In tough environmental conditions, not only railway cranes and slag pot carriers have to prove themselves. Electronic components, such as spring pressure connection technology and I/O controllers, must be able to withstand them too.
AFTER THE RAILWAY CRANES AND SLAG POT CARRIERS leave the factory hall of manufacturer Kirow in Leipzig, they often have to provide reliable service for over twenty years in severe conditions. Outdoor temperatures between -20 °C and +40 °C, hot slag material with temperatures of up to 1200 °C, severe shocks and increased electrical voltages are some of the requirements placed on the technology and electronics. In this environment Wago's spring pressure connection technology and I/O controllers must also prove themselves.
Kirow is the world market leader for railway cranes, and its Multitasker can be found in the depots of many railway companies. It is used wherever damaged vehicles have to be recovered from the rail network and whenever loads of up to 200 t have to be moved. The Tracklayer, a special addition for the Multitasker, is used for laying and replacing very long and heavy track and switch parts, which have to be regularly renewed due to severe wear, particularly as a result of high speed trains. The individual parts of the switch were previously transported to the site, where they were assembled and the tracks fitted. The switch segments weighing up to 18 t are now completely pre-assembled by the manufacturer and only then brought to the site for replacement at the trackside. With up to 4,4 m in width, the switches are too bulky for normal rail transport. They are tilted at 60 degrees on special switch transport wagons from Kirow, fastened securely and often transported to the sites over long distances.
Kirow's railway cranes and slag pot carriers are operated by a sophisticated control technology. A host of sensors monitor the actual operating state and several actuators ensure reliable control. The signals are routed via an I/O system, thus enabling, for example, the position of the additional stabilizing supports of a crane to be monitored with inductive sensors. Once the supports are located at the required distance, a digital output module in the system activates a control light. Other sensors check whether the tilt compensation is correctly locked during transport and unlocked during operation.
“The I/O system we were looking for had to be a tried and tested solution for the severe conditions of the railway environment. Compared to other manufacturers, Wago's reliable spring pressure connection technology and robust CANopen technology stood out,” reports Arnfried Wagner, responsible for control technology at Kirow. Kirow uses the Wago-I/O-System 750. The Minden-based manufacturer was able to certify the robustness of its technology for the special requirements of the railway industry according to EN 50155 (railway standard) and EN 50121/3/2 (EMC performance). The spring pressure connection technology and electronics have been tested for resistance to shaking, vibrations, and shock, with proven and certified resistance to extreme weather, interference, and vibrations.
According to Arnfried Wagner, the other benefits of the technology include the modular concept and the compact design. The space-saving I/O nodes can be positioned wherever sensors and actuators are required, and any expensive cabling to a central controller is unnecessary. Due to the short distances involved, the manufacturer uses cables with small cross sections that are less susceptible to electromagnetic interference. Thanks to the large number of analog and digital inputs and outputs available, the system is a suitable enhancement to Kirow's own control technology. For this reason, other functions, such as the movement of the support arms, will also be controlled in future by the Wago-I/O-System's output modules.
“We have been using Wago technology for five years and are very pleased with it. We never have any failures despite the extreme environment in which it is used. This technology offers highly flexible use for a wide range of requirements and has a good price/performance ratio,” said the engineer responsible for the control technology at Kirow. “In areas with extreme temperature fluctuations we initially underestimated the problems with condensation. We looked for a solution together with Wago and also found one by using special protective lacquer on the electronics. Since then we don't have any more problems with humidity and our customers are also very pleased with the reliability of the technology,” says Arnfried Wagner.
At Kirow, particular importance is also placed on standard interfaces like the coupler for CANopen as well as on simple handling. In spite of the very harsh environments that are frequently involved, the spring pressure connection technology has ensured absolute reliability for both modules and controllers. “The extended temperature range is becoming increasingly more important for us. For example, we have tenders from Lithuania and China in which the technology has to function error-free at -40 °C. Wago's new 750 XTR System offers the right approach here,” Arnfried Wagner states. The system features an extended temperature range from -40 °C to +70 °C. It also offers isolation up to 5 kV and vibration resistance up to 5 g of acceleration.
At Kirow, experience has shown that having a proven technology is not enough. Compliance with the standards for climatic conditions, EMC protection, and proof of safety also have to be certified. With its own certified testing laboratory, Wago is able to verify compliance with all standards.
The customers of the railway system manufacturer expect a product life cycle of at least 20 years. This must also be delivered by the quality of service and the availability of spare parts. However, the innovation cycle of software and electronic components is not conducive to these requirements. The control technology manager at Kirow has had several bad experiences with electronics suppliers: “We were repeatedly surprised by the discontinuation of important parts. Wago's product philosophy here is much better ,since new components are always downward compatible with previous versions. This continuity is very important for us.”
News and reports