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Safety alert issued after mobile crane fatality

The following article is a news item provided for the benefit of the Workplace Health and Safety profession. Its content does not necessarily reflect the views of the Australian Institute of Health & Safety.
Date: 
Monday, 1 November, 2021 - 12:00
Category: 
Policy & legislation
Location: 
Queensland

Workplace Health and Safety Queensland recently issued a safety alert following an incident in which a worker died after being struck by a mobile crane in pick-and-carry mode (lift and shift).

Early investigations indicate the man was acting as a dogger and in control of a load when he was holding a tag (tether) line attached to the load that was being relocated at a workplace.

It appears the worker was walking between the front of the mobile crane and the load when he was hit by the crane.

The alert noted that being positioned between the load and a moving mobile crane is very hazardous. If the crane operator’s view is temporarily obscured, or the operator is momentarily distracted or the worker stumbles, the risk of that person being run over is high.

In Queensland, the alert said there have been a worrying number of mobile crane incidents involving crane rollovers, people being struck, structural failures and loads falling.

Many of these incidents have occurred due to poor planning of the lifting operation, often because basic factors have been overlooked.

The use of a mobile crane can be hazardous, particularly as the complexity of the lift increases. If the work is high-risk construction work (as defined in the Work Health and Safety Regulation 2011), work method statements need to be prepared for the mobile crane operations and are important for pre-planning to help reduce the risk of an incident.

The alert said using a mobile crane on any worksite introduces the risk of collisions if sufficient clearances or exclusion zones are not maintained around the crane and load.

Collisions can occur when the mobile crane (including placing of the load) is being operated close to other plant, overhead powerlines, buildings, and workers on-site, including members of the crane crew.

Often when a mobile crane hits a person serious or fatal injury occurs. The risk to people increases when the operator’s visibility is impaired due to travel direction, or size and shape of the plant and load.

In relation to doggers walking with a pick-and-carry mobile crane, the alert recommended:

  • Initially see if the tag line(s) can be tied to the front of the crane to eliminate the need for the dogger to hold the end of the tag line.
  • The dogger should never be in the travel path of the crane.
  • The crane operator should stop the crane if he or she loses sight of the dogger.

The alert said planning for mobile crane operations should start as early as possible, and this involves:

  • consultation with people engaged in the work, such as the zprincipal contractor or crane hirer, crane supplier, engineer and crane operator
  • ensuring the type and number of mobile cranes selected suit the particulars of the lift
  • determining the size of the crane crew by undertaking a risk assessment and implement appropriate controls, especially in relation to minimising the risk of collision between the crane and other plant, and loads contacting other structures, overhead powerlines or workers
  • not siting a mobile crane until carefully considering if it:
    • has adequate capacity to lift the load at the maximum radius
    • could collide with other plant and structures at the workplace
  • using a reliable method of signalling between the crane operator and dogger
  • using documented lifting procedures to help to define responsibilities and approach the crane lift in a logical, systematic way. Safe work method statements must be prepared for a range of high-risk construction work associated with cranes
  • implementing effective exclusion zones around mobile cranes and adjoining areas to prevent people from entering the area. The size of the exclusion zone should be based on a written risk assessment. If the exclusion zone requires the closure of a public footpath or roadway, approval must be obtained from the relevant authority.

There are also a number of precautions to take with pick and carry cranes:

  • When moving a load in the pick-and-carry mode, the dogger should remain in sight of the crane operator, and not walk in the path of the crane.
  • Always travel slowly to prevent excessive swinging of the load. The load should be carried as close to the ground as possible, and should not lift higher until it is almost in position.
  • Where possible, avoid travelling the mobile crane across slopes or over potholes, depressions, soft ground, road chambers or shoulders, rail tracks, dunnage wood or any objects, as these could destabilise the crane or load.

For crane operators, the alert said they must:

  • have a comprehensive knowledge of the operating capabilities of the crane
  • be competent to carry out the lifting operation
  • ensure it is driven to suit the environmental conditions and slow enough to retain control in unexpected circumstances
  • reduce speed before turning or applying brakes
  • watch out for ditches, embankments, ground depressions as overturns can occur
  • ensure loads are evenly balanced and well secured.
  • thoroughly check safety devices and audible working alarms of mobile plant prior to commencing any work
  • hold the appropriate high-risk work licence for the type of crane being operated, and completed refresher training as required
  • know any workplace conditions that may affect crane operation, including ground conditions, the presence of overhead powerlines, nearby structures, cranes and concrete placement booms.

“The primary role of a dogger is to assist the crane operator in the safe and efficient operation of the crane, including the safe slinging of the load. The dogger’s role is crucial when the crane operator’s vision is obscured, or when operating in high-risk areas,” the alert said.

“A dogger should be positioned to safely observe the entire lifting operation with which they are assisting. However, a dogger must not be used to also perform the role of a ‘spotter’ when the crane is operating close to overhead powerlines.”