R. Burgess-Limerick et al. Ergonomics Australia. 2014; 10:2. [ 1 ] Bow-tie analysis of a fatal underground coal mine collision Robin Burgess-Limerick 1 , Tim Horberry 1 and Lisa Steiner 2 1 Minerals Industry Safety and Health Centre, The University of Queensland, Australia 2 Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, USA. Abstract Background: Bow-tie analysis combines aspects of fault-tree analysis and event-tree analysis to identify an initiating event; its causes and consequences; and potential preventive and mitigating control measures or barriers. Aims: The aim of the research is to analyse a fatality which occurred in a Queensland underground coal mine in 2007 to illustrate this technique. Method: The case study concerns a fatality which occurred at an underground coal mine in Queensland in 2007. Results: A continuous mining machine operator was crushed against the mine wall by a shuttle car following a loss of situation awareness by the shuttle car driver. The causes included the use of shuttle cars in close proximity to pedestrians, and driver inexperience. A directional control-response incompatibility contributed to the severity of the final consequence. A range of potential control measures are identified including: (i) replacing shuttle cars with a mobile conveyer; (ii) non-line-of-sight remote control of continuous miners; (iii) proximity detection interlocked with shuttle car controls; (iv) “always-compatible” shuttle car steering design. Conclusions: Proximity detection sensors interlocked with shuttle car control systems is a technically feasible control measure which should be implemented at all underground coal mines. Non-line-of-sight remote control of continuous mining machines or automation of continuous mining machines would remove operators from this hazard entirely. A bow-tie representation provides an effective way of systematically examining the causes, consequences, and potential preventive and mitigating control measures or barriers associated with a previous incident. ©Burgess-Limerick et al: Licensee HFESA Inc. Background Bow-tie analysis (sometime called “cause-consequence” analysis) is widely used in high hazard industries (e.g. aviation, chemical, petro-chemical) as a risk analysis technique which combines elements of fault-tree analysis and event-tree analysis [1-3]. Pitblado and Weijand [4] suggest that the barrier diagram or bow-tie diagram was developed simultaneously in Australia and the Netherlands in the early 1990s, building on the work of James Reason and Patrick Hudson; although the authors of the Bow-tie Pro software website attribute the term to David Gill of ICI stating “it is generally accepted that the earliest mention of the bowtie methodology appears in the ICI Hazan Course Notes 1979, presented by The University of Queensland, Australia” (www. bowtiepro.com/bowtie_history.asp). While there is no universally accepted standard bow- tie terminology and method, this paper will employ the terminology used by RISKGATE (riskgate.org), a major project funded by the Australian Coal Association Research Program [5,6]. RISKGATE is an on-line knowledge database which uses the bow-tie method to capture and present knowledge regarding the management of safety and health risk associated with coal mining. At the centre (or knot) of each bow-tie is an initiating event (or “top-event”). This is the point in time when there is a loss of control of a hazard (a source of energy with potential to do harm). The next step is to determine the causes of the initiating event, and the potential consequences of the event. For each cause, both the control measures (barriers) which can reduce the probability of the initiating event occurring (preventive controls), and the measures which can be taken to reduce the severity of the consequences of each initiating event (mitigating controls) are then identified. The bow-tie analysis can be further elaborated to examine the effectiveness of controls or barriers by including “barrier decay mechanisms” and assessment of the likely effectiveness of control measures. One of the particular strengths of the bow-tie method is that it provides an easily understood overview of the risk controls linked to initiating events. Equally, it can show both existing controls and potential/recommended controls for hazards. The aim of this paper is to illustrate the utility of a bow- tie analysis of an underground coal mine fatality as a means of identifying and communicating the potential control measures which may be adopted to reduce the risk of similar events. Method A case study of a fatality which occurred at an underground coal mine in Queensland in 2007. The first author was retained as an expert witness during the subsequent coronial inquiry [7]. A bow-tie analysis of the fatality was constructed by the first author based on the information presented during the inquest. Corresponding author: Robin Burgess-Limerick. Email: r.burgesslimerick@uq.edu.au Case study