In May 2004, Van der Ende began preserving the railroad bridge over the Waal River in Zaltbommel. This is a huge job, as the bridge has eleven spans and a total length of over 900 meters.
Over four years, the preservation system on the underside of the bridge, most of which consists of a thick layer of Flintkote of up to ten millimeters, will be removed. To remove this layer, the surface is first treated with Hydrojetting. To minimize environmental impact, the process water used in hydro-jetting is continuously recycled.
Then the rust is removed and the intact paint layers are roughened up with Torbo-Stralen. Then the new paint system is applied by brush, which consists of three coats of Epoxy paint with a total layer thickness of about 250 microns.
The work will be conducted above the water surface and above the floodplain of the Waal River. Therefore, a special structure had to be built to meet the requirements of the Surface Water Pollution Act.
In cooperation with a construction company, a preservation structure was designed to meet all requirements. The process water from hydro-jetting is collected on the floor of the bin, then discharged to the filtration plant through the drain. The total structure measures about 7 by 18 meters and is propelled by a hydraulic winch system.