Rigging: General Information on What Riggers Need to Know.
Rigging is a critical part of shipyard employment. Riggers prepare ships’ equipment, components or sections for lifting by cranes, hoists or other material handling equipment. Riggers also act as signalman. Worker safety is of utmost concern when performing rigging tasks.
Improper rigging of a load or a rigging failure can expose riggers and other workers nearby to a variety of potential hazards. Riggers have been injured or killed when loads have slipped from the rigging, or when the rigging has failed. Therefore all loads must be safely rigged, including adequate welds on pad eyes (page C-8) prior to a lift.
The following are topics that should be discussed with workers prior to beginning rigging operations:
- Hazards associated with rigging operations.
- Role and responsibility of each rigger’s assigned task.
- Establishing a goal for the day.
- Weight of material and equipment being hoisted.
- Identifying the various shapes on the surface of equipment being hoisted.
- Lifting limitations of gear and hoisting devices.
- Communication used by all personnel.
- Disconnecting techniques used to complete the task.
Sharing the safe work practices and information in this guidesheet will help keep workers safe.
Preventing damage to lifting gear, lifting equipment, vessel components and other loads is also critical.
Riggers must be:
- Trained to understand and recognize the hazards associated with the assigned task.
- Qualified to do assigned work and comply with proper procedures.
- Aware of the surface conditions upon which a crane is operating.
□ The surface should be level within 1% grade and firm enough to support the crane and load.
□ Examine where the load will be set. Remove unnecessary blocks, equipment or other materials that can injure workers if struck by the load.
- Familiar with the various and correct rigging techniques and rigging equipment (e.g., slings, shackles, hooks, hoist, blocks).
- Able to anticipate problems before they occur.
□ Stop the job when any potentially unsafe conditions are present.
- Aware of the weight of the load and understand the rated capacities of the crane and any rigging gear (1915.111(b)).
- All rigging gear and equipment provided by the employer must be inspected before each shift and at intervals during its use to minimize the possibility of a rigging failure (1915.111(a)).
- Overloading the crane and rigging gear may cause:
□ The crane hoist line to part or the rigging gear to fail.
□ The crane to tip over.
□ Damage to and possible failure of the crane.
- Defective gear and equipment must be immediately removed from service (1915.111(a)).
□ Check nylon slings for cuts or frayed areas.
□ Manila rope slings should be checked to determine that they are safe for the intended working loads (1915.112(a)(1)).
□ Check wire rope slings for kinks or broken wires or strands.
□ Check chain slings for stretched links (1915.112(c)(2)).
□ Check hooks to make sure they are not bent from overloading.
□ Check that the crane hook safety latch automatically retracts to the closed position upon release.
□ Bent or sprung hooks must not be used (1915.113(b)(3)).
□ See http://www.osha.gov/dsg/guidance/slings/nat-synth-fiber.html
Slings or Ropes:
- Slings must not be used over sharp corners without padding (1915.116(f)).
- Slings must not be covered with permanent padding that would prevent them from being inspected before each use.
- Use softeners, padding, chaffing gear or other sling protection as necessary to prevent damage to nylon slings.
- Kinked or knotted wire rope slings should be removed from service (1915.111). Wire rope shall not be secured by knots (1915.112(b)(4)).
- Avoid lifts near stacked material that may be knocked over by a swinging load (1915.116(k)).
- Always check for overhead power lines before lifting a load.
- Before loads or empty lifting gear are raised, lowered, or swung, advance warning must be given to workers operating in the vicinity (1915.116(p)).
- Use a designated spotter to assure that proper clearances are maintained.
- A worker or signalman who is familiar with signal codes must communicate with the crane operator (1915.116(l)).
- When walking with a load, keep it as close to the ground as possible.
□ Inspect the spot where the load is to be landed.
□ When lowering or setting a load, set it down slowly.
- Tag lines must be provided on loads likely to swing or need guidance (1915.116(d)).
□ Do not use tag lines to control lift when the lift is under or near electrical power lines.
- Riggers must not place themselves in a hazardous position between a swinging load and a fixed object (1915.116(q)).
- Workers are not to work under the load.
- Workers must not ride a load or hook (1915.116(i)).
- Riggers should keep fingers, hands and feet away from pinch points.
- Pad eyes should be designed for a specific use.
- Each pad eye should be able to hold the intended weight/force that will be applied to it after it is welded into place.
- Inspect pad eyes for cracks and other defects that will affect its capacity.
- Remove defective pad eyes from the work area.
- All pad eyes should be welded solidly all around. Weld the middle of the pad eye on both sides first, then weld both ends.
- Inspect fitting tools and equipment such as come-alongs, chain falls, turnbuckles, chains and hook ratchets that will be used with pad eyes.
- Make sure that the hooks from the come-alongs and chain falls are seated properly in the eye of the pad eye.
- Do not overstress the fitting tools – use up to 80% of their capacity.
- When applying pressure with fitting tools or equipment to pad eyes, make sure that everyone is well out of the danger zone in the event that the pad eye tears off the surface it was welded to.
Source: Indera Sadikin