The West Australian Department of Mines and Petroleum’s (DMP) recent safety bulletin addressing the importance of correct maintenance of refuge chambers in underground mines has highlighted industry concerns that the capacity for some refuge chambers to perform correctly in an emergency may have been compromised. These concerns arose following a number of recent refuge chamber inspections by the DMP, highlighting inadequate maintenance and ad-hoc modifications to chambers.
During an underground emergency when the ambient underground environment becomes unsuitable for breathing, personnel use their self-contained self-rescuers (SCSR) as breathing apparatus en-route to the safe environment of refuge chambers. Once inside the chamber, the internal volume is the last remaining respirable atmosphere until the emergency has passed and help arrives.
Refuge Chambers are defined and identified as Medical Life Support Devices by the WA DMP ‘Refuge Chambers in Underground Mines’ 2013 Guidelines, based on their application and several key features, including;
1. Sealing of the internal atmosphere from the external threat
2. Breathable air supply and redundancies, including:
- An appropriately filtered, dry compressed air connection
- Internal, chemically controlled recirculation (scrubbing) system and oxygen supply
3. Air Conditioning, including;
- Temperature control
- Humidity control
4. Uninterruptable power supply (UPS) and secure storage
The recent safety bulletin explains that a compromised refuge chamber may lead to the following issues during an emergency:
- Inability to support life for the recommended minimum duration of 36 hours
- Ingress of contaminants into the refuge chamber
- Failure of life support systems to operate effectively (e.g. scrubbing and temperature control)
- Reduced battery power capacity
The DMP recommend a number of actions that will assist in maintaining a refuge chamber so it can support life in an emergency situation. Among these actions, they suggest a ‘formal change management process to refuge chamber modifications, including the original equipment manufacturer’s (OEM) review and authorisation prior to modifying the chamber.
Before making any structural or component modifications to a refuge chamber, including the replacement of spare parts, it is imperative that the OEM is contacted to ensure the changes are compatible with the refuge chamber and will not hinder operation in the event of an emergency. If using non-OEM parts, proof of testing should always be supplied in order to ensure the safety and duration of the refuge chamber is not compromised.
MineARC has seen an increase in the use of non-OEM parts and ad-hoc modifications to refuge chambers in recent years; many of which impact the overall emergency duration of the refuge chamber. Some of the most common problems we encounter during a service or audit include:
- Replacement of scrubbing chemical with a different type or shape to the recommended OEM chemical
- Poor battery maintenance, such as replacement with alternate brands or battery types that have differing charging characteristics
- Incorrect installation of the door seal, resulting in a loss of internal positive pressure
- Poorly maintained air filter system, including incorrect replacement of parts and dirty filter elements
The DMP Safety Bulletin dictates that sites should ensure repair, replacement or maintenance work is ‘undertaken by a competent person(s)’, in accordance with the OEM’s specifications. MineARC Systems consider personnel who have undertaken MineARC’s service training program and are fully certified by a qualified MineARC Representative to be deemed competent in refuge chamber maintenance. MineARC offers a Service School free of charge to clients; held monthly at our Perth Training Centre, or offered as on-site training for larger groups. Once completed, personnel receive a unique Certification ID number which must be recorded on every refuge chamber that is serviced. This will help DMP inspectors to easily identify that a competent technician has serviced the chamber.
MineARC understands that this latest DMP Safety Bulletin may impact some sites and would like to provide assistance in ensuring all refuge chambers comply with DMP regulations. MineARC is offering free safety audits to all sites in order to provide peace of mind that they comply with these latest recommendations. When serviced by MineARC’s certified and experienced technicians, sites can be confident that their refuge chambers are fully covered by MineARC’s AUD$20 million product liability insurance and will operate optimally in case of emergency, as well as comply in full with all DMP guidelines.
If you have any queries or concerns regarding this bulletin and how it applies to your current refuge chamber maintenance regime, please do not hesitate to contact our experienced MineARC Systems Service Department via email firstname.lastname@example.org or telephone +61 8 9333 4966.