Seems like TfL have exercised all their options for Class 378s with
another 7 ordered.

http://www.tfl.gov.uk/corporate/medi...ntre/7821.aspx

No idea how that relates to the "1300 extra carriages" but a 7-8 min
service on the core section of the NLL will be a pretty impressive
frequency.

--
Paul C


Admits to working for London Underground!