Estimation on the ride comport and running stability for tilting train on the Gyeongbu line in the Korean rail Network

초록

Korea is a mountainous country, with as much as 70% of the area iscovered by hills and mountains. This geography places constraints on theminimum radius of curvature for the rail network and keeps from speeding up due to a lot of curves on railways. However, for attracting more traffic into the railway, it is important for railway to cost-effectively improve the competitiveness, especially as regards travel time or schedule speed. Thus, it was expected that thespeed of trains could be enhanced on the existing railway network withouta huge investment in infrastructure by using tilting trains. The development of tilting trains in Korea started in 2001 as research& devel-opment project. A 6-car prototype test tilting train, called theTilting Train eX-press (TTX), was built in December 2006 andexperimental trials began in 2007. TTX has distributed power, is designedto run at 200 km/h, and has a planned service speed of 180 km/h. Running time for tilting train is one of the most important factors, with which will be done whether the commercialization of tilting train is needed or not.In this paper, the running time and time savingof tilting train was evaluated compared with today’s conventional trains and non-tilting trains, based onthe Central line, which was candidate for tilting train operation between Cheong- nyangni and Youngju. So the time saving could be separated into two effects by higher track top-speed and tilting devices. We found a significant reduction of the journey times as of 2013 compared with today’s conventional trains. Approximately a 36% reduction is expected on the Central line. But the 90% of this reduction is due to the increased track speed through upgrading the line and the rest 10% by tilting technology. This large difference is explained by the fact that many sections of the line were rebuilt or will be rebuilt to larger curve radii, thus this leads not to fully using the speed benefits through tilting. Also, in the near future, the difference in running time between tilting and non-tilting trains will be more decreased, as most of the sectionson candidate route are to be straightened. Therefore, we need to find the best railway lines, where tilting trains could be a cost-effective alternative to reduce running times, of which alignment changes can be hardly practicable because of the existing infrastructure positions (such as bridges or tunnels) and huge large costs.Given these conditions, we have started to review the introduction of tilting train services into the Gyeongbu line (Seoul ~ Busan 441.7km) line which is the first arterial rail corridor of the country.In the next step of research, we will evaluate the potential of a speed-up of tilting trains on curves, on the basis of tilting train trial run data on the Gyeongbu line and present tilting trains’ competitiveness in terms of travel time and speed. We hope this will lead to introduce tilting train service on the existing Gyeongbu line in Koran rail network.