March 2013 - Tata Steel Scunthorpe VAC Degasser Safety System

Tata Steel has carried out an investigation of the existing safety system on VDG2 at BOS Plant.

A number of problems were identified. To address these problems the following actions were detailed as required:

  • Design a system to allow personnel safe access to the Vacuum Degasser 2 Ladle Car pit, the system to include lockable gates
  • Improve the reliability of the associated emergency stop system and provide a solution to the existing problems of resetting the emergency stop system

After consideration Tata Steel elected to undertake an upgrade of the emergency stop and plant access systems associated with the Ladle Car and platform hoist. This scope covers the requirements for the supply of a Vacuum Degasser 2 Safety Gate Access Control System based on an Allen-Bradley SmartGuard 600 Safety PLC. The system will interface to new and existing; limit switches, isolator switches, contactors, poppet & loading solenoids, key/gate release solenoids and a PowerFlex VSD all supplied by Tata Steel UK Limited. The system will also interface to the plants' existing SCADA system (alarm/reporting only) and new emergency stop pushbuttons supplied by Inspec Solutions. 

Safety Performance Level

Elements of the system have been deemed safety critical in terms of human safety and a Performance Level required of PL c (ref BS EN ISO 13849-1:2008) has been identified by Tata Steel UK Limited.