Alexa - can you murder my child?

Nor me. I'm surprised it was cost-effective to make spring-loaded shrouds rather than machining a notch in the L and N pins and surrounding it with plastic, as is done on all modern BS1363 pins. In the absence of the latter, it was a good solution to the problem.

As the site says, I imagine the extra cost explains why they were rarely seen.

I remember there was a phase (scuse the unintentional electricity-related pun) when you could buy slimline plugs made of slightly flexible plastic (nylon?) rather than the solid, thermosetting plastic which was used on all other BS1363 plugs and sockets. They were rectangular rather than narrower at the earth pin end, and significantly less tall from the top to the base through which the pins protruded. They seemed to fall out of favour after a few years. This is in the days before appliances came with a pre-moulded plug on the lead, when they first thing you had to do with any new appliance was wire a plug onto it.

In the 1970s my dad brought home from work a PSU for a calculator with a rechargeable battery (Texas Instruments which used Reverse Polish Notation) and it had been fitted with one of those plugs. The first time I came to unplug it, I found that the top (which bears all the force when pulling a plug from the socket) flexed enough to leave a gap from the base. I rewired a conventional Bakelite plug onto the cable, because I wasn't happy with the safety of a plug where the plastic was so flexible that the top would pull from the base at the edges.

The other dangerous plug that I removed and rewired was on my grandpa's lawn mower. It had a plug and socket which had three pins in a line

, all nicely shrouded so the plug overlapped the socket slightly so it was (more) water-resistant. One end was on a very short lead attached to the mower and the other was on a long cable to a BS1363 plug. A fairly standard arrangement that I've seen on other mowers. All went well until the cable got tangled and I had to temporarily unplug the long lead from the short one that came out of the motor, while I untangled it. And someone had wired the plug and socket the wrong way round, so the 3-in-line plug was on the end that was connected to the mains and the 3-in-line socket was on the mower. This meant that the exposed pins were on the end that was live. I'm not sure whether the mower had been supplied like that or whether Grandpa had wired the plug and socket himself. To spare his blushes, I very quietly swapped plug and socket over so the plug with exposed pins was on the mower and the socket with recessed receptacles was on the mains lead.