There is a generally accepted idea that capacity increases with the application levels of the ERTMS (European Rail Traffic Management System) signalling system; in other words, ERTMS Level 2 allows for greater capacity than Level 1, which in turn has greater capacity than a line with a traditional signalling system such as ASFA, which is deployed in the Spanish network.

However, there is currently no harmonized method in European or international regulations for assessing the impact of ERTMS deployment on railway line capacity: for this reason, Ineco, with its extensive experience and expertise in this field (see IT46), carried out an innovation project in 2016 with the aim of developing one. The conclusions reached in this project make it possible to propose improvements across the entire network or on specific lines in order to optimise capacity.

Why?

This qualitative and quantitative assessment method will serve as a basis for the development of different types of technical studies. First, as part of strategic railway plans to define which infrastructure actions are most appropriate, how to deploy or not to deploy ERTMS, and at which level, implications for rolling stock, etc.

This method makes it possible to assess the impact of the deployment of ERTMS on the capacity of a railway line

The method is also useful for optimizing the detailed design of the ERTMS functions of a railway line or network, taking into account aspects such as the network’s capacity and regularity. Lastly, this method can be used to calculate the capacity of a section after the deployment of the ERTMS system. In addition, it could be considered as a basis for the future development of a specific module in a tool for complete calculation of railway network capacity data.

Results

For the initial application of the method, the values of a typical high-speed network with a homogeneous fleet of passenger trains were taken as a starting point.

The data was divided into three categories: fixed data that cannot be changed in the network being studied, semi-fixed data that corresponds to the aspects of ERTMS functions common to most ERTMS projects, and variable design data within capacity analysis.

It should be noted that this classification may vary depending on the type of study performed. For example, line block sections may be fixed in cases in which only ERTMS will be installed, or variable in cases where some action on the line, in addition to ERTMS deployment, is allowed.

The variable data used in the study was: movement authority, the ERTMS braking algorithm, speed restrictions and gradient. The conclusions generated by the study included an improvement of 9.67% in time between trains by installing ERTMS Level 2 instead of Level 1 on the same section of line. However, applying the qualitative analysis, it is unlikely that this improvement would occur on a network with different characteristics.

Its application helps to formulate strategic plans to define which actions are most appropriate, how to deploy or not to deploy ERTMS, and at which level

Some conclusions were also reached regarding the impact on capacity with respect to other much more detailed characteristics of ERTMS, such as inhibition of the service brake in the ERTMS braking curve algorithm which results in an improvement of 0.51% in time between trains in this network.

The number of trains per hour is one of the most important characteristics to take into account in most railway operations, on both new and upgraded lines: the greater the number of trains that can circulate, the more profitable the infrastructure will be. This calculation is important in different project phases: in the strategic  decision stage (which sections of the network to upgrade, which ERTMS levels to install, etc.) as well as in more detailed phases, in which it is necessary to know the exact number of trains per hour to include in the business case or design ERTMS functionality to optimise this capacity.

Finally, it was also possible to identify some scenarios in which the ERTMS deployment reduces capacity, for example, the large impact that temporary speed restrictions in Level 1 can have. This demonstrates the need to carry out technical studies based on this method of assessing the impact of ERTMS on capacity before defining the actions required to upgrade a railway network.

With more than three million travellers in 2015, according to data from the Ministry of Public Works, passengers have given the ‘thumbs up’ to the Atlantic Axis, a railway infrastructure designed for speeds of up to 250 km/h. The renovation, electrification and duplication of existing routes in addition to the construction of new bypasses and several viaducts, bridges and tunnels have made it possible to transition from the old, non-electrified single tracks to high-performance rail infrastructure: greater speeds, capacity, safety, frequency and comfort for passengers who save up to 58% in travel time. In addition to making renovations to the rolling stock, Renfe has also maintained fares and reorganised rail services which are now divided into “express” and “local” services to cover direct routes between large cities as well as between the urban centres near these cities.

Ineco collaborated in the execution of these projects which have revitalised railway transport in Galicia. According to data from the Railway Observatory of the Ministry of Public Works, the A Coruña-Santiago route is one of the top five regional rail lines for traffic in all of Spain. The Businessmen’s Association of Galicia (Círculo de Empresarios de Galicia) considers that the growth in traffic along this route –a growth of more than 90% between 2008 and 2013– is “a fact that must be directly attributed to the improvement in infrastructure and the implementation of a high-performance rail line on this route of the Atlantic Axis”.

