In what seems to be a big curiosity for American readers, British devices did not agree with what we all agreed that the most basic items, a plug, before the legislation was adopted in 1
In almost all cases where you bought a large or small electrical appliance, whether it was a washing machine, microwave, toaster or lamp, you would also buy a plug separately and, upon returning home, you would sit down with a screwdriver and the connect the electrical plug itself to the cord.
If you look at this British ritual from the lens of the early 21st century, it seems almost absurd (especially for readers in a very litigious country such as the United States). What kind of company would entrust consumers to wire their own electrical device and why? The answer is part practical and part British frugality and pride.
Before the Second World War, residential and commercial electrical systems were not standardized. As a result, it was quite possible that, based on the age and location of a particular home or business, the sockets therein would have different protrusions and dimensions. Because of these deviations, it was impractical to ship devices with pre-attached plugs, as the consumer would often have to remove the plug and still have to fit a suitable plug in place. Instead, companies shipped products with a power cord that ended in bare wiring and the consumer would plug his own plug after he brought the product home.
After the Second World War when the electrical systems throughout the country were standardized to a national code, the use of products without plugs continued. For many British citizens, it was a point of pride and tradition to wire their own devices (and they hardly saw it as unusual to do this). Furthermore, they considered pre-wired devices to be too expensive because they assumed that the cost of running the wiring in the factory would be passed on to them. Up to the early 1990s, about 80 percent of all electrical appliances in Great Britain were sold with bare wire.
It was not until consumer protection groups, in the aftermath of various accidents resulting from the practice of self-assembling electrical plugs, that the government exerted mandates to ensure that all consumer products were supplied with the pre-wired plugs.
Now that everything may seem very retarded for an external observer, we can say one thing with certainty: the present incarnation of the British plug is a reasonably safe and smart little design. The earth pin on the plug is slightly longer than the power pins and serves as a safety mechanism that opens shutters that cover the socket when the plug is inserted (as such, it is very difficult for children to put fingers or objects into the socket); this is an unusual feature in other countries and virtually unheard of in the United States.
Furthermore, British plugs have built-in fuses in the plug itself (while in the United States the typical fuse / circuit breaker design is for the entire circuit to serve as a protective measure and molten plugs are quite unusual). So although there may have been a century of do-it-yourself wiring that more than certainly contributed to a few accidents, when everything was said and done, the British ended up with a very well designed and safe electrical plug (that you can't longer to install yourself).