Madrid-Galicia line
Ourense-Santiago Corridor
The Ourense-Santiago Corridor forms part of the North-Northwest Rail Corridor, which will connect the Northwest with the Centre and North of the Spanish peninsula via the Madrid-Segovia-Valladolid Corridor.
In Santiago it connects with the Atlantic Corridor (Ferrol-A Coruña- Santiago-Pontevedra-Vigo-Portuguese Border), also under construction. The completion of the comprehensive improvement and electrification works on the 62 km long section of the Atlantic Axis between Santiago and A Coruña enabled the entry into service, on 10 December 2011, of the new 150 km long connection between Ourense and A Coruña.
The estimated total investment for works on the Ourense-Santiago section (track-bed, tracks and facilities) is 2,547 million euros. Including the investment in the section between Santiago and A Coruña, the Spanish government has earmarked more than 3.3 billion for its construction.
The 87.5 km route has been designed with the highest quality parameters for electrified double track of international UIC gauge (1,435 mm), although, in the first phase, it has been decided to install Iberian gauge track (1,668 mm) with polyvalent sleepers, preventing the corridor from being isolated until the Madrid - Galicia high-speed line between Olmedo/Medina del Campo and Ourense comes into service. This solution means it is not necessary to build new gauge changers, or to install a third lane on the Santiago - A Coruña line.
The new line will incorporate the most advanced signalling and railway safety systems.
This line presents great construction challenges as it passes through very difficult terrain. To overcome these obstacles it has been necessary to build 31 tunnels, totalling 29.3 km under ground, and 38 viaducts with a total length of 20.4 km. Over 57% of the entire route runs through tunnels or over viaducts.
- 38 viaducts covering 20.4 km
- 31 tunnels covering 29.3 km
Viaducts
The Viaduct over the Arenteiro River (1,444 m), Viñao (1,357 m) and Deza 1 (913 m) stand out for their length.
In terms of height, the Viaduct over the Barbantiño river has the highest pile height at 97.9 m.
Tunnels
This area has the route’s longest tunnels, including the 4,068 m-long Burata Tunnel, which is the longest on the Ourense - Santiago Corridor . This tunnel also has a narrower-bore parallel gallery that connects to the main tunnel every 250 metres, giving access to maintenance and emergency vehicles.
Other important tunnels are those of: Outeiro (2,866 m), Piteira (2,135 m), San Fiz (2,135 m), Mundín (1,112 m) and Barro (1,494 m).
Viaducts
There are several outstanding viaducts on the Lalín-Santiago section, including the Rego das Lamas Viaduct (287 m) with its top cable-stayed arch, at the junction with the AP-53 motorway.
The Deza River Viaduct (1,175 m) and the O Eixo Viaduct (1,224.4 m) have central arches built using a process of gradually placing the half-arches, with heights of 96 and 84 m respectively.
The Sáramo River Viaduct (1,465 m) is the longest on the whole line.
Finally, mention should be made of the Ulla Viaduct, which has been awarded the San Telmo 2011 Prize by the Galician Association of Civil Engineers for the best civil engineering work carried out in the region of Galicia. It also received the best Civil Engineering works award from the Scientific-Technical Structural Concrete Association (ACHE).
The viaduct is 630 m long, with a maximum pier height of 116.9 m and a large central arch spanning 168 m. This was built using two moving cantilevered platforms, which represented the true civil engineering challenge of these works.
Its dimensions make the viaduct over the River Ulla the highest in Spain, both in terms of the height of the piers and the sagitta of the central arch (104.4 m).
The type of viaduct built responded to the need to safeguard the Ulla-Deza river system, thus meeting the requirements of the Environmental Impact Statement.
Other important viaducts along this part of the route are:Martixe (974 m), Covas (975.2 m) and Besteiros (730 m).
Tunnels
A total of 19 tunnels have been built on the Lalín-Santiago section.
The longest tunnels are the Carboeiro Tunnel (1,420 m.), Vilar do Xesta (1,215 m), Marrozos (1,158 m), Vilar do Xesta (1,215 m), Marrozos (1,158 m), Vilar do Xesta (1,215 m) and Vilar do Xesta (1,215 m), Vila de Cruces (890 m), O Curro (840 m), Agro (820 m) and A Pena (810 m).
Part of the high-speed lines construction budget goes towards ensuring their environmental integration and compliance with the Environmental Impact Statement (EIS), and making voluntary environmental improvements.
On some points of the Ourense-Santiago HSL, environmental actions have represented up to 33% of the budget, specifically on the Lalín (Anzo) - Lalín (Baxán) subsection.
Measures taken include protecting the river ecosystem, the flora and fauna of the area through which the rail corridor runs, and minimising the sound and visual impact on the landscape.
This includes the planting of around 160,000 trees, 2.9 million square metres of hydroseeding and 647,000 m2 of seeding. Protection against noise will involve putting up 13,165 m2 of acoustic screen and 640 linear metres of tree screens. More than 20 faunal passes have also been installed at different levels, as well as 134 escape mechanisms for any fauna that may penetrate the track-bed fencing.
On the other hand, Adif has also worked closely with Galicia’s Cultural Heritage Department to ensure the conservation of any archaeological heritage affected by new rail construction. The following action has been taken in this regard: archaeological surveys and monitoring, protection and cataloguing of new elements, and archaeological procedures and excavations.
All along the route it has been necessary to consider of elements of recognised cultural value, including the traditional grain store of Carboeiro, the Reguengo mill and the Castriño de Bendoiro archaeological site. In addition, the “Cruceiro de Pazos” stone cross has been moved and valorised and the “Chousa Nova” dolmen has been excavated and valorised.
Similarly, the design of certain structures has taken into account the presence of elements classified as cultural heritage, for example, the viaduct over the Portos River, due to its proximity to “Ponte Ceballos”, and the Sáramo viaduct, because there is a traditional granary listed nearby.