GBL makes extensive use of ADT rooftrack systems, in order to provide continuous and complete work access using track-riding platform support frames, material hoists, Beeche Mobile Boom Hoists, and other custom equipment. Tracks may be arranged directly on dunnage, may be anchored to structurally sound material to reduce the counterweight requirements of the track-riding equipment, or may be bolted to permanent window washer davit pedestals. Other track support options have been used, including clamping to structural steel members through catwalk gratings. Track systems may consist of single layer ADT, or to accommodate heavier loads and longer spans, of ADT truss assemblies.