Colin Rosenstiel wrote:

The 313s are 35 year old technology.

The units themselves are only about 30 years old though... (the 507s
and the 508s are the same age as me, 27).

They were also designed for a
maximum speed of 30MPH on DC (series only motors).

Really? Do they differ substantially from 507s and 508s? I always
assumed they were the same but with a 25kVAC-750VDC transformer on the
middle coach. The Merseyrail units are top speed 70mph, though I don't
know if they ever reach that, perhaps they do on the bit out to
Chester.

Neil