12. OPERATION 12.17 HANDLING TIRES 12.17.1 PRECAUTIONS WHEN HANDLING TIRES WARNING To ensure safety, the defective tires given below in items (1) to (6) must be replaced with new tires.
(1) Tires where the bead wire has been cut, broken, or greatly deformed (2) Excessively worn tires where more than 1/4 of the circum- ference of the carcass ply (excluding the breaker) is ex- posed (3) Tires where damage to the carcass exceeds 1/3 of the tire width (4) Tires where ply separation has occurred (5) Tires where radial cracks extend to the carcass (6) Tires where there is abnormal deterioration, deformation, and damage, and the tire cannot withstand use Breaker Carcass Bead wire AE133860 When replacing the tires, please contact your Komatsu distribu- tor. It is dangerous to jack up the machine without taking adequate precaution.
12.17.2 T.Km.P.H (Ton-Km-Per-Hour Rating) Tires for construction equipment are used under severe condi- tions that bear no comparison with the tires used on cars, buses, or ordinary trucks, so they are specially designed to withstand these conditions. Compared with ordinary tires, far greater heat is produced in the rubber internal parts of off-road tires when the machine is traveling. If they are used continuously under conditions which exceed the permitted load and speed of the tire, the internal temperature will exceed the limit, and the rubber may become soft and heat separa- tion occur. To prevent such problems from occurring, the T.Km.P.H.
is used as a standard to allow the machine to travel safely. If operations are carried out which exceed the T.Km.P.H. of the tire (when the T.Km.P.H. of the work exceeds the T.Km.P.H. of the tires), tire trouble will occur more frequently. In such cases, do as follows. Make the operating conditions easier so that the operation T.Km.P.H. is lowered. Increase the size of the tires to a tire with a high T.Km.P.H. 2-94