Sorry for the delay in checking for comments, guys.
Yes, theses are intriguing. I like the concept of replacable modules for the work required. This one is set up for cleaning of railheads with high pressure water.
There's major problems during autumn (fall) in the UK with leaves sticking to the railhead and beoing crushed by trains. Eventually two problems arise;
1. traction return is compromised in third rail areas and eventually stops the train, and/or
2 . signalling is compromised by the train isolating itself from the signalling system.
I believe they are experimenting with lasers to burn the leaves off the railhead. These units would be configuarable to carry that equipment too.
Far in the past, I remember someone posting about leaves, and slippage problems. Got any photos of this unit in service?