How it works
The parts of a crane on two kinds: a mobile crane on a truck, and a tower crane. Start with the 7 main parts, then each crane's own parts and the ones they share.
Read the full guide
Mobile crane
The boom rises from the upper, which swings on a turntable above the truck. The hoist drum winds the wire rope, which runs over sheaves at the boom tip down to the hook block. Outriggers steady it on the ground.
Tower crane
A tall mast stands on a concrete base. At the top, a turntable lets the jib swing round. A trolley runs along the jib to move the load in and out, and counterweights on the other side balance it.
- A mobile crane lifts on a boom that tilts; most tower cranes move the load along a level jib with a trolley.
Questions and answers
What is the arm of a crane called?
On a mobile crane it is the boom. On a tower crane the long arm across the top is the jib.
What is a counterweight on a crane?
Heavy weight on the far side from the load, which balances it so the crane does not tip.
What are outriggers on a crane?
Beams and legs that reach out from the carrier to pads on the ground, to steady the crane while it lifts.