John Band wrote:

Are you sure? I thought there were DC line platforms (used) and WCML
slow line platforms (used only in emergencies and being discussed in
the context of this thread), but no WCML fast line platforms.

That's correct. For some reason I was thinking of the DC lines as the slow
lines! I've no idea why, I've used them on and off for over thirty-five
years! Must be starting to get 'senior moments' ;-)