Riley Stoker Corporation, headquartered in Worcester, Massachusetts, was a manufacturer of steam generating equipment for power generation and industrial process applications, including marine steam boilers for naval and commercial vessels. Riley Stoker supplied marine boilers for US Navy ship applications — particularly in auxiliary and ship’s service steam plant roles — alongside the dominant marine boiler manufacturers Babcock & Wilcox and Combustion Engineering. Riley Stoker boilers incorporated asbestos-containing refractory materials in their firebox construction and asbestos block insulation on their casing systems, with these asbestos-containing materials creating exposure for Navy Boiler Technician (BT) ratings performing maintenance and overhaul operations on Riley Stoker boilers in Navy ships’ engineering spaces.

Asbestos in Riley Stoker Naval Boilers

Riley Stoker marine boilers used asbestos in multiple components:

  • Firebox refractory materials — the firebox refractory system in Riley Stoker marine boilers used asbestos-containing insulating castable refractory and asbestos-containing insulating firebrick in the backup insulation courses behind the hot-face refractory materials. BT ratings performing firebox rebricking operations on Riley Stoker boilers removed deteriorated asbestos refractory and applied new castable material, generating asbestos fiber in the confined firebox environment during each rebricking evolution
  • Boiler casing insulation — the external boiler casing insulation protecting the Riley Stoker boiler structure and reducing external heat loss used asbestos block insulation applied to the boiler casing surface. Maintenance personnel removing and replacing casing insulation during boiler overhaul operations encountered asbestos fiber from the removed block insulation
  • Boiler door and access cover seals — the combustion air register doors, inspection ports, and access cover seals on Riley Stoker boilers used asbestos rope gasket material for high-temperature sealing at these access points, with door seal replacement releasing asbestos fiber from deteriorated sealing material

Riley Stoker boilers appeared in Navy auxiliary and ship’s service boiler applications:

  • Carrier auxiliary boiler plants — the auxiliary steam systems on large aircraft carriers included auxiliary boilers separate from the main propulsion plant for ship’s service steam generation; Riley Stoker supplied auxiliary boilers in some carrier applications where auxiliary steam generation required dedicated boiler equipment
  • Larger auxiliary vessel boiler plants — various Navy auxiliary vessels — repair ships, tenders, and support vessels — used Riley Stoker and competitor boilers in their propulsion and auxiliary steam plants throughout the Cold War era

VA Claims for Veterans Exposed to Riley Stoker Products

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure from boiler maintenance in Navy steam plant engineering spaces. Boiler Technicians who performed maintenance on Riley Stoker boilers and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits.