Control of purchased or hired equipment

Successful management of occupational health and safety at a mining operation requires an integrated approach where safety and health needs are firstly identified, systems of control are developed and implemented, and then tested, audited and reviewed - all with a view to continuous improvement.

Management and control of purchased, hired or loan equipment or materials is no different. All mines should have established systems of control to ensure supplied equipment or materials conforms to safety and health requirements whether those requirements are set by regulation, standards and codes of practice or specific requirements determined at the mine.

There have been instances where the system of checks and balances have failed or been bypassed allowing non-conforming equipment or materials to be put into service.

Examples of incidents

The incidents below demonstrate how deficiencies in systems of control for purchasing and hire can introduce hazards into the workplace.

Incident 1

A multi-function welding unit had been directly purchased from a supplier on a corporate credit card. Electrical staff who were unaware of the purchase were able to inspect it prior to service at the mine. Defects capable of rendering the machine dangerous to operate were discovered including:

• inoperable 30mA earth leakage protection residual current device or safety switch (RCD)—it had been incorrectly connected and thus rendered inoperable
• inadequate mechanical protection of cables, conductors and enclosures housing electrical equipment
• inadequate degrees of protection for dust and moisture ingress
• inadequate insulation and separation of parts.

A comprehensive site standard detailing the requirements for this type of equipment had been developed and implemented at the mine. It included detailed requirements for suppliers to cross reference, and acceptance inspection and testing for all purchased or hired equipment prior to operation at the mine. The normal system of purchasing checks and balances were bypassed through the use of the credit card. The unit was sent back to the supplier for repair. Other problems included design issues and the competence of person who installed the RCD.

Other vulnerable areas include direct credit purchase orders and even petty cash; ie. any system outside the normal stores / purchasing system. In this case the desire to obtain the product and put it into service may have outweighed the necessity to observe the system of control.

Incident 2

During the service life of a Jeffrey miner conveyor pump motor, the yolk ring that holding the motor drive end shield was modified. The repair consisted of machining out part of the yolk without destroying the water jacket, and tack welding a keyed space ring into the yolk to enable the end shield to be attached.

The end shield was bolted to the keyed ring, so the end shield was in effect only attached to the motor by tack welding, which broke when bumped during transport causing the end shield to come loose.

The work undertaken was completed in an engineering workshop in a way that voided the compliance certification of this motor and which defeated the flameproof properties of the motor rendering it unfit to operate in the hazardous zone of an underground coal mine. The repairer in this instance did not meet safety and health requirements. Verification of their ability to perform the work was not confirmed. A service history for the motor could not be traced.

Incident 3

An aluminium cylinder containing pressurised nitrogen gas was discovered underground. An incendiary spark can result from impact between some aluminium alloys and a steel object. Compressed gases are generally supplied to underground mines only in steel cylinders, however the supplier was in the process of reducing the number of steel cylinders in preference for the aluminium type. This fact was unknown storeman who were also unaware of the existence of two types of cylinder. The cylinder had a standard bar code attached that indicated it was a steel cylinder.

Incident 4

Repetitive deficiencies have been discovered at underground coal mines having systems in place to ensure that contractors or hired vehicles are thoroughly checked before being put into service.

This equipment is regularly moved from mine to mine with a strong inference that equipment is allowed to operate in a non-complying condition. Contractors or hire firms are also not meeting requirements in ensuring for example:

• Inspections are within the required time frame as per relevant Australian Standard recommendations and that these inspections are conducted by competent personnel.
• Provision of all appropriate compliance, approval and supporting documentation including drawings is made with the machine.

Systems of control

SafeGuard - the Department of Mines and Energy audit tool Element 6 - Purchasing and Employment deals with ensuring safety and health requirements of purchased equipment and materials, suppliers of equipment and contractors are met. Other safety and health management systems will deal with the issues differently. However the key elements of responsibility, authority, rigid systems of control, audit and review and continuous improvement must be captured.

Recommendations

1. Purchase, hire or loan of equipment or materials should be subject to rigid systems of control.
2. Evaluation should be carried out before purchase decisions are made to ensure materials, equipment, people and organisations meet legal and standard requirements. Potential loopholes in existing systems including credit card and direct purchase need to be considered in the system of control.
3. Selection of contractors and suppliers of overhaul and repair services should be based upon their ability to meet clearly defined safety and health requirements including:
   
   • their ability to perform the work to the required standard
   • the competence of the personnel performing the work
   • the availability and access to relevant information to enable them to perform the work
     and 
   • the ability to supply equipment or materials that conforms to safety and health requirements.
4. Verification should be made that supplied equipment or materials, equipment and equipment overhauled or repaired meets safety and health requirements.
5. Sufficient information must be provided to enable people to safely handle, use, transport, store and dispose of equipment or materials.
6. Assurance must be gained that equipment is designed, constructed, operated and maintained to ensure safety of persons.
7. Responsibility and authority is set within the organisation to control purchase, hired, loan of equipment or materials.
8. The systems in use must be tested, audited and reviewed to ensure effectiveness. Adjustment of the system or practice subsequent to identification of non-conformance with the system must be conducted.

Authorised by Peter Minahan - Chief Inspector of Mines

Contact: minesafetyandhealth@dnrm.qld.gov.au

Issued by Queensland Department of Natural Resources and Mines