First use of WCML and ECML names?

[StephenHunter]

When did these names start being used? The former isn't exactly that accurate...

 

[30907]

The precise term is fairly modern, but the terms West/East Coast Route go back at nearly 170 years:
https://en.m.wikipedia.org/wiki/East_Coast_Joint_Stock
refers to an 1855 agreement, and to the first Joint vehicles in 1860

The earliest reference I can quickly find to the West Coast to the building of the first West Coast Joint Stock vehicles in 1862.
http://www.lnwrs.org.uk/Carriages/Wcjs01.php.
Although the route was open first (1848) it may be that the term "West Coast" was coined in response to "East Coast" - but it is a fair description of the route from a London perspective.

 

[DelW]

By the time of the "Races to the North" in the 1880s and 1890s, press reports refer to the competitors as the "East Coast train" and "West Coast train", suggesting that the terms were in fairly widespread use by the public by then.

For example, the Glasgow Herald in 1895:

The Glasgow Herald - Google News Archive Search

news.google.com

 

[LNW-GW Joint]

It'll have to change with HS2 (especially if the principal Edinburgh service runs via the West Coast route).
With the axing of the Golborne link, and a proposed upgrade of the ECML, this is now uncertain.