Crane Types & Operational Limits Flashcards

Which crane type uses a horizontal boom that can rotate 360 degrees and is mounted on a wheeled carrier?

Answer: Mobile hydraulic crane

A mobile hydraulic crane is mounted on a wheeled carrier with a boom that can rotate 360 degrees, allowing repositioning without dismantling.

What document specifies the maximum load a crane can lift at various radii and boom angles?

Answer: Crane load chart

The crane load chart (also called a capacity chart) specifies the maximum allowable load at each combination of radius, boom length, and configuration.

A crawler crane differs from a mobile crane primarily because it:

Answer: Travels on tracks instead of rubber tires

Crawler cranes travel on steel tracks (crawlers), which distribute load over a larger footprint and allow movement while under load.

When operating a crane near its maximum rated capacity, the operator should primarily consult:

Answer: The load chart for the exact boom length and radius

The load chart provides the exact rated capacity for the current boom length, radius, and crane configuration, which must be followed to prevent overloading.

What is the primary purpose of outriggers on a mobile crane?

Answer: To stabilize the crane and increase its lifting capacity

Outriggers extend from the crane's lower works to provide a wider, more stable base, which increases tipping resistance and allows higher lifting capacities.

Which of the following crane configurations typically has the highest rated lift capacity for a given boom length?

Answer: Shorter boom length with full outriggers extended and maximum counterweight

A shorter boom with full outriggers deployed and maximum counterweight installed provides the most stable configuration, yielding the highest rated capacity.

A tower crane's maximum load capacity is typically reduced when the load is lifted at:

Answer: A longer radius farther from the mast

As the load radius (horizontal distance from the mast) increases on a tower crane, the rated capacity decreases because the bending moment on the jib increases.