Isolation of plant containing stored energy

Scope

What is stored energy? There are varied and numerous examples of plant containing stored energy, a few are: springs, airlines, air receivers, hydraulic hoses, tyres, conveyor counterweights, capacitors and batteries. An example of compressed air is shown below. This is a 63mm poly air header commonly used to provide air in underground mines.

In 2003 a worker undid the poly nut on an air header similar to the one above while the pipe was pressurised and received fatal injuries. The recent coronial inquest found that the worker "received fatal injuries when struck a blow of considerable force to his forehead. The fatal blow was caused by an object being propelled onto the forehead of the worker by a sudden expansion of air from a 63 millimeter poly airline…".

The scope of isolation should always include the isolation of plant containing stored energy.

Isolation practice

There are four basic steps in isolating plant containing stored energy:

1. Isolating the energy source.
2. Maintaining the method of isolating the energy source.
3. Releasing or containing the stored energy.
4. Proving that the stored energy has been dissipated or contained.

The isolation of plant containing stored energy often depends upon an administrative procedure and reliance on this level of control makes it imperative that the use of the procedure becomes second nature.

Training and assessment

The outcome required is that training and assessment on the isolation of plant containing stored energy should specifically target the types of energy that will be required to be isolated during activities carried out in each occupation. It is generally not practical to obtain all of these outcomes at an induction forum. However induction training and assessment will usually include generic training and assessment on isolation of plant containing stored energy.

Training and assessment on the isolation of plant containing stored energy particular to any occupation should be linked to that occupation. The training and assessment must be carried out prior to the worker commencing in the occupation.

Training material

In addition to the four basic steps training material should include:

• the physical properties of the stored energy that is to be isolated
• instructions that whenever practicable, every person working on plant that has been isolated must check that stored energy has been released or contained, and most importantly
• instructions that mechanisms that release or contain the stored energy should remain in place while work is being carried out.

A valve that has been used to release compressed air should remain in the open position. It is then clear to everyone working in the area that the energy has been released and avoids the possibility of any pressure build-up due to a leaking valve.

National Competency Standard MNMUMS211A Install and Maintain Reticulation Systems

This is still in draft form and it is anticipated that the Australian National Training Authority will endorse it in August 2004

References

• AS 4024.1 – 1996 Safeguarding of Machinery, Part 1 General Principles, Section 14
• Department of Natural Resources and Mines, Guidance note - Isolation Procedures*
• Department of Natural Resources and Mines, Safety Bulletin No 41*
• Newsflash 17 February 2004 Coroner's Inquest fatal mine accident*
• Queensland Legislation, Mining and Quarrying Safety and Health Regulation 2001
• Queensland Legislation, Coal Mining Safety and Health Regulation 2001

*Denotes available on the Mining Safety and Health website.

Authorised by Peter Minahan - Chief Inspector of Mines

Contact: minesafetyandhealth@dnrm.qld.gov.au

Issued by Queensland Department of Natural Resources, Mines and Energy