Basic Principles of Cranes Practice Test

The main idea is stability through a solid base. Cribbing or matting under outriggers spreads the crane’s load over a larger area so the ground doesn’t fail under the feet. On soft or uneven ground, an outrigger can sink, tilt, or push the base into an unstable position, increasing the risk of tipping. By providing a firm, level surface, cribbing or mats reduce point loads and help the outriggers bear on ground that can support the crane’s weight, keeping the crane stable during lifting. This safety-focused function isn’t about speed, maintenance, or reach, which is why those options don’t fit.