Last April, Aena announced the completion of Aena’s remodelling work on the South Dock of Terminal T1 at Josep Tarradellas Barcelona-El Prat airport, a project carried out by Ineco in 2018 (see ITRANSPORTE 65).

The works were aimed at increasing the capacity of the Dock to cater for the growing number of wide-body aircraft operations, which now have five new parking positions. The south wing of T1 has also been remodelled with the construction of four new boarding bridges and the extension of an existing fifth, all equipped with moving walkways for large aircraft.

The interior of the building has been divided into three levels, separating incoming and outgoing passenger flows.

The railway, in its endeavour to facilitate public transportation, has been opening new stations in cities in order to connect them to the world. Since the days of coal, travellers arriving at stations have discovered the atmosphere of a place through the introduction provided by the platforms, marquees, halls and restaurants of the major stations. This is how it was and still is: the entrance to a great station is also the entrance to the city, making it the duty of stations to bid travellers a friendly welcome and farewell, offering convenience and positive memories that enhance the reputation of the location.

A great station cannot be separate from the urban fabric that surrounds it. A station is a city, as are its entrances and its railway yard, which have a decisive impact on the character of the neighbourhood to which it belongs and on the layout of the roads.

1. View of the roof 2. Platforms for high-speed services 3. Floor of the general hall 4. Platforms for Rodalies de Catalunya and regional train services. / INFOGRAPHIC_BSAV

A great railway station is also the main node that must make possible, in an orderly and efficient way, the routes that enable the mobility of the population. The need to travel must be satisfied by making an effort to minimise the external costs that transport entails, seeking formulas that are increasingly conscious of respecting the environment. The successful combination of different modes of transport in a single journey, taking advantage of the strengths of each one, has made multimodality a solution to be taken into account by regional planners, and it is in the design of large stations that this concept is of key importance.

Main node, city and gateway. The new intermodal station of La Sagrera, located in the Barcelona neighbourhood of the same name, aspires to all this

Main node, city and gateway. The new La Sagrera intermodal station, located in a neighbourhood in Barcelona bearing the same name, aspires to all these objectives. This aspiration is fully justified by the need to complement the existing node of Sants station and by the vocation to finish building a part of the city of Barcelona that over time had become a border separating two neighbourhoods: La Sagrera and Sant Martí de Provençals.

Sants station node, in operation since the 1970s, was adapted in 2008 to host Barcelona’s high-speed services. The station, which had 12 tracks with platforms, was expanded to 14 tracks, leaving 8 in Iberian gauge for conventional services and 6 in international gauge for high-speed services. There is no escaping the fact that practically all the commuter and regional service lines pass through this station, which is connected to two underground lines and is centrally located in the city, almost equidistant from the two arteries that cross Barcelona: Gran Via and Diagonal.

The conversion of long-distance intercity services, as well as some regional services, into high-speed services has gradually taken up the capacity offered by Sants station for this type of service. The Madrid-Barcelona high-speed corridor, which went into operation in 2008, was joined by the connection with France in 2013 and the link with the Mediterranean Corridor in 2020, generating a notable increase in demand for the use of the six international-gauge tracks at this station, as well as its associated workshop in the Can Tunis area.

Certainly, the possibilities offered by powerful infrastructure such as the Madrid-Barcelona-French border high-speed line invite us to think about future growth. The fight against climate change calls for the promotion of railways in the internal relations between the Member States of the European Union, especially on those corridors where the railway guarantees reliable service that takes less than three hours between city centres, thereby making it possible to only use aviation for longer connections to take advantage of its strengths. Initiatives in the high-speed rail sector have been developed to respond to this situation, ranging from the use of higher capacity trains (dual-composition trains or double-decker units, for example) to low-cost services or, in another sense, preferential services with open tickets that emulate those offered by some airlines; all of these initiatives will strengthen the amortisation and raison d’être of the infrastructure built in recent decades. Be that as it may, anticipating that demand for mobility will not slow down (on the contrary, it seems that it will continue to grow, once the ravages of the pandemic have been overcome), the high-speed services that will reach Barcelona in the coming years are going to need a greater number of tracks on which to hold trains, on which to park them (during off-peak hours and after business hours), and on which to maintain and repair them.

