Which device is a Category 1 operator aid for luffing jibs?

• A. Boom hoist limiting device
• B. Luffing jib limiting device
• C. Anti-two-block device
• D. Outrigger position monitor

Answer: (B)

In crane operation, Category 1 operator aids are basic devices that help the operator stay within safe limits for a specific function without taking control away. For luffing jibs, the main safety concern is keeping the jib within its allowable angle and range. A luffing jib limiting device provides a defined limit on how far the jib can be raised or lowered, and can warn or intervene when that limit is reached. This directly supports safe luffing jib operation as an aid to the operator, making it the best fit for a Category 1 device in this context.

The other options address different hazards or functions: a boom hoist limiting device controls the hoisting action of the main boom, not the luffing motion; an anti-two-block device prevents the hoist rope from stacking and causing a two-block situation; and an outrigger position monitor focuses on stability rather than restricting or guiding luffing jib movement.