Flexible ballast excavation for metros

Vacuum-scraper technology for low axle loads


VM 170 M Jumbo: High capacity vacuum scraper-excavator machine with one scraper and suction nozzle
Machine especially suited for work on tracks for low axle loads and lines with tight clearance gauges

Exchange of ballast using the VM 170 M Jumbo on Metro São Paulo, Brazil

The restricted space in certain sections of the line makes it impossible to perform conventional maintenance measures. This also includes ballast bed cleaning and exchange of ballast in the urban sector.

Both Metro and urban transport services in São Paulo therefore have been using the VM 170 M Jumbo vacuum scraper-excavator of SPAVIAS/Trail for three years now. The basic function of this machine is to suck in ballast via the rotating suction nozzle of the vacuum scraper-excavator and to transport it to the 6 m3 hopper. Unloading is performed using a turning spoil conveyor belt located at the front end of the machine either into rail-mounted MFS material conveyor and hopper units or onto lorries.

The VM 170 M Jumbo is in two-part design: The front part houses the drive unit and the spoil conveyor belts, the rear part is equipped with the vacuum scraper-excavator, the work cabin and the hopper.

During a night-time track possession of three hours the exchange of the entire ballast bed is performed on a track section of 20 m. This includes the complete excavation of five sleeper cribs that are immediately filled again with new ballast. Then, the improved section of track is tamped using the Unimat 08-275 GS universal tamping machine. Over three years, 120 km of ballast bed have been maintained.

The customer is absolutely satisfied with the reliability of the machine. In particular, the high performance of the vacuum scraper-excavator is emphasised.