On 1 February, the new 54-kilometre section of high-speed track between Monforte del Cid and Beniel –which includes the new stations of Elche Alta Velocidad and Orihuela Miguel Hernández– was opened by the Spanish Prime Minister Pedro Sánchez. He was accompanied by José Luis Ábalos, the Minister of Transport, Mobility and the Urban Agenda, and Ximo Puig, the President of the Autonomous Community of Valencia (the image shows the three men at the station in Elche along with the mayor, Carlos González, on the right). The minister highlighted the one-hour reduction in the travel time between Elche and Madrid and the two new daily connections between Murcia and the capital.

Ineco has worked on all of the high-speed sections in the Levante region (see IT47) and this time provided Adif with a range of services, such as the drafting of plans for safety installations, construction management, technical assistance for platforms and stations, signalling and telecommunications, track assembly, overhead lines, running tests, and supervising and testing the ERTMS Level 2 system. Of particular note in this respect is the technological milestone of the commissioning of Spain’s first handover between different technologies, which took place in the triangle formed by Murcia, the Vinalopó split and Monforte del Cid. The project was implemented by CAF Signalling and makes it possible for RBC systems from two different manufacturers, Hitachi and Alstom, to hand over control of the trains passing through their respective areas of operation.

On 26 October, the Minister for Transport, Mobility and Urban Agenda officially opened the high-speed line in Galicia between Zamora and Pedralba de la Pradería, leaving only one leg to complete the line. The new railway, 110 kilometres long and with 14 viaducts and 9 tunnels, is outfitted with level 2 ERTMS and has been built for speeds of 300 km/h.

Ineco has been heavily involved in work on the line. It is currently the works and environmental manager for several sites on the last unfinished section, between Pedralba and Ourense (see IT67). At 101 kilometres long, and with 32 viaducts and 31 tunnels, Transport Minister Abalos declared that “this is one of the most complicated stretches of high-speed railway in Spain and Europe”.

The official opening was also attended by the Minister of Work and Social Economy, Yolanda Díaz, and the Presidents of Adif and Renfe, Isabel Pardo de Vera and Isaías Táboas, along with other leading figures.

Ineco was involved in the assessment of the integration of the Birmingham to Leeds eastern leg of HS2 with other rail projects in the region, carried out by the UK’s National Infrastructure Commission (NIC) at the request of the Government. The report for that assessment concluded that investments in the North and the Midlands should be given higher priority since they offer significant improvements in capacity, connectivity and reductions of greenhouse gas emissions from the mid-2030s.

Having commissioned an independent review of the entire high-speed rail project, in February 2020, Prime Minister Boris Johnson confirmed the need for, and the importance of, HS2 as the new ‘backbone’ of the country’s transport network, while at the same time announcing a new rail plan for the North and the Midlands.

Meanwhile, in September, work officially started on Phase 1, which is expected to generate 22,000 jobs in the United Kingdom over the coming years.

Ineco has been working with AECOM and Capita on the preliminary design of the civil works and environmental impact studies for Lot 2 of Phase 2B of the Birmingham-Leeds leg since 2017. In 2012, Ineco started work with Capita on Phase 1, London to Birmingham.

Ineco’s technicians and engineers are working on projects, construction management and the provision of technical assistance for Adif and Adif Alta Velocidad, together with construction companies and other companies in the sector, for the modernisation of the conventional lines currently in operation and for the construction of the Madrid-Extremadura high-speed line, designed for passenger traffic with a maximum speed of 300 km/h and freight traffic up to 100 km/h.

The work is intense. In addition to having designed the Plasencia-Cáceres section, the company has been contracted for the management of platform works, track assembly, electrification, substations, removal of level crossings, noise protection, regulation of the effects on roads of the Regional Government of Extremadura, infrastructure conditioning, etc., all of which is essential for the trains to begin running on the new infrastructure. The doubling of the track between Cáceres and Mérida, the control, command and signalling installations, telecommunications, the electrification of the line and the remodelling of four stations on this route are the latest works in which Ineco is currently involved.

Most significant figures for the new infrastructure.

A route along the ancient Roman Silver Route

The Plasencia-Badajoz section, with a total length of 144.5 km, is the main axis of Phase 1 of the commissioning of the line. It has been designed with a platform for standard-gauge double track and mixed traffic, except for the Mérida-Badajoz section, which will be put into service with a single track. It passes through a large part of the province of Cáceres, on a route that in the section from Plasencia to Mérida runs parallel to the A-66 highway, the Ruta de la Plata, a modern testimony to a section of the ancient Roman road that crossed Extremadura from north to south.

The Tajo and Almonte viaducts, the latter having received several awards as the world’s longest arch-railway bridge, and the Santa Marina tunnel are the most notable individual works in this section. Experts from Ineco directed the work on this tunnel and are managing the works on the Plasencia, Cáceres, Mérida and Badajoz stations, for which they designed the remodelling projects.

Construction works: platform and track installation

The platform has been completed except for the sections of the Mérida bypass that are not included in Phase 1. In regard to track installation, the Mérida-Badajoz section has been completed, along with the installation of track 1 of the Cáceres-Mérida section, both in single track. The installation of the Plasencia-Cáceres section is more than 90% complete, and construction of  Track 2 of the Cáceres-Mérida section began in February 2020.

Track assembly work on the section between Plasencia and Cáceres in October 2019.

The technical construction challenges

The implementation of electric welding and the new method for rail unloading

Track installation involved the application of techniques that are rarely used in Spain, such as electric welding right on the track using mobile equipment, a procedure used with the high-speed line to Toledo and on the high-speed line between Makkah and Madinah in Saudi Arabia. This system produces higher quality, more durable welds than those produced by aluminothermic welding, aiming to achieve the goal of ‘zero maintenance’. The work is completely automated and if executed sequentially with stress neutralisation, both activities can be optimised.

In addition to the rail supplied by rail trains in 270-metre bars, rail in 108-metre bars was supplied on conventional platforms consisting of two sextets, which required the development of a new unloading procedure to optimise work performance.

