At Ealing Common Depot, a railway service workshop of the London Underground, the tube subway trains used on the District Line will now be maintained with the aid of a lifting system from Pfaff Verkehrstechnik GmbH located in Kissing, Germany. On account of its futuristic design, the maintenance staff has nicknamed the versatile and unique system the “Transformer.”
The dual-purpose system is comprised of a total of 28 stationary hybrid lifting jacks from Pfaff Verkehrstechnik with bogie lifting beams and body supports that raise and hold the trains, which measure up to 384 ft (117 m) long and 4.7 ft (1.44 m) high. This design gives engineers ample and safe access underneath the train when performing service.
Precision and Versatility
The versatility of the lifting system from Pfaff Verkehrstechnik lies with its ability to lift the tube trains as either a complete unit or as individual carriages to infinitely adjustable, ergonomic heights. The 28 jacks can lift up to 308 tons (280 metric tons), and the supports can carry a load of up to 218 tons (196 metric tons). This is a task that requires utmost precision. If a complete train is lifted, the lifting process of the Pfaff-silberblau jacks runs in precise synchronization with a deviation of less than ± 2 mm. The worm gear screw jacks achieve this precision through a series of frequency converters, which also permit different lifting speeds within the system.
Once the vehicle has been lifted, the next set of system components is ready to go into action. The jacks feature additional motor-driven supports for holding up the carriage bodies. This, in turn, makes it possible to lower the individual bogies back down onto the rails and roll them out from underneath the raised vehicle. Large, bright LED lights integrated into the lifting beams ensure illumination of the work area under the raised vehicle.
Once the Pfaff Verkehrstechnik system is lowered, the lifting beams mesh together with the main rail and sit flush with the floor. As soon as the lifting beams go up, they are followed by gap covers, thereby resealing the recesses, which would otherwise remain open, such that they can be stood on.
The lifting system and the work processes are controlled by an easy-to-use touch display, which also enables the maintenance staff to check the status of all major system components at all times.
New and Cost-Efficient Concept
Pfaff Verkehrstechnik’s hybrid lifting jack system is a new concept and will serve as a cost-effective alternative to established underfloor lifting and support systems. It is an excellent value for our customers due in part to the fact that extremely shallow pit depths require significantly less foundation work.
The motion technology for the lifting system from Pfaff Verkehrstechnik GmbH was developed by Pfaff’s sister company also based in Kissing – Columbus McKinnon Engineered Products (CMEP). Working together, they were able to provide a sophisticated system that will meet the ongoing needs of the London Underground.