R 408.12216 Overhead guards.

Rule 2216. (1) When a load is lifted higher than the head of the operator, and the load creates a hazard to the operator, or when the operator is endangered by a hazard of falling objects other than the load, an overhead guard shall be provided. The overhead guard shall be as prescribed in SAE J167A, “Overhead Protection for Agricultural Tractors Standard,” as referenced in R 408.12202. (2) The overhead guard shall be constructed in a manner that minimizes interference with the driver’s horizontal visibility. The overhead guard may be constructed of a solid material. If a grid or mesh is used, a 1.5-inch diameter circle shall be the maximum circle that can be inserted between the elements of the grid or mesh. The guard shall be large enough to extend over the operator under all normal circumstances of tractor operation, including forward and rearward tilt of the mast. (3) On a tractor, a vertical clearance of not less than 39 inches should be maintained from the point of maximum depression of the operator’s seat to the underside of the section of the overhead guard under which the operator’s head moves during normal operation. (4) Where head room conditions limit the overall lowered height of the tractor, the normal clearance height may be reduced if the operator wears safety head protection as prescribed in General Industry Safety Standard Part 33 “Personal Protective Equipment,” as referenced in R 408.12202.