NCCCO Pick and Carry Operations 2 — Questions and Answers
Question 1: What must be consulted before performing a pick and carry operation with a mobile crane?
- Only the operator's experience and judgment are needed
- The crane manufacturer's load chart and operational instructions must be consulted to confirm that pick and carry is permitted for the specific crane model and to determine the load limits and travel requirements (Correct answer)
- Only the site safety officer's approval is required
- Pick and carry is always permitted for loads under 50% of crane capacity
Correct answer: The crane manufacturer's load chart and operational instructions must be consulted to confirm that pick and carry is permitted for the specific crane model and to determine the load limits and travel requirements
Not all cranes are rated for pick and carry. The manufacturer's documentation must confirm it is permitted, and specific load charts for traveling operations (which are lower than static lift charts) must be used.
Pick and carry (traveling with a load) is a specialized operation that creates dynamic loads from acceleration, deceleration, and travel surface conditions that do not occur in static lifts. Not all crane models permit traveling with a load — some are restricted to static lifting only. For cranes that permit pick and carry: the manufacturer's operational manual must confirm the operation is permitted, separate load charts (travel charts) apply and are typically lower than the static lift charts, boom position requirements during travel must be followed, and maximum travel speeds with a load are specified and must not be exceeded. ASME B30.5 requires compliance with manufacturer requirements for traveling with loads.
Question 2: What is the recommended boom position relative to the direction of travel when a lattice boom crane is traveling with a suspended load?
- The boom should be perpendicular (90 degrees) to the direction of travel for maximum stability
- The boom should be positioned in line with the direction of travel (pointing forward or backward) to minimize lateral bending on the boom structure (Correct answer)
- The boom angle should be lowered to 20 degrees for travel to reduce center of gravity height
- Boom position is irrelevant during pick and carry — only load weight matters
Correct answer: The boom should be positioned in line with the direction of travel (pointing forward or backward) to minimize lateral bending on the boom structure
For lattice boom cranes, the boom should be aligned with the direction of travel to ensure dynamic forces from travel go along the boom's longitudinal axis (which it is designed for) rather than creating lateral loads that could damage the boom.
A lattice boom crane's structural design is optimized for loads applied along its longitudinal axis (compression and tension in the chord members). When the crane travels with a load, acceleration, deceleration, and terrain-induced dynamic loads create horizontal forces at the load point. If the boom is perpendicular to the travel direction, these horizontal forces act as lateral (side) loads on the boom structure, which is its weakest direction. By aligning the boom with the direction of travel, the dynamic horizontal forces are applied along the boom's strong axis. Manufacturer instructions for pick and carry operations on lattice boom cranes typically specify boom position requirements. For hydraulic telescoping boom cranes, the specific position required is stated in the manufacturer's manual, which varies by model.
Question 3: What is the maximum recommended travel speed for a crane traveling with a suspended load?
- 25 mph on paved surfaces
- The speed must be limited to what is specified in the manufacturer's load chart for traveling operations, typically very slow (often under 2 mph) (Correct answer)
- Crane speed is only limited during wind events
- Normal driving speed is acceptable on paved job site roads
Correct answer: The speed must be limited to what is specified in the manufacturer's load chart for traveling operations, typically very slow (often under 2 mph)
Pick and carry operations must be performed at the speed specified by the crane manufacturer for traveling with loads — typically very slow speeds (under 2 mph for many cranes) to minimize dynamic forces.
The dynamic forces created during crane travel increase significantly with speed. Travel speed creates inertial forces from acceleration and deceleration, vibration from surface irregularities, and potential load swing. Most manufacturers limit pick and carry speed to 0.5 to 2 mph (walking speed), depending on the crane model, load weight, travel surface, and load attachment geometry. Exceeding travel speed limits creates excessive dynamic amplification of the load, risk of load swing, potential loss of crane stability from dynamic tip-over forces, and damage to the boom from lateral travel forces. Operators must observe load behavior during travel — if the load begins to swing, the crane must be stopped and the load stabilized before continuing.
