Tower crane safety

Technical information for tower crane owners and operators that includes two safety alerts with links to the relevant codes of practice, guides and Australian standards.

Risks associated with fires on tower cranes - safety alert

The purpose of this alert is to advise officers and workers of businesses (or other PCBUs) of the potential risks from fires on tower cranes, following the catastrophic incident in Sydney in 2012.

A number of potential contributing factors have been identified, and given the serious consequences, this safety alert is being released to provide advice on inspections and possible modifications to control the risks.

Although the incident involved a diesel/hydraulic tower crane it is possible for a fire on electric tower cranes, so the following information should also be considered by those with electric tower cranes.

BACKGROUND

During a fire on the machine deck of a diesel/hydraulic powered luffing tower crane, the luff rope failed, allowing the jib to collapse onto the worksite below. Fortunately there were no injuries as the worksite had been evacuated and the jib fell into the evacuated worksite, rather than into a populated area.

The incident appears to have resulted from the fire heating the luff rope and weakening it to the point where it could no longer support the jib and consequently failed. The fire could have been fuelled by the diesel fuel or the hydraulic fluid used to power the crane motions, however at this stage the ignition source has not been identified.

CONTRIBUTING FACTORS

There are a number of potential contributing factors on the machine deck to the fire starting and then continuing for sufficient time to damage the rope.

ACTION REQUIRED

PCBUs that use plant must ensure risks to the health and safety of workers and others due to the plant is minimised as far as reasonably practicable.

As well as the general obligations to provide and maintain plant, it is expected that PCBUs with tower cranes undertake the following applicable actions, if they have not already done so since the incident:

This incident also acts as a reminder to principal contractors of the importance of a site evacuation plan and communication systems to effect the evacuation. Principal contractors are advised to review, and if necessary update, their site evacuation plans and communication systems in light of this example of a structural collapse. They are reminded that the WHS Regulation requires the emergency procedures to be tested.

FURTHER INFORMATION

Originally issued by the Industry Plant Consultative Committee in December 2012.

Acknowledgements

Industry plant consultative committee comprising WorkCover, the Master Builders Association of NSW and the Construction, Forestry, Mining and Energy Union.

Catalogue No.WC03947 © Copyright WorkCover NSW 0315

Risk of falls from tower cranes - safety alert

This alert provides guidance to designers, manufacturers, suppliers, installers, operators, and persons with control of sites on how to minimise the risk of falls when using tower cranes.

Background

Persons who access areas of a tower crane may be exposed to the risk of a fall resulting in serious injury or death. Crane personnel have fallen from the machine deck, and also from the access system within the tower.

Contributing factors

Falls can occur over unguarded edges, through open penetrations and from ladders. The likelihood of falls occurring is substantially influenced by the design of the access system.

Recent inspections of tower cranes indicate that fall protection, particularly the design of access systems, can be improved. These improvements may apply to both older and newer model cranes, from various manufacturers and suppliers.

Action required

Tower cranes must have sufficient access to all work areas of the crane, including control stations and all parts requiring regular inspection or maintenance.

Risk management is usually most effective at the design stage. Designers and manufacturers of new tower cranes or components must ensure access is designed to minimise risk of falls, including by:

Where risk of falls cannot be sufficiently minimised by design, information on the remaining risk and alternate controls must be passed down the supply chain, for example fall arrest equipment used during crane erection.

Persons who supply tower cranes to site must ensure access sufficiently minimises risk of falls, so far as reasonably practicable. This includes:

Issues identified on out of service cranes are likely to be present on similar models currently in service. Whilst it may be reasonably practicable to wait until a crane is dismantled before making the modifications, interim measures to minimise falls may need to be developed for the duration of any current installation.

Persons who install, erect and commission tower cranes also have a responsibility for minimising risk of falls from tower cranes, including by:

Persons who service, maintain, operate or have control of site with tower cranes can also minimise risk of falls from tower cranes by:

Persons should not, however, make alterations to tower cranes without permission from a suitably qualified person, such as the designer or manufacturer.

Further information

The Work Health and Safety (WHS) Act requires persons conducting a business or undertaking to ensure, so far as is reasonably practicable, that workers and other persons at a workplace are not exposed to risks arising from the business or undertaking, including the risk of falls. Refer sections 19 to 24 of the WHS Act.

Part 4.4 of the WHS Regulation place specific obligations on duty holders to identify reasonably foreseeable risk of falls, and then manage accordingly.

Also, refer to:

The Master Builders Association of NSW and the Construction Forestry Mining Energy Union NSW have more information.

Acknowledgements

Industry plant consultative committee comprising WorkCover, the Master Builders Association of NSW and the Construction, Forestry, Mining and Energy Union.

