Cranes, trains and autosafety
November 1st 2007

Overhead cranes from Verlinde are selected for the Le Mans tramway's maintenance centre for their safety and reliability

Bouyer Manutention, a member of the Verlinde Europont network, was selected to install and put into service the handling systems in the maintenance centre for the Le Mans tramway in France. The special safety systems proposed by Bouyer Manutention, combined with the reliability of the Europont overhead cranes, made the difference.

The Le Mans tramway should be ready for commercial operation in November this year, after more than two years work all over the city. The choice of the Le Mans Métropole was in favour of the Citadis, a tramway made by the French equipment manufacturer, Alstom.

Heulin was selected by the SEM (the Le Mans equipment company) to build the whole centre for maintaining the 23 trams which will serve the city. Heulin, a subsidiary located in Le Mans, belonging to the building and public works group Vinci Construction, was responsible for all the building professions involved in the construction of the 5000m2 building, including the hoisting equipment. The project lasted 16 months.

"With regard to the hoisting equipment, Bouyer Manutention was the sole manufacturer who proposed us a solution which corresponded completely to the in the SEM specifications, in particular for the special automatic safety systems. Moreover, the Europont equipment guarantees a very good level of reliability, necessary for this type of equipment" said Mr. Boulaire, the works foreman at Heulin.

The maintenance centre has three single-girder overhead travelling cranes installed equipped with electric chain hoists with a capacity of 1000kg and a profiled doublegirder crane with a cable hoist with a capacity of 6500kg. The first ones were intended to handle the elements on the trams' roofs: airconditioning units and pantographs.

Ultrasound sensors were added by Bouyer Manutention to detect the opened-up pantographs and to ensure that the hoisting is carried out only when it is in the folded down position. Manipulating an open pantograph would in fact run the risk of catching and and tearing off the catenary system. As for the 6500kg crane, it is used for handling the bogies between the pit and the workshop when the wheels have to be reprofiled by grinding.

The safety system

Another special safety system was added to all the cranes to ensure that, when the pantographs, the airconditioner units, or the bogies are handled, the LAC (Catenary Power Supply Line) is not carrying current.

The cranes cannot move when the catenary system is carrying current.

"To power up the catenary system, the five keys must first be correctly positioned. A primary key is set at the level of each overhead travelling crane. It enables the crane concerned to be started. It is freed by an electronic signal when the position of the overhead travelling crane is detected, when it is in a secure position. When the key is withdrawn into a non-secure position it means the current will be cut off immediately. Once the four primary keys are correctly set, they unlock the mother key which enables the catenary system power supply to be operated," commented Mr. Chaboche, project head at Bouyer Manutention.

"Bouyer Manutention was able to customise a standard hoisting system, within a short delivery time limit. When once again we have this type of specific need, we will not fail to consult them." concluded Mr. Boulaire.

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