Dedicated to a specific building and owner purchased, Pro-Bel roof car systems and similar equipment e.g. rubber tire and long span boom machines, represent a generation of suspended maintenance equipment above that of other primary rigging equipment. A roof car, normally mounted at the highest elevation of the building, travels along I-Beam tracks, pipe rails, or concrete corridors/runways. Roof cars are engineered to accommodate long span booms making it possible to extend the platform beyond terraces or roofs at lower levels. This feature can reduce or eliminate the need for additional roof cars, davits, or other primary equipment at lower levels.