The systematisation of the electric welding procedure with mobile equipment presented a major challenge. After supervising the execution of more than 1,400 welds and the subsequent performance analysis, the information gathered by Ineco made it possible to compare the technical work procedures associated with this activity with existing procedures. This experience could potentially lead to an improvement in projects and technical reference documents, in line with the company’s Strategic Plan ATENEA 2019-2022.

Unique infrastructures

Santa Marina, the longest tunnel on the line

The line between Plasencia and Badajoz has two tunnels totalling 4.4 kilometres in length, with 3.4 kilometres corresponding to the Santa Marina tunnel, in addition to its 1.5 kilometres of evacuation galleries. Located halfway between Plasencia and Cáceres, this tunnel crosses the Sierra de Santa Marina and is designed for high-speed double track and mixed traffic.

The Santa Marina tunnel crosses the regional Alentejo-Plasencia fault, one of the largest on the Iberian Peninsula. Ineco managed the construction of the 3.4 km tunnel that passes through the Los Castaños pass.

The tunnel was built using the New Austrian Method, has a waterproofing system that uses PVC membranes and a concrete lining. The waterproofing was done using an unconventional system, with sections of reinjectable double PVC membrane, to provide it with a high degree of watertightness to allow the recovery of the aquifer in the mountain range.

22 viaducts totalling over nine kilometres

The line has a total of 22 viaducts totalling more than nine kilometres. The most important viaducts are the ones crossing the Tajo and Almonte rivers in the section between Plasencia and Cáceres. The Almonte viaduct holds the world record for arch bridges and the Tajo viaduct is a close second in terms of span, with both representing outstanding feats of engineering.

The Almonte viaduct, awarded the prestigious Gustav Lindenthal Medal, crosses the reservoir using a long concrete arch with an upper deck and a main span 384 m long, making it the world’s longest high-speed concrete arch bridge.

In addition to the Almonte and Tajo River viaducts, the Vadetravieso viaduct, 1,596 metres long and crossing the river with the same name, is also worthy of note.

Designed by Spanish engineer Juan José Arenas and built by the Spanish-Portuguese consortium FCC Construcción-Conduril, this structure respects the habitat of the Alcántara reservoir, following the measures indicated in the EIS with maximum respect for the surroundings and the environment, including corrective measures to restore the environment and landscape and to facilitate the crossing of the infrastructure by the fauna. The viaduct also included the installation of innovative bird screens, which reduce wind thrusts on the structure, causing the birds to ascend in flight to avoid colliding with the trains.

Wildlife and ornithology reports

The richness of the natural habitat of the region of Extremadura, its pastureland and natural parks –including the Monfragüe, Cornalvo, and Los Barruecos natural parks– are areas of exceptional beauty and refuge for a multitude of birds and other species. From white storks to protected black storks, golden eagles, griffon vultures, kestrels, grey herons, spoonbills, and bustards, 74.1% of the territory of the Autonomous Community of Extremadura has been declared an Important Bird Area.

Ineco prepared monthly reports on the barrier effect on wildlife crossings and the effect on bird life in sensitive areas such as the Llanos de Cáceres y Sierra de Fuentes and the embalse de Alcántara special bird protections areas

The works pass through areas with different degrees of protection: A Special Bird Protection Area (SPA), a Site of Community Interest (SCI) –also known today as a Special Conservation Area (SCA)–, a Habitat of Community Interest and an IBA (Important Birds Area). Studies and preventive and corrective measures for the environmental impact were therefore required, which meant biological stops, population control reports, monitoring of the barrier effect, monitoring of lek mating areas, control of seeded crop areas, etc. Ridges were also built to protect wildlife, which uncovered an archaeological site with a building covering more than 500 square metres, an environment that was studied, catalogued and protected.

Electrification comes to Extremadura

Ineco is leading these works in the Plasencia-Badajoz-Portuguese
Border section, the first electrified section in this region, with the process to be continued in the future to connect to Madrid.

The excavation work, installation of rebar and pouring of foundations for the posts, gantries and overhead line anchors represented a milestone in the history of the Extremadura railway.

Extremadura was the only region in Spain without a single kilometre of electrified track; not for metro, tram, or conventional rail, let alone high speed. Work is currently progressing on the electrification of the Plasencia-Badajoz-Portuguese Border section, both on the overhead contact line and its associated systems and on the traction substations and transformer substations.

The overhead line catenary, designed by Ineco engineers, is an interoperable C-350 type overhead catenary system, suitable for running at 350 km/h, according to the regulations and specifically, the TSI for the energy subsystem and the UNE EN-50119 standard, which means that electric trains can run from Extremadura to Europe.

These works are being carried out on the 125-kilometre stretch between Plasencia and the Peñas Blancas split, approximately 15 kilometres north of Mérida. Approximately 4,200 catenary posts will be erected in this section, covering some 105 kilometres of double track and 20 kilometres of single track, with two railway stations: Plasencia and Cáceres.

The catenary works were divided into four areas, covering a total of 125 km of track

In addition, in regard to the conventional network that complements the high-speed network, work will be carried out on the Monfragüe-Plasencia line (between the Plasencia junction and Plasencia station), Madrid-Valencia de Alcántara (between the junction with the high-speed line section and Cáceres station) and on the Aljucén-Cáceres line (junction with the high-speed platform of the Cáceres-Aldea del Cano section and Cáceres station), as well as the southern branch of Cáceres. This project also includes the electrification of stations, sidings (PAET) and block stations (BP).

In the Plasencia station, tracks 1, 2 and 3 will be electrified, and in Cáceres station, tracks 1, 2, 5 and 7. The block stations will be electrified at the Terzuelo split and at KM 46/308, as well as at the Aldea del Cano PAET. Work and maintenance of the electric traction substations and auto-transformer substations on the Plasencia-Badajoz section is also underway. This work includes the energy installations required for the 2×25 kV electrification of the Plasencia-Badajoz section, which are mainly the Cañaveral (Cáceres), Carmonita and Sagrajas electricity substations (both in the province of Badajoz). In addition to these substations, there are a total of 12 associated auto-transformer substations.

Meanwhile, Adif has already started the bidding process for the electrification of the section between Mérida (Peñas Blancas) and Badajoz, which requires technical approval once it has passed the environmental procedures.

