On 04/05/2004 13:01, in article , "Roland Perry"
wrote:

I'm trying to compile a list of interesting things to go see on the
"tube" on a day trip. Engineering mainly, like the crossover at the end
of the Oxford St Bakerloo, the scale of Canary Wharf and the tunnel out
of Bank-DLR. What others can the team suggest?

At least two locations on LU have switches which may well be unique to LU,
inasmuch as they can be set with both blades open, when they act as
catchpoints. The locations are a) east end of Earls Court District station,
and b) the turnback siding beyond West Hampstead (Jubilee Line). a
photograph of the latter appears on p.150 of "Principles of London
Underground Operations" by John Glover.