Судя по табличке в переднем окне, в прицепном вагоне работал кондуктор?

This was also the case in Belgium at the end of the conductors' occupation.

https://transphoto.org/photo/1574637/?gid=7932

In Belgium, the motor vehicle had a '1 agent' sign, which literally meant that there was only one staff member present in that particular vehicle (the driver, of course).
There were several reasons for this. The older receivers couldn't be retrained. In contrast to the more modern trams, the older trailers often did not have electric operation of the doors yet, or could not be operated from the motor car. This last was not the case in Hamburg.
The ticket system was also much more complicated and more time-consuming than it is now.

Цитата (Антон Чиграй, 27.04.2022):
> в прицепном вагоне работал кондуктор?

Именно.

Эксплуатация последних прицепных вагонов V6B и V7B прекращена в 1976 году вместе с окончательным отказом от кондукторов (моторные вагоны были перекроены под бескондукторный режим до того). Ещё два года последние трамваи работали строго одиночками.