Boilermaker Special III featured an all-new body that was much larger and visually different than the Baldwin-manufactured body used on Boilermaker Specials I and II. The cab and coal tender were constructed of plywood with facings of sheet steel on each side. Forward of the cab, the body was heavy sheet steel and steel plate. The brass bell originally installed on Boilermaker Specials I and II was installed on the boiler. A new headlight was installed at the front of the boiler. It featured a small 12-volt bulb reflected by a large parabolic mirror. It was so bright it could only be used during parades. A locomotive air horn was installed on the top left side of the cab. When the horn was sounded, the Boilermaker Special III could be heard from miles away. To complete the locomotive theme, "steam" could be sprayed from the smokestack. The steam was actually carbon dioxide released by the driver from a fire extinguisher cylinder within the cab and plumbed to a nozzle just below the top of the smokestack.