Meet the ATC Williams Laboratory Experts John Walker & Luke Renkin

We talk to our in-house ATC Williams Laboratory experts, John Walker and Luke Renkin, about their diverse backgrounds and work lives as lab technicians.

L–R John Walker, Luke Renkin

John Walker, Laboratory Manager

Hi John, tell us about your work overseas before joining ATC Williams.

My career pathway began in the UK in the early 1980s. My Dad worked as an operator for earthworks contractors, so I grew up around civil engineering and plant machinery. My first job in materials testing was for a North Sea oil and gas pipeline project. The welders drove Triumph TR7s and Porsche 911s while wearing Stetsons and cowboy boots. I thought this was the life for me! Not every job was quite like that, but I worked for consultants, contractors, and materials suppliers all over the UK for the next twelve years. By the early 1990s, I was working as an Area Supervisor for a Regional Council.

In 1995 I moved to Hong Kong with Fugro for the construction of Chek Lap Kok Airport. The island is a 13.8 km2 platform reclaimed from the sea. My wife Hazel and I had started a family, and we decided to stay in Hong Kong after the contract ended. I joined Stanger Asia to set up a HOKLAS Accredited soil testing department, and for the next ten years, we serviced the construction boom happening in Hong Kong and Macau.

In 2007, I felt it was time for a change and heard of MPA Williams in Australia looking for a laboratory manager. When I enquired, the first thing I said was, “I must tell you I know nothing about tailings”, and I was met with an Australian classic, “Ah mate, no drama’s”. I learned the company had plenty of tailings experts, and they had just moved from Bonbeach to a large new facility in Mordialloc. My first task would be to implement ISO/IEC 17025:2005 requirements into the laboratories NATA accreditation.

What work does the lab do outside of soil or tailings testing?

Over the last 11 years, the laboratory has become well known for Transportable Moisture Limit (TML) testing. The iron ore industry was the first to contact us about liquefaction onboard bulk carriers. Internationally the iron ore industry had lost six ships in 2010, and the Australian iron ore producers wanted to understand the cause and prevent this from happening here. We worked closely with the iron ore working group, and we still carry out routine testing of iron ore fines. In 2013 we received NATA accreditation for TML testing, now a requirement of the Australian Maritime Safety Authority (AMSA). Other commodities such as coal, copper, zinc, lead and nickel concentrate require TML testing, with bauxite added after the loss of a bulk carrier with eighteen crew from Malaysia in 2017.

What stands out for you over the last 15 years of your career?

Now I can say I know more than a bit about mine tailings! Through the assistance of Peter Lam, I also learned to do rheology testing. When a recent tailings sample from Africa demonstrated Newtonian properties, I was reminded that you never stop learning. The lab and the ATC Williams engineers work closely to achieve quality results for our clients. We are unique in our ability to provide that collaborative level of service.

The development of the TML testing and the work we do in Australia and overseas also stands out. Such as working with manganese ore from South Africa and bauxite from Jamaica. Along with the tailings and soil testing we provide directly for consultants and mining companies.

Becoming a NATA technical assessor is very rewarding. I have had the opportunity to do technical assessments for commercial labs and government facilities locally and interstate. The best assessments are where you meet like-minded people and share knowledge and experience, and if you learn something new, that’s a good day.


Luke Renkin, Geotechnican

Hi Luke, tell us about your work before ATC Williams.

After leaving University with engineering and science degrees, I took a winter break snowboarding in the USA. While living in the mountains, I found work in geotechnical testing and stayed in the states for ten years. I worked for ATC Williams upon my return to Australia, and I’ve been here ten years this month.

Did you always work in the company-owned lab?

Along with laboratory work, I was involved in construction supervision and geotechnical investigation projects on remote sites in Australia for the first few years. Onsite work has provided a great background and context to my ongoing work in the ATC Williams lab.

What do you enjoy about your workday?

I enjoy the complexities and ever-changing nature of lab work and how the analysis we complete in the lab is able to assist the engineers with their design work.

We’ve got about fifteen different projects on the go in the lab right now from various places in Australia and around the world. Currently, most of my time is spent on material classification and triaxial testing.

Laboratory Testing is typically an ongoing and interactive process between the lab and the engineers. We will report our initial findings and work with the engineers to develop a testing program to provide the parameters required for design. The engineers have a good practical appreciation of what goes on in the lab, so it’s collaborative at every stage.

How do students benefit from working in the lab?

Our summer program gives undergraduates a good foundation in soil and tailings classification and geotechnical laboratory test work. We hope that the students can continually use the foundational skills they develop in the laboratory throughout their careers in geotechnical investigation and design. In addition, we have up to four students doing placement work throughout the year. It’s great that we can offer tailings testing experience to students. A few universities offer tailings testings, and there are plenty of labs that do geotechnical testing. Still, we are unique in the complexity of testing experience the graduates receive when they are with us.

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