"So far, we have saved €935.6m and I think we will reach the target or even exceed it," Nemetz said.
ÖBB is trying to reduce the total cost of running its 5700km network and the objective is to achieve permanent cost reductions without reducing quality. "Our owner expects a reliable and safe system, but we are also expected to make efficient use of our financial resources," says Nemetz.
The process follows a set pattern using a systematic approach starting with an idea followed by analysis, pilot implementation of a solution, and if that is successful the solution is made permanent. A spin-off from the process is that the search for efficiencies has promoted innovation. Finally the measures undertaken are monitored. "We first have to identify a problem and then work out what improvements can be made while keeping an eye out for any quick wins - our management is always keen to see quick wins," Nemetz explained. "We then prioritise the measures, implement them and control and optimise the improvements."
To capture the status of track and structures, ÖBB operates an EM250 inspection and measuring car which can travel at up to 250km/h and is able to measure track geometry, rail wear and the rail surface. It also has an EM80 vehicle to measure track geometry, rail wear and tunnel cross-sections.
For new-build projects, the main source of savings has come from technical optimisation which accounts for 41% of total savings. This is followed by optimising construction methods and track availability which generates another 17% of savings. Reducing the amount of track equipment, both for the subgrade and the superstructure, saves another 13% along with optimising the route and planning. Perhaps surprisingly, reducing the amount of land required for a project only cuts the total cost by 3%.
ÖBB analysed where the savings came from on renewal schemes by examining projects which cost more than €1m. It found that 55% of total savings were produced by improving planning, while another 10% could be saved by optimising the organisation of the work. Reducing the cost of disposing of waste materials also saved 10%, whereas carrying out only a partial renewal saved just 7%.
Not surprisingly, ÖBB sets great store by planning, and works to a time horizon of about six years for both renewal and new construction schemes. This means it already has a rough plan for the whole network for 2015 showing each project and which machines will be needed each day.
Specific cost savings
Savings have also been achieved by reviewing standards. An examination of the subgrade on a double-track line showed that by reducing its width by about 1.25m would enable the ballast bed to be reduced in both width and depth. This was made possible by altering the arrangement of electrification masts and cable troughs, which themselves could be reduced in size, while track centres were limited to 4.5m or even 4m on lines with a maximum speed of 160km/h.
ÖBB also discovered that it is possible to reduce the cross-section of a single-bore tunnel from a radius of 4.4m (from the tunnel centre line to the wall) to 3.95m. This was achieved through measures in three key areas:
- displacement of the track towards the tunnel axis, optimising the slab track, and adapting the suspension system
- modifying the drainage system, installing an overhead conductor rail rather than conventional catenary, and eliminating the water supply line, and
- conducting aerodynamic modelling including scenario studies.
ÖBB has developed a metholodogy called the New Austrian Track Analysis System (Natas) to help it analyse the condition of the track better and determine the best course of action. For example, Natas can show where the rate of track settlement has increased due to poor drainage. The system contains various rail wear parameters and their limits which help ÖBB to plan rail replacement more effectively.
"We produced a geotechnical information map of the network to see what condition the track is in," Nemetz explained. "We found that out of 2375km of track substructure analysed, 1600km was in good condition, 549km needs attention in the long term, 95km requires short-term action, and immediate action is needed on the remaining 31km."
ÖBB calculates life-cycle track renewals costs using two options for a line carrying 30,000 to 45,000 tonnes of traffic per day per track. One consists of total renewal using 60 E1 profile R 250 rails laid on concrete soled sleepers, while the second involves partial renewal in year one followed by complete renewal nine years later using 49 E1 or 60 E1 profile R 200 rails laid on a mixture of concrete and concrete soled sleepers. A cost-effectiveness comparison of the two renewal options has been mandatory since 2011 for each work site.
Studies have shown that the longer the track renewal section the more cost-effective the work becomes. For example unit costs fall from €850/m to renew a 1km section of track to €600/m for a 5km section.
ÖBB has found that using soled concrete sleepers reduces the rate of settlement in the track on heavily-used lines which lowers maintenance costs and improves availability. ÖBB also uses what it describes as plug-and-play turnouts, which are assembled off-site and are then transported on special wagons to the worksite. This cuts the time it takes to replace turnouts and thereby reduces disruption to services. ÖBB is also a strong believer in ballast recycling as this not only reduces the amount of new ballast required but also cuts transport costs.
An analysis of overhead electrification equipment on plain track showed that it was possible to simplify the design so that more lightweight masts could be used, the length of a span of contact wire could also be increased from 1120m to 1340m, which meant less contact wire is needed because there are fewer overlap sections, and fewer wire tensioners are required. Overall the change produced a 10% cost saving.
Challenging existing designs, equipment used, and working methods, coupled with meticulous long-term planning and measuring and testing are the key ingredients of ÖBB's long-term quest to reduce infrastructure costs without affecting quality.