the skeleton of the roof cathedral is build in concrete! Surprising structure!

The skeleton of this cathedral is in concrete!

The structure of the dome of the Hôtel-Dieu de Lyon was made of wood. But during the Second World War, a fire destroyed it Sept. 4, 1944. It was only that funds be provided by the state for its reconstruction, hospices have not enough money. The repair was carried out by the Chief Architect of Historic Monuments Jean-Gabriel Mortamet according to architectural plans of Soufflot.

source: Lyon patrimoine (FR)

Reservoirs of the Plaine Saint-Denis (here, the smallest tank), located under the France stadium are one of the largest type of construction. It can hold up to 165.000m ³ of water. The irregular shape of the pillars is due to the construction technique by molding (digging the soil, concrete injection and clearing the land around the pillar).

Concrete structure of a former chemical plant in Saint-Brieuc.

Those jacks allowed the main concrete railroad to get down and free the hovertrain from the track.

At the end of the underground quarry of Saint-Leu d'Esserent a curious concrete ramp.

Control Room of the NATO radar base, the fort of Mount Salbert.

Fort Lefebvre culminates at the top of Mount Salbert 650m altitude. It said a strong "Sere River". It was built from 1874 to 1877. On May 12, 1955, NATO reuses the fort to house a communications center and a radar base. The book is officially delivered to the Air Force ole March 26, 1958. The book "G" Air Defense Planning (DAT) has 7 radio antennas. The old fort is used as a barracks for soldiers.

The radar base is not exactly the strong, but under the fort. Access from the fort is a long staircase of 322 stairs that descends into a concrete wall strongly.

The site is no longer running quickly but it remains occupied by the army until 1972. The mayor of Belfort is the current owner. It secures the site is now a promenade.

The sky train, the train on air cushion. Bertin The company developed several prototypes of this type of train. The test tracks were built in 1965. The smallest to the Gometz Chatel and the largest near Orleans, over 20 kilometers long.

The concrete track is shaped like an inverted T. The world record speed for a vehicle air-cushion was established March 5, 1974. The record speed is 430 km / h. In June 1974, the company Bertin sign a contract for the construction of a high-speed line between the town of Cergy and business district "La Défense". A few months later, the French government reversed its decision and abandon the project.

The failure of the project has several assumptions:
- The oil crisis of 1973.
- Lobbying by the company National Railways (SNCF) and the metallurgic industry.

The engineer Jean Bertin died December 21, 1975. In 1978, the permanent cessation of testing. The prototypes are still 14 years in the hangar. Then the hangar is the victim of arson. The test track Gometz le Châtel no longer exists. It has been replaced by a tunnel bypass to relieve the downtown traffic jams.

Orleans-Saran line still dominates the fields of the campaign. That would be too expensive to demolish it, especially since it nobody.

source: Wikipedia

Panoramic view on the rooftop of CNIT (Centre of New Industries and Technologies).

CNIT was built in 1958. Its architects are Robert Camelot, Jean de Mailly, Bernard Zehrfuss and Jean Prouvé. In 2010, the building still has the largest range of concrete arch in the world: 218m.