Backing gates may be simple, hand-operated structures right through to highly sophisticated facilities with sensors to avoid injuring cows. Most modern backing gates are driven. The options are water-powered turbines or electric motors with or without cable systems. The gates may be carried on driven ground wheels, driven wheels on rails on the yard fence or cable and pulley systems with the gates on rails on top of the fences.
All backing gates must be fitted with hock rails. These are rails 500 mm above the ground and 350-400 mm out from the leading side of the gate. These must be fitted to the backing gate without creating any points where cows' legs can be trapped, as shown in the picture alongside.
The backing gates in circular yards are generally much simpler in construction and operation than those in rectangular yards. With the central pivot post, power supply to the drive motor is much simpler. The hinge at the centre post must be flexible, so that the weight of the gate is carried predominantly by the wheels and so that any variation in the concrete levels can be accommodated. Articulation near the hinge is needed where more than one backing gate is fitted, so that the ends of the gates can be brought close together. Water jets for an automatic wash system may be fixed to the bottom of the gate. For best results with automatic washing some form of scraper must be fitted in conjunction with the water jets to break up dense cowpats so that the water carries all away to a central sump.
