Ben Southgate, Frazer-Nash Consultancy
The SS Richard Montgomery grounded in the Thames Estuary in 1944 carrying approximately 1400 tons net explosive quantity. The wreck site remains stable but significant corrosion and structural damage presents a threat of mass detonation. The current wreck management strategy of non-interference requires re-evaluation to ensure the safety risk to the public is minimised.
On behalf of the Department for Transport, Dstl and Frazer-Nash have assembled a Munitions Working Group (MWG) of Subject Matter Experts (SMEs) including SDE Ltd, OTS Ltd, Cranfield University and QinetiQ Ltd to investigate this problem. The MWG is delivering an innovative work package to analyse different wreck management strategies and provide an associated probability of mass detonation. The first phase has been completed. The MWG has produced tailored fault and event tree models that represent sequences of events that could lead to mass detonation for each strategy. To obtain event probabilities, a range of data gathering exercises ranging from literature reviews to trials have been defined. The potential for estimation error has led Frazer-Nash to develop a bespoke approach and software tool that utilises SME defined probability density functions and Monte-Carlo simulation to calculate a mean mass detonation probability with associated confidence limits. Our testing has proven the concept of utilising this approach and tool.
The MWG’s innovative approach demonstrates the value and success of utilising industry skills and experience collaboratively and provides a clear process for assessing future novel high hazard safety scenarios in the future.