On Fri, 27 Apr 2007 09:55:17 +0100, "Dave Plowman (News)"
mused:

In article ,
Lurch wrote:
Ring mains were originally introduced as an easy way of converting the
very common 15A radial circuit into a 30A circuit for being able to
plug new fangled electric heaters and such like in. You'd do this by
running a cable from the end of the radial back to the consumer unit
and sticking a 30A fuse in it rather than rewiring the whole circuit.

I'm not so sure - electric heating was around long before rings which were
a post WW2 device - or at least only became common then. Several birds
were killed with one stone - the standardisation of an outlet for any
portable appliance, rather than the many before. More economical use of
cable. And the ability to have near limitless outlets - since in practice
domestically few would be loaded to maximum. That it predated the hundreds
of low current appliances we all have now was simply brilliant foresight.
Or luck.

Well, whether it was heating or not, the idea behind the ring being
easily achievable by running an extra cable form the end of a radial
was the main point in the post.
--
Regards,
Stuart.