Occupational Skills and Safety
Occupational Skills and Safety checks that you can protect yourself, your coworkers, and the machine before any wrench turns. Questions cover WHMIS 2015 (GHS) labels and Safety Data Sheets, PPE selection, lockout/tagout, blocking and cribbing, confined-space entry, jacking and lifting, fire classes, and the agriculture-specific hazards of hydraulic injection, battery explosion, and stored mechanical energy.
Isolate energy and verify it
- Lockout/tagout follows a fixed sequence: shut down, isolate, lock and tag, release stored energy, then verify zero energy before touching the machine.
- Stored energy on farm equipment includes raised headers and implements, pressurized hydraulic oil, charged accumulators, compressed springs, and batteries.
- Never rely on a hydraulic cylinder to hold a load while you are underneath. Internal piston-seal leakage lets a raised frame drift down. Lower it to the ground, or fit the manufacturer's mechanical locks and cribbing rated for the load.
- Relieve pressure at the remote couplers before cracking a hydraulic line, and discharge accumulators as the service manual directs.
- Grain bins, slurry tanks, and hoppers are confined spaces. Entry needs a permit, a standby attendant, ventilation, and continuous monitoring. Typical acceptance limits are oxygen 19.5 to 23 percent, flammables under 10 percent of the lower explosive limit, hydrogen sulphide under 10 ppm, and carbon monoxide under 25 ppm.
Fire classes and PPE
Class A is ordinary combustible, B is flammable liquid, C is energized electrical, D is combustible metal, and K is cooking oil. ABC dry chemical suits a general shop; CO2 is preferred around electronics. PPE is the last line of defence: eye and face protection, hearing protection around engines and air tools, gloves matched to the task, and respiratory protection that is fit-tested.
Worked example
A field cultivator is held up on its hydraulics so you can replace a broken sweep. The engine is off and the key is in your pocket, which feels safe but is not sufficient. Correct sequence: lower the implement to the ground where possible; if it must stay raised, install mechanical locks or cribbing under the frame; shut down and lock out the battery disconnect; cycle the remote levers to bleed residual pressure; then work. The reasoning is that an engine-off cylinder is still a pressurized vessel, and a leaking seal or a bumped lever can drop the frame onto you.
Traps that cost marks
- Treating "key removed" as full lockout while hydraulic pressure and gravity remain stored.
- Choosing water for a Class B fuel fire, or a pressurized water extinguisher on energized electrical equipment.
- Assuming a ROPS protects you without the seatbelt; ROPS and seatbelt are a matched system, and a folded ROPS gives no rollover protection.
- Using a hand to search for a pinhole leak; use cardboard, because injected fluid at system pressure causes severe injury.