leyland510:
It is that Garry Harts new motor. 
from another angle ontrackplant.com/photo/linsinger
what is it for?
It’s a rail miller, there’s a milling cutter (with 176 cutting heads) on the trailer which can reprofile worn rails and remove defects from the rails. The sparks you can see are from the grinder which is providing a smoother finish to the rail. The tractor unit is a standard MAN chassis which has been modified by Linsinger for this specific purpose.
The practice of rail milling is commonplace in Germany, but not in the UK. It is an alternative to rail grinding which is slower. Where a rail grinder might require 20 or so ‘passes’ along the rail, the rail miller can achieve this in 2 passes, therefore output is significantly higher when compared to a grinder.
This is a relatively small rail ginder being offloaded (and at work) in the middle of Nottingham City Centre earlier this year, coincidentally with a MAN tractor;
Or how about a floating Volvo?
