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It also suggests some of the occasionally proposed extensions to Sutton etc are dead, otherwise why just 16 in a possible further batch, instead of say 25 to allow sufficient if it got funded in next few years.
Whilst I am also doubtful we will see any progress on said extensions, 16 extra trams would be more than sufficient to operate the most recent proposal for the Sutton line - you could probably do it with about 10 with 7 or 8 tph.
B. Johnson used a possible extension to Crystal Palace in his manifesto on two occasions, so there's 'form' on this which any sensible person would best ignore.