Understanding the relationship between cost and time can enhance the planning of maintenance and renewals through efficient resource allocation. SBB has experimented with fixed slots on several routes: Totally four routes in 2012, two of them main lines (Lausanne-Sion, Cadenazzo-Locarno). SBB is rolling them out across more of its network (2013 eleven lines, 2014 seventeen lines). Maintenance costs depend on several factors. The type of work undertaken is the main driver, and track renewals in particular are both expensive and time consuming (e.g. major maintenance with machine application 8 h, day or night; renewal 8h, weekend or long-lasting; extension and upgrading 8 to 10 h, weekend single track operation, continuous single track operation). It is not usually possible to complete the work in one possession, requiring several consecutive night shifts with up to 8 h of continuous track possession each. Other considerations are the length of productive time in each possession. The influence of slot length on costs was not initially clear. SBB derived a quantitative cost model for track renewals by analysing the costs of sample projects in relation to the time available. Taking in account the renewal techniques used, the length of track renewed and the distance between the work sites and the stabling places for the machines differ. The new approach to slot assignments and fixed maintenance windows offers several advantages. From the train operators' perspective there is more predictability about the train services, and less need to inform customers about diversions or cancellations. Having a negotiated time frame means that the maintenance projects can be planned more reliably. Timetable planners do not have to adjust the seasonal timetables to allow for major projects, as it is possible to build in standard allowances for a given number of temporary speed restrictions. Extending the length of individual possessions (e.g. up to 8 h reduces costs up to 40 % against a 3 h slot), reducing the total number, and clustering the opportunities to undertake work in parallel all offer significant savings. Cost savings on the two main lines were 22 % and 23 %. Along with accurate planning and capacity management, SBB anticipates that the new strategy will help to reduce the overall cost of infrastructure maintenance by between S Fr 30m and S Fr 50m a year, or almost 10% of the total projected expenditure.
Possession policies drive down maintenance costs
Railway Gazette International ; 170 , 5 ; 64-67
2014
4 Seiten, Bilder, Tabellen
Aufsatz (Zeitschrift)
Englisch
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