For radiation shielding at the particle accelerator facility FAIR (Facility for Antiproton and Ion Research) under construction in Darmstadt, Germany, many steel blocks and bars shall be manufactured. The blocks and bars are part of an enclosing of the target and beam catchers in a beamline for intense heavy ion beams. After assembly together with already existing similar blocks as side walls, they will lead to an enclosure of the area.

The delivery consists of about 14 blocks with weight from 16 to 40 tons. For ease of manufacturing and transport bigger blocks can be split into two provided their function remains unchanged. The total mass is about 356 tons. Blocks are needed in thicknesses of up to 870 mm. Each block has its individual shape described in drawings. The manufacturer should present a design how these blocks can be combined out of layers from the thinner material available (welded or bolted together). Rough milled steel slabs could be cut into appropriate pieces. Mechanical tolerances are according to DIN ISO 2768-1 c (2768-2 L).

Two block have bigger round cut outs, and two blocks require through holes of diameter 100-150 mm. The shielding blocks have to be made of structural steel with a cobalt content of less than 0.01%, a nickel content below 0.5% and a density of at least 7.85 g/cm3. As an alternative cast iron of lower density can be offered, but due to its lower shielding capability it will be rated lower in the technical evaluation of the offer. The composition of the material has to be guaranteed and certified. The blocks have to be painted for protection.

All shielding blocks have to be equipped with threaded holes and lifting eye bolts for crane transport. Some threads require extension tubes. All shielding blocks have to be transported to the FAIR construction site and provided fully assembled ready for mounting over the beamline. Simple assembly work on site is possible, the hall is equipped with an 80 ton crane.