Design evaluation of flange back steering for railway switches

Bezin, Y. (Speaker), Dimitrios Kostovasilis (Speaker), Sergio Goncalves Moreira Das Neves (Speaker), Andy Foan (Speaker)

Activity: Talk or presentation typesOral presentation

Description

In the project In2Rail, a team of researchers from the University of Huddersfield helped evaluate the basic principles and potential benefits or disadvantages of using Flange Back Steering (FBS) concept for switches. This was achieved in a virtual environment using multibody dynamics simulation software to understand loading requirements before any physical prototype is built or proposed for further Shift2Rail development. A specific realisation of the FBS concept was proposed by ERT in the form of the SureSwitch design. The simulation process was used to allow the design to evolve, for example by making slight changes to the knee design (longitudinal position, width, shape and topping angle) to improve load transfer in the knee area and reduce potential damage in this area. The simulation allowed a comparison of this new interface with current loads generated in crossing panels to ensure that the performance was appropriate. The simulation allowed the team to scientifically explain and quantify the fact that FBS removes the necessary steering from the outer wheel-rail contact and places it entirely on the back of the inner wheel. Doing so removes the need for typical switch-stock rail assembly, prone to the largest amount of failures, also including failures of point operating equipment necessary to drive the long switch rail, but displaces the requirement for lateral steering forces onto the interface between the back of wheel and the steering bars. Large loads are generated there up to the knee position because of the lack of steering from the axle as a result of removing the thin switch blade below the outer wheel. Quantifying the lateral load transfer applied to the steering components, drove the requirement for specific material use on these components, which are the steering and control bars as well as the knee. Safety criteria were also investigated looking at derailment factor (Y/Q) and wheel unloading (ΔQ/Q) to ensure the proposed system is at least as safe as the existing ones. Because the flange back contact is practically vertical, this is not seen as posing a risk of derailment, however there is a need to carefully look at the knee structural support and tolerance to ensure no risk of knee strike is possible and that shape deterioration is minimised.
Period2018
Held atThe Fourth International Conference on Railway Technology
Event typeConference
Conference number4
LocationSitges, Spain
Degree of RecognitionInternational