From phone blocks to Full Supervision

The renovation of the railway installations in the Plasencia-Cáceres and Mérida-Badajoz sections is combined with the implementation of the national network’s most efficient and advanced protection and traffic control systems on the new infrastructure in the Plasencia-Badajoz section. Ineco is providing the experience that it has acquired on high-speed lines in Spain to provide technical assistance for the traffic control installations.

The ultimate goal of the work on the control, command and signalling installations, for which Ineco is providing technical assistance to Adif Alta Velocidad, is to outfit the Plasencia- Badajoz-Portuguese Border section with the ERTMS Level 2 train protection system, which will make it possible to travel at the maximum commercial operating speed of 300 km/h in the region for the first time.

Previously, Extremadura had a single unelectrified track that still included routes with telephone blocking and mechanical interlocking, which is why the modernisation of the installations to adapt them to the new standards required on high-speed lines (unifying them with the new platform sections), poses a more than obvious challenge and constitutes the greatest technological leap forward undertaken in the railway sector at a national level.

To guarantee this, an intermediate phase of renovation of the installations has been designed that will allow the Plasencia-Badajoz section to be put into operation under the protection of the digital ASFA system at a maximum speed of 200 km/h. This initial phase will result in a significant increase in safety, capacity and regularity of operation, since it will have double track along practically the entire route, eliminating telephone blocks and centralising control and management of the line at the Seville control centre.

The signalling installations are based on interlockings, together with their intermediate blocks, which allow the safe movement of the trains through the application of SIL 4 systems. The solution designed for the railway network on the Plasencia-Badajoz section has electronic interlockings based on Alstom’s Smartlock technology, with BAB and BLAU automatic block systems. In order to facilitate future maintenance, the interlockings are being upgraded. Some of the interlockings are electrical or even mechanical, as in the case of the Cañaveral or Aldea del Cano installations, which are still operated with a telephone block and will be replaced by a BAU type block. This equipment consists of six electronic interlockings located in Plasencia, Cañaveral RC, Cáceres, Mérida, Guadiana and Badajoz, supported by train detection systems installed in the field (Bombardier EBITRACK 400 coded audio frequency track circuits and Frauscher axle counters), Modular LED trackside signals from ICF, ASFA digital balises from Indra and Siemens MD2000 single-phase electric point machines to replace turnouts and derailers still equipped with manual switch stands, and Thales three-phase point machines for turnouts on the new platform.

The overpasses and tunnel entrances are equipped with Logytel Falling Object Detectors (FODs), which trigger trackside signals in the event of an alarm

Unlike other lines, the energy system designed in this project includes a main supply from the electricity company at all locations, using the overhead line as a backup system. This solution, combined with the inclusion of medium voltage networks as an alternative supply in certain sections, makes it possible to minimise the number of emergency power generator sets to be installed. This all results in a more stable, efficient and clean power supply, reaffirming the railway’s commitment to reducing greenhouse gas emissions.

These unique features, together with the particularly rich and protected environment, add to the complexity of Ineco’s work, which ranges from the drafting of the basic projects, environmental and expropriation documentation, inspection and testing of systems in the field, to the final supervision of the process of powering the installations, not to mention providing advice on the legalisation and contracting of the supplies.

Ineco is participating in the drafting of the basic projects, environmental documentation, expropriations, field tests, legal advice and final supervision

As a final complement, the deployment of the Bombardier ERTMS Level 2 system is planned for the installations of the new line between Plasencia, Cáceres and San Nicolás split, as well as on the line between Mérida and Badajoz. This train protection system is managed through two RBCs located in Cáceres and Badajoz, which are in constant communication with the electronic interlockings supported by the GSM-R mobile communications network, and grant movement authorisations to the trains on the lines that they protect.

The Santa Justa control centre in Seville will provide support for the centralised control and efficient operation of these installations. The Thales CTC will unify the remote control of the interlockings of lines L026 (Plasencia-Cáceres-San Nicolás split), L500 (Monfragüe-Casar de Cáceres triangle) and L520 (Villanueva de la Serena-Badajoz), which was previously distributed between the Chamartín and Manzanares CTCs. A new Bombardier ERTMS central control station will be responsible for controlling this train protection system, and a new Indra remote control for auxiliary detection systems will provide operators with all the necessary information regarding the falling-object detectors.

Videographic of the Badajoz station.

Correction: On page 14 of the print edition, the reference regarding the “province of Extremadura” should be “province of Cáceres”.

Modernisation of conventional lines

In parallel with the construction of the new line, Adif is also renovating its conventional lines, replacing material in some sections and refurbishing level crossings. The aim is to improve the track superstructure, unifying conditions to adapt them to the rail traffic demands. The work involves the improvement of the reliability, safety and quality of the track, reducing the level of incidents, increasing traffic speed and reducing travel times. In future editions of Ineco’s magazine, experts will describe the different conventional-track works being carried out, such as the completed works on the Aljucén-El Carrascalejo section, or the projects in the Monfragüe-Plasencia section that will soon be opened for tenders. Planned works include the renovation of the track superstructure, construction of walls, ballast retaining walls and service walkways, and platform drainage improvements.

New fixed and mobile installations

Work is currently underway on the Plasencia-Cáceres section. The civil works and laying of the optical fibre in the fixed telecommunications installations have been completed, as well as the civil works and installation of the mobile communications equipment between Cáceres and Badajoz. Other projects to be carried out after the commissioning of Phase 1 include:

• Renovation of the track between the Monfragüe and Plasencia stations.
• Doubling of the track between Mérida and Aljucén.
• Renovation of the track yard and accesses to the stations of Cáceres, Mérida, Aljucén and Badajoz.
• Connection of the Montijo station to the HSL.
• Reconfiguration of the splits at La Isla (Mérida) and San Nicolás (Badajoz).
• Remodelling and sustainable integration of the Navalmoral de la Mata station.
• Signalling and telecommunications installations on the doubling of the track in the Cáceres-Mérida section, final location of the Mérida bypass and renovation of the track yards at the stations.
• Logistics platforms in Mérida and Navalmoral de la Mata.

