As you know, the East London Line is no more to allow it to be upgraded, extended and reopened as part of the London Overground network. The Brunel Museum want to make use of the closure to operate a heritage train with guide through the Thames Tunnel. They are currently drumming up support on their website. Anyone interested in the tours can show their interest by emailing the museum via their website; http://www.brunel-museum.org.uk/train_tour.aspx