Metro miller-grinder unveiled
LINSINGER: Launched at the InnoTrans 2016 fair in Berlin, the small-profile MG11 rail profiling machine developed by Austrian specialist Linsinger combines both milling and grinding units in a single vehicle, in order to make best use of limited track time on busy urban rail networks.
Designed to fit within the profile of the London Underground deep tube lines, the MG11 is intended for use on metro, light rail or tram networks. With an overall length of 11.9 m, the vehicle is powered by a Tier IV compliant John Deere engine rated at 240 kW. Apart from the hydraulic equipment to raise and lower the cutter heads, all drives are electric.
With a cab at each end, the MG11 can run to and from worksites at up to 50 km/h. Working speed is around 8 m/min, but only in one direction.
Rail profiling is undertaken in a single pass. The 400 mm diameter miller cuts between 0.3 and 0.8 mm as required to restore the profile and the running surface is then smoothed using the 600 mm grinding wheel, which is angled at 5 deg to the running direction. Because the grinder is only used at a low pressure, there is less risk of bluing or metallurgical damage to the rails.
The steel chips and grinding dust are collected by a vacuum extraction system and stored in a 1.5 m3 container for subsequent recycling. No fire prevention or water sprays are needed for tunnel operation.
According to Linsinger, the prototype machine has already undertaken initial testing in Austria. Following the fair it will undertake three weeks of trials and demonstrations with Berlin U-Bahn operator BVG before its final commissioning. Delivery to the un-named end customer is expected before the end of this year.