The fight against climate change and the liberalisation of the railways, among other circumstances, make it necessary for Barcelona to have a new high-speed station

In addition to these circumstances, the process of railway liberalisation already that is under way, sponsored by the European Union, should be added to the list in order to create a more efficient system capable of achieving the best possible transport supply. The high-speed infrastructure must be prepared for a multi-operator scenario, where tracks with platforms and auxiliary track and workshop facilities are no longer used by a single incumbent operator, but must be shared or distributed among different railway operators.

All of this makes it absolutely essential for Barcelona to have a new station and parking tracks for high-speed services. It is, in short, the fundamental purpose of La Sagrera station. Its location is not as central as that of Sants station, but it will not be at a disadvantage. On the contrary, both stations will complement each other: if Sants station, due to its central position in the urban fabric of Barcelona, will play a key role for users of high-speed services who live in a large part of the city and its nearby metropolitan area, La Sagrera station, given its good connections to the highway network, will be provide an advantage for those coming from the metropolitan region and beyond.

The two lines of the Rodalies network running through La Sagrera. / PHOTO_LUIS UBALDE

In addition to the six international-gauge tracks currently housed at Sants station, eight tracks with their four respective platforms will be added in La Sagrera station. The station building will contain, in addition to the commercial platform area, a technical train management area equipped with ten parking tracks with their corresponding technical platforms (apart from the two general passing tracks) where preparatory operations can be carried out for a new service for those trains that have La Sagrera as their station of origin. This involves cleaning operations, emptying WCs and supplying them with bactericidal liquid and water, changing the position of the seats and replenishing food supplies. These operations, which in part are being carried out in the existing stations on the commercial platforms themselves, will have two completely separate spaces in La Sagrera, increasing operational capacity and safety. Considering that the platforms for high-speed services must allow trains of up to 400 metres in length to be parked, a building is being built in La Sagrera that is almost a kilometre long, which includes the commercial platform area, the technical platform area and an intermediate space where the track devices that connect the parking tracks with the sidings are located.

The track layout was designed so that the station serves both trains that use La Sagrera as an intermediate station and those coming from south of Barcelona that end their journeys at this station. To do this, it was decided that the general tracks would be the ones outside the station’s train yard, leaving the sidings in the central area, so that train rotation can take place without any shear stress at the station’s head. Excluding the general tracks, the remaining six tracks of the commercial platform area are related to the parking tracks of the technical train management area as follows: each pair of parking tracks is assigned three siding tracks, leaving one extra parking track.

This new urban area will have a particularly environmentally sensitive design that optimises energy efficiency and supply and waste management

In addition to the two areas described (commercial platform area and technical train management area) there is a third area, which, though not connected to the previous areas, is very close to them. This is a workshop area with reception and working tracks equipped with pits, directly connected to the tracks in the technical train management area, without having to occupy the main track to go from one area to another.

The intermodal nature of La Sagrera node makes this facility a station of stations. In fact, in addition to everything that has been said about high-speed services, there is also a section devoted to commuter and regional train services on two lines of the conventional network: the line from Barcelona to Mataró and the line from Barcelona to Granollers, which continues to Girona and Portbou. In addition, the station is complemented by an underground intercity bus station and the connection with two lines of the Barcelona underground network (lines L4 and L9/L10). All of this is organised into a structure formed by three main levels: on the lower level of the station, the tracks of the conventional network (four tracks of the Barcelona-Mataró line and four tracks of the Barcelona-Granollers line with their respective platforms); on the intermediate level, the station hall (with a part for commuter users; another part for high-speed users) and on both sides of the hall, a parking area for cars; and lastly, on the upper level, the international-gauge tracks and their platforms for high-speed services.

CROSS SECTION OF THE STATION. The design of La Sagrera intermodal station facilitates transfers between different modes of transport. / IMAGE_ADIF ALTA VELOCIDAD AND BSAV

Currently, the execution of the works is at the point where, having completed the curtain walls that surround the lower level of the station, the floor slab (2.5 metres thick) and having finished the first slab, the line from Barcelona to Mataró has been put into service inside the station structure and its accesses. Of course, trains have not yet started to pick up and drop off passengers, but merely passing through the heart of the future station undoubtedly represents a major milestone. Subsequently, a similar procedure will be followed for the line from Barcelona to Granollers, and lastly, the high-speed line will move from its current provisional alignment to its definitive location inside the station.

