If an incident occurs during a confined space entry and an entrant is not able to escape, retrieval from outside the space must be done. In this case, the attendant should call for help before operating any retrieval device.
If external retrieval will be used in an emergency situation, the entrant must wear a full body harness. Wristlets are acceptable under very specific situations, but should be used as a last result. The best and safest option is to use a combination of both wristlets and full harness. Because wristlets allow for retrieval by hands-first, it is an effective method to use when the space opening is narrow.
Retrieval devices
There are two main types of mechanical retrieval devices. One is a mounted tripod or davit arm that uses a cable mechanism to lift an entrant. This system requires low maintenance and is relatively easy for an attendant to use. The cable system is appropriate if flexibility is not required. The other retrieval device allows for flexibility, using a rope instead of cable. Disadvantages of the rope system include the increased maintenance and a higher level of difficulty to operate.
Lifelines and other devices
Lifelines with self-retracting features are appropriate if retrieval can be accomplished using a ladder or other similar devices. These lines help protect an entrant from falling. However, not all types of lifelines are appropriate for confined space entry because some have no capabilities for retrieval.
If an entrant needs to be lowered into a space, a cable winch may be used. Manufacturers provide accessories such as tripods to complete this entry and retrieval system. A portable davit arm is also an excellent piece of equipment to use for retrieval; however, if the space is entered frequently, a fixed davit arm is more effective.
Other devices are available for specific confined space configurations. Horizontal entries often use column extraction systems. Forklift davit arms can be very useful in locations that are difficult to reach and field operations may require a vehicle hitch mount davit arm.
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