I wonder how many people can remember these "notorious" establishments. As I recall the chain was founded by someone who was an advocate of moderate drinking as an antidote to the Victorian Gin Palaces. By the time I got to visit any of them they were the equivalent of today's roughest Spoons imaginable, frequented by older folk knocking back Docks of draught Australian White. Most of them would make today's Spoons Daytime Brigade (who mostly drink lager in my experience) look like supporters of the Temperance Movement. What I don't know and can't find any reference to is what measure was a "Dock". A large wine today is 250ml which is a third of a bottle. Surely a "Dock" couldn't have been larger than that? I don't know how strong the Australian White was but vaguely recall there being a snooker based joke where the punch line included the phrase "Bouncing Off The White".
I went to a few of them up North and in the Midlands but the only one I went to more than once was the one on London's Strand.