The work on La Sagrera station goes beyond what has been described here: its scope goes as far as constructing a piece of Barcelona. The station is also a part of the city. It is located on a railway corridor along which three railway lines run, which will no longer be above ground and will be covered by a city park. With its 40 hectares, this will be the largest urban park in the city, running above the train tracks over a distance of 3.7 kilometres. Its construction is associated with the urban development of the old railway area of La Sagrera, which, from the generation of 1.25 million m² of buildable roof, will mean the creation of housing for 25,000 inhabitants at the end of the whole process (more than 40%, will be protected housing), as well as generating some 30,000 jobs throughout the area.

THE EVOLUTION OF THE WORK IN PICTURES. / PHOTOS_ADIF ALTA VELOCIDAD

This new urban area will have a particularly environmentally sensitive design that optimises energy efficiency and supply and waste management. In this respect, groundwater will be used for the irrigation system for the landscaped areas and the sewer tanks of the tertiary buildings; there are also plans to implement a centralised air-conditioning system, which will use the waste heat from an existing incineration plant in cold weather and will provide cooling by using sea water; the buildings will have pneumatic waste collection and will be connected to a state-of-the-art telecommunications network, all in accordance with the criteria of a truly smart city.

As a result of all this, a new gateway is being built in Barcelona, La Sagrera station, and this gateway will serve not only those who enter and leave the city, but also introduce more efficient, attractive and sustainable form of mobility, based on multimodality. Given the urgency of the situation, we cannot falter in our fight against climate change: this work is a step in the right direction.

The Barcelona-El Prat Airport has seen an increase in the number of wide-body aircraft operations in recent years. To manage this growth, Aena considered it necessary to increase the number of aircraft stands and boarding gates to accommodate aircraft that require a passenger boarding bridge and larger stands.

With the addition of two floors along the whole of the South Pier –approximately symmetrical to the North Pier– and the installation of several pre-boarding bridges, the airport will be able to serve more large aircraft on international routes.

Terminal T1 of Barcelona Airport has three boarding docks: the Longitudinal Pier, North Pier and South Pier. The Longitudinal Pier is generally used for Schengen flights, the North Pier for international flights (and also for the shuttle), and the South Pier for regional flights.

With the Addition of two floors and the installation of passenger boarding bridges, the South Pier of El Prat’s Terminal T1 will be able to serve greater numbers of large aircraft on international routes

Because of the different kinds of operations carried out in each one, the docks have different configurations: the Longitudinal Pier has a single level on floor P10, through which boarding and deplaning take place; the North Pier has three levels (P10 for domestic boarding and deplaning, P20 for international deplaning and P30 for international boarding); and the South Pier currently has a single level for boarding and deplaning.

Along both the North and South Piers, there are a number of aircraft stands that are used for operations with large-capacity aircraft (type-E and F). Due to an increase in the number of operations with these aircraft at Barcelona-El Prat Airport, the number of aircraft stands and boarding gates that can accommodate these types of aircraft needs to be increased, since they require two and sometimes even three passenger boarding bridges (at different levels) at the same time, and larger stands on the apron.

Aena will be undertaking two main infrastructure projects in the airport’s Terminal T1: the first one involves reconfiguring the apron of the South Pier to create 9 type-C positions, 3 type-E and 2 type-F. The second consists of redesigning the South Pier to adapt it to the new operations, namely, arrivals and departures of international flights and accommodation of large-capacity aircraft.

Redesign and enlargement

The South Pier redesign and enlargement project drafted by Ineco proposes an expansion of the constructed areas of the Terminal T1 building, with the completion of the P20 and P30 floors along the entire length of the dock (approximately symmetrical to the construction arrangement of the North Pier) and the construction of four new walkways with separation of departure/arrival flows.

Later, 10 new passenger boarding bridges will be added to the new walkways (two or three per walkway) to enable type-E and F aircraft to board and deplane with at least two boarding bridges simultaneously, in addition to a second boarding bridge attached to the existing walkway (P37) of the South Pier so that type-E aircraft can operate.

On 30 July 2018, Aena awarded the works to Sacyr Infraestructuras and Sacyr Construcción.

When the new commuter rail access is completed and operational, it is estimated that between 8 and 9 million passengers will be able to use it to travel from Sants station to Barcelona-El Prat Airport’s terminal T1 in just 19 minutes. Until now, the commuter rail line (known locally as Rodalies) only reached the old terminal, T2, where a new underground intermodal station is currently being built.

