Holborn Viaduct long had late night (especially Saturday night) newspaper trains. When I first moved to Canary Wharf in the mid-1980s I was struck late on periodic weekend nights by hearing what was obviously a Sulzer diesel sound coming from afar over the rooftops, which I initially thought was a Class 47 climbing out of Liverpool Street through Mile End, but which I later discovered was a Class 33 coming through Greenwich. Later research showed me it was the newspaper train down to Kent, which on Saturday nights took a wide variety of routes depending where the weekend works were, and might be a Class 73 if there were no current shutoffs, but more commonly needed a diesel.