In July, Carmen Librero, president of Ineco, visited the works being carried out on the high-speed line between Plasencia and Cáceres accompanied by Ana Rojo, director of Engineering and Consulting, and Celestino Rodríguez, director of the Office of the President. Ineco is in charge of works management and technical assistance for the track assembly works on this 59-kilometre stretch of standard-gauge double track, of which 3,700 is slab mounted and the rest on ballast, plus 4 kilometres of single track branches to connect the section to the conventional network.

Accreditation as an Independent Safety Assessor has allowed Ineco to participate in the assessment of the safety processes applied by Adif to numerous service commencements, the most recent and relevant of which was the high-speed line between Antequera and Granada, which culminated last June, and the ERTMS Level 2 of the high-speed line between Valladolid and León.

Ineco is currently working on the independent safety assessment of works on the Recoletos tunnel, and on the high-speed sections Olmedo-Zamora-Pedralba; Monforte del Cid-Murcia; and Chamartín-Torrejón de Velasco. All of which are projects of maximum interest to Adif (see report on page 38).

The arrival of high-speed rail in this region in northwestern Spain had its first historical milestone at the end of 2011, with the entry into operation of the 150-kilometre stretch between Ourense, Santiago and A Coruña. After the service commissioning of the line between Olmedo and Zamora in 2015, all that remained to complete the connection between Galicia and the centre of the Iberian Peninsula was the construction of three sections totalling approximately 230 kilometres: Zamora-Pedralba de la Pradería, Pedralba de la Pradería-Taboadela and Taboadela-Ourense.

The difficult route between Pedralba and Ourense

Built for the most part on two separate tracks, the 101-kilometre section between Pedralba and Ourense crosses the different mountain ranges that form the Central Ourensan Massif, a route that the AVE will be able to cover thanks to the construction of 32 viaducts and 31 tunnels, many of them bi-tube, or with one tube for each track. More than 60% of the route was either underground or over viaducts and required special works: in total, the section has almost 11 kilometres of viaducts, the longest of which is the Requejo viaduct (1.72 km), and 126 kilometres of tunnel (62.45 km on the right-hand track plus 55.87 km on the left-hand track and 7.84 km of double track), the longest being the O Corno tunnel (8.6 km).

MADRID-GALICIA HIGH-SPEED LINE. The Madrid-Galicia HSL is co-financed by the European Regional Development Fund (ERDF), ERDF/Cohesion Fund 2007-2013 and Spanish Multiregional OP 2014-2020.

The works that are covered in this report belong to this complex route between Pedralba and Ourense, which Adif Alta Velocidad constructed to provide the highest levels of railway technology, with standard-gauge double track (1,435 mm) throughout the route, and designed for speed limits of up to 350 km/h, with 2×25 kV 50 Hz alternating-current electrification, ERTMS Level 2 and Asfa traffic control systems, and a GSM-R mobile communications system.

Five of the most notable works

THIS SECTION FEATURES A NUMBER OF INFRASTRUCTURES THAT STAND OUT FOR THEIR COMPLEXITY, EITHER IN TERMS OF THE CONSTRUCTION METHODS USED, THEIR DIMENSIONS OR THEIR ENVIRONMENTAL CHARACTERISTICS.

1. The jacked caissons of the Requejo tunnel

Two caissons 80 and 100 metres long jacked under the conventional railway tracks complete the Requejo tunnels.

In the foreground, shoring of the track. Behind, crossways, one of the two caissons already executed. In the background, the opening of the Requejo tunnel.

Several kilometres from Pedralba, the AVE works are progressing through the mountains of the Sanabria region with several notable actions, including the construction of the caissons jacked into the Requejo tunnel, structures built in situ at the western opening of the Galicia side and jacked under the railway tracks, allowing Adif to maintain rail service on the Zamora-A Coruña national gauge line, which intersects with the new high-speed line at this point.

This intersection of the high-speed line with the conventional track was resolved by constructing two reinforced concrete caissons measuring 8.5 metres high and 8.5 metres wide on the inside, with lengths of 79.5 metres for the caisson for the right-hand track and 100.5 metres for the caisson on the left.

In their final position, the caissons form the cut and cover exits of the Requejo tunnels. The execution procedure included the shoring of the conventional track and the construction of engineering structures on a sliding platform close to their final location prior to subsequent relocation by means of a hydraulic jacking across the track to their final positions.

The shoring consisted of a metal structure that allowed the caisson to be moved without affecting the track, ensuring its stability. Due to the shoring work, trains had to run at a speed limit of 30 km/h during the works, as opposed to the normal speed of the route in this area of over 100 km/h. The speed restriction was necessary as a safety measure because the level and alignment of the track in this situation can generate movements that are not compatible with higher speeds. Given the jacking lengths, the caissons were divided longitudinally into two sections that were jacked successively, each with a corresponding battery of 15 hydraulic cylinders with a force of 300 tons per cylinder. At the same time that the successive 50- centimetre thrusts were carried out, the earth was removed by mechanical means, ensuring that the stability of the tracks was not compromised, until the structures reached their final positions.

2. The Padornelo tunnels

A high-speed tunnel built just 20 metres from the longest tunnel on the entire Spanish conventional line.

Ineco provided construction management for Adif Alta Velocidad on this 6,406-metre tunnel with a 52-square metre clear cross-section, which runs parallel to the tunnel of the Zamora-A Coruña national gauge line, and is located between the municipalities of Requejo and Lubián (Zamora), below the Padornelo mountain pass.

The Padornelo tunnel is part of the Padornelo-Lubián section, and consists of the supporting layer of the single UIC-gauge track on the right, measuring 7.6 kilometres long. The left-hand high-speed track will be executed at a later stage as part of a new project that will adapt the old 5.97-kilometre Padornelo tunnel on the Zamora-A Coruña line for mixed traffic on the left-hand high-speed track and freight on the conventional line.

Construction was carried out with conventional excavation, applying supports consisting of shotcrete, bolts and trusses. Excavation was carried out by blasting the areas with the hardest terrain and using mechanical means (backhoes, hydraulic demolition hammers, etc.) in the softer ground and terrain with lower geotechnical quality.