With the excavation of the final metres of the 3,400-metre tunnel –3,048 metres of which were excavated using a TBM– in December 2018, one of the major milestones of the works, which began in 2015, was achieved. This first phase, for which Ineco was commissioned by Adif to carry out site and environmental management, will conclude when the works on the new intermodal station and shafts are completed. The next step will be to install and equip the tracks, power supply and railway facilities and commission the two new stations, projects on which Ineco is also working.

The new double-track stretch starts on the Barcelona-Tarragona conventional line, and runs to terminal T1, with an intermediate stop at terminal T2, where it will connect to Metro Line 9. The access includes a new station at terminal T1, not included in this project (the civil works were executed during the construction of the terminal itself). According to Adif, it is the largest project of its kind in terms of scope and budget currently being carried out on Spain’s conventional and commuter rail network.

Underground challenge

Excavating a tunnel with an enormous tunnel boring machine through ground with low bearing capacity –Barcelona Airport is located on the delta of the Llobregat River, meaning that terminal T1 had to be built on a gigantic concrete caisson– and under a large building (terminal T2) and runway that operates 24 hours a day, was no easy task.

Ineco drafted the construction project in 2009 taking all of these factors into account. To resolve the issues of soil quality and presence of a shallow water table (just over 2 metres), ground improvement treatment was carried out: a total of 126,802 m³ of ground was jet grouted (soil improvement using high-pressure reinforcement material) and 4,410 metres of micropiles were installed.

For the excavation, an earth pressure balance tunnel boring machine (EPBTBM), with earth pressure balance shield and 10.60-metre excavation diameter and 9.60-metre internal diameter, was chosen. The tunnel, which is lined with 32-cm thick concrete segments, has a maximum depth of approximately 28 metres and was executed between 56,700 m² of screen walls.

In the end, the excavation was completed with no significant subsidence on the surface. Special care had to be taken under the T2 building, where the TBM had to manoeuvre between foundation piles with a margin of just over one metre, and, under the runway, which Aena decided to close for 20 days in order to excavate a 300-metre section below it. In addition to hydrogeological and geotechnical studies prior to the beginning of the works, during excavation, a sounding system, consisting of more than 3,000 devices, was installed, including automated systems to monitor the stability of the ground and construction at all times.

The new stretch starts on the Barcelona-Tarragona conventional line, and runs to terminal T1, with an intermediate stop at terminal T2, where it will connect to Metro Line 9

Environmental works management

Ineco was also in charge of environmental works management to ensure compliance with the project’s environmental impact study (EIS) during the different phases of the work and after acceptance.

From the environmental point of view, the most notable aspects were monitoring impact on the hydrogeological system of the area, consisting of two aquifers, one deep and the other on the surface, management of anthropic landfills (soil containing waste) found in some areas and corrective measures to avoid noise disturbances.

To supervise the hydrological system, in 2012, before the start of the works, a network of 14 piezometers was installed (nine in the surface aquifer and five in the deep one, which supplies part of the city of Barcelona) to learn about the aquifers’ charging and recharging processes. Monitoring of the piezometric levels and water quality carried out previously and during the execution of the works will continue for two more years, once the civil works have been completed, in accordance with the requirements of the Catalonian Water Board (ACA). The application of preventative and corrective measures, together with the above monitoring, has minimised the potential impact of the works and reduced the risk of the tunnel affecting communication between the aquifers, causing contamination and creating a drainage barrier effect.

The anthropic landfills found in the area of emergency exit No. 3 (Vidaleta shaft) were examined, sorted and transferred to the appropriate waste management centres. To address noise issues, temporary acoustic screens were installed near a hotel and tennis academy located next to the construction site.

Tunnel boring, the construction of access ramps and the building of the multimodal station generated large volumes of excavated earth, which, in accordance with the EIS, was collected and removed and will be reused on other projects such as works on the port of Barcelona and the regeneration of two nearby quarries located in the municipality of Gavá. All removed soil containing vegetation was also reused later to restore any affected areas to their former state.

Excavating below the water table also required the drainage and collection of excess water (effluents), which were then treated and purified before being discharged into either the public water system through the airport’s drainage network or storm drains or reused on construction site roadways to reduce dust. To ensure the quality of the air, filters were also fitted to lime, bentonite and cement silos, and sprinkler systems were installed in the concrete plant to clean machinery before leaving the site. All works waste was collected, sorted and disposed of appropriately.

Regarding the protection of cultural and natural heritage during the works, no archaeological remains of interest were found and none of the local animal life was affected.

