Due Diligence Requirements of Owning a Mobile Crane

Applied to occupational health and safety, due diligence means that that the employer/owner shall take all-reasonable precautions, under a particular set of circumstances, to prevent injuries or accidents in the workplace.

Due diligence is important as a legal defense for an employer/owner charged under occupational health and safety legislation. If charged, a defendant may be found not guilty if he or she can prove that due diligence was exercised. In other words, the defendant must be able to prove that all due precautions, reasonable under the circumstances, were taken to protect the health and safety of workers.

If you are the owner or lessee of a mobile crane how can you ensure due diligence?

To ensure due diligence you must:

• Have in place a written Occupational Health and Safety policy, practices and procedures. These would demonstrate that the employer carried out workplace safety audits, identified hazardous practices and conditions and made necessary changes to these conditions, and provided workers with information to enable them to work safely.

• Ensure that the crane is operated as hoisting devices only by a trained, experienced and competent operator who holds a certificate of qualification (license) issued by the appropriate regulatory authority.

• Ensure that a supervisor is a competent person as defined by the legislation.

• Understand and apply the requirements of the Regulations and current applicable standards.

• Maintain the crane in such a condition that it does not constitute a hazard. A preventative maintenance program based on the crane manufacturer’s recommendations shall be established. In addition, the crane shall be maintained as required by the Regulations and CSA Z150 (current edition).

• Have an accident investigation and reporting system in place. Employees must be encouraged to report “near misses” and these should be investigated. Incorporating information from these investigations into revised, improved policies and procedures will also establish the practice of due diligence.

• Document all of the above in writing. A crane logbook must be kept updated of all inspections, repairs and modifications to a crane.

Modern cranes are complicated machines equipped with a rated capacity limiter (RCL) or a rated capacity indicator (RCI). This equipment helps prevent overloading of a machine past the recommended load set by the manufacturer for the crane for a particular crane set-up.

These systems, however, must be maintained to remain operative and accurate.

A crane is usually subjected to a variety of stresses and strains. The structural components, welds, bolts, pins, wire rope, cylinders etc., must be regularly inspected by qualified personnel to ensure their integrity. During annual inspection, non-destructive testing techniques such as Magnetic Particle Inspection and Ultrasonic Inspection may also be applied to identify both safety and maintenance issues that arise during normal and abnormal operating conditions. Below is an example of indications that arise during Ultrasonic Inspection.

Figure 1 – Schematic of the crane subsection and stud cross section

Figure 2 – Graphic representation showing stud locations; darkened areas show where shearing occurred.

Figure 3 – This drawing shows the crane boom and base in relation to the source of the side impact loading.

The CSA Z150-98 (currently under review) requires that a complete inspection, at least annually, be carried out by a competent person and supervised by a professional engineer competent in the inspection of cranes.

Visual inspection of the welds must be performed and documented to the CSA W59 standard by a qualified person to the requirements of CSA W178.2.

Critical, suspect areas and other inconsistencies identified by the manufacturer, the supervising professional engineer, the competent person, or the qualified visual inspector, must be further examined by a person(s) qualified to meet the requirements of CGSB Standard CAN/CGSB 48.9712.

In addition to the annual inspection, the standard requires the teardown inspection and re-lubrication of the swivel hooknut at least every five years.

A complete structural inspection of a telescopic boom is also required at any time the boom is disassembled or at a minimum once every 10 years or 10,000 hours of service whichever comes first. The interior welds of a telescopic boom will then be tested non-destructively by a licensed professional.

As Ministry of Labour Engineering Consultant, currently President of HITE Engineering Corporation, I have investigated and provided litigation support on a large number of crane accidents.

The causes of these accidents can be summarized thus:

• Poor maintenance.

• Failure of wire ropes cause by snagging, overloading or poor maintenance and inspection procedures.

• Overloading causing overturning or structural failure.

• The failure of a poorly designed part by the crane manufacturer.

• Poor soil conditions and settlement of outrigger pads causing instability.

• Inoperative or deliberately disengaged load moment indicating systems.

• Repairs made using parts and hardware other than what is specified by the manufacturer.

• Operator error.

• Lack of lift planning or the absence of a signaler.

• Operating a crane near energized overhead electrical conductors.

— Ralph Balbaa M.Eng., P.Eng., is a health and safety expert with more than 40 years of engineering experience and a former Ministry of Labour consultant. He is the President of HITE Engineering, a Mississauga-based consulting firm specializing in industrial and construction safety.