Question 4: When traveling with a load on an unpaved surface, what ground condition concern is most critical?
- Surface dust that may obscure the operator's vision
- Soft spots, holes, ruts, or cross-slopes that can cause the crane to tilt or an outrigger to drop into a void, potentially causing upset (Correct answer)
- The surface must be asphalt or concrete for all pick and carry operations
- The color markings on the ground surface
Correct answer: Soft spots, holes, ruts, or cross-slopes that can cause the crane to tilt or an outrigger to drop into a void, potentially causing upset
Soft ground, holes, ruts, and slopes encountered during travel can dynamically tilt the crane or cause wheel or track to sink suddenly, changing the load moment unexpectedly and potentially causing crane overturn.
When a crane travels over uneven terrain with a suspended load, the ground surface becomes a dynamic variable. Soft spots cause one side to sink, tilting the crane and shifting the load's effective radius. A rut or hole can cause sudden tilting, creating dynamic overturning forces. Cross-slopes increase the effective load moment on the downhill side. The travel path must be walked and assessed before pick and carry operations. Soft spots must be filled, holes backfilled, and cross-slopes assessed against the crane's permissible operating slope limits from the manufacturer. The crane operator should have a dedicated spotter walking alongside and ahead of the crane during pick and carry to identify hazards.
Question 5: What is the role of a tag line during a pick and carry operation?
- Tag lines are not used during traveling — they create a tripping hazard
- Tag lines are held by ground personnel to control load swing, prevent the load from rotating, and guide the load around obstacles during travel (Correct answer)
- Tag lines are used to attach the load to the crane boom for stability
- Tag lines replace the need for an outrigger during pick and carry
Correct answer: Tag lines are held by ground personnel to control load swing, prevent the load from rotating, and guide the load around obstacles during travel
Tag lines held by ground workers allow them to control load movement during travel — preventing swinging, managing rotation, and guiding the load safely around site obstacles during pick and carry operations.
Tag lines are critical safety tools during pick and carry operations. As the crane travels, the suspended load can develop pendulum-like oscillations due to acceleration, deceleration, and terrain variations. Tag lines allow ground workers to: dampen and prevent load swing, control load rotation (loads tend to rotate when swinging), steer the load around site obstacles, columns, or pipe racks, and stop the load from contacting structures during tight maneuvers. Tag lines should be long enough that ground workers can maintain control without being positioned under the load, must be attended by trained personnel at all times, and must be released promptly if they become caught on an obstacle to prevent workers from being pulled off-balance.
Question 6: Before beginning a pick and carry operation, what is the primary inspection that should be performed on the travel path?
- Inspection of the path for other crane operations that may be in the area
- A walking survey of the entire travel path by a qualified person to identify soft spots, slopes, grade changes, overhead obstructions, underground hazards, and surface obstacles before the crane begins moving with the load (Correct answer)
- Only the starting point and ending point of travel need to be inspected
- The operator can inspect the path visually from the crane cab before beginning travel
Correct answer: A walking survey of the entire travel path by a qualified person to identify soft spots, slopes, grade changes, overhead obstructions, underground hazards, and surface obstacles before the crane begins moving with the load
The entire travel path must be physically walked and inspected — overhead clearances, surface conditions, slopes, and underground hazards must be identified and addressed before the crane moves with any load.
A pre-travel path inspection by a qualified person is mandatory before any pick and carry operation. The inspection must cover: overhead obstructions (power lines, beams, pipes, vegetation) and verify adequate clearance for the crane boom and load at all points along the path, surface conditions (soft spots, holes, ruts, loose material, drainage issues), slope and cross-slope to ensure they are within crane manufacturer's limits for traveling with a load, underground hazards (utility lines, vaults, culverts, or compacted fill that could fail under crawler or wheel loads), width constraints (enough room for the crane to travel with its full track or wheel width plus load swing zone), and destination area suitability. The results of this survey should be communicated to the operator and all involved personnel.
NCCCO Pick and Carry Operations 2
What must be consulted before performing a pick and carry operation with a mobile crane?