Counter weight flying system

A Counterweight Flying System is system for suspending scenery, lighting bars, etc above a stage that allows them to be flown out (raised) or lowered in with ease.  The items are attached to a bar, which in turn is suspended by steel cables, which run up to pulley blocks on the grid, across to pulley blocks on the wall, then down the wall to the weight cradle. The cradle runs up and down along tracks bolted to the wall. For every kilo of items attached to the bar, a weight is put in the cradle to balance the weight of the loaded bar. Once the counter weight system is balanced to the weight of the loaded bar it can be flown in and out (up and down) without exerting much physical effort