Simms, P, Williams, MPA, Fitton, TG & McPhail, G 2011, 'Beaching angles and evolution of stack geomoetry for thickened tailings - a review', in R Jewell & AB Fourie (eds), Paste 2011: Proceedings of the 14th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 323-338, https://doi.org/10.36487/ACG_rep/1104_29_Simms (https://papers.acg.uwa.edu.au/p/1104_29_Simms/) Abstract: The reliable prediction or management of beach slope and stack geometry is integral to realisation of the potential benefits of thickened tailings technology. Stack geometry not only controls the storage capacity for a given footprint, but also strongly influences post-deposition geotechnical and geoenvironmental performance. Unfortunately, accurate prediction in design has proved difficult. However, there has been significant improvement in understanding the behaviour of tailings after they exit the pipe, and a number of methods for beach slope prediction have been proposed and developed. This paper reviews a selection of these methods, and examines their applicability to different deposition scenarios. Some recommendations are made to assist engineers and operators to achieve a given stack geometry.