The works continue

Ineco is also participating in the second phase of the works, for which it is drafting the project of necessary actions for the operational readiness of the new commuter rail access. These works include connection to the main line, track superstructure, electrification, telecommunications, facilities inside the tunnel and design of the stations at terminals T1 and T2.

The drafting of the project needs to consider certain specific conditions that affect both the design and the execution of the works, such as ensuring that connection to the existing line does not affect its operation. The tunnel evacuation plan will need to take into account that the T1 and T2 stations are separated by more than one kilometre, but an evacuation exit cannot be built because that section of the tunnel runs under the airfield. The T2 station will have to be compatible for use by passengers from both the Metro and the commuter rail, and in the T1 station, the design of the emergency exits and fume extraction system will be subject to the conditions imposed by its location in the air zone.

Lastly, the security facilities will be considered by Adif.

The company continues with several civil works projects, technical assistance work and design and feasibility studies for the Madrid, Barcelona and Malaga metros. Track inspection and monitoring work is being carried out on the Malaga metro; different unique and regulatory projects are underway on the Barcelona metro in addition to monitoring work. Aside from the Framework Agreement projects, Ineco has been hired to provide technical assistance during the inspection of track cars in the Madrid metro.

With regard to Light Rail West –which connects the towns of Pozuelo de Alarcón and Boadilla del Monte to Madrid–, work includes speed validation studies. In 2004, Ineco carried out the construction of Light Rail West infrastructure and facilities.

“To create a unique symbol for each place”

Bruce Fairbanks, founder of Fairbanks Arquitectos, has accumulated extensive experience in the design of airport buildings since 1996 when he won the tender for the construction of the Madrid-Barajas control tower.

Presently in the world of airports there is a trend to promote the control tower as a symbol, an image that represents the airport and a reference point for the arrival in, and departure from the city where it is located. This trend has created increased interest in architectural execution in the design of control towers in addition to their functional requirements. It is precisely the individuality of these requirements that significantly affects the type of building, such that throughout history there are various examples of “types” of tower designs, which, once designed, were repeated in various airports: one notable case is the leoh Ming Pei control tower. It was designed between 1962 and 1965 with the objective implementation in 70 airports, although in the end 16 were built. The concept of locating in upper levels strictly that which was necessary was developed, putting the maximum amount of functions in the base building, which was adapted to the specific characteristics of each location. As such, the tower could be prefabricated and repeated with standardised equipment, giving the airport network an image of safety since a controller could work in any location without having to adapt. The tower was designed with 5 standardised heights (18-46 m) in accordance with visibility requirements in each location. The control tower’s cab is pentagonal so there are no parallel façades and so as to avoid reflections. In Spain, in the 1970s, Juan Montero Romero, an aeronautical engineer, built a tower, which was repeated in several cities: Málaga, Alicante, Valencia, etc.

To create a landmark, the architect must find within the functionality the characteristics that distinguish one tower from others

Converting control towers into airport landmarks and reference points for cities is a challenge in the work of an architect: creating a symbol, always unique for each location, which meets all of the requirements for the optimal functioning of the tower. The location, the height of the control room, its form and the layout of its structural elements are some of the first elements to define. Control towers typically have a base building and a shaft that supports the upper floors, which are designed to adapt to the control operations. Given the form, with an upper part and a lower part and the height of the type of building, in my opinion it is essential to incorporate the construction process into the design of the tower, and this is what I have done in those which I have designed. This design comes from an analysis of the functional aspects, the programme and the location. To create a landmark, the architect must find within the functionality the characteristics that can distinguish one tower from others and strengthen them to create a unique tower with its own character in each case.

Analysis of four cases

The following examples of control towers show diferente conceptual approaches to design this building type and the elements that diversify its design.

1962. Dulles airport, Washington DC
Eero Saarinen

The Dulles tower has all of the equipment rooms at a height, elegantly assembled by Saarinen with two juxtaposed bodies. The form of the tower is integrated with that of the terminal building, also designed by the same architect.

1992. JFK airport, Nueva York
Pei Cobb Freed & Partners

The upper part of the JFK tower, 97.5 metres in height, contains only the aerodrome control cab and half way up the shaft there is the platform control room, which takes the same form as the upper levels.

