Not seen mention of this before, but Schweerbau are testing a a variety of new kit at the EKR.

The 4 car grinding train looks likely to replace the existing LU offering? A single loco/unit with GPR (ground penetrating radar) modules on, presumable for track bed investigations, then a German registered unimog with unknown trailer. The album can be found here:

https://www.facebook.com/photo/?fbid=1114248217473112&set=pcb.1114239224140678