The service concerns preventive and corrective maintenance, preparation and assistance with regulatory checks on the overhead traveling cranes of three ULM units: the ALN, AMT center and AMT northwest.

- normal and permanent maintenance, in accordance with the rules of the art of the profession of fifty seven lifting tools distributed on the six sites;

- intervention for curative maintenance and repair following receipt by email of a "intervention voucher", on which the lifting tool, the nature of the intervention, the intervention time slots, the location of the 'intervention;

- regulatory controls are not the responsibility of the holder. However, the company can ask the holder to assist the regulatory control body of the ALN bridges;

- the annual telephone availability twenty four hours a day, seven days a week is requested by the company for strategic bridges. The company can appeal to the holder twenty four hours / twenty four, seven days / seven who will intervene physically within a period equal to or less than two hours from the time of call for the strategic bridges of Saint-Leu d ' Esserent and two and a half hours for Dieppedalle and three hours for Velaines.