Navy Equipment Operators — EOs — are the Seabee rating responsible for operating and maintaining the heavy construction equipment that enables Naval Mobile Construction Battalion (NMCB) missions: earthmoving, site preparation, airfield construction, and facility construction in forward-deployed and combat support environments. EO billets are concentrated in NMCBs homeported at NMCB Gulfport, Mississippi and Naval Construction Battalion Center Port Hueneme, California, and at Naval Mobile Construction Battalion units deployed worldwide. EOs operating and maintaining heavy construction machinery accumulated asbestos exposure from asbestos-containing materials in diesel engine maintenance and in equipment brake and clutch systems.

Heavy Equipment Diesel Engine Maintenance

EOs performed scheduled maintenance on the diesel engines powering Seabee construction equipment:

  • Bulldozer and scraper diesel engine maintenance — the large diesel engines powering tracked construction equipment (D7, D8, and D9-size bulldozers; motor scrapers) used asbestos-containing head gaskets, exhaust manifold gaskets, and turbocharger gaskets in the diesel engine rebuild procedures that EOs performed during NMCB equipment maintenance cycles. Engine rebuild gasket replacement disturbed asbestos gasket materials in the engine compartment
  • Motor grader and crane diesel maintenance — motor graders and mobile cranes used in Seabee construction operations were powered by diesel engines with asbestos-containing gasket sets. EOs and Construction Mechanic (CM) ratings performing engine maintenance on these machines encountered asbestos gasket materials at each engine overhaul interval
  • Wheel loader and rough terrain forklift maintenance — medium-duty wheel loaders and rough terrain forklifts maintained in NMCB equipment parks used diesel engines with asbestos-containing gasket materials in scheduled engine maintenance

Equipment Brake and Clutch Systems

Heavy construction equipment used asbestos-containing friction materials in brake and steering clutch systems through the mid-1980s:

  • Tracked equipment steering clutch overhaul — large tracked equipment (bulldozers, tracked loaders) used multi-disc steering clutches controlled by hydraulic or mechanical linkage. EOs and CMs overhauling steering clutch assemblies encountered asbestos-containing clutch disc friction materials in the clutch pack replacement procedures
  • Brake system maintenance — construction equipment brake systems — drum brakes on wheel-mounted equipment, parking brakes on tracked machines — used asbestos-containing brake shoe and lining materials throughout the period when asbestos friction materials were standard in construction equipment manufacturing
  • Torque converter and transmission service — some heavy construction equipment transmission maintenance involved asbestos-containing internal friction materials in torque converter and transmission clutch assemblies

NMCB Deployment Asbestos Exposures

EOs deployed with NMCBs to construction support missions encountered asbestos from construction materials used in NMCB construction projects:

  • Construction material handling — EOs operating equipment at NMCB construction sites handled asbestos-containing construction materials (pipe insulation, roofing materials, tile) using construction equipment to move and place these materials at project sites. Prior to the asbestos phase-down in military construction materials, NMCB construction projects routinely incorporated asbestos-containing building products that EOs encountered throughout the construction operation

VA Claims for EO Veterans

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure in Seabee construction equipment maintenance. Equipment Operators who served in NMCB billets and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits.