On 24 Sep, 11:16, "John Salmon" wrote:

Merseyrail isn't a good example of how it should be done. *The entire
electrified system including the loop and link lines were designed for
six-car operation, then after a very short time the trains were reduced to
three cars - which is why SET and LO ended up with Class 508 units.

No. The 508s were spare because they didn't need to go to 6-car on
all trains due to lower demand than expected, and because MTL thought
they could make do with fewer (and us passengers saw the short-
formations and cancellations start straight away). 6 cars are still
used in the peaks.

Neil