In message . com, John
B writes

We know A-stock can get between Liverpool Street and Aldgate East
(because that's how units get to and from the ELL) - so why can LUL not
divert [some of] the Met service from Aldgate to join up with the
District?

The usual panoply of reasons:

- A stock drivers don't have route knowledge beyond Aldgate Junction (do
they?)

Presumably some of them do, since there's pretty regular rotation of
ELL trains (and indeed, ELL trains are maintained at Neasden).

Only ELL drivers know that bit (but there's not a lot of them), but not
Met drivers.
--
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