Photograph of vegetation of flood detention structures. The use of the machinery on slopes of 3:1 or steeper requires a cable set up to hold equipment , both for safety and to prevent damage to the seedbed by equipment slippage. This contractor used a reenforced railroad rail secured to a cat-tractor with a wench mounted on each and for two cables--one for the tractor and one for the sprigging machine. Note box for hauling extra supplies of roots. An operator on sprigging machine is essential to keep roots supplied to the plaster. (D). One of a series. OK-256-11.