Sere Maintenance modernises concrete handling for KP1

Founded in 1962 in Vertou, in the Loire-Atlantique department, Sere Maintenance specialises in designing and selling lifting equipment, handling systems and overhead cranes across Brittany. Its versatile team also handles every required study, inspection (General Periodic Inspections) and repair for this machinery and equipment. To keep metal structures durable and high-performing, the company manufactures and exports cathodic-protection products and accessories (rectifiers, anodes, electrodes, cabinets, boxes, etc.). Sere Maintenance markets VERLINDE equipment and belongs to the EUROPONT network. Sere Maintenance was approached by KP1, France's leading maker of prefabricated construction systems, to design and build a custom process overhead crane for transporting and handling concrete at one of its 20 production plants, in Saint-Jacques de la Lande (35).

KP1 is a building-industry player firmly rooted in local economies, with 39 sites spread across France. The group invests steadily in optimising its manufacturing performance and logistics through major overhaul programmes for its concrete plants and production lines, while also integrating new processes for its products. It has also launched a large-scale CSR programme aimed at moving toward a more responsible industry.

5 years ago, KP1 entrusted the renewal and upkeep of its lifting devices and systems to Sere Maintenance. The services offered by Sere Maintenance made the difference compared with competing companies.

At its precast concrete slab plant, KP1 needed to optimise its overhead crane. The crane moved a load of 3,6 tonnes of concrete from the production plant to the hoppers, over a distance of roughly ten metres, where the slabs are cast. When renewing it, KP1 wanted the crane automated to increase the security of the concrete load, which was liquid, and therefore unstable, and offset from the crane's centreline. Since approach clearances were tight, the crane had to be custom-built.

A process crane that automates and secures load transport via a suspended tank

Sere Maintenance proposed a double-girder bridge crane rated at 5 tonnes (5 x 14 metres) with a VERLINDE EUROBLOC VT3 electric hoist with dual cable outlet. Since the load is offset from the crane, the two lifting points ensure its stability. The hoist offers variable travel speed for very precise positioning of loads, along with an ergonomic hook.

In the raised position, the load is held inside a funnel by electric jacks that lock it in place. Its handling is then secure. The double-girder bridge is suspended, which reduces its approach clearances, notably around the casting zone, where an operator takes back manual control of the load. The dual-rail trolley is likewise suspended.

Sere Maintenance ran the project in 5 months, from design to commissioning. KP1 is pleased with the benefits the new process crane delivers: a smaller footprint, greater safety and easier handling.