Catalogue No.WC01450 © Copyright WorkCover NSW 0315

Expectations for tower cranes - position paper

The following are the SafeWork NSW expectations in relation to the matters raised by the Coroners in relation to the tower crane fire and collapse at Broadway in 2012 and the death of a crane operator at North Sydney in 2014.

Under the Work Health and Safety (WHS) legislation various entities have obligations in relation to tower cranes, including the crane owners, others with management or control of the crane, those maintaining the crane and those with onsite management of the crane (usually the Principal Contractor).

Fire control and warning

As there are a wide range of tower crane designs and power sources there is no one size fits all solution.  Whilst it is possible to minimise the risk of a fire on a tower crane it is not considered reasonably practicable to eliminate the possibility of a fire occurring, therefore the focus here is on minimising the risk by preventing a fire from reaching an intensity that could endanger the operator or result in catastrophic failure of the crane.

Cranes with a significant quantity of combustible fluids (diesel or hydraulic fluid)

There is potential for combustible fluids to leak on to an existing fire causing a longer, more intense fire which could cause mechanical or structural damage to the crane. 

These cranes should be fitted with a pre-plumbed, extinguisher system aimed at locations where the combustible fluids could pool and burn. Unless automatically activated, the control should be readily accessible to the crane operator.

The fitting of a fire warning system, eg a fire detection system or camera within the power pack with operator cabin display, should be considered.  Where a fire warning system is not fitted, you will need to record that consideration and determination in the crane documentation, eg how the existing engine monitoring systems etc already provide adequate early warning.

Cranes with no, or low quantities of, combustible fluids

Many electric cranes are considered to have insufficient quantities of combustible fluids to cause a fire of sufficient intensity and duration to warrant the above measures.

All tower cranes

Even tower cranes without an operator cabin have inspection or maintenance workers working at height and should have fire extinguishers fitted to allow evacuation in the event of a fire.

Maintenance

The provision of programmed maintenance is a task relying on coordination between the site and maintenance provider to enable the maintenance to be conducted on schedule and in a safe manner. Unfortunately, like many outdoor activities, maintenance may be disrupted by the weather and may need to be rescheduled at short notice.

The WHS legislation requires that where more than one entity has a duty in relation to the same matter they must, so far as is reasonably practicable, consult, co-operate and coordinate activities with the other duty holders. However, each entity retains responsibility for their duty even if they delegate the actual actions needed to discharge the duty to others.

The site controller, usually the principal contractor, needs to consult, co-operate and coordinate activities with the maintenance provider to minimise, so far as reasonably practicable, the risks to health and safety of the maintenance personnel caused by the site controller’s actions or inactions.  Issues to consider include:

Replacement and/or fitting of IROFSD suction and feed hoses

All IROFSD suction and feed hoses running from the hydraulic oil tank should be replaced with fire resistant, or better grade, hydraulic hoses.  The selection of replacement hoses should be made in consultation with a specialist hydraulic hose supplier or the crane manufacturer.

Where a crane is already erected on site, IROFSD hoses should be protected by a fire resistant cover, and the hose replaced as above before the crane is next erected.

The maintenance manual should be updated to list the new hose specifications, rather than the old IROFSD hoses, as the specification for future replacement hoses.

New cranes are to be supplied with fire resistant suction and feed hoses.

Safety of persons ascending/descending or working on the crane.

When crane operators or maintenance personnel are ascending/descending or working on the crane they are often alone and from the time they begin to climb the crane are engaged in remote or isolated work.  Therefore an effective communication system is required to manage the risk of them being unable to get help in an emergency.

For crane operators, this could be as simple as having a 2-way radio in the cabin and advising a specified person that they are about to ascend/descend and for that person to wait for advice of completion of the climb before attending to other duties.  If no such advice is received in a reasonable climbing time the specified person is to investigate and if necessary raise the alarm.

For maintenance workers, what is an effective communication system will depend on the circumstances, eg how many people are working on the crane, their locations, the tasks and weather. It may be carrying a 2-way radio or some other system.

Updating crane documentation

Any changes made to the crane, fire warning systems or systems of work regarding the crane should be updated in the relevant crane documentation.

Tower cranes critical faults

This document is intended to assist crane crews and those persons with management or control of operating tower cranes.

It contains a list of faults which, if identified by the operator during an inspection or crane operation, are considered to warrant the immediate make safe and shut down of the crane until clearance to resume operation is given by a competent person.

Depending on the fault this clearance may be based on a diagnosis from a competent person with the crane company that operation can continue as is, or may require a site inspection, or repair / part replacement.

Note, the list does not include:

List of critical faults

Tower and other structural members including boom

Slew

Hoist

Luff, where fitted

Trolley travel, where fitted (ie non luffing cranes)

Hydraulic system, where fitted

Controls, limiters and indicators (where fitted)

Fire extinguisher or extinguishing system

Acknowledgements

Industry plant consultative committee comprising WorkCover, the Master Builders Association of NSW and the Construction, Forestry, Mining and Energy Union.

