The minimum stability value of 75% applies to which crane type?

• A. Crawler cranes
• B. Boom trucks
• C. Tower cranes
• D. All crane types

Answer: (A)

In crane practice, the safety margin for stability is built into the load chart as a percentage of the crane’s rated capacity. This percentage represents how much of the rated capacity you can use while still keeping the crane within a stable, non-tipping envelope under typical conditions. Different crane types have different stability allowances because their bases, ballast, geometry, and ground interaction vary.

The minimum stability value of 75% is the standard applied to crawler cranes. This means their practical lifting limit, in standard configurations, is defined with a 75% stability consideration in mind, reflecting their broad, low-profile footprint and track-based stability. Other crane types—like tower cranes or boom trucks—follow different stability criteria and thresholds based on their distinct designs and support systems.

So, the 75% minimum stability value specifically applies to crawler cranes.