The Düsseldorf-based band Die KRUPPS, named after the notorious steel dynasty, remains one of the longest-lived German post-industrial groups. In its first work, Stahlwerksynfonie (1981), it tried to simulate the sound of an industrial assembly shop using orchestral means. Inspired by the industrial plants typically found in the Ruhrgebiet, such as the Mannesmann pipe plant, the musicians use drills, sledgehammers and other steel tools (including a Stahlofon (Eng.: steelophone) they built themselves) to capture the resonant atmsphere of heavy industry over a driving bass theme. The two 15-minute pieces with reminiscences of blast furnaces, rolling plants and other ironworks equipment appeared on the independent label Zickzack as Heavy Metal 1. The cover, designed by the musicians Jürgen Engler and Bernward Malaka, combined pictures of an orchestra with images of chainsaws and steel drills.