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Safety Talk
Chocking and blocking are good practices which serve the purpose of keeping heavy loads and vehicles stationary. Any worker loading or unloading, hitching or unhitching, or performing maintenance on a vehicle should take care to chock and block to prevent unintended movement of equipment and/or cargo.
What’s at Stake?
Chocking is the act of using a wedge to immobilize a wheel, keeping the vehicle or mobile equipment from moving accidentally. Chocking the wheels of a vehicle, such as a truck or trailer, physically stops the movement of wheels to prevent runaways that can injure workers and destroy property.
Blocking is the act of using lumber to keep cargo in place. Blocking stabilizes cargo to prevent shifting and trailer overturns. Blocking also creates a physical barrier on equipment to prevent unintentional activation during maintenance.
What Can Go Wrong?
A truck driver carrying a heavy load stops at a service station but forgets to chock and block. His truck rolls away down a hill, striking a utility pole and eventually coming to rest in a public playground. Thankfully, no one is injured; however, 700 county residents lose power as a result of the utility pole collision.
How to Protect Yourself:
If you drive a truck, tractor, or other mobile equipment, use special caution when exiting the vehicle. Ensure that the brakes are set, the vehicle is at a complete standstill, and that it will not roll forward or backward before you exit.
To chock, place correctly sized wheel chocks on both rear-axle wheels. Always chock the wheels closest to the dock. A lift truck entering the trailer can exert a downward force which helps pin the wheels more effectively against the chock. When only the front axle is chocked, the forward motion of a forklift entering the trailer may loosen the chock, allowing the trailer to move forward or jump the chock. However, you also may chock the front-axle wheels for extra safety. It is safest to chock both the front and back wheels on both sides of a vehicle. Only use genuine wheel chocks. Cement blocks, blocks of wood, or other home-made stop mechanisms are not adequate substitutes.
To block, use sound lumber and nails to block each cargo item separately and on all four sides. Use nails or spikes long enough to secure the lumber and drive them in at opposing angles. Never place your hands or fingers between the equipment and blocks. Never use other cargo for blocking— this will not restrict movement in the same way that a block can, and may cause your cargo to overturn.
Final Word
Don’t let yourself be caught in the embarrassing (and sometimes fatal) predicament of having to run from a rollaway vehicle. Always chock and block and keep your loads secure.