actuator 18 to draw the rail section 24 back into line with main rail 12 and after a few more moments of being pushed the trolley returns to the main rail 12 and proceeds downstream usually to another subsidiary loop and an associated work station fig3 illustrates that the subsidiary loops 17 and 19 are substantially elevated relative to the subsidiary loop 16 and the associated work station for example eight feet higher than the subsidiary loop 16 this is done to conserve work space the storage loops and the stored trolleys and work pieces 50 are elevated enough to allow people to walk or work underneath to allow other workpieces or equipment to be positioned underneath or to allow other functions to be performed underneath a downwardly sloping portion 90 of the rail 12 leads from the subsidiary loop 19 to the subsidiary loop 16 fig4 shows a rear view of the trolley 14 indicated as n a pusher 15 indicated as c which engages it and the restricting bracket 70 the trolley 14n has two wheels 144 and 146 which ride on one of the rails of the system 5 the wheels attach to the inside of an upper hook shaped portion 141 of the trolley and straddle the rail upon which they ride to provide balance at the top of.