Execution was determined by the proximity of the tunnel on the Zamora-A Coruña conventional line. During the works, trains continued to run, so certain protocols were established to monitor for deformations in both tunnels, and reinforcements consisting of mesh and shotcrete were necessary in some sections of the old tunnel. 15 connection galleries were also built between the tunnels and an evacuation platform along the existing tunnel, to create the evacuation route necessary for the commissioning of the high-speed line. To carry out these works, the entire track was renovated with UIC 60 E1 rail, PR-01 concrete sleepers and type 1 ballast.

The works were accompanied by a series of specific environmental and landscape integration actions due to the proximity of two protected areas or sites of community importance (SCI):  the banks of the Tera and Tuela rivers and their tributaries. In this regard, different measures were agreed with the regional authorities to prevent the impact on the protected flora and fauna. One example was the treatment of water coming from the tunnel, which was subjected to different processes before being discharged into the waterway, in order to ensure that its physical and chemical parameters complied with legislation. In addition, from the beginning of the works, the waters of the rivers belonging to the aforementioned SCIs had their physical and chemical characteristics monitored and a follow-up assessment was carried on the area’s populations of Pyrenean desman (Galemys pyrenaicus), brown trout (Salmo trutta), freshwater pearl mussel (Margaritifera margaritifera) and aquatic macroinvertebrates.

3. The Espiño tunnels

Two large high-speed tunnels constructed using eight simultaneous excavation fronts.

View of the western tunnel opening. The tunnels were designed to integrate with the hillside as much as possible.

The Espiño tunnels are unique in that they were excavated simultaneously from four fronts: in addition to the two end fronts, there were also two intermediate excavation fronts. To do this, an intermediate gallery was built that ended in a large cavern, from which four additional fronts could be started for excavation in the direction of Madrid and Ourense. The large number of fronts reduced the excavation times for the tunnel.

The bi-tube tunnel runs through the municipalities of A Gudiña and Vilariño de Conso in the province of Ourense. With approximately 8 kilometres on each track and connections between tunnels every 400 metres (20 emergency galleries), it is one of the largest tunnels in the section.

Both tunnels were excavated using the New Austrian tunnelling method, with top-heading and bench, from the eastern tunnel opening, from the western tunnel opening and from the intermediate galleries of attack towards both tunnel openings. The right-hand track has an exact length of 7,924 metres including 30 and 40-metre artificial tunnels in each of the openings for improved visual integration into the hillsides. The remainder (7,854 m) was mine excavated, that is, under natural terrain. The left-hand track has an excavated length of 7,838 m underground, to which 30 and 36 metres respectively were added to each of the openings as artificial or cut-and-cover tunnels, giving the left-hand Espiño tunnel a total length of 7,904 m. Cut-and-cover tunnel structures were also included for improved visual integration into the hillsides.

The presence of metal sulphides and carbonaceous matter in some slatey rock required the use of technosols to treat some of the excavated material in the waste sites. This technique made it possible to control the oxidation of these sulphides, which are capable of generating acidic water, thus creating a reducing environment and also decreasing oxidation kinetics. Technosols also act as a buffer, adsorbing any heavy metals that may be present in the runoff water in the form of leachate, and are eutrophising, which promotes eventual environmental integration.

4. The Bolaños tunnels

The only two tunnels on the Madrid-Galicia line executed BY TBM.

Assembly of the 230-metre-long, 2,900-ton TBM in May 2015.

The Bolaños tunnels are the only ones on the entire line executed by a TBM. Bi-tube by design, they form part of the Vilariño-Campobecerros section, and consist of a 6.96-kilometre right-hand track and 7.91-kilometre left-hand track. The route runs through the municipalities of Vilariño de Conso, A Gudiña and Castrelo do Val, in the province of Ourense.

Both were executed using a TBM with the exception of the first 55.91 metres of the western opening and the first 15 metres of the eastern opening on the right-hand track and the first 76.13 metres of the western opening on the left-hand track, which were executed by conventional methods to move beyond a fault.

The dimensioning of the tunnel cross-section was limited by compliance with the UIC’s health and comfort criteria to ensure high-quality high-speed passenger transport. Following these criteria, the final open cross-section of the tunnels was 52 square metres. The excavation cross-section of the TBM was 9.80 metres in diameter, with 37-centimetre-thick segments of precast reinforced concrete lining with an internal diameter of 8.76 m. The concrete in the segments contains polypropylene fibres as a fire protection measure. The gap between the TBM excavation and segment lining was filled with two-component mortar, a mixture of conventional mortar with hydrated bentonite and silicate.

The waterproofing of the precast lining was achieved by fabricating the segments with a low-permeability concrete; installing a double waterproofing seal at the segment joints; and injecting the two-component mortar into the space that remained between the excavated surface and the ring of segments. The injected voussoir is the primary waterproofing, since, in practice, it is the first barrier encountered by groundwater on its way towards the interior of the tunnel, with secondary waterproofing being that provided by the seals.

The two tubes are connected by 18 galleries, one of which is used specifically for installations. The cross-section of the galleries has an open width of 4.70 m and a lining of 25 cm of plain concrete, with the addition of polypropylene fibres as a fire protection measure.

During the tunnel excavation, a large amount of water was generated by the construction processes, and it was necessary to treat it in a large treatment plant in order to comply with the parameters required by the competent bodies. The suspended solids present in the water were removed using a separation process, with the help of coagulants and flocculants. The pH was adjusted through the use of CO₂ (for basic process water) or caustic soda (for acidic process water).

5. The Teixeiras viaduct

A 100-metre-high central arch over the Arroyo Teixeiras.

The central piers are over 90 metres high, with two half-arches that provide a separation of 132 metres between them.

The Teixeiras viaduct, for which Ineco was in charge of works and environmental management, is without a doubt the most spectacular structure on the entire Madrid-Galicia HSL.

