running board

A running board is a narrow metal walkway mounted on the exterior of a locomotive, typically 12 to 18 inches wide, positioned above or beside the driving wheels. It provides safe passage for crew members to move along the locomotive frame while the engine is stationary or moving slowly, essential for tasks like oiling journal bearings, checking steam fittings, coupling or uncoupling cars, and inspecting the locomotive during operation. Early steam locomotives had crude handholds; the running board became a standard safety feature as locomotives grew larger and more powerful.

On steam locomotives, running boards run along both sides of the boiler and firebox, beginning just above the driving wheel assemblies and extending rearward. They are typically fabricated from expanded metal or perforated steel plate, secured to the locomotive frame with brackets and bolts. On larger steam engines, especially compound or articulated locomotives, running boards may extend further forward over the smokebox and include extensions that climb toward the boiler top. Diesel-electric locomotives, having lower profiles and different geometry, feature running boards that are often simpler, sometimes consisting of a single footway on one side.

The surfaces must provide reliable grip even when wet or oily, so running boards are typically serrated or have raised ribs cast or welded into their upper surface. In freight yards and during switching operations, crews depend on running boards to dismount quickly and safely from moving equipment traveling at speeds up to 5 or 10 mph. Handholds and grab irons, bolted to the boiler jacket or frame at regular intervals, run parallel to the running board to prevent falls.

Running boards accumulate dirt, grease, and corrosion products from the locomotive's operation. Crews routinely brush or scrape them clean to maintain footing and to allow inspection of the underlying frame for cracks or damage. On older steam locomotives, running boards are common failure points where expansion and contraction of the boiler jacket can crack the welds that anchor the footway brackets, and where corrosion eats through the metal plate itself.

The term appears to derive from the action of running or quickly moving along the board, distinguishing it from static platforms. Running boards are distinct from the footplates at the ends of the locomotive, which serve as standing areas for the crew in the cab, and from pilot beams or couplers. Modern rail practice has largely eliminated the need for crew movement along the locomotive during operation, so running boards on contemporary diesel locomotives are minimal and primarily serve inspection and maintenance access rather than active crew movement.