Control system upgrade project delivers maximum results for production-critical steel plant
The success of any control system upgrade is dependant not only on the end result – the measure of a truly successful upgrade project considers also the impact of that project on production through-put during implementation. This is true of any manufacturing industry but none more so than production-critical businesses where prolonged interruption to production through-put during upgrade completion impacts negatively on production output – and, significantly, on your bottom line.
The 60-tonne gantry overhead slab crane at BlueScope Steel’s Port Kembla Steelworks forms a key component of the integrated steel manufacturing plant, where production capacity currently sits at 5 million tonnes per annum. Outdated relay logic on the gantry crane control system was no longer providing the technology required for smooth operation and system maintenance. While a total control system upgrade to new advanced PLC controls was clearly needed, disruption to BlueScope Steel’s high through-put of steel slab supplies to the plant was not an option.
The only viable solution was an upgrade that could deliver advanced technology in record time.
Advanced technology delivers trouble-free troubleshooting and a smooth ride
The existing control system at BlueScope Steel relied upon old relay logic to operate the gantry overhead slab crane. While overall performance was satisfactory the outdated control system couldn’t compete with advanced control system technology in three key areas: fault-finding; driver comfort; and documentation.
Due to the age of the existing control systems and equipment the system was functioning without PLC control, alarm monitoring and system control monitoring resulting in poor fault-finding ability and maintenance difficulties. Add to this inadequate driver comfort and handling – the result of run-down cabin equipment, aging joystick controllers, console operations with no labelling and inadequate indication, and poor timing control of crane functions – along with inaccurate documentation missing crucial wiring additions and it soon became clear that only advanced PLC control system technology could deliver the flawless fault-finding capabilities, effective monitoring and system alarming, and smooth crane operation required in BlueScope Steel’s production-critical environment.
The control system upgrade solution delivered by Machinery Automation & Robotics (MAR) tackled the three key operational issues head on. Replacement of the outmoded relay/timer logic controls with PLC controls provides BlueScope Steel with a highly flexible control platform. This allows control modifications to be made without the need for problematic – and expensive – hardware changes. The upgraded system now allows engineers to view the program and understand crane operation from a single local point. The benefits of this are twofold: a control system that is easier to operate and more efficient in pinpointing faults. In addition, the PLC control system delivers a significant reduction in overall machine downtime boosting production through-put – a huge bonus for any production-critical manufacturer.
Driver comfort within the cabin has been increased dramatically as a result of the control system upgrade thanks to enhanced system operation, which enables the operator to fine tune the timing functions of the crane’s hoist, as well as its long- and cross-travel controls. Providing new and improved joystick controllers with labelled driver consoles and distribution controls enhances driver comfort during crane operation.
Complete hard and soft copies of the gantry crane’s electrical schematics and PLC/HMI programs give BlueScope Steel a clear understanding of the system’s features and functionality and facilitate troubleshooting, when required.
Installation completed in record time
Sensitive to the negative impact of downtime to the overall productivity and profitability of the client’s manufacturing plant, MAR tailored their upgrade project to work within BlueScope Steels pre-determined maintenance and shutdown periods to eliminate any effects on production.
With this in mind all crane control panels and cabin equipment were tested according to BlueScope Steel’s detailed factory acceptance plan. This ensured a smooth transition from the existing to the new control system equipment. In addition, all pre-installation work was completed onsite within the client’s existing maintenance periods.
Project completion was scheduled for a public holiday shutdown and MAR’s installation teams worked twelve-hour shifts around the clock to ensure a swift and full installation and changeover of all control equipment.
Adding up the benefits
MAR’s prompt and fully operational implementation of the gantry crane control system upgrade delivered a range of benefits to BlueScope Steel including:
- Removal of redundant relay/timer control equipment and replacement with new PLC control equipment;
- Manufacture of new PLC and interface relay panels to control crane operations;
- Supply of a fully networked Allen Bradley ControlLogix PLC platform with Ethernet and ControlNet capabilities;
- Allen Bradley remote I/O for control equipment connections not local to the PLC, considerably reducing interfacing control and multi-core cable installation costs;
- A complete upgrade of the driver’s cabin, including joystick controllers, seat, distribution control, lighting, and radio equipment;
- Complete design of PLC logic with comments, providing the engineering teams with easy and accurate timing changes for all crane operations to allow hoisting, and long- and cross-travel operations to be fine tuned, enhancing driver comfort;
- Design of an operator interface touch panel for all monitoring of crane operations and alarms, allowing the engineers to easily track crane performance;
- Complete documentation of the PLC, operator interface programs, and electrical schematics of the new improved system controls.
Technology at work for BlueScope Steel
- The system comprises a complete Allen Bradley ControlLogix PLC platform solution with Ethernet and ControlNet communications, remote I/O and a PanelView Plus operator interface, and has scope for future additions and modifications, as required
- The Allen Bradley ControlLogix PLC 2MByte CPU platform with flash memory card allows the system to be powered down for long periods of time
- The system includes an Allen Bradley ControlLogix 17-slot PLC I/O rack
- An advanced high-speed network connection to the PLC is facilitated by an Allen Bradley ControlLogix Ethernet network module
- An accurate and robust link between the PLC and remote equipment is achieved through use of an Allen Bradley ControlLogix ControlNet communications module
- Allen Bradley Flex I/O modules are used for all remote interface connections to the PLC
- All monitoring, alarming and diagnostic requirements for the crane are controlled via an Allen Bradley PanelView Plus touch screen