Ensuring safety at Australian Defence Force sites

Earthing systems, like any safety mechanism, need testing to ensure they’ll perform when the need arises. Ventia engaged Middleton Group to test the safety of high voltage electrical systems and conduct earthing system performance testing on the 24 bases they manage for the Australian Defence Force (ADF) across four states – Victoria, South Australia, Western Australia and the Northern Territory. 

This was a big and sometimes challenging job. Principal Earthing Consultant Scott Mitcherson took the lead, which involved long journeys in a four-wheel-drive loaded with 250kg of testing equipment.  

Some of our young engineers, who included Suvasmita Srichandan (in the pics), Amber Truong, Vincent Wong, Phillip Chau and Steve Smith, each joined Scott for several weeks at a time to gain hands-on experience in gathering field data and test measurements, analysing the data and writing reports. They used the advanced testing technique of off-frequency current injection testing to safely assess the earthing systems without the need for isolations. Any non-complying installations were identified, and hazard mitigation recommended. 

The project was a valuable experience for the engineers, and for Scott as a mentor: “Field work allows our young engineers to see how earthing systems are implemented in construction, which helps them when they are designing systems themselves,” he says. “I say to the team that my challenge is to teach them all I know about earthing before I forget it.” 

However, for the Earthlings, as they called themselves, the work was challenging, logistically and physically. Scott says that testing is difficult in rain, humidity, and high temperatures. In the Northern Territory, in particular, the characteristics of the soil in areas of hard ground made it difficult to inject current into the earth and take accurate measurements: “We put fatigue management plans together to assist in looking after the staff,” he says. 

According to Ventia’s National Asset Manager, Lincoln Turner, the project was a great success: “Close collaboration and support from all parties throughout this project means optimal outcomes have been and are continuing to be achieved,” he said. Not only is Middleton Group a highly capable and professional service provider, he added, but the company shares values with Ventia and Defence, which is important to all parties: “Safety, service excellence, and a strong commitment to delivering sustainable and innovative solutions for its clients.”