CNES improves 300-tonne slab carriers from Port Talbot

01 Mar 2008

Corus Northern Engineering Services (CNES) has successfully completed refurbishment work on a MultiServ operated 300-tonne slab carrier vehicle used for transporting steel slabs around Corus’ production site at Port Talbot in South Wales. MultiServ offers a range of outsourced mill services to the metals industry, including Corus plants worldwide.

As part of its continuous improvement programme and maintenance operation at Port Talbot, site operator MultiServ identified a number of ways in which they could extend the life of the existing Kress Fleet. Because of the long association between MultiServ and CNES in Rotherham – where CNES had carried out structural refurbishment work on Kress machines over the last 15 years – CNES was the obvious choice to provide the necessary expertise to carry out the refurbishment programme instigated by MultiServ.

The first machine for refurbishment work was a 300-tonne Kress slab carrier was carried out by CNES’ workshops in Rotherham, which had been transporting slab around Port Talbot for a number of years and was due for a major overhaul as part of the scheduled maintenance plan.

MultiServ contacted CNES workshops in Rotherham to inspect the stripped-down slab carrier, in order to provide a professional opinion and to recommend a course of action for other slab carrier units.

An inspection at Rotherham by CNES structural engineers suggested that the unit – the two arms, torque tube and ‘swan-neck’ – required refurbishment and so a scope of work was generated. CNES concluded that both rear sides and a section of torque tube would need to be replaced, along with the swan-neck at the front of the vehicle. The torque tube transmits the traction forces generated by the wheels to the carrier frame, twisting as the unit moves.

CNES generated a refurbishment procedure for the torque tube and discussions were held with the slab carrier manufacturer Kress in the US. Kress approved the procedure and material selections for the tube, as well as the back end replacement.

Due to lack of technical drawings, CNES had to reverse engineer the templates for the back end side plates, which had to be formed, then profiled, before fabrication. All fabrication work was carried out to a very high standard, with 100% inspection before the unit was released back to Port Talbot. Once delivered to Port Talbot, the unit was painted, and then re-assembled ready for use.

Jackie Dixon, Senior Engineering Plant Metallurgist at Corus Engineering Steels comments: “Reverse engineering the back end side plates is not easy. Fortunately, CNES has some very experienced platers, who were able to take the dimensions of the bends in the plates in order to achieve the precise profile required for the job.”

The refurbishment of the 300-tonne slab carrier was completed over a six-month time frame by CNES and MultiServ now has the carrier fully operational on site at Port Talbot. A second carrier unit from Port Talbot is now at CNES’ Rotherham workshops undergoing refurbishment, along with a smaller unit from Corus Teesside. CNES is now involved with MultiServ on a ‘rolling rebuild’ programme for the carrier fleet. The Teesside machine required a wider torque tube as part of its upgrade, so segments were fitted that were provided by Kress.