by an alternator. It supplied power to concealed four-beam headlights, parking/marker lights, brake lights, backup lights, instrument lights, electric windshield wipers, a single-speed heater blower, and a radio/public address system. With this equipment, the Boilermaker Special III was capable of day or night operation on most improved roads, including highways. The original headlight from Boilermaker Special I was initially installed on the back of the coal tender as a rear-facing safety light. It was later removed and installed as the headlight of the Boilermaker IV in 1979 (see below). A white block P was displayed on the front of the boiler directly below the large front headlight. The block P was mounted to a metal mesh screen which allowed external cool air to be drawn through the radiator by the engine's radiator fan. In the 1970s, the original engine and transmission were replaced with a carbureted Chevrolet 350 cubic inch V-8 and a three-speed automatic transmission. The two-speed differential was locked in high gear and shift mechanism removed. A power steering pump and steering assist cylinder were installed to reduce steering effort. In the early 1980s, a brass whistle was installed next to the brass bell and used the same source of compressed air as the large train horn. In this final configuration, the Boilermaker Special III weighed about 9,300 pounds (4,218 kg). When it was retired in 1993, it had traveled over 110,000 miles (177,027 km). Boilermaker X-tra Special IV In 1979, a small version of the Boilermaker Special was introduced. The Boilermaker Special IV, or "X-tra Special" as it became known, was built on an E-Z-GO electric golf cart chassis. This allowed the mascot to be displayed at indoor functions or on softer surfaces (i.e. a turf athletic field) where its massive gasoline-powered, and later diesel-powered big brother could never go. The headlight was the original headlight used on Boilermaker Special I and II. The top of the smokestack could be removed to allow the X-tra Special to fit inside freight elevators and move through standard height, side-by-side walk-through doors. The IV also featured a white block P on the front of the boiler directly below the headlight, just like the Boilermaker Special III. Boilermaker Special V Boilermaker Special V was introduced on September 25, 1993. It was built on a Navistar Low-Profile 4600 chassis and powered by a non-turbocharged V-8 diesel engine. The Navistar chassis was donated