San Martin, YH, Hurtado, JP, Vargas, JP & Acuña, EI 2017, 'Rapid selection strategies for tunnel development auxiliary ventilation systems', in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 177-187, https://doi.org/10.36487/ACG_rep/1710_14_Hurtado (https://papers.acg.uwa.edu.au/p/1710_14_Hurtado/) Abstract: Auxiliary ventilation system selection in tunnel development projects can be challenging depending on different site limitations, such as opening size and length, available power, environmental conditions, expected fleet, advance rates and equipment dimensions. This paper presents the technical and economic analysis study developed for various alternatives of auxiliary ventilation systems to support the development of mining tunnels. The represented variables are the different components of ventilation systems and five different tunnel drift cross-sections. The auxiliary ventilation system configurations considered in this study are in accordance with the legislated Chilean requirements, which are similar to Canadian regulations with regards to mining development. The methodology proposed in this paper consists of elaborate pre-calculated scenarios that allow a faster approach to the design of auxiliary ventilation systems in horizontal developments considering reduced cost of investment (CAPEX) and operations (OPEX) while complying with local regulations. The methodology used consisted of collecting the information available from the mine sites, and then a set of case studies for the calculations of the various parameters of the auxiliary ventilation systems. Technical and economic ranges are then estimated to select the ducting size, material roughness (friction or k factor) and geometrical parameters for the design of the mining tunnel auxiliary systems. This strategy provided ease and speed in the calculation and analysis of the costs associated with auxiliary ventilation systems, allowing for a faster convergence to a good solution when selecting a ventilation system for mining tunnel development. Keywords: auxiliary mine ventilation systems, rapid selection methodology, tunnel development