Что случилось с музеем? Почему закрыт?
What happened with the museum?

It was an initiative of 1 person. When he passed away, his son tried to continue it.
Such museums have to be run by a team, so continuity is guaranteed, even if someone falls ill or dies.
His son did his best, but on his own the whole line and infrastructure as well as maintaining the vehicles is impossible.

https://www.britishtrolley.org.uk/foxton