A few nights ago I decided to 'self isolate' in the second bedroom of our house, which overlooks the Edinburgh to Glasgow line. I don't have Coronavirus, just a nasty cold, but I didn't sleep very well. I was aware of several trains passing in the night, but one stands out. I have a memory of being woken by a train of some sort. I took a peep out the curtains and saw what looked like a train no longer than a Transit van. It was yellow and I could clearly see workers on it, dressed in orange overalls. They were brightly lit, as was the area around this train. It didn't appear to have a normal cab structure, and wasn't passing particularly quickly. It was reasonably loud, but the noise seemed to relate to its function rather than anything involved in moving it (like a loud diesel engine). I couldn't match this to anything on RTT, beyond general maintenance moves over the past few days which seem to vary wildly from the times plotted out in RTT. I also can't find a corresponding train when scouring photos of Network Rail equipment online. I'm semi ready to chalk this up as a fever dream, but thought I would check with you lot first! I did find photos of tamper trains in the US that looked semi similar.