Catalogue No.WC01715 © Copyright WorkCover NSW 0315

Tower crane considerations

This document provides a summary of high level information for consideration throughout the life cycle stages of a tower crane.

Design

Pre-erection inspection and testing

Erection and commissioning

Specific training

Ongoing inspection and maintenance

Site operational hazards

Dismantle and removal

Further information

Acknowledgements

Industry plant consultative committee comprising WorkCover, the Master Builders Association of NSW and the Construction, Forestry, Mining and Energy Union.

Catalogue No.WC01716 © Copyright WorkCover NSW 0315

Key messages on tower cranes

The following key messages to industry were identified by the investigation and subsequent verification project following the November 2012 crane fire at Broadway in Sydney. They are most relevant to tower crane manufacturers and suppliers, however may also help crane crews or persons with management or control of tower cranes to work with crane companies to address site issues.

Service (maintenance) intervals

Service intervals, as defined by the manufacturer should be followed.

The system used should include:

  1. identifying the manufacturer’s requirements
  2. scheduling and resourcing to ensure that the manufacturer’s requirements are met
    1. proactive processes to ensure that intervals are met include:
      1. manufacturer’s maintenance schedules
      2. receipt of logbook copies
      3. electronic back to base reporting systems
      4. incorporated into the build schedule of the principal contractor
    2. audits to confirm compliance with the service intervals and related service requirements
  3. reducing the service intervals where the root cause analysis, see below, identifies that the service intervals are inadequate, eg considering the life of components and the crane’s breakdown history.

Principal contractors (hirers) and crane companies (suppliers) have a joint legislated obligation to consult, cooperate and communicate in matters where they have joint responsibility, which would include ensuring this servicing occurs.

Documentation

Documentation and record keeping should be improved to better meet the needs of the various parties, eg:

  1. to advise the operator that an issue identified by the operator and entered into the logbook has been rectified, eg by noting in the logbook with a reference to the service docket number
  2. to enable to crane company to identify trends, by providing sufficient detail of the issue rectified, and stored in a way to facilitate review
  3. to enable the principal contractor to reschedule time in the construction program for the next service when a service was conducted along with a breakdown call out.
  4. to be systematic, referenced and assist with traceability (for example, a certificate of compliance with major inspection to reference relevant reports it relies on, or, erection sign off to reference accompanying documentation such as slew ring NDT report).

Operator’s logbook (crane checklists)

Operator’s Logbook systems are a part of ensuring safe crane use.

The logbook should:

  1. form part of the induction process for the operator
  2. be relevant for the specific crane
  3. be accurately completed by the operator, with site arrangements allowing adequate time for the inspection before commencing lifting each day
  4. have information from it supplied to the crane supply company, eg sending a copy of the daily inspection checklist page
  5. be a closed system with issues closed off (sign-off by mechanical servicing staff or by reference to specific servicing document)
  6. any issue not closed off must be raised with the operator
  7. be verified/audited as a part of the crane supplier’s systems
  8. be verified/audited as a part of the hirer’s systems.

Operator induction and assessment of competence

Operator induction and assessment of competence should be conducted by a person(s) competent in use of the crane and site procedures, and may include:

  1. a handover pack (daily, and more detailed inspection check lists)
  2. sighting of the operator’s tower crane high risk work licence
  3. practical induction on the features and controls on the crane, including supervised use by the operator
  4. information on processes for operator performed maintenance, if any, and procedures to arrange crane servicing, both routine and breakdown
  5. confirmation of logbook processes
  6. confirmation of delegations, ie to what level can an operator make decisions, for example can the operator make a call that a hydraulic leak is minor, or are they to contact and discuss with the crane company
  7. crane evacuation procedures for the site
  8. record induction, signed by provider(s) and the operator.

Where there is no-one on site familiar with the specific crane it would be expected that the crane company be involved in inducting the first operator.

The crane company should be advised when a new crane operator commences.

Crane supervisor

A person from the hiring entity (usually the principal contractor) should be nominated as the crane supervisor.

This person should:

  1. be the main contact between the crane company and the hirer, including reviewing and on-forwarding of the operator logbook information
  2. have an understanding of safe crane operation requirements, including site arrangements for servicing and recording of log book information
  3. coordinate the response to issues with the crane
  4. coordinate and receive sign-off for crane after-maintenance
  5. coordinate servicing times and breakdown maintenance, and
  6. have the authority to take the crane out of service, whether due to a fault, weather conditions or to allow for scheduled servicing.

Principal contractor responsibilities

Principal contractors have legal obligations as principal contractors and also as a PCBU with joint responsibility for the crane.