1997. Adolfo Suárez Madrid-Barajas airport
Bruce Fairbanks

The Adolfo Suárez Madrid-Barajas control tower had the specific feature of a 400 m² equipment room located at a height. To resolve the transition between the shaft of the tower and the projection, an inverted half sphere was adopted, with a floor for air conditioning equipment being inserted in the support. The octagonal shape defined for the
cab is extended throughout the top of the building, the structural design of a central column and 8 perimeter columns is repeated on all levels.

Another particular feature of the tower is the construction system designed as an integral part of the design. The shaft is built with prefabricated segments assembled in spirals, which, on the inside, contain the service ducts and circumscribe the emergency stairway. The upper floors were built with a metallic structure on the floor and subsequently hoisted onto the shaft. The system allowed the tower to be built in nine months, without using scaffolding.

2004. Barcelona-El Prat airport
Bruce Fairbanks

The functional requirements were similar to those of Barajas, with the exception that a large part of the equipment is located in the base building. The resistant structure is defined independently from the functional elements of the shaft, which was developed as a representative design element. An eight-pointed hyperbola generated from the octagonal shape of the cab holds the upper floors.

The hyperbola links the tower with Catalan Modernism and Antoni Gaudí, who used this form in many of his designs, including on the domes of the Sagrada Familia. The construction system is a representative part of his design. The assembly of the hyperbola, built with prefabricated concrete girders, was guided by a central aluminium structure designed to contain the elements of the shaft. The upper floors were built on land and hoisted into position, supported by the eight points of the hyperbola, consolidating the whole structure when it was under load.

“In the future, it will not be necessary to view operations”

Roberto Serrano has participated in more than 50 aeronautical projects, amongst them, the NET and SAT control towers of Madrid-Barajas airport and the new control tower of Eldorado airport (Bogotá).

Although the first control towers date back to the 1920s (in 1921, Croydon airport in London was the first in the world to introduce air traffic control), it was from the 1930s that they became commonplace, due to the fact that growing aircraft traffic made controlling and managing it necessary. At that time, in which technology was nothing like the current systems, the need to visually supervise aeronautical operations around the airport was met by placing the control room (cab) in an elevated and predominant position of the airport (control tower).

To date, the first steps in designing a control tower involve establishing its site and the height of the cab. Internationally, to meet the viewing requirements from the cab, the recommendations of the Federal Aviation Administration (FAA) are applied. The optimum height and location of a control tower is the result of weighing up many considerations. The view from the cab requires the air traffic controller to be able to distinguish the aircraft and vehicles that circulate in the manoeuvring area, as well as aircraft that fly over the airport, particularly in take-off and landing paths. The objective is to have the maximum visibility possible and avoid the sun, external light sources and reflections from adjacent buildings affecting the visibility of the controller.

Nowadays, technology allows a practically blind landing

With regard to the location, we must consider the potential effects of local weather: flood areas or areas susceptible to fog. Its compatibility with the potential future development of the airport must also be studied, thereby avoiding the need to relocate the tower before the end of its life cycle. Insofar as possible, the tower and its buildings should be located on the landside of the airport, thus avoiding access through the airfield and facilitating the entry of staff. Furthermore, the location should be such that it does not affect the quality of the signals of the airport’s radio navigation aids (ILS, VOR, DME, etc.), or communication systems. The minimum height required for the control tower can be obtained with the aid of the FAA visibility analysis tool, ATCTVAT (Airport Traffic Control Tower Visibility Analysis Tool), in accordance with the physical conditions of the airport.

Once the position and height has been determined, the infrastructure is designed, and generally includes a cab and an antenna field, which, located on the roof of the cab, normally has communications antennas, radio relays, and other electronic and lightening protection elements. Furthermore, there are areas for staff, equipment, power, air conditioning, etc.

In an era in which technology provides information to pilots to allow a practically blind landing, is it necessary to keep air traffic controllers in a high position so they can see these operations? In the future, air traffic control rooms will probably be in buildings that are more similar to those of offices or air traffic control centres than the current towers.

The future has already become reality

2015. Control tower of Örnsköldsvik airport, Sweden

Recently, Örnsköldsvik airport in Sweden replaced its control tower with high-tech cameras. Signals are sent to controllers stationed in Sunvsal airport, located around 150 kilometres away, from a 25-metre mast with 14 high-definition cameras. The high performance of these cameras eliminates blind spots, provides information in rain, fog or snow and, along with a whole series of weather sensors, microphones and other devices, it allows controllers to feel as if they were beside the runway. The Swedish Transport Agency approved remotely operated towers on 31 October 2014. Six months later, the first airplane landed in Örnsköldsvik airport using the remote tower services.

