Client: REGIONAL PROVIDER OF WATER SERVICES IN WALLONIA (BELGIUM)
Location: JOIDOIGNE - WALLONIA - BELGIUM
Application sector: POTABLE WATER RESERVOIRS
Objectives
The client needed to create structures for the safe inspection of drinking water storage tanks that, once emptied, require periodic sanitization and the repair of the inner lining. The works involved the replacement of damaged painted steel parapets, in addition to the construction of a circular walkway on brackets, overhanging the gap between the circular walls of the drinking water tank, with an internal diameter of 13.3 m at 7.7 m elevation. A new external fixed ladder was also required for access to the walkway at that height, along with the installation of a new 7.7 m fixed ladder inside the drinking water tank. Therefore, the structures had to be light, easy to install, not requiring maintenance, as well as being suitable for direct contact with drinking water.
Solution
The client opted for the composite material rather thantraditional stainless steel. The choice was based not only on the competitive price but also on the lightness of the structures (a 6 m fixed ladder with 3.5 m safety cage is weighing approximately 40 kg), on the lack of any requirement for post-installation maintenance and on the ease of installing completely or partially preassembled elements. In particular, the ladder with ACS formulation inside the tank was supplied in small modules, to be inter-connected on-site with special bolted joints, small enough for handling and hoisting inside the gap. The installation position, however, made it impossible to install the ladder closed to the internal wall of the tank and so simple standard anchor plates could not be used. To solve the problem, truss beam retainers were made with ACS-certified profiles and stainless steel bolted joints, which made it possible to reach and connect to the closest anchor point on the curved walls. M.M.’s technical office oversaw the entire project, from design to construction.
