Unknown stock
Introduction
The photograph on this page of Unknown stock by Robert Lamb as part of the Geograph project.
The Geograph project started in 2005 with the aim of publishing, organising and preserving representative images for every square kilometre of Great Britain, Ireland and the Isle of Man.
There are currently over 7.5m images from over 14,400 individuals and you can help contribute to the project by visiting https://www.geograph.org.uk

Image: © Robert Lamb Taken: 30 Aug 2009
I'm unsure exactly which stock this is as there is no front carriage to tell which one it is. According to Image, it's either 1920 (F) or 1938 (Q) stock used on the District line, or 1927 (O/P) stock used on the Metropolitan, Circle and Hammersmith and City lines.