Modified Tower Crane with an Expired Expert Examination
At a precast concrete plant, a 16 t tower crane is due to lift formwork for a weekend pour. The crane’s last expert examination was four years ago; the operator relies on the manufacturer’s certificate of conformity and an annual inspection by the plant mechanic. Six months ago a local welder shortened the jib by 1.2 m and added 300 kg of counterweight to increase capacity at a tight radius. The load chart still shows the original configuration. The mechanic signed a permit because the crane “looks stable” and the hook has a valid test tag. The state inspector arrives for a scheduled audit and sees the crane lifting within an hour. The site manager says stopping the crane will breach the client’s deadline.
1. May the crane continue operating? Give the reasoning, not just a yes/no.
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No. The crane is a lifting structure used at a hazardous production facility, so it is subject to industrial safety rules for technical devices. A manufacturer’s certificate of conformity proves that the crane met the design standard when supplied; it does not replace the required expert examination and periodic technical examination in service. An annual inspection by the plant mechanic is also not a substitute for the statutory examination.
The modification is decisive. Shortening the jib and adding counterweight changes the load moment and stability of the crane. That is not routine maintenance; it is a reconstruction/alteration that invalidates the original load chart and requires a new industrial safety expert review before use. The existing load chart no longer describes the crane. Continuing to lift formwork would be an uncontrolled lifting operation. The client deadline is not a legal justification. The crane should be stopped, the load lowered and the crane isolated until the alteration is reviewed and the crane is re-examined.
2. What immediate actions and documentation should the inspector require?
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The inspector should require immediate suspension of the crane and any lifting operation under the invalid permit. The crane should be lowered, the load removed, the power isolated and the control cabin or remote control locked out/tagged. The inspector should secure the modified load chart, the mechanic’s permit, the manufacturer’s certificate and the last expert examination report as evidence.
Next, the operator must obtain an industrial safety expert review of the alteration, restore the crane to a documented configuration or have the modification approved by the designer/manufacturer, issue a corrected load chart, and complete the required technical examination before returning the crane to service. The mechanic’s competence and the permit-to-work process should be reviewed. The inspector should also assess administrative liability for operating a lifting structure after alteration without expert review and for allowing an unqualified/unauthorised modification. A written rectification plan should be required, and the crane should not be released just because the hook test tag is valid.
3. Who bears responsibility: the plant mechanic, the site manager, or the legal entity?
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Responsibility is layered. The plant mechanic signed a permit without the legal basis to do so and failed to recognise that the alteration invalidated the load chart; that is an individual disciplinary and possibly administrative matter. The site manager pressured operations and allowed the crane to be used despite the expired expert examination; management responsibility attaches there too. But the legal entity, as the operator of the hazardous production facility, bears the primary duty to ensure that technical devices are examined, that alterations are controlled, and that permits are issued only by authorised persons.
The fact that a mechanic “signed” does not shift the duty away from the employer. The employer must have a documented procedure for lifting structures, a register of technical devices, valid examination dates, change control for modifications, and competent lifting supervisors. The inspector should therefore address the systemic failure, not only the individual signature.