Since last August, more than 20,000 residents of this new construction zone have been able to reach the centre of Madrid in 25 minutes thanks to the new halt, without having to go to the centre of Torrejón de Ardoz. Located in this Madrid municipality of 127,000 inhabitants in the north-east of Madrid, the new station belongs to the C7 commuter line and serves the districts of Soto del Henares, Mancha Amarilla and Zarzuela, a zone near the Hospital of Torrejón and the new Casablanca industrial estate. Ineco has carried out the architectural, structural and installation design, as well as construction management for Adif. It is a modular structure of porticos that eliminates the need for interior pillars (open plan) and can be easily adapted to any type of station. The main building, direction Alcalá de Henares, has a rectangular floor, a foyer with waiting areas, automatic ticket vending machines and six faregates, with the possibility of increasing this number to nine. It also has a space for offices, toilets and utility rooms.

Ineco has carried out the architectural, structural and installation design, as well as construction management for Adif

A modular and extendible design

The halt has two buildings, one for each direction. In the interior, all uses are distributed by independent building volumes (‘building within a building’). The station was designed with a capacity to receive 6,000 passengers a day, although the modular structure facilitates its future expansion.

Golden ratio

The geometry of the buildings is based on the golden ratio of a two-metre square, which forms rectangles of 2.8282 x 2m. When doubled they create a module of 5.6564 x 2m, and from the division of this module come all of the internal distances between porticos and different spaces are created.

A light box

The main building is laid out as a rectangular prism with two façades, which provides a maintenance area between them. While the “skin” tinges the interior-exterior light (‘light box’ effect), the outer layer generates permeability and allows the design to be changed.

Platforms

The platform edges are 1.75 metres from the track centres, with a width of 5 metres and a length of 210 metres, with 6 metre slopes at each end. Thanks to the 80 metres of canopy extending from the buildings, passengers are always sheltered when they access the platforms.

Other stations designed by Ineco

Ineco has extensive experience in drawing up architectural designs, as well as in construction management and technical assistance and the preparation of feasibility studies in different types of stations, both overground and underground.

• In Cercanías (commuter rail) we should highlight, amongst others, projects such as the Miribilla station in Bilbao, built at a depth of 50 metres; the two in the Málaga airport access and a few others in the Valencian town of Alboraya, all of which are also underground, or the modern Cercanías halt of the Manuel-Énova bypass of the high-speed line to Levante.
• With regard to modular stations, in 2009 it developed an innovation project taking a small halt in the north of Madrid, Las Zorreras, as a reference. A similar solution was also planned, the predecessor of that of Soto del Henares, for the Las Margaritas-Universidad station, in Getafe, in the southern zone of Madrid. Abroad, in 2011, eight modern modular stations were designed for the Bogotá Western Corridor in Colombia.
• With regard to the renovation of historical stations, we can highlight the design and construction management of the historic façade of Atocha (2012), that of the full renovation of Aranjuez station (2008) currently underway, or the modernisation works in around twenty Catalan stations (2009).
• As well as architecture projects, we can also highlight other services, such as technical assistance for the work of the new La Sagrera-Meridiana commuter station in Barcelona (2010) or the prior feasibility studies for the Belgrade light rail in Serbia, with 25 stations, 10 of them underground; or for the São Paulo commuter network in Brazil, which included the construction of nine stations and the renovation of 65 others.
• With regard to highspeed stations, Ineco has carried out around twenty projects, both in construction management and in drawing up architectural designs: this is the case for the stations of Puente Genil, Camp and Antequera-Santa Ana (2007), that of Vigo-Guixar or the projects in nine other stations of the Galician Atlantic corridor in 2010 (see article). Ineco has also worked in the construction management to adapt stations in the whole network for high speed: Santa Justa in Seville, Sants in Barcelona, Atocha in Madrid, Toledo, Zaragoza, A Coruña, Santiago and Ourense in Galicia, etc., as well as in that of enlargement of the Atocha railway complex and its new AVE terminal, begun in 2010.

The renovation work is part of the comprehensive restoration project drawn up by Ineco in 2008 which sought to remedy shortcomings while remaining consistent with the historic character of the architecture. These large, riveted iron structures were built as a result of the Industrial Revolution during the 19th century and are epitomised by the Eiffel tower. Spain lagged a bit behind other cities with regard to the use of iron in architecture and engineering as can be seen in countless examples from Paris, London, Amsterdam, Belgium and Germany in addition to Boston and New York in the United States.

