This model is part of a Plasser and Theurer HOBCS5 (High Output Ballast Cleaning Train) train used in the UK by Network Rail and arround the world. The train consist of a number of wagons available from myself and other Shapeways vendeors.
The wagons I have designed are the 09-2X/CM Tamper (this model) and the PW-RT and NPW-RT power cars which load and unload the ballast. The HOBC itself is available from Modern Image Models
https://www.shapeways.com/product/YFCV5GEXH/n-gauge-rm900-rt-high-output-ballast-cleaner?optionId=43889619&li=shops and they also have the VM80 Vacuum Wagon
https://www.shapeways.com/product/4574EE9E3/n-gauge-plasser-theurer-vm-80-vacuum-wagon?optionId=56566896&li=shops. In addition to these the MFS-D ballast wagons are available form Smiths Models
https://www.shapeways.com/shops/morrissentinel-s-shop. You will need one of each wagon ecept the MFS-D's were the number is potentially unlimited up to about 70 wagons, however a reasonable train that an N loco can pull is possible with 10- 16.