The deck of the Teixeiras viaduct was executed using self-launching formwork, and has a length of 508 metres distributed in eight spans (56 m + 4×66 m+56 m). Its uniqueness lies in the construction procedure chosen to negotiate the Arroyo Teixeiras with maximum respect for the environment. The foundations of the central piers (which are more than 90 metres high) are shared by two half arches, which were erected and angled inward to meet at a fixed point under the deck, providing a separation between piers of 132 metres, equivalent to two spans, which, in addition to minimising the impact on the environment, gives the structure greater transparency and beauty. The Arroyo Teixeiras, a tributary of the Támega River, has protected riverbank vegetation and, on the surrounding slopes, a forest consisting of native species with large chestnut and oak trees.

The construction of a large structure like the Teixeiras viaduct requires large auxiliary areas to house the facilities that support the construction: from large cranes to site huts; from storage yards to vehicle car parks. For this site, ways of minimising the impact of this area were studied thoroughly. Detailed analysis was carried out on the opening of roads with steep slopes to reduce their grade, areas of auxiliary facilities on bends or between foundations, work platforms adjacent to jobs with strict occupation limits, etc. All of these installations were located on both hillsides that, in addition to being very steep, had soils made up of highly fragmented materials with high potential for displacement of soil that would reach the waterway below in the case of rain.

In order to prevent or mitigate the effects that this soil displacement could have on the water quality of the Arroyo Teixeiras, an ingenious anti-displacement system was implemented, basically consisting of a network of pipes (concrete ditches, pipes, sandpits, settling pools, intermediate reservoirs, etc.) deployed along the access roads to the foundations, which converge at pumping reservoirs located very close to the waterway. To reduce earthwork and facilitate subsequent integration, metal containers were used as pumping reservoirs so that they could be easily removed after the completion of the works.

In the event of heavy rain, sediment-laden runoff was redirected –by means of powerful pumps– to a treatment system located at the height of abutment 2 of the structure, expanding the response capacity in the case of a heavy rains. In this treatment system, coagulants and flocculants were also be used to accelerate separation if necessary.

By the Ineco construction managers Arturo Pastor, Iago Rodríguez-Lorasque and Noelia Cobo, technical engineer Jesús Pena, and environmental worksite managers Iñaki G. Seoane, Enrique M. Agüera and Luis Álvarez-Pardiñas with the collaboration of Raúl Correas, deputy director of Construction V at Adif Alta Velocidad.

Load tests: ready for action

Prior being put into operation, Ineco carried out the load testing of 25 structures and inspection of 70 bridges for Adif on the Olmedo-Pedralba section of the Madrid-Galicia high-speed line.

By Pablo Sánchez Gareta, civil engineer

The Ineco team, from left to right: Jorge Benito, Amadeo Cano, Pablo Martín-Romo, Javier Ortiz, Pablo S. Gareta and Carlos Sánchez.

During the months of March and April 2019, a team of seven specialists from Ineco carried out an important task for Adif Alta Velocidad prior to the commissioning of the new Olmedo-Pedralba de la Pradería section: load testing and inspection of the bridges and viaducts over which the complex route of the Madrid-Galicia HSL runs, all with satisfactory results.

Load tests were carried out on a total of 25 structures, in addition to the main inspections of 70 bridges (14 viaducts, 2 pergolas and 54 underpasses). In the case of the bridges, and since they were newly constructed, the data collected during the inspections provides a baseline situation (zero state) for subsequent analysis and monitoring of the evolution of the structure.

During the tests, which are compulsory for all new bridges with spans 10 metres or longer, actions of actual use of the works are reproduced under controlled conditions.

In other words, checks are carried out to ensure that the bridge is safe, well built and able to withstand the loads of the trains that will travel over it over time. For these verifications, static and dynamic tests are carried out with loaded trains running at different speeds. Data collected by sensors installed on the structure is analysed and the actual and expected responses are compared. The results are sent to the Railway Safety Agency, which is responsible for authorising the entry into operation of the section.

One of the most representative structures that was tested was the Ricobayo viaduct over the reservoir of the same name, measuring 368 metres long and consisting of four spans of between 50 and 155 metres long. For the test, 2 locomotives and 20 hopper wagons loaded with ballast weighing a total of 1,863 tons were used. On the spectacular viaduct over the Tera River, measuring 645 metres long and consisting of nine spans of between 60 and 75 metres, two trains with eight hopper wagons each, weighing a total of 1,536 tons, travelled at speeds of between 10 and 80 km/h.

Gauge matters

While the Zamora-Ourense high-speed section was being completed, a gauge changer was built in Pedralba de la Pradería to enable trains to travel on tracks with two different gauges without stopping. Ineco managed the works, as it is doing in the Taboadela changer at the other end of the section.

By Marta González, and Noelia Sánchez, civil engineers

Ineco is managing works for Adif Alta Velocidad on the Pedralba de la Pradería gauge changer in Zamora, a railway facility that allow uninterrupted travel by trains between Madrid and Galicia, automatically switching from high-speed track in standard gauge (1,435 mm) to conventional track in Iberian gauge (1,668 mm). In addition, at the opposite end of the section, works have also begun on another changer in Taboadela, Ourense, also managed by Ineco.

A gauge changer is a railway facility that allows trains equipped with variable-gauge axles or semi-axles to automatically change their gauge while travelling at a constant speed (approximately 15 km/h) and without the need for human intervention. In Spain, where the high-speed network in standard gauge coexists with the conventional Iberian gauge (IT57), these systems are essential to enable trains to switch from one to another at points where both exist. This is the case of the Pedralba-Taboadela-Ourense section.

From left to right, engineers Noelia Sánchez, head of the ACO unit, and Marta González, manager of the gauge-changer works in Pedralba, Zamora.

The Pedralba gauge changer is a TCRS3 dual gauge changer, that is to say, suitable for both CAF and Talgo technology. Works included the installation of points that connect the Zamora-A Coruña conventional line to the changer at kilometre 112/405. The installations consist of a metal structure with a main trench where the gauge-change platform is located, equipped with a video recording system. On both sides, there are two observation trenches that allow inspection of the rolling system, which also has an automatic de-icing system for Talgo train wheels. This is a temporary solution until the next high-speed section is put into service, at which point the platform and equipment will be dismantled and moved to another changer.

