Austria: Andritz AG

The old town of Graz, at one time the residence of the Hapsburg monarchy, is one of the best preserved medieval towns in Europe and is now a UNESCO World Heritage Site.

Andritz AG was founded in 1852 as a foundry and machine works. Since then it has grown enormously and now employs more than 1000 people. This company forms part of the Andritz Group which has 18 production sites, over 35 affiliates and sales offices worldwide and 4000 employees.

Among the products made by Andritz are water turbines and pumps; high-tech production systems for pulp and paper, steel and other specialised industries; and advanced technology for space.

One of Andritz AG’s clients is the European Space Agency. Andritz AG is responsible for making the DAAR retaining rings for the two boosters that provide the power needed by the Ariane-5 launcher at liftoff. The DAAR rings, together with the DAAR struts, form part of the DAAR attachment that holds the booster securely to the main stage of the launcher. These rings also help to distribute the weight of the booster and to increase its rigidity.

In view of the high thrust and tension involved, as well as the tremendous pressure at liftoff, the retaining rings must have exceptional rigidity and strength. The rings have a diameter of 3.5 m and weigh approximately 650 kg each.