Page 222 - 360.revista de Alta Velocidad - Nº 5

Escobar, Adrián. Zamorano, Clara Isabel. Jiménez, Pablo Lorenzo. Escobar, Jorge.

1. Introduction

High-speed railway systems have been widely accepted in modern society, positioning themselves
as one of the most important means of transport to guarantee the territorial structure. These
systems present different conceptions or design philosophies regarding the superstructure
subsystem, which has led to the generation of different infrastructure models characterized by
a predominance of ballasted track or by a predominance of ballastless track.

Although historically the first lines had only the typology of ballasted track, nowadays, it is
possible to find regions in which the implementation of the slab track is majority. The choice
of typology will depend on technical factors such as relief, environmental conditions, design
speed, availability of materials, etc.; and economic factors mainly characterized by the
financing capacity and operating and maintenance costs.

However, in the last years, different High-speed projects have been launched in different
parts of the world, where new technological challenges are being pursued, among them, the
achievement of a maximum speed of around 400 km/h or, the fact of leading a High-speed line
through an environment with extreme meteorological conditions. The main objective of this
article is to make a deep reflection on the typology of railway superstructure that will be used
to face these new technological challenges and to discuss the main limitations that can present
the typology of ballasted track regarding to its use in the future High-speed lines.

With this aim, a brief historical review of the main track typologies used in the High-speed lines
will be carried out, then the main limitations of the ballasted track will be described, in the
third place, the main High-speed projects that are currently being developed around the world
will be shown and, finally, it will be analyzed if there is any trend for the implementation of a
typology of superstructure in particular.

2. State of the art

2.1 Historical review

With a length of 515 kilometers, the first High-speed line came into operation in Japan in
1964 from Tokyo Central to Shin Osaka, as shown in Li et al. (2016). This line has currently a
maximum operating speed that reaches 285 km/h and has a track superstructure belonging
to the ballasted track typology, as per UIC (2015). However, it was not until 1975, with the
completion of the Sanyo line, when the first High-speed line with a ballastless superstructure
was implemented in Japan, as explained by Yokoyama (2010), which currently has a maximum
operating speed that reaches the 300 km/h, as per UIC (2016). This line was the first Highspeed
line in the world that introduced the use of the slab track in a percentage around 50% of the
total length of the infrastructure. The Japanese High-speed network had a total length of 1,244
km of slab track in the year 2001, as shown in Ando et al. (2001).
However, before 1964 there were already several attempts by countries such as Germany, France
or the United States to launch High-speed Rail projects, which eventually became separated
historical records, as described by Hughes (2015).

In the case of Germany, in 1903, 200 km/h was exceeded with an electrically powered train
between Marienfeld and Zossen, over a ballasted track, as shown in Ebeling (2005). Nevertheless,
it will not be until 1991 when the regular High-speed service will finally be implemented with
the ICE train, using a superstructure of ballasted track, on the lines from Mannheim to Stuttgart
and from Hannover to Würzburg, with a maximum speed of 280 km/h, as explained by Beck
(2006). Although, the first ballastless track system is developed in 1972 at the Rheda Station,
it will not be until 1998 with the construction of the line between Hannover and Berlin, when

220 360.revista de alta velocidad