1. Sustainable maintenance of high-speed lines with mixed traffic
Florian Auer
January 12th, 13th 2017
Mumbai

2. High speed and mixed traffic - What does it mean?
High speed -> highest quality demands
Freight -> high dynamical forces, high stresses
The design of the tracks and the maintenance regime have to cope with these circumstances. The role of measurement cars is of utmost importance.
Maintenance is much morre than just the maintenance work itself.
Efficient and sustainable maintenance planning needs an holistic infrastructure strategy.
Including the network strategy, dealing with the size of network, dealing with track access charges and so on.
But more important for this presentation is the operational point of view, here we deal with the optimum track possesions, then furtheron the track strategy and last but not least the core maintenance strategy dealing with the question maintenance versus renewal.

3. Rail / Wheel Interface
Rail / Wheel contact has to be considered as an holistic system, especially on high speed networks.
Running behaviour (equivalent conicity according TSI).
High contact forces leading to rolling contact fatigue.

4. Track geometry quality
The Technical Specification for Interoperability (TSI, EN13848) defines the track geometry quality.
For high-speed traffic, the highest level of track geometry quality is required.
However, the possible track geometry quality also depends on the ballast quality.

5. It all begins with the design…
Particularly on high-speed lines, elastic components are increasingly used on railway track to reduce the dynamic forces in the ballast bed.
In particular, this applies to bridges, where the ballast would be subjected to overstressing without the use of elastic components (soft rail pads, under sleeper pads, under ballast mats) …
This requires high capacity tamping machines.

6. Ballast bed cleaning Sleeper type Axle load Ballast quality Speed
High-speed
conventional
Speed
wooden sleeper / concrete sleeper with USP
concrete sleeper
Sleeper type
Factors influencing ballast bed fouling
high
low
Axle load
poor
high
Ballast quality
Mill. load tons

7. Need of sweeping units ICE passenger train moving with 300km/h over ballast stones located on the sleeper surface. VIDEO AUSTRIAN FEDERAL RAILWAYS
The followoing video shows the importance of the sweeping. You see four different ballast stones on a sleeper. The stones differ in size and weight.
The train travelling o the track is an ICE running at 300km/h, of course you see it in slow motion.
The dynamic air pressure is swirling up the stones, the smallest stone just falls down and rests in it‘s postion. The biggest is to heavy to move and also rests after falling into the ballast bed. The stones nr. 2 and 3 keep moving over the adjacent sleeper and will fall on other stones.

8. Highest level of process safety
The design of the tamping units meets highest quality and process safety standards. For the purpose of quality assurance, the relevant tamping parameters should be recorded during work.

9. 3D compaction of the ballast bed
The highest compaction is to be achieved when applying the ballast bed with the Dynamic Track Stabiliser.
Lateral vibrations of the track panel lead to a wearless relocation of the ballast stones.
Another point regarding process safety is the measurement of platform distance during the work.

10. Welding technology
The flash-butt welding technology increases process safety and reduces the heat-affected zone.
It should be preferred over the alumino-thermic welding technology, especially on sections with highest demands of reliability, such as high-speed lines with mixed traffic.

11. Premium product ballasted track
Ballast bed correctly installed in layers leads to highest track geometry quality.
Initial quality 0.3 mm SD (D1)
Tamping intervals: 100 – 150 mill.
“Premium product ballasted track“ -
A sustainable solution for high-speed lines with mixed traffic.
High speed lines have contributed to the development of more wear-resistant components in recent years.