Ineco has worked in construction & environmental management & monitoring, project drafting, inspections & structural testing

In April 2015 the Santiago de Compostela-Vigo section was inaugurated –the third of the three sections that make up the majority of this route which represents a milestone in the modernisation of the Galician railway. The territory of this region is characterised by a great dispersion of populated areas: few big cities –concentrated in costal areas–, many small, isolated areas –especially inland– and very rugged terrain. In addition to these characteristics we can also mention the natural geographical barriers that separate Galicia from the Meseta –barriers that have historically stood in the way of constructing land transport infrastructures, both road and rail.

A far-reaching project

The Axis, spanning 155 kilometres, runs along Galicia’s Atlantic Coast and connects the main areas of industrial and economic activity as well as universities, areas which fuel the demand for transport. The pre-study phase is already underway for the connections A Coruña-Ferrol (63.2 km) to the north of the Axis, in addition to Vigo-Border of Portugal (22.1 km) in the far south of Galicia. The route also connects Santiago with Ourense in the east where this section links up with the high-speed access route to Madrid which is currently under construction.

Initial work on the transformation of existing infrastructure into a modern, high-performance, rapid railway corridor began in 2002. Work was carried out in phases and consisted in installing, along the entire route, a double track with multi-purpose sleepers that will later allow for the change from the Iberian gauge to the standard gauge. The line has also been electrified to 25 kV at 50 Hz, and bypasses have been constructed which have shortened the route by almost 22 kilometres. New sections of the line, owing to the land’s rugged terrain, required several structures: 37 tunnels –totalling a distance of more than 60 kilometres– and 32 viaducts that span a total of 14.9 kilometres. The majority of these structures are located along the section between Santiago and Vigo. This was the most complex part of the route to construct and was the last to begin operating, following both A Coruña-Santiago in 2009 and the Santiago-Ourense connection in December 2011.

In addition to the work concerning electrification, platforms and route corrections (bypasses), adapting the line to new, high speeds also required the remodelling of stations at A Coruña, Santiago de Compostela, Pontevedra, Uxes, Villagarcía de Arousa and Arcade-Apeadero, as well as the construction of new stations: Cerceda-Meirama, Ordes, Padrón-Barbanza, Redondela High Speed and Vigo-Urzáiz, as well as the “temporary” Vigo-Guixar station.

Ineco on the Atlantic Axis

Throughout these years, Ineco has offered their services to the Ministry of Public Works, Renfe and Adif in these highly technical and complex activities, just as they did for the rest of the rail network. Ineco was thus responsible for carrying out tasks regarding the management, coordination and surveillance of construction work, the environmental management of different sections along the whole of the Axis, and the drafting of architectural plans (stations) and railway installations (signalling, safety, telecommunications, etc.).The company also conducted a number of studies in addition to inspections and structural load tests, some as exceptional as that of the Ulla viaduct (see IT54)

Ineco furthermore provided assistance in the management and coordination of tunnel construction work, such as the Vigo access tunnel measuring 8,266 metres long which was carried out using tunnelling machinery, and in the installation of safety systems: electrical installations, ventilation, fire protection systems, etc..

Also worth mentioning in relation to architectural work is the drafting of the construction project for the Vigo-Guixar station which, starting in 2011, has operated as the sole station following demolition of the old building while the new terminal was constructed (in the same location). The Guixar station is a two-storey passenger building boasting 1,000 square metres of space, three platforms measuring 285, 165 and 100 metres long for long-distance and regional rail trains, parking, and bus and taxi stops. When the new Vigo-Urzáiz station began operating in 2015, the Ministry of Public Works decided to keep the Guixar station open to freight transport as well as to local trains.

Ineco also carried out a project, completed in 2010, to standardise architectural elements such as marquees, enclosure gates, decorative elements and locks at nine stations: Redondela, Pontevedra, Padrón, Ordes, Cerceda, Uxes, Pontevedra-Universidad, Arcade and Vilagarcía de Arousa. New passenger buildings were also designed for the latter two stations.