BRIEF HISTORY OF A GROUND-BREAKING TECHNOLOGY

• The first gauge changers were installed in Spain in 1968 in Irún and Portbou to allow Talgo trains to travel to Paris and Zurich.
• Gauge changers spread at the same time as the high speed network; the first generation included different types for each of the two variable rail technologies in Spain (RD by Talgo and Brava by CAF). The dual system, which was suitable for both, was developed later. Adif installed the first third-generation system (TCRS3) in 2009.
• For more than twenty years, Ineco has participated in the design of most of the different generations of gauge changers. Currently, it is also responsible for the maintenance and operation of more than twenty automatic gauge changers throughout Spain.

On 25 June, the new AVE high-speed line between Madrid and Granada officially opened with an inaugural journey attended by the acting prime minister, Pedro Sánchez (in the centre of the image), the acting minister of Public Works, José Luis Ábalos, the president of Adif, Isabel Pardo de Vera (right), the president of Renfe, Isaías Taboas, and the secretary of state for Infrastructure, Transport and Housing, Pedro Saura, (left), among other guests and dignitaries.

Commercial operation began the following day, on 26 June, with three services in each direction between Granada and Madrid, a distance of 568 km and with a maximum travelling time of 3 hours 19 minutes. A daily service has also been established between Granada and Barcelona with a travelling time of 6 hours 25 minutes. All services stop in Cordoba.

The new high-speed line has three stations, in Antequera, Loja and Granada, and is equipped with ERTMS level 2 and GSM-R mobile communications (see report on page 10).

From left to right: The presidents of Adif and Ineco, Isabel Pardo and Carmen Librero, with Pedro Ruiz, Moisés Gilaberte and Laura López, from Ineco.

Pre-validation tests on the line between Antequera and Granada ended on 20 December 2018, when traffic control was transferred to Adif Alta Velocidad. The infrastructure manager then gave the green light for the start of a period of internal ERTMS traffic testing between Antequera and Granada, prior to reliability and training processes. Once this phase is complete, the high-speed AVE connection between the capital of Spain and the city that is home to the Alhambra will be a reality.

The 114 kilometres of line between Antequera and Granada and its direct connection to Málaga via the Gobantes Junction have been built predominantly in standard gauge, 33% double-track and the rest single track electrified at 25 kV with a top speed of 300 km/h. The exception is 26.3 kilometres of mixed-gauge line consisting of three rails where the line passes through Loja and at the entry into Granada. With the commissioning of the new line, Granada is now finally connected to the rest of the Spanish high-speed network through the Córdoba-Málaga line.

Ineco has participated in the development and construction of this line since its beginnings, carrying out various projects that include consulting and technical assistance for the environmental management of the entire final stretch in Andalusia; platform construction management, project and construction management of the Antequera, Loja and Granada high-speed stations; clearance studies and adaptation of the Loja tunnels; consulting and technical assistance for the construction management of track assembly, and power, signalling and communications facilities along the entire line.

Comprehensive rail traffic management

Traffic testing was the final job carried out by Ineco for Adif and Adif Alta Velocidad. In 2018, Ineco’s traffic management team directed traffic control and performed functional testing during phase 3 of track assembly, facilities and overhead contact line works on all sections. Ineco’s qualified personnel were responsible for comprehensive rail traffic management, which involved directing operations, supervising safety in dangerous areas of the works and ensuring compliance with train safety, construction and testing regulations prior to handover to Adif. The team also managed safety facilities from the CTC located in Granada and was responsible for managing geometric and dynamic testing with laboratory trains to ensure optimum traffic conditions at >10% of the maximum speeds allowed at each point.

The first steps: the construction projects

In 2005, as part of its 2005-2020 Strategic Infrastructure and Transport Plan, the Ministry of Public Works, through a public tender, awarded Ineco the infrastructure and track construction project for the high-speed line between Bobadilla and Granada, part of the Tocón-Valderrubio stretch. The section was designed to allow general speeds of up to 350 km/h and 220 km/h over points. The total length of the section was 14.082 kilometres, with the most significant structures being a 734-metre-long viaduct over the Brácana ravine and the 650 metre Íllora cut-and-cover tunnel. With the project in the home stretch prior to handover, archaeological remains were discovered in the town of Escóznar known as ‘El Pago de El Tesorillo,’ a place mentioned vaguely in a scientific article as the location of undetermined Roman ruins. In order to minimise impact on the area, the railway gradient was raised, and the embankment was replaced by a 150-metre viaduct. The design of El Tesorillo viaduct consisted of five 30-metre spans, a maximum height of 5 metres and detachable beams, in case further excavation is required in the future.

Neolithic village and Roman villa

To reach Granada, at an altitude of 738 metres above sea level, AVE trains have to ascend from 380 metres at Antequera, Málaga, crossing gentle plains interrupted only by the complex geography near the town of Loja, flanked by two mountain ranges and crossed by several rivers and aquifers, where the train line has followed a meandering route that dates back to the 19th century.

It is here when they pass through this town – and until the Loja bypass is built – that fast AVE trains have to slow down to travel along the old conventional track adapted with a third rail, a project carried out by Ineco, as well as the 2.3 kilometres of the access to Granada station.

The company approached this complex passage through Loja by carrying out the platform construction and connection route project, including the construction of a new station, renovation of the track and permeabilization of the route. Ineco also adapted and reinforced three small tunnels and the existing geotechnical structures between them for the passage of the AVE high-speed line and several grade crossings were eliminated and replaced by new access routes.

In the construction of this infrastructure, Ineco adopted measures to eliminate or minimise the impact on the environment and cultural heritage, in compliance with legislation. Many affected heritage sites are defined in the construction project, meaning that corrective measures are taken before the works begin. Other elements are found in the subsoil and are only discovered when earthmoving begins, making it necessary to coordinate all of the archaeological activities.

