I was recently asked by a correspondent about electric real ale dispense and thought it would be worth turning my response into a blogpost.
My legal drinking memories go back to 1977. At that time, probably at least 40% of all real ale in the UK was dispensed by electric pump, and much more across large swathes of the Midlands and North.
Electric pumps were divided into two main types - the free-flow, which was visually indistinguishable from a keg dispenser, and the metered, which was either of the sliding cylinder "diaphragm" type or had a push-button to dispense a half-pint from a separate nozzle. I am told that some Stones' and Ward's pubs in the Sheffield area had diaphragm pumps dispensing a pint at a time, but I have never seen these. There were one or two other types occasionally seen, such as one with what looked like a revolving vane in a glass sphere which cropped up in some Wilson's pubs.
In my experience, the free-flow pumps were only widely used for real ale in pubs owned by the Bass group, although I have seen them in a few Lees, Holt's and Robinson's pubs. The obvious drawback was that they were outwardly indistinguishable from keg dispensers, which once CAMRA made a major point of promoting real ale could all too easily deter prospective drinkers. A few said "cask conditioned" on the mounting, but this wasn't usual.
Metered dispense was more common, and in particular was widely used by Banks's, Greenall's, Boddington's, Robinson's, Hyde's, Home and Shipstone's, although I have seen it in many other brewers' pubs, even including Gale's down in Hampshire. At first the diaphragm-type pump was much more numerous, but from maybe about the late 80s onwards it came to be increasingly replaced by illuminated bar mountings which were harder to distinguish from keg taps.
I have always associated metered dispense with real ale, but it was also widely used for bright and keg beers, and also for lager and Guinness. In the 1980s I recall my local Hyde's pub, the Nursery, having Harp Lager, Strongbow and even Guinness on meters alongside Mild and Bitter. Metered dispense for non-real beers was very common in clubs. I remember being taken aback once to be served obviously fizzy beer from diaphragm pumps in a Border pub south of Oswestry, so that must have been a rarity.
Two big advantages of metered dispense were that it ensured a full pint, and that it greatly reduced the ability of bar staff to ruin decent beer by an incompetent pulling technique.
From the late 80s onwards it began to slowly disappear - breweries seeing the advantage of at the same time pushing a more obvious image of "real ale" and also being able to use brim-measure glasses and serve less beer per pint. In my view CAMRA mistakenly encouraged this process by presenting handpumped beer as superior and apparently putting image before full measure.
By 2000, metered dispense had become pretty rare and as far as I know has pretty much entirely disappeared now. The last pub I saw it in was Robinson's Queens Arms on Portwood in Stockport which isn't one I regularly pass and tends only to be visited by the local CAMRA branch every two years on a Stagger. The Flying Dutchman retained it for a long time but has now been sold off and is the Fairway free house, of course with handpumps and brim-measure glasses.
I am also told that one or two of the more traditional former Banks's houses still serve their Mild using electric meters, although I haven't seen this myself in recent years.
Personally I miss it as something that added variety to the pub scene and have written about it here. Incidentally, I couldn’t find a single picture of a diaphragm dispenser on Google Images.