Judging by CSI: Crime Scene Investigation, Forensic Files, Cold Case Files, Silent Witness and numerous other extremely popular TV shows featuring forensic investigators, we humans are fascinated by this science. While it makes for great – and often chilling – entertainment, in the real world, uncovering the solutions is no less thrilling and fascinating. It’s also of extreme importance when it comes to disaster prevention.
With the infamous Titanic, the reason the steel hull failed is that back then it wasn’t known that steel changed from a ductile material to a brittle one in freezing temperatures. Forensic investigation of salvaged pieces of the ship enabled an understanding of steel and its behaviour. Nowadays, steelmaking technology has been improved dramatically so that steel doesn’t become brittle in very cold temperatures – so ships no longer break in half if they hit an iceberg.
In South Arica, there have been several high-profile engineering failures that required forensic engineering and root-cause analysis to explain them. The most significant of these is probably the delays in commissioning Eskom’s Medupi and Kusile power stations, which were ‘a result of poor welding-procedure qualifications, lack of control of materials, and lack of application of metallurgical engineering skills’, says leading materials engineer Dr Janet Cotton of local forensic metallurgy company One Eighty Degrees.
Another example that hit the news was the failure of a Darling Cellars wine tank. Dr Cotton’s team members were the metallurgists who did the root-cause analysis on site. What they found was that the tank had been poorly manufactured, and as a result, it had collapsed, setting off a calamitous domino effect and causing massive losses to the cellars.
The need for metallurgical forensic analysis is clear: it’s important to know why things break, to prevent them from failing in the future. ‘You need to be able to look at the failure, at the fractured surface or the failed area, to give you the clues as to why the failure occurred,’ Dr Cotton explains. ‘That’s why you need metallurgical and materials engineering expertise, because you need to know why and how materials behave under stress or how materials behave in various states of corrosion.’
To uncover ‘whodunnit’, various metallurgical and materials engineering analysis tools are employed. These include high-tech analysis tools such as scanning electron microscopy, mechanical testing, tensile testing, impact testing and hardness testing. ‘Some of the very advanced investigative tools are Fourier Transform, infrared spectroscopy, X-ray diffraction and atomic force microscopy,’ Dr Cotton continues, but adds that part of the training as a materials engineer is learning how to use these techniques, processes and procedures, and how to interpret the results. ‘I could go on and get very excited about the number of fantastic diagnostic tools available to us, but the thing about being a qualified materials engineer is that you need to understand how these methods work. You need to know how to interpret the information, and if you can’t do that correctly, you can make a horrifically poor judgement as to what you’re seeing and interpreting from the results and data.’
Dr Cotton’s company abounds with fascinating case studies and ingenious solves, including having applied some of these techniques to solving for South African Breweries’ stress-cracked hot-water line in Newlands, Cape Town, back in 2002. Her recommendations are still going strong today, having robustly outlasted their anticipated 20-year lifespan. Work for major fishery I&J helped protect both sailors and their catch, while Consol Glass benefited from increased longevity for their glass-blowing moulds.
Now Dr Cotton is on a new mission: to make her field more widely known in this country. ‘The problem that we have in South Africa is that people don’t really know about, understand, perceive or consider the value of forensic root-cause analysis.’ Recently, she launched the country’s first Root Cause Analysis Conference, which ran at the Vineyard Hotel in Cape Town from 11 to 14 March. The speaker line-up featured a range of global and sub-Saharan thought leaders and experts. To find out more about the event and this specialised field, visit https://www.one-eighty-degrees.com/.
