I saw a YouTube video of 555005 a couple of days ago, and spotted a partition in the saloon immediately behind the leading cab, it had at least the words “driver” and “instruction” visible on it. The interior cab door appeared to be open to the saloon. That definitely suggested instruction to me…
The video is here, have a look about 40-50 secs in, you’ll have to pause it. I don’t think it’s been linked yet:
(link to YouTube video of 555005 at various locations around the system)
View attachment 158558
(A screen grab from the video showing partial view of “Driver under instruction” partition in saloon)