Derricks

A derrick is a hoisting machine with a mast or boom held by guy lines or stiff legs. Derricks are older than most cranes, but they are still used on construction sites, in marine yards and in industrial plants. They have special rules because of how they are supported.

• Construction
• Marine
• Industrial

Main types

• Guy derrick: a mast held upright by guy lines to the ground; the boom pivots at the foot.
• Stiff-leg derrick: supported by two rigid legs braced against the mast, so it can sit on a structure or base without guy lines.
• Gin pole: a simple pole raised to lift materials; it can be rigged to a structure.

Cranes and derricks in construction are covered by the same OSHA rule, Subpart CC, with additional sections for derricks (1926.1436). See Crane Basics.

Hazards

• Loss of guy line tension or a broken guy line, which can drop the mast.
• Overloading or lifting outside the load chart. See Load Charts.
• Wire rope failure and damaged sheaves. See Wire Rope.
• Power lines and wind. See Lift Wind Limits.
• Falling loads and swinging booms that strike people.

Key practices

• Have a qualified operator who knows the derrick's load chart and how it is rigged.
• Inspect before each shift: guy lines and anchors, mast, boom, hoist drums, sheaves, rope, brakes and clutches. See Crane Inspections.
• Maintain the guy line tension and angles required by the maker, and keep anchors secure.
• Rig loads with correct slings and keep them under control with tag lines.
• Use standard signals and a qualified signal person where the operator cannot see the load. See Crane Hand Signals.
• Stay outside the swing radius. Keep everyone clear of the load path.
• Stop work in high wind or lightning and secure the boom.

Last updated: October 8, 2026