Railway Transportation Systems

Design, Construction and Operation

Christos N. Pyrgidis

• Editorial: CRC Press
• Año: 2021
• ISBN:
  9781000462876
• Edición: 2
• Categoría: Technik & Maschinenbau
• Categoría: Transport & Navigation

Railway Transportation Systems covers the entire range of railway passenger systems, from conventional and high-speed intercity systems to suburban, regional, operating on steep gradients, and urban ones. It also examines in depth freight railway systems transporting conventional loads, heavy loads, and dangerous goods.

For each system, the text provides a definition; an overview of its evolution and examples of good practice; the main design, construction, and operational characteristics; and the preconditions for its selection. Additionally, it offers a general overview of safety, interfaces with the environment, forces acting on the track, and techniques that govern the stability and guidance of railway vehicles.

This new edition brings two new chapters. One concerns pre-feasibility studies of urban rail projects, and the other analyses the operation of railway systems under specific weather conditions and natural phenomena. New material examines dilemmas, trends and innovations in rail freight transportation; a new definition for high-speed rail; a number of case studies; and an update of cutting-edge technologies. It is ideal for graduate students, engineers, consultants, manufacturers, and transport company executives who need a reference and guide.

Chapter 1 The railway as a transport system

DOI: 10.1201/9781003046073-1

1.1 Definition

The ‘railway’ or ‘rail’ is a terrestrial-guided mass transport system. Trains move on their own (diesel traction) or through remotely transmitted power (electrical traction) using steel wheels¹ rolling on a dedicated steel guideway defined by two parallel rails.

1 For a small number of metro lines and for many cases of driverless railway systems (cable-propelled and self-propelled) of low/medium transport capacity, rubber-tyred wheels are also used.

The railway transports passengers and freight. Its capability can extend to cover any distance in any environment (urban, suburban, periurban, regional, and interurban). Its range for passengers’ transportation is usually suited to approximately 1,500 km², while for freight the distances can be much greater³.

2 The longest railway route worldwide has a length of 2,439 km (Hong Kong–Beijing Xi, China) (Hartill, 2019). 3 The longest freight train routes connect Europe and Asia (distances in the range of more than 10,000 km).

From a transport system point of view, it is by default considered to comprise three constituents:

• Railway infrastructure.
• Rolling stock.
• Railway operation.

1.2 Constituents

1.2.1 Railway infrastructure

The term ‘railway infrastructure’ describes the railway track and all the civil engineering structures and systems/premises that ensure the railway traffic (Figure 1.1).

Figure 1.1 Constituents and components of the railway infrastructure.

The railway track consists of a series of components of varying stiffness that transfer the static and dynamic traffic loads to the foundation. Hence, the railway track comprises successively from top to bottom the rails, the sleepers, the ballast, the sub-ballast, the formation layer, and the subgrade (Figures 1.2 and 1.3) (Giannakos, 2002; Profillidis, 2014).

Figure 1.2 Railway track. (Adapted from Giannakos, K. 2002, Actions in Railways, Papazisi (in Greek), Athens.)

Figure 1.3 Railway track; ballasted track superstructure, Athens-E. Venizelos Airport suburban line, Greece. (Photo: A. Klonos.)

The rails are mounted on the sleepers on top of elastic pads to which they are attached by means of a rail hold-down assembly called the rail fastening (Figure 1.4).

Figure 1.4 DFS (Direct Fastening System) with adjustable steel baseplate. (From edilon)(sedra, 2015.)

Rails, sleepers, fastenings, elastic pads, ballast, and sub-ballast constitute the ‘track superstructure’, while the subgrade and the formation layer constitute the ‘track substructure’ (Figure 1.2).

The upper section of the track superstructure that comprises the rails, the sleepers, the fastenings, and the rail pads forms what could be commonly called the ‘track panel’. Switches and crossings by means of which the convergence, cross section, separation, and joining of tracks at specific points of the network are accomplished are also considered to be part of it (Figure 1.5).

Figure 1.5 Switches and crossings configurations, Zurich, Switzerland. (Photo: A. Klonos.)

The lower part of the track superstructure that comprises the ballast and its sublayers is called ‘track bed layers’. The track bed layers and the track subgrade, considered as a whole, are called ‘track bed’.

Apart from the ballasted track bed (conventional or flexible track bed), a concrete track bed (slab track or rigid track bed) is more and more frequently used. The latter solution has proven to be very efficient in the case of underground track sections, where maintenance requirements are greatly restricted (Figure 1.6).

Figure 1.6 Slab track, Tempi tunnel, Greece. (Photo: A. Klonos.)

A third ...