The 155-km line has reduced the average travel time between A Coruña and Vigo by 58% and is one of the most widely travelled routes Spain

With regard to new sections of the line, Ineco coordinated the construction of the Ordes bypass in the province of A Coruña, a section that, over a span of just 7.2 kilometres, required two tunnels and a handful of viaducts. The Vilagarcía-Padrón bypass located between Santiago and Vigo stands out for its complexity, reaching a length of 26.1 kilometres. The company provided technical assistance throughout the management of construction work as well as during the environmental management, control and surveillance of several subsections. The bypass was one of the corridor’s most complex sections with seven tunnels and a dozen viaducts, including one which crosses the Ulla river (spanning a distance of 16 kilometres) and another that crosses over the Sar river –the longest on the Axis- measuring 2.4 kilometres.

Ineco also played a role during each of the phases of development of another high-performance railway connection: the line which links the Atlantic Axis to Ourense from Santiago (see IT18 and 44). The company was highly involved in all of the stages of development of this 150-kilometre section of the line, from project drafting to drawing up operations and maintenance plans, as well as during the construction phases including construction and environmental management services, technical assistance, surveillance and coordination services, etc. Since it entered into service in December 2011, the Santiago-Ourense corridor has also contributed to improving railway connections with the Meseta by reducing existing conventional service travel time by 50 minutes.

How can we ensure that a taximeter is reliable or that a nuclear facility is safe, that a bulletproof vest is really bulletproof or that the MOT that reviews a vehicle does not act arbitrarily? In Spain, more than 1,600 entities ensure that many products, procedures and services available in the market comply with the regulations of their respective sector. A Spanish government body, the National Accreditation Entity (ENAC), is responsible for authorising who guarantees the safety of consumers and end users. Entities must renew their accreditation every year, demonstrating that they comply with the strict requirements of independence, rigour and transparency that are required for this work.

Rail lines

The wide range of products and services subject to receiving a certification endorsed by an ENAC entity covers any type of production and different types of entities, such as testing or calibration laboratories, inspectors, or certifiers and environmental verifiers from practically any sector: industry, energy, environment, health, agriculture and food, research, development and innovation, telecommunications, tourism, services, construction, transport, etc.

The inspection activity of Ineco falls within the latter, specifically within railway, and in 2009 it obtained its first ENAC accreditation as an ‘independent safety assessor’ with the number 76/EI058. In 2015, it was renewed and extended to the fields of rolling stock, energy, infrastructure, maintenance and exploitation and traffic management. The company has a multidisciplinary team consisting of professionals accredited by ENAC. The work of the entities certified by ENAC, moreover, is not only valid in Spain, but also in the over 70 countries with which it has mutual recognition agreements, including the European Union, United States, Canada, China, Japan, Australia, Brazil, India, United Arab Emirates and Mexico, amongst others.

Why an independent safety assessment?

In addition to rolling stock, since the beginning of rail at the end of the 19th century, the main rail elements related to safety have been signalling systems, in order to avoid the greatest risk of all: collisions between trains. From manual signals to lights, to digital systems and radio without physical signals on the tracks –as is the case for ERTMS level 2–, the different control, command and signalling systems (ASFA, LZB, ERTMS, etc.) have evolved to become more complex and sophisticated, always with the objective of guaranteeing the safe circulation of trains.

The current rail lines –conventional and high speed–, are very complex infrastructure that consist of a large number of elements and undergo very extensive legal and technical regulation that requires a high degree of specialisation by the inspectors. From the time they are planned until they are commissioned, European and international regulations require verification that each and every one of the elements and subsystems work correctly, from the simplest, such as the ventilation of a tunnel, to the most complex, such as software.

For this purpose, two types of safety study are carried out. On one hand, risk analyses, in which threats are identified that could bring the system to a potentially dangerous situation and work is being carried out on mitigation measures or barriers to avoid them. They can be carried out in any stage of the project and seek to detect the weak points of the system. Moreover, and on a higher level, there is the type of study known as ISA (Independent Safety Assessment). Unlike risk analyses, ISA can only be carried out by an accredited entity. They are essential to guarantee for a third party –the operator or rail authority– that a new line or modification of an existing line is safe and can begin or continue to be used.