REVAMPING OF THE RAIL ROLLING-MILL OF THY SSEN-STAHL-AG

The 5-stand two-high reversing mill ofThyssen Stahl AG built in the '2 0s rolls a largely specialized track programme. The time required for section change amounted to about 4 hours. In order to be able to react flexibly to the market demand also at decreasing lot sizes it was nec essary to drastically reduce the time of changing. This has become pos sible by installing new change ''cassette''-type roll stands. This tec hnology has enabled the change times from section to section to be red uced to about one hour. At approximately 25 section changes per month this results in an increase of the possible plant operating time by ab out 75 hours per month. The transfer of the setting operations from th e mill to the change yard has led to better working conditions and a d ecrease of accident frequency. The application of modern measuring and control techni ques has made it possible to achieve a more accurate a djustment of the top rolls. The new technology and the sturdy, hydraul ically prestressed stands have resulted also in closer rolling toleran ces.