Engineering principles for the design of a personnel transportation system

摘要

This article describes the re-engineering principles applied in the design of a personneltransportation system for a platinum mine in the Rustenburg area of South Africa. Itincorporates conveyor belt travelling, chairlift operation and also includes consideration ofproposed changes / modifications to existing conveyor belt infrastructure.The purpose of the project was to identify the appropriate option and / or combination oftransportation options through a process of evaluation that would be safe in terms ofpersonnel transportation and cost effectiveness. If alternative measures could be found totransport personnel (in other words not using belt riding as a means of transport), it wouldhave a significant positive spin-off increasing the availability of the belt, to increaseproduction. This paper therefore explores the feasibility of new interventions investigated.The design in consideration at the Bafokeng Rasimone Platinum Mine consisted of twoshaft systems, namely the North Shaft and South Shaft. Each shaft system comprises of twindecline shafts. One of which is equipped with a conveyor belt for rock and personneltransportation and the other with a winder for track bound material transport. From thedate of commissioning of the shafts, the conveyor belt was used for personnel transportation.The conveyor belt is equipped with platforms for getting off and on the belt and a number ofsafety devices designed to ensure the safety of personnel travelling on the conveyor belt.Intensive training in the practical aspects of belt riding was given to each and every personand unsupervised riding on the belt was only undertaken once belt riding competence wasdemonstrated. Despite this, the safety results were poor, having experienced 106 injuriesbetween 2006 and May 2013. Fortunately no fatalities were reported during this period.It was therefore needed to investigate alternative means for personnel transportation orthrough engineered solutions to the current conveyor belt infrastructure in the safest, mosteffective and most economical way. There was a major risk of safety related stoppages beingimposed following another belt incident. This would prevent the mine from transportingpersonnel underground by belt and subsequently result in major production losses. From thecommissioning of the Phase 2 shaft deepening project on both shafts, the decision was toinstall dedicated chairlifts for personnel transportation opposed to the man riding conveyorbelt installed in the Phase 1 area. The chairlift installations were in operation since 2004 andno chairlift related incidents were recorded thus far. According to safety statistics it wasclear that the chairlift installation is the safer method for the transportation of people in theshaft. To fulfil the study objectives, it was recommended that both primary (new chairliftdecline with infrastructure) and secondary options (modifications to the current conveyorbelt infrastructure) be considered for implementation on both North Shaft and South Shaft toeliminate accidents and incidents as a result of belt transportation. The associated capitalexpenditure (CAPEX) would be approximately ZAR 200 million. Considering the futureimpact on the business as a whole, this would definitely be CAPEX well spent! Theapproximate amount due to section 54 related stoppages varies but conservatively spoken isnormally in excess of R 10 million per day.