the invention is a traveling highline aerial cable rail system . embodiments of the invention can move objects throughout three - dimensional space quickly , accurately and stably by moving the highline itself laterally along two substantially parallel truss members , providing movement in the x - axis direction , while moving a skate along the highline in the y - axis direction , and vertically moving a platform suspended from the skate in the z - axis . many types of useful devices may then be attached to the platform . in addition , the truss and track sections may be modular to allow for expansion in the x - axis . [ 0031 ] fig1 shows a perspective view of an embodiment of the present invention . for the purpose of this discussion , the truss 101 forms the x - axis , the highline 130 forms the y - axis of the system and the support structure 100 forms the z - axis . in this configuration , vertical support structure 100 and 199 separates truss 101 from the terrain . the support structures are anchored to the terrain via rope 102 and stake 103 and rope 198 and heavy block 104 . the reader will note that any fastening device that can hold the tension required can be used to secure the structures . the vertical support structures and trusses may be built from lightweight metal , and may be modular to enable quick disassembly and shipping in standard cargo containers . hand winch 105 provides tensioning of rope 102 . hand winches can be used on the other fastening lines as well . truss support rope 106 supports the middle of truss 101 , by looping over top support structures 108 , 109 , connecting to truss 101 at truss midpoint 197 . one skilled in the art will recognize that these particular vertical support structures are not required to practice the invention as large trees , buildings , the side of a canyon or hill or any other structure that would provide vertical clearance from the terrain below the trusses would enable the invention to be practiced . truss section 112 is located distantly from truss 101 and is substantially parallel to truss 101 . alignment can be performed with a commonly available contractors leveling system . in other embodiments of the invention , multiple highlines may be utilized by employing additional track dollies utilizing existing tracks or independent tracks per truss . additional x , y and z ropes and associated sheaves are utilized in this embodiment in order to independently control each platform . generator 192 powers the system . electronics drive units 750 , 850 and 950 derive power from generator 192 , and electrically control the rotation of the motors 700 , 800 and 900 respectively . computer 170 can run off an internal battery or be powered via generator 192 . an embodiment of the invention can run fiber optics cables or power cables along highline 130 draping the cables between at least one skate that follows skate 150 along the highline . [ 0034 ] fig2 shows track dolly 115 riding in track 196 attached beneath truss 101 , the track dolly provides movement in the x - axis direction . by placing the modular sections end to end , any width of truss and track can be constructed . the truss sections and tracks that are connected via pins 201 . the sections are then bolted together or connected together with any other fastening apparatus . an embodiment of the invention uses multiple sheaves 216 , 217 and 218 in place of a single sheave in order to provide for a more secure change of direction for the rope that is less susceptible to derailing . different embodiments of the invention can use multiple sheave arrangements virtually anywhere where a single sheave is used in order to change direction of a rope . although sheaves that with groove shapes and rounded edges that minimize the lateral friction on ropes passing through the sheaves may be utilized in order to minimize the amount of wasted power in the system , different embodiments of the invention may use any type of sheave that works with the rope specified for the system . fig3 shows a side view of fig2 . [ 0035 ] fig1 shows track dolly 116 riding in track 195 attached beneath truss 112 , the track dolly provides movement in the x - axis direction on the other end of highline 130 . the x - axis ropes are configured for automatic or manual control of tensioners 119 , 120 , 121 and 122 allowing the track dollies to smoothly and symmetrically traverse the tracks . if track dollies 115 and 116 are not kept equidistance from their respective ends , a jerky movement results . the reeving pattern for the x - axis ropes allows adjustment of x - axis track dolly 115 position relative to opposing track dolly 116 . highline 130 connects track dollies 115 and 116 riding under opposing trusses , and can be tensioned at approximately 20 % of the rated strength of the rope for a margin of safety . for example , use of commercially available rope such as spectron # 2 , synthetic 1 . 