With all of this, transport infrastructure in 19th-century Spain such as stations, bridges and viaducts requiring versatility, luminosity, spaciousness and low prices were easily adapted to the engineering of iron which was best received by engineers of that time period as well as by architects. Examples of riveted iron infrastructures in Spain include the Atocha and Delicias railway stations, the Catalonia Railway Museum, the Valencia railway station and the Aranjuez railway station –the main feature of this article. Furthermore, some quite representative buildings include Sabatini’s Royal Firearms Factory in Toledo and the Geological and Mining Institute of Spain, in addition to bridges and viaducts such as the prominent Triana Bridge.

Spanish transport infrastructure in 19th-century such as stations, bridges and viaducts requiring versatility, luminosity, spaciousness and low prices were easily adapted to the engineering of iron

Aranjuez station is one of the most characteristic vestiges of the industrial age of the 19th century. The earliest railway facilities at Aranjuez were built in 1851 for the line connecting Madrid with Alicante, popularly known back then as the ‘Tren de la Fresa’ (The Strawberry Train) and whose name is now in use once again for tourist services. This station also provides service to the C3 Madrid-Aranjuez commuter rail line. It is the second oldest railway line in Spain (the oldest is the Barcelona-Mataró line, 1943) and is one of the monuments of the Royal Sites of Aranjuez, a Unesco World Heritage Landscape Site since 2001. This line originally reached all the way to the Royal Palace. The original station faced towards the palace on grounds of the company’s prestige and the fact that they needed support from the monarchy. Nevertheless, this location caused so many problems affecting train traffic that it became necessary to build a new station with a completely different layout. The platform marquees are living proof of the iron beams and framework –signs of progress from that time period– that were used to construct public buildings such as stations, markets, factories, libraries and bridges.

The technique of riveting

The steel marquees, roofed by fibre cement and fluted glass, were built around 1851 to provide shelter over the station’s three platforms which were later renovated around 1980 in order to adapt them to the trains and general regulations at that time. As can be observed in the images, the marquees suffered from corrosion problems that affected their structural framework, foundation and ornamentation due to an unsatisfactory roof water drainage system, thus causing damage to the suspended wooden ceiling and corroding the metal. Rehabilitation and restoration of these marquees was a year-long, painstaking process that rediscovered the traditional technique of riveting.

Riveting is the process of joining together several metallic pieces (metal sheets and/or profiles) using rivets. Rivets are elements that are similar to screws –but without the thread– consisting of a cylindrical shaft called a shank or the body, and a head normally shaped like a spherical cap, such as the rivets utilised for the marquees at Aranjuez station. These rivets are manufactured from ductile, malleable and durable metals such as copper, aluminium, some alloys and mild steel, such is the case with the rivets presented herein.

Riveting is the process of joining together several metallic pieces using rivets –elements similar to screws but without the thread- consisting of a cylindrical shaft and a head

To join together metal pieces made from steel, rivets are used –also made from steel– whose quality and characteristics can vary. Holes are drilled just once, piercing through two or more pieces, after having assembled, clamped and tightly screwed said pieces together. Once the holes have been drilled, the pieces are separated from each other in order to eliminate metal scrap, remnants and sharp edges from the surface. The diameter of the holes, save for exceptional cases, is made 1 millimetre larger than the diameter of the body of the rivet. Selecting the length of the body of the rivet is very important: after the rivet is placed in a furnace and uniformly heated to a temperature between 950 and 1,050 ºC in order to allow for its moulding, the riveting process is carried out by introducing the heated rivet into the hole on the pieces which are to be joined together. The body of the rivet should be cast and forged in order to form the shop head of the rivet. This piece must completely fill the hole. To form the shop head, either a riveting machine applying uniform compression is utilised, or a pneumatic hammer with a riveting pin or a bucking bar is used, always held steadily in place. These tools –not the direct strike of a hammer– are used to form the rivet’s second head. Both the furnace and the riveting machine need to be located close to the area where the riveting is to take place so as to avoid significant cooling of the rivet before it is set into place. The pieces that are joined together must lie perfectly flush and tight against each other to ensure a union without bending or warping. Afterwards, the rivet is introduced into the pieces that are being joined together, and the body of the rivet is forged. This process is carried out using a pneumatic hammer and a bucking bar on the spherical head of the rivet.