The Bakerloo line trains, at over 50 years old, are by far the oldest passenger trains in use in the UK, and that means it's not really possible to simply swap in some new trains as replacements. That's because the technology in trains has changed so much over the past half-century that it would be a huge waste of an opportunity not to take advantage of the improvements.
All of the MBTA Green Line's downtown portion and much of its branches will be closed for 15 days in December to fix a nearly 130-year-old tunnel piece, the transit agency announced. From Dec. 8 through 22, the Green Line's main branch will be closed from Kenmore to North Station. The E Branch will be entirely closed, and the B Branch will run from Boston College to Babcock Street, with shuttle buses running from Babcock to Back Bay. The C and D Branches will run only between their terminuses and Kenmore.