FORENSIC ENGINEERING SERVICES
Consulting Forensic Engineers undertaking Systems Failure Investigation
Design Fault Forensics for Alternative Dispute Resolution
Structural, Process and Design Failure Mode Analysis
Three Interesting Cases
A third of the 6000 tubes in a large thermal recuperator failed within 24 hours of start-up.
During this warm-through phase, only a very light, temperate flow had passed over the matrix.
From the Strouhal Number for the array, these conditions were shown to correspond with those necessary for vortex-shedding. It was demonstrated that the frequency at which this occurred coincided with the tubes' natural resonant frequency at the prevailing temperature, causing failure under high cycle fatigue. Acting as consulting forensic engineers to the State Court of Ohio in Cleveland, we presented our findings over the course of a five-day hearing and received commendations from attorneys on both sides.
We were appointed as forensic engineers for the defence in a criminal prosecution.
Its operatives had admitted to sabotaging a high pressure plant for essential oils extraction.
Although they had claimed it to be dangerous, each one of them faced a long prison term.
The owners had said it was worth a seven-figure sum - but its price was not its value.
Neither the owners' expert nor the plant's designers could stand against our findings.
We demonstrated that the equipment had never worked in commercial production;
Also, that it could never be made to work without disproportionate expense;
Further, that its design and construction presented clear operational hazard.
The men were fined and released.
A leading manufacturer of waste heat boilers and economisers engaged us as their forensic engineers to investigate the increasing number of ship's funnel fires, given their equipment was installed in the flue systems. Library searches at Lloyds of London revealed little of direct interest, whilst investigation into the clients' heat transfer and fluid mechanical design procedures showed them to be entirely conventional. Analysis of reporting dates reflected a history roughly coincident with changing practices in marine plant operation - particularly the burning of increasingly heavy cuts of fuel oil and much-reduced times alongside. Calculation and further investigation showed that under these circumstances, a tacky film would develop on tubes and flue walls at the end of one operating cycle, attracting solid smuts blown through at the start of the next- when the system was cool. It was demonstrated that temperatures would then increase as the systems warmed through until the LEL was exceeded within the economiser tubestack and ignition was caused by sparks entrained in the exhaust gas stream.