On 26 Jul, 15:35, Boltar wrote:
From google earth there seems to be a single track line that runs past

Drayton Park station on the east side at a higher level than the
moorgate line then disappears into its own tunnel further south. What
line is this?

B2003

I think it is the connection to Canonbury on the North London Line.
This used to carry some peak hour passenger trains into Broad Street.
I do not know if it is still in use.

It can be seen in the 1:50k map at
http://www.streetmap.co.uk/newmap.sr...reater+London+[Station]&searchp=newsearch.srf&mapp=newmap.srf

Jon