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Third Rail Insulator

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A third rail insulator carries the conductor rail that powers a metro or light-rail vehicle. It has to hold that rail at a fixed height and gauge, keep it electrically separated from the track structure, and survive the mechanical shock of every collector shoe that passes over it — outdoors or in a tunnel, through thousands of thermal cycles.

Indisol manufactures third rail insulators in cast epoxy resin for systems up to 1500 V DC. Each one is engineered to your specification — rail profile, fixing centres, mechanical load and service temperature — rather than selected from a fixed catalogue.

Designed around your conductor rail

The seat is moulded to receive your rail profile directly, so the rail sits captive without an intermediate clamp. The base is cast with your fixing centres and drilled for the bolts you already use, which means the insulator drops into the existing track structure instead of the track structure being adapted to the insulator.

Creepage distance and withstand voltage are dimensioned to the system voltage, up to 1500 V DC. Support spacing is set with you, against the mechanical load and deflection your installation allows.

Fire and smoke behaviour

Cast in a cycloaliphatic epoxy system that meets the EN 45545-2 fire and smoke requirements for railway rolling stock and infrastructure. Part-level test reports are available on request.

This matters in tunnels and enclosed stations, where the fire and smoke classification of every component in the tunnel envelope is part of the safety case rather than a specification detail.

Built for the trackside environment

Cycloaliphatic epoxy is used because it holds up outdoors: it resists UV, tracking and weathering without the surface degradation that limits general-purpose resins. The same part is used in open air and in tunnel installations.

Cast resin also means the geometry is free. Ribs, creepage profiles and mounting features are moulded in one piece, with no assembly and no fasteners inside the insulating path.