Stability and Machine Capability
Stability and machine capability tests your judgement of load, slope, ground and attachment effects on tipping and traction.
Stability factors
- Centre of gravity rises with blade load, a raised attachment and uneven ground.
- Side slopes are more dangerous than straight up or down; keep the blade low and avoid turns on slopes.
- Ground bearing must support the machine; soft edges and stockpile crests can collapse.
Capability
- Work within manufacturer's slope and load limits; do not use a dozer as a crane.
- Push-loading and ripping increase reaction forces; match gear, blade load and track grip.
Worked example: A dozer is side-casting on a 1:4 cross-slope and the downhill track begins to sink. Reasoning: stop, lower the blade, then reverse carefully to firm ground. The combination of side slope and reduced bearing has narrowed the stability margin; continuing could cause a roll-over.
Traps: using speed to compensate for load, judging slope by eye, and ignoring the effect of a full blade or raised ripper.
Key points
- Keep blade low on slopes.
- Avoid side slopes and turns on gradients.
- Work within manufacturer's slope and load limits.
- Check ground bearing at edges and crests.
- Reduce load if stability is uncertain.