When might you need to disable a portion of the outriggers or use partial outriggers, and what are hazards?

• A. On uneven or restricted sites; risk includes reduced stability and increased tipping tendency; always verify remaining stability and rating.
• B. On perfectly flat, stable ground.
• C. When the ground is perfectly dry.
• D. Only when performing maintenance on the crane.

Answer: (C)

Outriggers stabilize the crane, and you may need to disable a portion or use partial outriggers when the work area is tight or obstructed. On uneven or restricted sites, deploying the full outrigger footprint might be impossible or could interfere with nearby structures, roads, or equipment. In these cases you adjust by using fewer outriggers or retracting some, but you must know exactly how this changes the crane’s stability.

The main hazard is reduced stability: with a smaller base, the crane is more prone to tipping, especially if the load is lifted high, the ground bears unevenly, or wind loads are present. Because the supported capacity changes with the outrigger configuration, you have to reassess the remaining stability and the load rating for the chosen setup before lifting. Using partial outriggers also increases the risk of uneven ground bearing and slippage, so ground preparation, cribbing, and careful planning become even more important.

On perfectly flat, stable ground you wouldn’t normally use partial outriggers; you would typically deploy the full outrigger system to maximize stability. Dryness of the ground or maintenance-only scenarios don’t usually dictate using partial outriggers for lifting operations.