Steel mill repairs
Due to the tight time limits of the plant shutdown, the Metalock Engineering Group had designed jigs and milling devices to permit simultaneous operations on both operator and drive side windows. The housing windows were machined for their full height of 4.3 metres and 356mm wide to open up the window width from 1524mm to 1536mm, removing equal amounts from each side. Additional cut outs were machined to accommodate the new ‘E’ blocks by extending the window width to 1618mm for 920mm by 44mm deep above and below the pass line.
As well as the window faces, Metalock had to drill and tap 136 holes ranging from M16 up to M24 in the ‘E’ block areas. A further 72 holes were required in each of the front faces of the operator side for latches to hold the mill rolls in place and spindle supports for roll changes. Prior to the shutdown, Metalock designed and produced a series of special purpose rail type drill jigs and high speed drilling and tapping machines which substantially reduced the time required for all the drilling and tapping operations.
Metalock also machined the base on the mill’s H4 and H5 stands. This was to ensure that the base was flat, level and true to the vertical windows.
A similar upgrade was also planned for the cold mill and for this Metalock machined 80mm wide by 20mm deep keyways across each of the housing posts on Stands 7, 8 & 9. Instead of large ‘E’ blocks, a similar system, devised to cause less disturbance to the mill, was to be fitted and located in the new keyways.
On site machining team
To ensure that all the operations could be completed within the allotted time the Metalock Engineering Group had a team of 25 engineers available on site. On completion of the project, Alcan Rolled Products’ Chief Engineer, SandyFraser complimented the Metalock team on its professionalism, safe working practices and its ability to integrate very well into what was a busy area of the mill.