125 diameter rope allows for tensioning up to 10 tons . however , the reader should note that the invention is not limited to a specific type of rope or gauge . platform 141 is suspended from skate 150 and comprises large sheave 142 . any desired payload is attached to the platform . a dynamometer 160 can be inserted in - line with the highline to provide tension readings to computer 170 , via a wireless signal . the skate 150 is pulled along the y - axis direction via y - axis rope 151 and in fig4 the skate rides the highline on sheaves 401 and 402 . [ 0037 ] fig5 shows x - axis ropes 117 , 118 which are driven by two gears 701 , 702 mounted on a common shaft by x - axis motor 700 . as motor 700 rotates in a given direction , rope 117 is pulled from one side of track dolly 115 , which moves the track dolly in that direction . rope 117 moving upward into sheave 742 moves into sheave 745 attached to track dolly 115 , increasing the length of rope between sheave 745 and tensioner 761 . as the rope moves in this direction , it flows downward from sheave 741 , directly from sheave 743 on the opposing side of the truss 101 , out of sheave 744 , decreasing the distance from sheave 744 to tensioner 762 . this motion of rope pulls track dolly 115 to the right . the opposite direction of movement of rope 117 pulls the track dolly to the left . the movement of track dolly 116 on the opposing truss 112 occurs in the same manner although the x - axis rope 118 traverses the entire y - axis length to and from truss 112 . as the motor 700 rotates in a given direction , the rope 118 is pulled from one side of the track dolly 116 , which moves the track dolly an equal amount as track dolly 115 is moving since the two ropes 117 and 118 are driven from a common shaft . rope 118 moving upward into sheave 721 moves into sheave 723 and then sheave 726 which is attached to track dolly 116 , increasing the distance to tensioner 763 . as rope 118 moves in this direction , it flows downward from sheave 727 , directly from sheave 722 , from sheave 724 , from sheave 725 , thereby decreasing the distance from sheave 725 to tensioner 764 . this motion of rope pulls the track dolly 116 to the right . the opposite direction of movement of the rope pulls the track dolly to the left . [ 0039 ] fig6 shows the y - axis rope 151 which is driven by drive gear 801 coupled to y - axis motor 800 . as motor 800 rotates in one direction , rope 151 is pulled from one side of skate 150 , pulling the skate along in that direction . rope 151 moving upward into sheave 824 moves into sheave 825 which moves into sheave 826 which flows into sheave 828 which is attached to the side of the skate , as it unwinds the rope out to sheave 827 , effecting motion of the skate away from truss 112 . rope 151 flows downward from sheave 821 directly from sheave 822 from sheave 829 which is attached to the side of the skate , which pulls the skate closer to truss 101 . sheaves 826 , 827 , 828 , 822 , 823 and 829 allow skate 150 y - axis position to remain constant when the track dollies 115 and 116 move from one x - axis position to another , by freely rotating , therefore , with drive gear 801 stopped , these six y - axis sheaves will still rotate when track dollies 115 and 116 move in the x - axis direction even though the skate 150 remains at a constant y - axis position . [ 0040 ] fig7 shows the z - axis rope 131 which is tied and wound onto a drum winch 901 . by unwinding rope from the drum winch , rope 131 is moves up into sheave 921 into sheave 922 which is attached to track dolly 115 , moves into sheave 923 which is attached to skate 150 which flows into large sheave 924 , which is connected to the platform , which lengths the distance between sheave 924 and sheave 925 , and effects a lowering of platform 141 . the opposite motion of the rope effects a raising of the platform . sheaves 926 , 925 , 924 , 923 and 922 allow the platform 141 z - axis position to remain constant when the track dollies 115 and 116 move from one x - axis position to another , by freely rotating as the same amount of rope flowing out of sheave 926 is flowing into sheave 922 , therefore , with the drum winch stopped , these five z - axis sheaves will still rotate when track dollies 115 and 116 move in the x - axis direction even though the platform 141 remains at a constant z - axis position , in other words , at the same height . the three axes of movement are completely independent of each other , so when the z - axis position of the platform moves , the x - axis and y - axis positions of the platform do not move , likewise , when the x - axis position moves , the y - axis and z - axis positions do not move and when the y axis position moves , the x - axis and z - axis positions do not move . an embodiment of the invention contains a simple block and tackle fitted between the drum winch 901 and 921 in order to provide a z - axis n - factor multiplier . this allows a multiplication factor to be calculated by determining the total amount of rope that each side of the block and tackle assembly contains and dividing the amount of rope on the sheave side by the amount of rope extendable on the drum winch side . for example , if there were two pulleys on the sheave side with corresponding mounted pulley and terminator on the sheave side , and one pulley on the drum winch side terminated at the height of the drum winch , then the total amount of rope that each side could let