In message , Paul Corfield
writes

A guess on my part but stocks have different braking and acceleration
profiles relative to loadings, number of cars and line / track geometry.
Newer stocks are also much more complex with in car diagnostic systems
and different control set ups. Therefore moves between say the Met Line
and the Northern Line will involve a steep learning curve. Drivers have
to be trained to a high level of stock knowledge so that they can assist
in getting a defective or failed train out of the way or work with a
rolling stock technician who may be providing advice via radio from the
control room.

There is then the issue of route learning and understanding route
characteristics and signal positions etc. This all takes time as well.
There may also be line specific issues such as working over National
Rail infrastructure if you were on the Bakerloo or District Lines.

I'm sure our resident drivers will fill in the gaps in my "amateur"
reply.

No, all seems pretty accurate to me.

Wanna job?
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