French construction group Panthéon deployed its Terex® AC 700 all-terrain crane to help raise a complex scaffolding structure at the famous monument.
Since 1791, the Panthéon is the secular temple of the French Republic, the resting place of citizens venerated by the nation. Buried within the Panthéon are writers like Rousseau, Voltaire, and Victor Hugo; scientists Pierre and Marie Curie and heroes like Jean Moulin, among other illustrious names.
As the structure weakened, the Centre des Monuments Nationaux, the main caretaker for the National Monument System, has now undertaken a massive restoration project. The first phase of this restoration work will last until 2015, starting with the upper part of the structure at 82 m high (nearly 270 ft). There is one major challenge: the monument has to remain open to the public while restoration takes place.
The Panthéon is fragile, and in order to repair its upper structure without using the historical building itself as a support, the colonnaded drum supporting the dome will be completely covered by free-standing scaffolding. In order to raise 350 tonne of scaffolding into the air, Paris Echafaudage designed a metallic structure shaped like a kitchen stool. It consists of a reinforced hoop tightened around the base of the drum and resting on four legs, each 37 m high and anchored by micropilons. One of the legs will serve as the base for a 96 m high tower crane. In order to assemble the scaffolding, Panthéon brought in its Terex AC 700 all terrain crane, equipped with a 42 m luffing jib and 140T of counterweight. "Obtaining the permits necessary to truck in and install this kind of equipment in the heart of Paris was no easy thing. But it turned out to be the best option for this type of project," explained Stéphane Yorgui from Panthéon's engineering office.
Only four weeks were needed to lift the individual structures into their desired positions. The largest of these structural elements were 20 x 20 m in size, weighed 42T, and had to be hoisted to a height of 40 m. To cope with different lift profiles, the team at Panthéon used the 42 m luffing jib and worked with varied main boom extensions and angles.
Franck Mikaelian, the main crane operator, has worked with Terex cranes for over ten years and he has logged four years of experience working with the AC 700. "I am crazy about this crane," he stated. "I immediately felt comfortable with it. It's comfortable, precise, and powerful."
After several weeks of methodical planning and four weeks of precise execution, the structure was assembled and ready to be used for the massive restoration project. "The work went smoothly. The crane operators are true professionals. Their advice was very useful to our team. We will likely work with them during the disassembly process too," said Dejan Kostovski, Project Manager for the scaffolding company, Paris Charpente.
Terex® A AC 700
The Terex® AC 700 all terrain crane is one of the most powerful telescopic cranes in the 700 T capacity class that can be transported together with its complete 60-m (196 ft) main boom within an axle load of 12 metric tonne. An increase in lifting capacity, especially when working with steep boom positions, is achieved with the patented sideways superlift (SSL) system. Thanks to the crane's star-type outriggers, system deformation is reduced and exceptional lifting capacities are achieved with a support base measuring 12.2 x 12.4 m. The crane combines large lifting capacities with a compact undercarriage length of only 18.60 m. A state-of-the-art engine and a fully-automatic transmission provide the crane with its outstanding power, and its four drive axles (3+4 and 8+9) feature differential locks. The crane is versatile at the construction site: eight of its axles are steerable (one to five and seven to nine). An automatic levelling mechanism is available in order to complete the picture. The crane can be configured with a luffing fly jib measuring 24 to 96 m. With only a few steps, the luffing fly jib can be rearranged into a rigid fly jib with a length of 20 to 50 m, or, as a light system with a length of 6 to 36 m.