What is the minimum stability for a crane on outriggers?

• A. 75%
• B. 85%
• C. 90%
• D. 95%

Answer: (B)

Stability is about how much load you can lift without the crane tipping when it’s supported by outriggers. With outriggers properly deployed, the crane gains a safety margin to resist tipping, and the standard minimum stability used for planning is 85% of the crane’s rated capacity in that configuration. This 85% gives a practical buffer for real-world factors like load distribution on the hook, wind, dynamic forces during slewing, and ground conditions. It means you should not plan lifts that require more than 85% of the rated capacity when outriggers are down; you can lift less with confidence, and for higher loads you’d re-check stability with the chart, counterweights, and ground setup. The other percentages would either reduce the safety margin too much or set an unnecessarily higher threshold, which isn’t the typical minimum for outrigged operation.