers
  • Buildings
  • Gas insulated switchgear (GIS)
  • Generators
  • Other high-voltage equipment

Whatever your requirement is, the Trench & HSP Group has the right bushing for your application.

HSP Hochspannungsgeräte GmbH

HSP is a future-oriented energy technology company. HSP manufactures bushings for transformers, switchgear and generators, as well as HVDC and test bushings.


STAROIP is the new generation of OIP (Oil Impregnated Paper) condenser bushing according to IEEE Standard.