Protection of the operator and critical tractor parts are vital to the safe and successful use of tractors in vegetation control and other phases of revegetation. Heavy frames with special screens are needed to protect cabs or operators in open canopies when crawler tractors are used to fell large trees. When operating in areas dominated by thorny shrubs, rubber-tired tractors need special tires, front-end guards, belly pans, shielding of the operator or cabin, and, in some circumstances, engine side guards. When shrubs are being shredded, sturdy shielding behind the operator is needed.
Very few companies provide protective frameworks for crawler tractors. Most adaptations are fabricated in a welding shop. Protection for rubber-tired tractors is universally constructed at local welding or fabrication shops. Various methods are used for tire protection. These include steel-belted tires, tire liners, airplane tires (used), rice-tires with 3- to 4-inch lug height (R-2 treads), liquid sealants, and “foam” filling. Foam filling is not foam, but a special polyurethane compound used to completely fill the tire. The product is available in several grades of hardness, and these solid tires do not deflate when punctured. They do retain some of the pneumatic characteristics of air-filled tires. Foam filling is expensive but may be cost effective because there are no flats. Airplane tires require modification of wheels and rims to be used on tractors.