"Recliner" wrote in message
...

I believe that the two new stations on the old Broad St line take
advantage of the four-track formation. In other words, the new platforms
are built over the previous outer lines. So they wouldn't have been able
to fit in more than double track on the viaduct south of Dalston.

They certainly do, in fact the BBC time lapse video linked to in the other
thread shows how the two tracks take full advantage of the whole formation -
using both of the existing Kingsland Rd overbridges is a further example.

Paul S