Las Raíces Tunnel
Las Raíces Tunnel (Spanish: Túnel Las Raíces) is a road tunnel on Route 181 in the Araucanía Region of Chile, connecting the communes of Curacautín and Lonquimay through the Cordillera de Las Raíces in the upper Biobío River basin.
It is the longest of the very few tunnels in the southern Andes and is the second longest in South America (after the 2006 inauguration of the 4,600-metre (15,100 ft) long tunnel Fernando Gómez Martínez in Colombia); it remains the longest road tunnel in Chile. It is located about 700 kilometres (430 mi) south of Santiago de Chile on the paved Route 181 connecting the city of Temuco with the pass of Pino Hachado towards Argentina. As such, the tunnel serves as a link between the Pacific and Atlantic Oceans, from Lebu in Chile to Bahía Blanca in Argentina. It is 4,528 metres (14,856 ft) long, 4.2 metres (14 ft) wide, 5.6 metres (18 ft) high, located 1,010 metres (3,310 ft) above sea level, and was inaugurated in 1939.
Description
Owing to its great length, it is not possible to see daylight from one end of the tunnel from the other, and even from its midpoint neither entrance is visible. Before the 2005 renovation, the unlit interior was a stretch of near-total darkness, particularly around its midpoint.
An alternative to the tunnel is the old scenic gravel road Cuesta de Las Raíces, which branches off northwards about 5 kilometres (3.1 mi) before the western entrance or 11 kilometres (6.8 mi) before the eastern entrance; it is commonly used by trucks too large to pass through the tunnel.
History
Feasibility studies for the tunnel began in 1911, though final blueprints were not ready until 1929. Construction began in 1930 and continued until 1940, at an investment of more than 32 million Chilean pesos of that time.
The tunnel's construction was originally driven by a proposed bioceanic railway that would have linked the ports of Talcahuano in Chile and Bahía Blanca in Argentina; this larger rail project was never completed. Instead, the finished tunnel was put to use by a Chilean rail branch line connecting the station of Púa, on the country's longitudinal railway network, with the town of Lonquimay in the Andean foothills of the Araucanía Region. This branch line operated through the tunnel from 1956 until the 1990s, when it fell out of use and the tunnel was converted for road traffic.
During construction, a landslide is recorded to have sealed the tunnel entrance and trapped 42 workers inside for more than ninety hours, an episode later documented by historian Héctor Alarcón Carrasco in his book Rieles Fronterizos, ramal Púa Lonquimay (2011).
Through the late 1980s and early 1990s, the tunnel carried both rail track for the cargo and passenger trains still using the branch line and wooden planking alongside the rails for motor vehicles and horse-drawn carts. After the railway was fully withdrawn from the area, the deteriorated planking—much of it rotted by chronic dampness and leaks through cracks in the tunnel's concrete lining—was removed and the former rail bed was filled in, leaving the tunnel for the exclusive use of road vehicles. A renovation completed in 2005 left the tunnel fully paved, with interior lighting and traffic signals installed at each entrance.
Toll and traffic
This tunnel allows only one-way traffic, regulated by a toll station where a fee of 400 Chilean pesos (0.53 USD) per car is charged.[1] Its average traffic is about 450 vehicles daily, including heavy fuel trucks arriving from Argentina, which are charged a higher toll of up to about US$22 for vehicles with more than two axles.[2]
See also
Sources
References
- ↑ "Ministerio de Obras Públicas - Dirección de Vialidad". Archived from the original on 2021-04-13. Retrieved 2010-10-09.
- ↑ "Ministerio de Obras Públicas - Dirección de Vialidad". Archived from the original on 2021-04-13. Retrieved 2010-10-09.