Malpas Tunnel
Encyclopedia
Hérault
Hérault is a department in the south of France named after the Hérault river.-History:Hérault is one of the original 83 departments created during the French Revolution on 4 March 1790...
, allowing the passage of the Canal du Midi
Canal du Midi
The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...
. It was Europe's first navigable canal tunnel and a monument to the determination of Pierre-Paul Riquet
Pierre-Paul Riquet
Pierre-Paul Riquet was the engineer and canal-builder responsible for the construction of the Canal du Midi.-Background:...
, the chief engineer. It is located in the commune
Communes of France
The commune is the lowest level of administrative division in the French Republic. French communes are roughly equivalent to incorporated municipalities or villages in the United States or Gemeinden in Germany...
of Nissan-lez-Ensérune
Nissan-lez-Enserune
Nissan-lez-Enserune is a commune in the Hérault department in Languedoc-Roussillon in southern France.Is situated just south of Beziers. It is twinned with Ampthill in England.-References:Based on the French Wikipedia....
. The Oppidum d'Ensérune
Oppidum d'Ensérune
The Oppidum d'Ensérune is an ancient hill-town near the village of Nissan-lez-Ensérune, France, located between Béziers and Narbonne close to the D609 and Canal du Midi....
is located on the surface a short distance from the tunnel.
There was great disappointment when the works reached the hill d'Ensérune. A few metres of digging in hard rock revealed a very brittle sandstone subject to slippage. Colbert
Jean-Baptiste Colbert
Jean-Baptiste Colbert was a French politician who served as the Minister of Finances of France from 1665 to 1683 under the rule of King Louis XIV. His relentless hard work and thrift made him an esteemed minister. He achieved a reputation for his work of improving the state of French manufacturing...
, the prime minister, halted the works when he was made aware of the situation. The portal was blocked and the workings re-sited. Riquet's detractors took advantage of this situation to impede the project. Colbert announced that he would send royal commissioners to decide the canal's future. The advice of the Chevalier de Clerville, architect to Louis XIV, was to cross the River Aude
Aude River
The Aude River is a river of southwestern France. Its source is in the Pyrenees mountains and it then runs to Carcassonne and turns, reaching the Mediterranean Sea near Narbonne...
rather than tunnel through the hill. Riquet, however, maintained his preference for a tunnel because of the extra problems that crossing the Aude would create.
Riquet's response was to ask his master mason, Pascal de Nissan, to continue tunneling in secret despite the risk of collapse. In less than eight days the tunnel was complete with a concrete ceiling throughout. The tunnel is 165m long and removed the necessity for an extra lock
Lock (water transport)
A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...
.
By the time the Malpas Tunnel was excavated in the seventeenth century, the hill had already for several centuries been the site of a tunnel, dug in the Middle Ages, to drain the Étang de Montady
Étang de Montady
The Étang de Montady, the "pond of Montady", is a drained "lagoon" or more accurately a former freshwater wetland that is popularly said to be "constructed by the Visigoths" but was realised by monks during the second half of the 13th century, under authorization of the archbishop of Narbonne...
. This preexisting tunnel is said to have been Riquet's inspiration for the Malpas Tunnel. In the nineteenth century, a third tunnel was excavated, passing through the Hill d'Ensérune beneath the Malpas tunnel to house the Béziers
Béziers
Béziers is a town in Languedoc in southern France. It is a sub-prefecture of the Hérault department. Béziers hosts the famous Feria de Béziers, centred around bullfighting, every August. A million visitors are attracted to the five-day event...
to Narbonne
Narbonne
Narbonne is a commune in southern France in the Languedoc-Roussillon region. It lies from Paris in the Aude department, of which it is a sub-prefecture. Once a prosperous port, it is now located about from the shores of the Mediterranean Sea...
railway line.