TATA Steel is Europe's second largest steel producer and supplies more than 28 million tonnes of crude steel around the world for construction, automotive, packaging, mechanical & electrical engineering, metal goods, plus oil & gas. The company’s main UK steelmaking operation is based in Scunthorpe, and supplies projects throughout Europe, such as 84,000 tonnes of steel destined for the new South-Europe-Atlantique rail line in France.
The Scunthorpe works contains blast furnaces named for English queens- Mary, Anne and Victoria. Within these furnaces fuel, ore and flux (limestone) are continuously supplied from above, whilst air is blown into the bottom of the chamber. The resultant chemical reactions produce the molten metal. To achieve this, temperatures may be as high as 2300°C (4200°F). In such working environments the safety of workers is paramount. TATA steel’s Scunthorpe works had deployed a radio based alarm system for the operators of the blast furnaces, to inform them of an evacuation alert. The system was also used to advise supervisors if there is a worker in a particular pit. This legacy system - originally designed and installed by leading creator of wireless products and services Wood & Douglas - had recently become obsolete.
TATA Steel once again turned to Wood & Douglas, to supply a new, very fast, flexible radio based network which could replace the old radio alarm system. The new system consists of four base station units on different frequencies and system Identifications.
Each base station panel consists of an Opennet 6000 Max RTU complete with SX450G radio and power supply. The OpenNET 6000 Max is a programmable controller which can be interfaced with Low Power Radio solutions to enable telemetry operation for data acquisition, process control and monitoring. Via an Ethernet interface to the site data network, it is possible to access system status, receive alerts and see ‘worker in pit’ indications. Each Base Station panel also has an alert pushbutton.
The new system also incorporates four portable outstations consisting of the same hardware, with the addition of a battery pack supplying up to seven hours of operation, or the ability to run off a stable supply from a vehicle. Using the SX450G, a compact, professional radio transceiver, Wood & Douglas was able to balance power and battery economy for the portable application, which can call for medium to long range data communication and telemetry. In addition the new system incorporates a standalone test base station for checking these portable outstations, delivering an additional layer of failover for the alarm network.
Together, the Base Station and portable outstation radios, operating on licensed exempt telemetry frequencies, create a polled network (PNDB) with the central master station responsible for all radio communications. With the master continuously polling all of the nodes and each slave only responding if it receives a message specifically addressed to it, the update time is very quick. The advantage of this approach is to deliver near instantaneous speed to the system, which is critical when protecting the lives of operators in the blast furnaces.
Each portable is equipped with a Base Station selector switch, comms alarms, evacuate LED and buzzer. A green LED indicates RF Comms status and that the area is safe. The red LED and pulsed buzzer is used to warn of low battery charge, or if continuous indicates an evacuation. A latching pushbutton is used to show when a worker is in the blast furnace pit. In this condition the alarm system will illuminate in yellow to warn that workers are operating at the location.
- Fast, proven radio safety alarm system
- Fixed Base Stations and portable outstation deliver flexibility in deployment across large site.
- Powerful transmission/reception, yet economic when drawing power from batteries ensures reliability of the system