Product Description

Westinghouse Electric Corporation was, alongside General Electric, one of the two dominant U.S. suppliers of large industrial motors, turbo-generators, and rotating apparatus for the mid-twentieth-century industrial base. Steel mills, paper mills, refineries, cement plants, utility plants, and Navy shipyards were populated with Westinghouse motors ranging from a few horsepower on process pumps to multi-thousand-horsepower drives on rolling mills and pipeline pumping stations.

Every one of those machines carried an insulation system on its copper windings. Plaintiffs alleged in publicly filed U.S. asbestos litigation that Westinghouse specified a family of asbestos-containing coil insulation components on its large motors, generators, and rotating apparatus manufactured from the 1940s through the mid-1970s, including:

  • Woven asbestos-cloth coil-lead wrap — asbestos fabric tape wound around the exposed copper leads at the coil exit, protecting the lead from mechanical damage and heat where it entered the terminal box.
  • Asbestos-tape end-turn wrap — narrower asbestos tape wound around the exposed end-turns of coil bundles, providing dielectric and thermal insulation at the coil ends.
  • Asbestos-varnish impregnation — the completed coil assembly dipped in asbestos-loaded varnish and baked, producing a hard fiber-reinforced dielectric shell.

These fabric-based insulation systems worked in parallel with the phenolic-laminate insulation products for which Westinghouse is separately known (Micarta H-grade cloth phenolic, transformer-grade Micarta, and related grades).

Workers Exposed

The dominant exposure pathway was motor rewind at Westinghouse service centers and at the independent motor-repair shops that maintained the installed base. Rewinding a large Westinghouse motor required stripping and burning out the old winding assembly in a bake-out oven, chipping bonded insulation debris out of the stator slots, and installing fresh asbestos-cloth-wrapped leads and asbestos tape on the new coils.

Plaintiffs alleged that motor-shop electricians, winders, and helpers cut asbestos tape by hand from parent rolls, wound it onto coil leads and end-turns in tight spirals, and dipped and baked the finished assemblies in varnish-loaded ovens — all without respiratory protection and without warning labeling identifying the material as asbestos.

Utility electricians and industrial plant electricians who pulled and replaced coils in place — inside large stator frames on hydro generators, turbo-generators, and mill-motor drives — encountered the same insulation system during field repair.