Reducing control selection errors associated with underground bolting equipment Robin Burgess-Limerick a, * , Veronica Krupenia a , Christine Zupanc a , Guy Wallis a , Lisa Steiner b a School of Human Movement Studies, The University of Queensland 4072, Australia b Mining Injury Prevention Branch, National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, USA article info Article history: Received 27 April 2009 Accepted 25 November 2009 Keywords: Equipment design Shape coding Simulation Mining abstract Selecting the incorrect control during the operation of underground bolting and drilling equipment causes serious injuries. Shape coding and the layout of dual control banks are two aspects of control design which require further examination. The aims of this research were: (i) to determine whether arbitrary shape coding was effective in reducing selection error rates in a virtual analogy of roof-bolting; and (ii) to determine whether any advantages exist for mirror or place layouts for dual control situations in this situation. Two experiments were conducted to address these questions. No benefits of arbitrary shape coding were evident while control location remained constant. When control location was altered, shape coding did provide a significant reduction in selection error rate. No differences between mirror or place arrangements were detected and this question remains open. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction The introduction of roof and rib bolting to prevent rock falls in underground coal mines was a major safety advance (Mark, 2002). However, additional hazards were introduced in the process. Analyses of narratives describing injuries occurring in both Australia and the United States of America have highlighted the potential of control errors during drilling and bolting to cause serious injuries (Burgess-Limerick and Steiner, 2006; 2007). Examples of typical bolting controls are illustrated in Fig. 1 . Standardising the controls on bolting machines has been sug- gested many times as a means of reducing the probability of control errors. Miller and McLellan (1973) commented on the ‘‘obvious need’’ to redesign roof-bolting machines, suggesting, for example, that of 759 bolting machine related injuries, 72 involved operating the wrong control, while Helander et al. (1983) determined that 5% of bolting machine accidents were caused by control activation errors. Helander et al. (1980) suggested that ‘‘poor human factors principles in the design and placement of controls and inappro- priately designed workstations contribute to a large percentage of the reported injuries’’ (p. 18). A Society of Automotive Engineers (SAE) standard titled ‘‘Human factors design guidelines for mobile underground mining equipment’’ which addressed these issues was defeated at a ballot in 1984 (Gilbert, 1990). A subsequent report (Klishis et al., 1993) again noted the lack of standardisation of bolting machine controls, even among machines from the same manufacturer, and com- mented on the potential for injuries due to incorrect control operation. While there are a number of aspects of bolting control design which require consideration, the experiments reported here focus on two topics related to reducing the probability of operating the wrong control, i.e. selection errors. The first issue is shape coding; the second concerns the layout of controls in the situation where multiple banks of controls are provided. 1.1. Shape coding In a six-week period in 1994, three operators of roof-bolting machines in the USA were killed. Two were crushed between drill head and machine frame while rib bolting, the third crushed between drill head and canopy. A ‘‘Coal Mine Safety and Health Roof-Bolting-Machine Committee’’ was formed by the US Mine Safety and Health Authority (MSHA) to investigate, and a report released (MSHA, 1994) which determined the causes to be the unintentional operation of controls. Amongst other suggestions, a recommendation included in this report was: ‘‘Provide industry-wide accepted distinct and consistent knob shapes’’. The MSHA subsequently called for industry comment on an advance notice of proposed rulemaking titled ‘‘Safety standards for the use of roof-bolting machines in underground mines’’ (MSHA, 1997) which suggested that MSHA was developing design criteria for underground bolting machines. The New South Wales Department of Primary Industries publishes ‘‘Mining Design Guidelines’’ to assist mining companies and * Corresponding author. Tel.: þ61 7 3365 4718; fax: þ61 3 3365 6877. E-mail address: robin@hms.uq.edu.au (R. Burgess-Limerick). Contents lists available at ScienceDirect Applied Ergonomics journal homepage: www.elsevier.com/locate/apergo 0003-6870/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.apergo.2009.11.008 Applied Ergonomics 41 (2010) 549–555