Modern automation enables novel train lift system
07 June 2015
Eaton has been selected by systems integrator, Jenkinson Electrical Engineering, to supply the automation components that will form the basis of a new and exceptionally versatile train lifting system designed by mechanical handling equipment specialist, Mechan.
The new lifting system will allow a virtually unlimited number of lifting jacks to be synchronised accurately within ±2mm or better, allowing even the longest trains to be conveniently and safely lifted for the removal of bogies or other servicing and maintenance requirements.
In today’s cost-conscious rail industry, it is more essential than ever to maximise the in-service time for rolling stock. As a result, conventional approaches to train lifting, which is part of the routine maintenance of modern rolling stock, have largely been superseded by the use of sophisticated jacking systems. With these systems, four jacks are typically used per vehicle, allowing the whole train to be lifted as a single unit in a matter of minutes.
A key requirement for the success of these jacking systems is that the jacks must be accurately synchronised while they are lifting and lowering the train, so that the risk of distorting the vehicle bodies is eliminated, and the weight of the train, which may be as much as several hundred tonnes, is evenly distributed between the jacks.
Moreover, to ensure that the system is fully compatible with current and future train types, the individual jacks must be physically separate units so that they can be positioned as required to suit different types of train body.
These were among the essential requirements that mechanical handling equipment specialist, Mechan presented to Jenkinson Electrical Engineering - a company with wide experience of developing specialised automation systems - when it was looking for ways to upgrade the control systems used in its products.
The control system that Mechan was already using offered satisfactory performance but it was limited to controlling a maximum of 24 jacks simultaneously. Because it was based on proprietary electronic systems, developing it further in order to handle more jacks and to add other new features would have been both costly and time consuming.
After looking carefully at Mechan’s requirements, Jenkinson Electrical Engineering proposed a solution based on modern automation products incorporating the latest technology, but which were readily available off-the-shelf. The key products chosen were Eaton’s XC100 programmable logic controllers (PLCs) and its XV100 touch-screen operator interface units. Keith Atkins, general manager of Jenkinson Electrical Engineering, takes up the story:
“We’ve had long experience of working with Eaton products, so we knew we could rely on them to provide excellent performance and value for money. We also knew that by using the XC100 and the XV100 we could produce a versatile control system that could be easily upgraded, should the need arise, simply by making software changes.”
The XC100 PLCs are compact modular devices that can easily be expanded to meet future requirements. This, and the fact that they also support the CANopen fieldbus system without the need for additional hardware, influenced Jenkinson Electrical Engineering’s decision to go with this hardware. The XV100 operator interface panels were chosen because of their robust construction, high quality colour screens and their ease of programming. Keith Atkins again:
“The PLC software needed to for this project was quite complex, as we’ve built in a large number of options to cater for different configurations of jacks. But Eaton’s XSoft-CoDeSys-2 programming system, which is IEC 61131-1 compliant, made the programs easy to develop and test. The result is a system that’s dependable, and that offers all of the flexibility and versatility that Mechan was looking for.”
Mechan has now used the new train lift control system – complete with Eaton’s automation products - on several train lift systems ranging in size from a small single-vehicle lifting system with just four jacks, to a full train lifting system with 44 jacks.
In all cases, the control system has performed flawlessly and delivered synchronisation between the jacks that easily meets the ±2mm accuracy requirement. In principle, any number of jacks can be synchronised using the new control system, and Mechan plans to make full use of it on future projects.
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