To comply with those obligations they should:

  1. incorporate maintenance into the build program, considering the need to allow for cool down time between operating and servicing, any curfew restrictions on the site and whether for safety the maintenance needs to be conducted during daylight hours
  2. provide site personnel and services required for health and safety of service crew, eg crane crew for crane operation, plus if out of normal site hours, builder’s hoist operator and security for access and maintain lighting for access and amenities
  3. ensure induction of crane operators in the crane supplier’s systems and associated sign-offs, site systems including reporting of crane information and crane evacuation procedures
  4. incorporate tower crane reviews into safety systems
  5. audit documentation
  6. have the operator provide confirmation against general safety audits (for example, provide photos of house-keeping, materials storage, flammable liquids storage, also provide daily/weekly/monthly checks)

Emergency planning / emergency response

Emergency planning for the site must include a response to issues with tower cranes. The plan should include:

  1. identification of risks (load fall, component loss, jib collapse, tower collapse)
  2. identification of construction zones and public zones potentially at risk
  3. evacuation plan for construction zones
  4. notification contact details for public zones for example, in the CBD, a consultative approach with near neighbours and respective fire warden may be required
  5. a system of putting emergency services in direct contact with specialist crane staff (crane supplier, crane engineers, etc), and
  6. when necessary, principal contractors should also liaise with emergency services regarding their emergency preparedness and plan.

Improving technology

There have been many advances in technology over the years that now provide reasonably practicable means to control risks better than when many of the tower cranes were manufactured. Improvements in technology should be considered for retrofitting in older cranes. Some are now considered mandatory in new cranes.

These advances include the features specified in Australian Standard AS1418.4 and the following:

  1. data logging systems to better understand the crane usage, utilisation and load spectrum, and therefore remaining life of structural and mechanical components
  2. remote monitoring to assist with identification of unsafe operation, defect identification and more direct planning of servicing. Available for real time monitoring, delayed reporting or instant messaging of alarm situations
  3. anti-collision systems, although not fool proof, provide assistance when more than one crane is sharing the same airspace
  4. anemometers for better information on wind conditions.

Root cause analysis

Crane companies should have systems in place to review similar and reoccurring faults.  Crane companies should identify why parts are failing and if maintenance needs to extend beyond fixing the immediate failed part.  This analysis would include:

  1. analysing trends; investigation of failures to determine root cause
  2. ensuring that the service schedule was/is being completed as planned
  3. a review to determine if the service regime and schedules are appropriate, and
  4. if the service regime or schedule is not appropriate, amend as necessary.

This analysis should include consideration of industry trends, known incidents, service bulletins and alerts issued by manufacturers and other information sources to identify factors that influence the service life of components.

The designer / manufacturer should also be informed, to provide them information that may assist them in identifying trends and therefore, if appropriate, addressing the issue more globally.

Design changes (alterations)

When a design change occurs, that may affect health and safety of a tower crane, the legislated design alteration process must be followed:

  1. the new design should be documented
  2. a Design Compliance Statement must be obtained from the designer of the alteration
  3. a Design Verification Statement must be issued from an independent verifier, following verification of the alteration
  4. the altered design must be Design Registered with a WHS regulator.

Alterations include:

WorkCover’s position is that this process must be followed for any design alteration that has already occurred or future design alterations that have the potential to affect health and safety.

The message is particularly important given the age of some tower cranes.

Fire extinguishing equipment

Fire extinguishers appropriate for the potential fire risk, during both operation and maintenance, should be provided in appropriate locations for the crane operator and maintenance personnel and consider the working location of the people and possible fire sources.

Fire prevention / suppression

  1. separating potential fuel sources from potential ignitions sources, eg
    1. relocating hoses or other fuel sources away from ignition sources
    2. providing guarding to separate flammables from ignition sources
    3. lagging of hot components such as exhausts
  2. adequacy of fire fighting equipment
  3. fire detection or engine compartment monitoring, to allow for early intervention
  4. practicability of installing a fire suppression system.

Falls

The risk of a fall must be managed in accordance with the hierarchy of control which requires using engineering, isolation and substitution controls in favour of administrative controls such as fall arrest systems.

Information on the risk of falls and control measures to be used must be passed down the supply chain.

Where the risk is managed by the use of a fall arrest system, emergency procedures, including rescue procedures, must be established and tested so that they are effective.

Acknowledgements

Industry plant consultative committee comprising WorkCover, the Master Builders Association of NSW and the Construction, Forestry, Mining and Energy Union.

Tower crane maintenance

Tower crane maintenance has come under increased scrutiny following the UTS fire. Three issues consistently raised are:

  1. lack of maintenance of cranes causing job stoppages
  2. incorporation of crane servicing/ maintenance into project schedule.
  3. allocated servicing times

To address these, the Industry Plant Consultative Committee advises the following:

Following these will not only make your site safer, but also prevent costly delays waiting for parts or maintenance workers to become available after a failure has stopped the crane operating.