Tilting trains are a solution for reducing railway journey times. Especially suitable for existing highly curved routes where traffic flows do not justify investment in new lines or new lines and realignments are precluded by environmental/ecological considerations. The effectiveness of the investments may be jeopardised by comfort and nausea constraints.
Currently each manufacturer tries to find an acceptable compromise for the operation of their vehicles, in the absence of basic knowledge of the causes of nausea. In many cases different data and methodologies are used in different countries for upgrading railway infrastructure for tilting trains.
This proposal will produce criteria for nausea constraints and integrate it with available comfort criteria to provide a common solution applicable to all countries solving the problem at an international level.
- To provide the methodology for upgrading infrastructure to achieve the optimal performance for using tilting trains, with special attention to mixed traffic conditions.
- To identify the boundary conditions which limit the number of passengers experiencing nausea to a statistically acceptable level.
- To identify the conditions for which some passenger experiences nausea.
- To search for procedures, for using tilting train technology, which maximise performance whilst avoiding the onset of nausea.
- To produce a specialised verified simulation tool, for performing simulation without the need for full scale experiments on the track.
- To identify economic design of track and/or coach for a given performance and a given comfort level.
- To reduce the time needed for introducing new rolling stock on new, renewed and existing lines.
- To maximise the performance of a tilting train for a given configuration of track and coach design.
The methodology of this project involved the following phases:
- Phase 1: Exchange of knowledge, not every partner had the same knowledge on the problem. It was necessary to inform each other in such a way that everybody had enough and equal information to start the common study.
- Phase 2: Organise laboratory investigations, to complete the lacking information we need to prepare and analyse the line tests with success.
- Phase 3: Organise and execute the line tests. Prepare the recorded data for analysis.
- Phase 4: Analyse the line tests. Describe the results.
- Phase 5: Communicate the results of the analysis of the line tests and complete the track layout album taking into account the latest results.
In WP1 (Questions Related to Track Layout), two reports were published, giving rich synthetic information on the consequences of track layout and comparing European Standards and national limits.
In WP2 (Questions Related to Onset of Nausea), a method was found and applied that permits a regression analysis of the results test runs who investigate nausea. Key elements in the new method are:
• Net dose evaluation of the parameters having influence on nausea
• Excel solver like optimising of parameters like time constant; scale factor and regression constant (Or a binary method finding local extreme)
The key recommendations relate to the further work required. On the basis of the experience of the tests executed by the consortium and the general knowledge in this field, the following aspects need to be studied further before new line experiments can be held:
- What is the confidence zone of the average net dose parameters an homogeneous group of males, exposed to a sinusoidal vibration of X Hz, level Y m/sec2?
- What is the confidence zone of the average net dose parameters a homogeneous group of females, exposed to an identical stimulation?
- What is the influence of age and homogeneous group?
- What is the influence of reusing people?
- What is the best weighting function for roll speed?
- What is the best weighting function for fore and aft acceleration?