Personnel lifting in a man basket during a shutdown
During a refinery shutdown, a maintenance planner asks you to lift two fitters in a man basket to a height of 9 m so they can replace a valve on a pipe rack. The basket and its rigging weigh 220 kg; the two fitters and their tools weigh 210 kg. The crane is a 100 t slewing mobile crane, and at the required 10 m radius the chart gives a rated capacity of 12.5 t. The crane is not fitted with a rated capacity limiter override for personnel lifting, and the man basket is a general-purpose cage that has no manufacturer's data plate. The wind is 25 km/h gusting to 35 km/h. The area below the work is a live process unit with hot pipework.
1. Determine whether this personnel lift is permitted and identify the deficiencies.
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The lift is not permitted as described. Several deficiencies are decisive.
First, personnel lifting by crane is a high-risk activity that requires a documented lift plan, a crane and basket designed or approved for the purpose, and a competent operator and rigger briefed on the specific hazards. A general-purpose cage without a data plate cannot be shown to meet the design and testing requirements, so it must not be used.
Second, the crane must be configured for personnel lifting. That typically means a rated capacity limiter set appropriately, a controlled lowering system, and a free-fall lockout. The absence of the required limiter configuration is a stop point.
Third, the wind. At 25 km/h gusting to 35 km/h, the basket and its occupants will be buffeted, and the crane's chart does not account for the sail area of a basket with two people. Personnel lifts are normally suspended above a much lower wind threshold.
Fourth, the area below is a live process unit with hot pipework. There is no safe drop zone and no means of rescue if the basket becomes stuck or a person is injured at height. A rescue plan is mandatory.
The capacity margin (430 kg against 12.5 t) is comfortable, but capacity is not the limiting factor here.
2. What would need to change before a personnel lift could be considered, and what emergency arrangements are required?
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The lift would need a purpose-built man basket with a data plate, rated for the number of occupants and the tools, and inspected and tested within its required interval. The crane would need to be configured for personnel lifting per the manufacturer, including the correct rated capacity limiter settings, and the operator would need to be assessed as competent for personnel lifts.
A written lift plan would be required, covering the radius, the load, the wind limit, the travel path and the landing point. The wind limit would be set by the basket manufacturer and the crane manufacturer, and the lift would be suspended if gusts approached it. The area below would need to be cleared and barricaded, and the work relocated if the live process unit cannot be isolated.
Emergency arrangements: a rescue plan for retrieving an injured or unconscious person from the basket, including a secondary means of lowering; a means of communication between the occupants, the operator and the supervisor at all times; first aid provision at the landing point; and a defined procedure for lowering the basket if the crane loses power or a hydraulic fault occurs. The occupants would need harnesses anchored to the basket, not to the crane hook. None of these can be improvised on the day.