Pictured above is a sketch of a typical hayfork installation in a center drive barn.
(Click the image for a larger view.)
The track (A) is suspended from the rafter peaks and a trip block (B) is installed on the track and centered over the wagon unloading area. The draft rope (C) is tied to the hay carrier (D), passes down around the lower pulley (E) and back up over the rope pulley (F). From the carrier the draft rope passes through draft pulleys (G, H and I) before being hooked to the horse’s singletree.
After the operator on the loaded wagon sets the double-harpoon fork (J) into the hay, the horse is driven forward, causing the loaded fork to be pulled straight up until it locks into the carrier.
At that time, the trip block is operated and the carrier is released to move along the track to the left.
When the fork load of hay is over the desired spot, the wagon man pulls the trip rope (K) and the hay drops into the mow, where the man with the pitchfork spreads it into position.
After the fork is emptied, the horse is backed up and the carrier is pulled back into the trip block by the rope (L) attached to its right side which passes through draft pulleys (M and N). A bag of sand (O) provides the weight for this operation.
When the carrier locks onto the trip block, the fork pulley is released and the fork and pulley should drop back onto the wagon of their own weight.
When filling the mow on the right, the draft and weight ropes are reversed and the carrier is swiveled to allow operation in the opposite direction, at which time another draft pulley (P) comes into use. FC
Read more about hayfork pulley systems: “ Mechanization Meets Haymow: Hayfork Pulley Systems .”