MANY things have changed in Spain's economic and institutional landscape since the Great Recession hit the country hard in late 2008 and brought its banking sector to its knees in 2012. But a single trait has remained steadfast through the avalanche of structural reforms of the last few years: the tireless extension of a state-of-the-art high-speed rail network, which is planned to reach every corner of the Iberian Peninsula.

With the latest line openings in 2015, Spain's 2900km high-speed network is now the world's second largest after China, just ahead of Japan, and Europe's largest, with plans in place to eventually develop 5000km of lines.

Spain HSpeedThe first project, the Madrid - Seville line, opened in 1992 using 1435mm standard gauge instead of Spain's conventional 1668mm Iberian gauge. This was intended to allow straightforward integration with the European network via France but has multiplied the number of internal interoperability border points. This problem was solved through the extensive deployment of variable-gauge trains and standardised gauge-changing facilities using Talgo and CAF technology. They are in effect movable border points: once work to extend a new line is complete, the gauge-changer which was serving its former end section is disassembled, transferred to the new extremity of the route and reassembled again.

Renfe's high-speed services carried more than 35 million passengers in 2015 and are marketed in three different categories: AVE and Avant brands are used for long-distance and regional routes respectively, and reach most of the major cities with four main lines radiating from Madrid to Barcelona and France, Valencia and Alicante on the east coast, Seville and Malaga in Andalusia, and Valladolid, Leon and Zamora in the north west quadrant which is still severed from the rest of the network. Finally, dual-gauge Alvia services are routed over both the new lines and the conventional network to reach destinations still not served by high-speed rail.

The character of Spanish high-speed is defined not by its length or the volume of the resources mobilised, but the frantic rate of development. It took Japan three decades to surpass the 2000km mark, but Spain reached this milestone in just 18 years. With a gross average of 114km of high-speed lines entering service every year up to October 2014 since its first opening, Spain's construction pace is second only to China's, and lies well ahead of France, Germany and Italy, the other three European countries with comparable systems. As a result, Spain's lines are also the youngest on the continent: a weighted mean of nine years, compared with 18 in France, 15 in Germany and 13 years in Italy.

The same has happened with its high-speed train fleet, comprising 230 trains with an average age of just 11 years. Of these 101 are dual-gauge capable and 14 also have hybrid traction to run on lines without electrification. Renfe has invested €5.5bn since 1992 (adjusted for inflation), with five manufacturers - Talgo, CAF, Alstom, Siemens and Bombardier - supplying 11 different train series.

In late 2015 Renfe launched a tender to buy a minimum of 15 more high-speed trains for €1.1bn. This was the first contract of this kind for a decade and will include 15-years' maintenance, with an option to buy up to 30 additional units and extend maintenance to 40 years. With 400 seats each and a maximum commercial speed of 320km/h, the new trains will be multi-system (25kV 50Hz ac/1.5kV dc/3kV dc) and some of them will be equipped with TVM 430 to enable operation in France. The contract is expected to be awarded this year.

To become the world's second longest network, Spain has invested more than €45bn in completed infrastructures and has allocated e12bn more to lines currently under construction. That may seem a big sum given the size of the country, equating to around 4% of GDP. But it is a modest amount when compared with the per-km cost of other high-speed networks around the world. It should also be taken into consideration that more than one fifth of the total investment in the completed lines - around €10bn - has been funded directly by the European Union through different transfer programmes.

A study by AT Kearney, commissioned by construction companies association Seopan and published in September 2015, concluded that Spanish high-speed rail has come not only at a lower cost in absolute terms, but also compared with other countries. With a price tag of €14m per kilometre, its average cost is the same as France, and lies well below that of Germany (€22m per-km), Italy (€40m) or Japan (€30m).

The reasons for this relatively inexpensive cost structure are varied, but include low land acquisition costs because of a low population density in most areas, cheaper financial guarantees for Spanish companies, and according to the report, "a workforce at a lower cost than in the Nordic countries and more productive than that of the emerging markets." It also estimates the total impact of infrastructure for the Spanish economy as a whole at €1.90 per one euro invested, and its final return for the Treasury through taxation at 50 cents.

While the expansion plans have recently attracted some criticism because of their ambitions for development, high-speed rail is favoured by a clear majority in the Spanish parliament and remains a must-have for major municipalities not already on the network. However, this massive investment programme's momentum has had to confront the stark reality of public debt and deficit.

