In message
-septe
mber.org, at 10:06:07 on Thu, 24 Nov 2016, Recliner
remarked:

Incidentally, although the Piccadilly line is largely above ground from
Baron's Court, it's largely on viaducts rather than cuttings, so it
shouldn't be affected very much by leaf fall.

And the branch to Uxbridge, and the part in North London?
--
Roland Perry