out would be 4 * z lengths of rope on the sheave side and 2 * z lengths of rope on the drum winch side , where z is the height of the support structure 199 , therefore the multiplication factor would be 2 . this would allow platform 141 to descend to two times the height of support 199 . increasing the number of sheaves looped through on one side or the other of the block alters the multiplication factor accordingly . in addition , if the rope attached to the drum winch broke , the furthest that the platform 141 would fall would be the amount of rope on the sheave side , in this case two times the height of the support structure . after altering the reeving , computer 170 can recalibrate to take the rope length changes into account immediately . another embodiment of the invention involves using three sheaves each time a long reach rope changes direction . a vertical sheave supports rope that has traveled a long distance , this is attached to a horizontal sheave for direction change , which then feeds another vertical sheave in the next direction of travel . fig2 and fig3 show sheaves 216 , 217 and 218 assembled in this arrangement . in addition , all sheaves in this embodiment are built using high speed bearings and are built to capture the rope to prevent derailing . this is an important safety aspect of this embodiment . [ 0044 ] fig3 shows the wheels 301 on the track dollies which are built to maintain fluid x - axis carriage movement while under y - axis tensions of up to 10 , 000 pounds or more on the highline . in an embodiment of the invention , the wheels are constructed from high density delrin ® and the bearings are preloaded , although any material capable of handling high loads and smooth travel along the track may be substituted for delrin ®. an embodiment allowing for even higher stability platform control is shown in fig8 and comprises a lower skate 1005 that can be narrower , as shown , or wider than skate 150 in the y - axis direction of the invention . z - axis rope passes through sheave 1000 and 1001 , and with wider distances between these two sheaves the platform is less susceptible to twisting about the z - axis . the platform 141 is suspended from at least one dampener , and in this embodiment is suspended from three dampeners 1002 , 1003 and 1004 . the dampeners can be active or passive in stabilization . platform gimbal 1006 rotates about its circumference and is attached to “ tag line ” 1007 in order to provide immediate control of the platform oscillations when stopping or starting motion of the platform . the use of a tag line allows for any perturbation of the system to be eliminated including , but not limited to , gusts of wind , swaying of the highline , explosions , earthquakes , or any other external force that would inject unwanted movement into the platform . tag line 1007 may be vectored to any location within three dimensional space and may be operated by hand , winch or any other mechanism that winds and unwinds rope . tag line 1007 may be “ passive ” meaning that the length of the tag line does not change as the platform moves , or “ active ” meaning that the tag line is set in motion while moving the platform . another embodiment allows the tag - line to attach to skate 150 directly without using gimbal 1006 , which is useful in high wind situations . another embodiment employing an active tag line runs the tag line off of motor 800 using a subset of the grooves of drive gear 801 so that they two lines travel out the same amount when moving the platform in the y - axis direction , this configuration keeps the z - axis height from varying as much as the passive tag line embodiment . another embodiment of the invention employs a counterweight on the tag line at the end of a loop that hangs over truss 112 in order to compensate for the weight of platform 141 . depending on the obstacles that need to be traversed in these higher stability requirement scenarios , the point at which the tag line is pulled from may dynamically change as well in addition to changing the amount of rope dispensed . in each of these “ tag line assemblies ”, the platform or skate is held or moved in or away from the point at which tag line 1007 is vectored to . platform 141 can have many different apparatus attached to it to perform a variety of functions including but not limited to stabilization devices , gimbals , camera equipment , mining loaders , ship - to - ship loaders , logging devices , ski lift seats , gondolas , body sensing flight simulator suits for allowing a person to simulate flight like a bird including wireless transmitter back to computer 170 to transmit flapping gestures , reduced gravity simulator suits , lifting harnesses , munitions depot bomb retrievers , digital video equipment for security checks in railroad yards or nuclear facilities , robotic agricultural harvest pickers for quickly picking and storing grapes or other produce or any other device that benefits from repeatable placement and motion in three dimensional space . in another embodiment , platform 141 comprises a witness camera mounted pointing down from the platform , providing a picture from the viewpoint of the platform .