Constrained by a thorough reform programme agreed with the EU four years ago, the central government has made several concessions and adapted its ambitious projects. Indeed, while high-speed rail has continued to appear year-after-year as the infrastructure investment budget's top priority, some corridors have been postponed, works have been delayed and central planners are now taking a more pragmatic and phased approach to network growth.

This is the case with two new high-speed lines which opened last year. After inaugurating the Ourense - Santiago (2011) and Albacete - Alicante (2013) lines, in 2015 the Madrid - Valladolid trunk was extended towards León and Zamora. The latest stretches consist of two single-track sections but which were designed and constructed for double track, with passing loops installed in some sections and in major towns. This approach cut some superstructure installation and maintenance costs while adjusting actual line capacity to demand.

The same option was chosen for the Valladolid - Burgos and Antequera - Granada lines, both of which are in the final stages of construction and are expected to open in 2016. For the Extremadura corridor from Madrid to the Portuguese border, a different approach was taken. The western portion of this line will open several years before the eastern section, but without electrification with diesel traction the only option to connect Madrid with Badajoz and Portugal. As a consequence, the newly-built section will consist of a single track of Iberian gauge, and without electrification or ETCS.

Heavy upgrades

This approach also implies that new infrastructure planned for some links will be replaced by a mere refurbishment of the existing line. Spain has already tested the heavy upgrade approach taken on the Iberian gauge lines from A Coruña to Vigo and from Sevilla to Cadiz, where works started in the early 2000's and finally completed in 2015. However, the idea now is to make small, fast and cost-effective improvements on conventional sections in order to enhance interoperability, as it has on the existing Medina del Campo - Salamanca line. This has been electrified at 25kV ac and since December is used by daily Alvia services connecting Madrid and Salamanca via the new Madrid - Zamora high-speed line. Between Palencia and Santander, modernisation of 3kV dc electrification is underway to offer higher reliability for high-speed services using the conventional network.

In addition, work is underway to electrify at 25kV ac a 27km section of the Antequera - Granada conventional line around Loja. A third rail will provide dual-gauge capability so that the new high-speed line to Granada, which is almost complete, can open despite a delay to the construction of the Loja bypass which is expected to take several years to complete. Dual-gauge track and 25kV ac electrification has also been chosen for the refurbishment of the conventional line from Murcia to Cartagena.

The extension of standard gauge from Barcelona to Valencia and Alicante is also underway in an effort to foster international freight and passenger traffic between France and major destinations on Spain's Mediterranean coast. This complex project includes finishing the long-awaited Vandellós bypass, where work first began in 2000, installation of third rail on some existing sections, and the migration of Iberian-gauge tracks to standard-gauge on others between Vandellós and Valencia. In the mid-term the plan is to reopen a disused section from Xátiva to La Encina junction to Iberian-gauge traffic while standardising the current line.

Deploying dual-gauge systems over the Mediterranean Corridor has proven more difficult than expected because all work must be carried out without disrupting existing traffic. As a result, a project completion date is still not specified for this section. The pace of expansion has also slowed south of Murcia, although the geologically-complex Pajares bypass between Leon and Oviedo in northern Spain, which includes a 25km twin bore tunnel, is nearing completion.

Despite these problems, Spain expects to open no less than four new line extensions - Venta de Baños - Burgos, Zamora - Pedralba, Antequera - Granada, and Alicante - Murcia - in the coming months, although no specific opening dates have been announced and some will not see trains until 2017. In addition, a crucial link to connect the two halves of the Spanish high-speed network for the first time is expected to enter service in 2016.

This 35km line includes a 1435mm-gauge tunnel beneath Madrid, and will allow new through services between destinations in the north and the southern and eastern arc of the Iberian Peninsula, multiplying commercial routes and easing high-speed operations for Renfe, although with two limitations. Trains using Madrid Chamartin station and the new tunnel will be unable to stop at Atocha - Madrid's main high-speed hub - or connect with the Madrid - Barcelona line, as projects for the construction of a new suburban station in Atocha and a flyover south of Madrid have been postponed.

Developing rail in Spain is now a game of balancing priorities, in which the question is 'how?' rather than 'when?' If Spain kept pushing to construct an even greater high-speed network during the hardest part of the Great Recession, it is unlikely that the trend for a growing and a more integrated long-distance rail network will reverse now that the economy is expanding at a steady pace. Matching construction plans with tight budgets, while managing interoperability and looming market liberalisation, will surely keep rail planners busy in Madrid for years to come.