This was the case of the discovery of a Neolithic village near Antequera that affected the route of the AVE high-speed line. A Roman oven from the 1st-century AD was discovered, which Ineco and Adif turned over to Antequera museum in collaboration with the Regional Government of Andalusia’s Department of Culture and the local city council. Removal, structure consolidation and final transfer works were done by a specialized company, Taller de Investigaciones Arqueológicas. Another important site discovered in Antequera was the ‘Casería Mayorga/Silverio’ Roman villa and necropolis, a discovery that highlighted the economic and demographic importance of the Vega de Antequera region in Roman times. One of the most important conservation measures carried out during the infrastructure construction works was the recovery and transport of the most significant elements of this residential villa complex (its mosaic floors and a sculpture of its owner) to the Antequera Museum.

Platform and track assembly works

Construction of the platform began in 2006, with Ineco and Adif in charge of construction management. Track assembly was carried out in several sections: Antequera-Loja, Gobantes-Bobadilla, Loja-Tocón, Tocón-Granada and Granada station and accesses. In the Antequera-Loja and Tocón-Granada sections, Ineco provided track assembly technical assistance to construction management, while, in the Loja-Tocón section and the Granada station and accesses, the company was in charge of construction management for the platform and track.

The goal of the project was to put the track into service on the platforms that would allow high-speed traffic to take advantage of the longer section compatible with the current arrangement. The Antequera work base was also connected using 1.435 gauge to the new high-speed line in order to facilitate maintenance operations on the Antequera-Granada line during the operating phase.

Signalling and communications systems

Ineco was responsible for technical assistance in relation to the supervision and oversight of project drafting, execution of works, maintenance and upkeep of signalling control points, train protection systems, CTC and auxiliary detection systems, as well as the technical assistance for fixed telecommunications, protection and security facilities, and GSM-R.

When it begins to operate, the line will have ERTMS Level 2. Ineco is currently participating in the dynamic testing of the ERTMS L2 system, as well as ERTMS/ETCS level transitions between the Córdoba-Málaga and Antequera-Granada high-speed lines.

LSB (lateral signalling block) was used with AVE mode ASFA as a backup system to the ERTMS, using audio frequency track circuits and axle counters in mixed track areas. On the conventional line, which will be accessed from Antequera-Granada, an automatic single-track release block was established and the automatic single-track block between Granada and Albolote was adapted.

The facilities that were made available for performing the ERTMS tests included Antequera HS, and Íllora and Granada HS electronic signalling control, with their associated trackside and cabin elements, as well as LSB along the entire Antequera-Granada line; the updating and integration of new equipment for the Antequera Santa Ana CTC; falling objects detectors in elevated sections and tunnel mouths, hot-box detectors, lateral wind detectors and their integration into the remote control of auxiliary detection systems on the Córdoba-Málaga high-speed line; fixed and mobile telecommunications network (GSM-R), fibre optic network, SDH transmission systems, IP/MPLS data network, switched telephone network, etc.; video surveillance and access control and the installation and integration of new CTC equipment into the Antequera control and regulation centre and the centralised control centre in Madrid-Atocha.

Prior to these tests, the Córdoba-Málaga high-speed line was connected via the Gobantes junction for integration into the LZB systems, adapting the field elements, electronic signalling control and existing train protection systems in Antequera Santa Ana belonging to the Córdoba-Málaga high-speed line, due to the new connection of the station to the Antequera-Granada high-speed line and the replacement of the electric signalling control of Granada station with ENCE, integrating the connection of the Antequera-Granada high-speed line.

Energy supply and civil protection of tunnels

In terms of energy systems, Ineco was in charge of technical assistance on works relating to electric traction substations and auto transformation centres, energy remote control and overhead contact lines and associated systems, such as point heating, tunnel lighting and power supply to consumers, in addition to civil protection and safety facilities.

The company was also commissioned to carry out an independent safety assessment (ISA) of the control, command and signalling system, as well as an independent assessment under Regulation 402/2013 (ASBO) of the rest of the TSI subsystems, their interfaces and their secure integration for the commissioning of the line.

Three high-speed stations

Ineco drafted the projects to adapt three stations on the last section of this line to high speed: Antequera, Loja, and Granada. At the Antequera station, the project included a new passenger building, access road, car park, pedestrian connection and track overpasses to connect to the conventional station.

For Loja’s new high-speed station, Ineco was responsible for drafting the project and construction management. It also drafted projects for an underpass between platforms and is currently finalising a project for a footbridge in the neighbourhood of Esperanza. The last works on the station include the construction of the canopies over its central platform.

As for the Granada station, the project for the arrival of high speed included the renovation and extension of its passenger building. The result is a building with a U-shaped layout that brackets the track yard and platforms, which are joined by the head house. The extension is carried out by means of a large canopy that joins the existing and new buildings; it extends and looks out over the plaza to mark the new entrance and is curved to protect the new concourse from the passage of the metro. This outer covered threshold is the hinge point between the existing building and the extension. The eastern façade of the boarding area is transparent to enhance views of the Alhambra and Sierra Nevada.

This report was made possible thanks to special contributions by Pedro Asegurado and Pablo Nieto, specialized railway technicians; Fernando Díez, traffic expert; Javier Cáceres, biologist; Marisa de la Hoz, Diego Martínez, Aránzazu Fernández and Lidia Sainz-Maza, civil engineers; Carlos Montero, Antonio Sancho, Carlos Palomino and Arantxa Azcárraga, architects; Manuel Fernández, electrical engineer; Rafael Soler, mechanical engineer; Javier Millán, telecommunications engineer; Laura L. Brunner, bachelor of physical sciences; Manuel González, industrial technical engineer; Daniel Pérez, signalling expert; David Carrasco, industrial engineer; Fernando Cardeña, communications, video surveillance and access control expert; Javier Barragán, overhead line technician; Rafael Arévalo, energy expert; Francisco Perrino, auxiliary detection system expert; and Manuel Tirado, ERTMS expert.

The company has been awarded two contracts that are part of the Rail Baltica project, a modern high-speed rail corridor that will link the Baltic Republics to the Trans-European Transport Network (TEN-T). The new infrastructure will connect Poland to Finland via Estonia, Latvia and Lithuania with an 870-kilometre double-track railway line (213 km in Estonia, 265 in Latvia and 392 in Lithuania).

One of the contracts involves the definition of a strategy to implement the energy system and, the other, the definition of maintenance facilities along the entire line. Both projects will be carried out in consortium with the Spanish company Ardanuy.