[emeritus]

My first house had a 100' garden. To minimise voltage drop, I bought a 50m drum of 2.5mm TRS cable to make up two approx 20m extension leads. The cable has string reinforcement laid in with the conductors. I found that the 13A plugs and extension sockets available at the time (1976) would just accommodate the cable. I have noticed that current extension sockets seem to have a smaller cable entry than my old Duraplug version. The mains cable of the circa 1953 washing machine that came with the house had a mains cable of about the same external diameter as my extension lead. I guess that experience has found that flexible cables used to be unnecessarily conservatively rated.