Mizter T wrote:
Tom Anderson wrote:

Fourth question! How did Broad Street once function as it apparently
did as a terminus of the Great Northern? How do you get from
Finsbury Park to Broad Street? Ah, no, i see - there's a curve from
just below Drayton Park to the NLL. Isn't that single-track, though?


The "Canonbury Curve" (search for it on uk.railway) used to be a two
track railway. If you look through the fence opposite of Drayton Park
station you'll see that the trackbed and tunnel do have space for two
tracks.

The Canonbury Curve was singled when electrified, I think because there
wasn't enough room for two lines with overhead.