a traveling highline aerial cable rail system for moving objects over large distances in three - dimensional space . a pair of track dollies mounted beneath substantially parallel and distantly separated support trusses allow the entire load bearing highline itself to traverse x - axis space . the highline defines the y - axis of the system and supports a skate that moves along this axis . a platform suspended from the skate moves vertically in the z - axis and can support extremely heavy loads depending on the gauge of the rope used in the system . a three motor pulley system with a multiplicity of sheaves allow independent movement of all three axes . the system can move objects weighing thousands of pounds stably at 60 miles per hour or more through three - dimensional space . the system can be modularly widened along the x - axis by adding truss sections , and the highline can be configured to up to 1000 feet or more , using rope that can support several tons or more . the z - axis displacement can be multiplied via a pulley arrangement .