In article , N.
Thornton wrote:

And even earlier than 3 pin round pin were the 2 pin 5A round pin
plugs.

I remember some seriously lethal versions of those as a child in the
1950's. The plugs had round covers with a central flex outlet and a
moulded thread fixing them to the base. You could easily unscrew the
tops from the plugs without unplugging them :-(

I've also come across 2 peculiar type of plugs in the distant past,
probably also 1950's or very early 1960's era:

* One type were 13A with round pins. They were about the same size
as 5A ones but the earth pin had a groove running along it's
length (presumably so the socket could be keyed to prevent a 5A
plug being used) and the cartridge fuse was threaded at one end
and screwed into the plug to form the live pin. I think they
were a proprietary Reyrole design.

* There were some really weird plugs with a central round earth
pin and flat power pins to either side of it. They came in 2 (or
more ?) different sizes and ratings. The larger ones had a
socket for a lower rating built into the cover so you could
piggy back a smaller plug off them. ISTR the plugs had cartridge
fuses and were designed in such a way that the lower rated ones
could also be inserted into higher rated sockets.


--
Mike Clarke