Length: 14 Min.
Basic Rigging Concepts
Working within the oil and gas exploration and producing industries requires a commitment to safe work practices due to the volatile forces that employees face on a daily basis; high pressures, extreme temperatures, the fury of the oceans, and complex equipment on the cutting edge of technology! The complexity of the varied multitude of procedures undertaken by these dedicated men and women, often working in harsh and remote environments, leaves little margin for error.
The nature of the energy industry requires moving equipment, tools, supplies, and even personnel to and from isolated locations. Usually there are no roads leading to a loading dock where you work.
A great deal of this responsibility lies with the crane operator and the assisting riggers. It is their job to safely and efficiently utilize the lifting machinery and rigging gear available to them in order to support all ongoing operations. Cranes, rigging, and the personnel who harness and control their power are some of the most essential players on the energy exploration and production team.
Questions to Insure Safe Rigging Operations
Who are the competent persons responsible for rigging the load and establishing lines of communication?
* Are the rigging gear and crane components in acceptable condition, suitable for lifting and properly identified?
* Are the working load limits adequate, taking into account the following conditions:
• weight of the load?
• sling angle?
• capacity of the gear?
• need for padding slings against sharp corners?
* Will the load be under control?
• Is the hitch appropriate?
• Is the load rigged to the center of gravity?
• Is a tag line available?
• Is there any possibility of fouling or snag- ging of the load on nearby obstructions?
• Will the suspended load be clear of all personnel?
* Do any unusual side loading or environmen- tal conditions such as excessive wind, waves or temperature exist?
* And are there special requirements imposed by the customer or local regulations?
Before Starting A Lift
Before starting a lift the following conditions must be verified so that the load is free to be lifted from the deck or ground.
* If a slack rope condition exists, check that the wire rope is properly seated on the drum and in the sheaves. No fewer than 5 full wraps of rope should remain on the drum in any operating condition.
* Position the hook directly over the load in such a manner as to minimize swinging upon lifting. No external forces should be applied to loads which will create side loading of the boom. Cranes are not to be used for dragging loads!
* Care should be taken when swinging the crane in order to minimize the pendulum action of the hook and suspended load.
* Select appropriate slings and hardware checking their rated capacity and making sure they are sufficient for the weight of the load to be lifted.
* The hoist rope is never to be wrapped around the load. The load must always be attached to the hook by means of slings or other suitable devices.
* Be sure to untangle any multiple part lines that would not separate upon application of the load.
* Attach a tag line to control the swing of the load.
* Make certain that the load is secured and properly balanced in the sling or lifting device before it is lifted. If the load shifts, set it back down and adjust the rigging.
* Always check that the lift and swing paths are clear of obstructions and personnel. The Operator should avoid moving loads over personnel.
* The operator will not hoist, lower or swing while any personnel are on the load or hook. A certified Personnel Basket or carrier is required for transporting personnel.
* The hook latch must be closed to secure loose slings. All hooks used for support of personnel must be of the type that can be closed and locked including a safety latch with a redundant locking method.
* When making personnel lifts, the load must be under control in both the up and down directions. No Free Fall. All personnel to be lifted will use approved personal flotation devices and should stand on the outer rim facing inward.
* Loads which are suspended by use of slings or hoists should be blocked or cribbed before personnel are permitted to work beneath or between them.
When signals are required to control operations, a designated signal person will be assigned to work with the crane operator. Reliable radio communication protocols and the use of standard hand signals are encouraged.
Shown here is a hand signal chart published within the API offshore standard RP2D. These standardized signals are recommended for all crane operations regardless of location.