In the days when only the rich needed to keep their possessions "safe" they would be guarded by trusted armed men. Locks and bolts of various sorts could be used to increase security but a lock on a wooden box would only delay a determined thief who could hack the box open reasonably easily.
In the late eighteenth century it became possible for more secure boxes to be made using cast iron. This meant that the lock was now the weakest link and in 1784 Joseph Bramah patented the safety lock which was considered unpickable. It comprises a metal tube with slots cut in the end. A cylindrical key with slides exactly the right length must fit into the slots or the bolt will not move. Bramah was so convinced the lock could not be picked he offered a huge reward for anyone who succeeded. The reward was claimed 65 years later by an American locksmith but it took him 51 hours to pick the lock!
The name "safe" (rather than "strong box") came into being to describe boxes designed to protect against fire as well as theft. Richard Scott took out a patent as early as 1801 for the fire-proofing of "coffers"; William Marr patented another design in 1834 and Thomas Milner expanded on them in 1840 but it was not until 1851 that Silas C. Herring exhibited a "Fire-Proof Safe" at the Great Exhibition at Crystal Palace. This was judged an infringement of Thomas Milner`s patent later that year.
The nineteenth century saw various innovations as both thieves` and safe-maker`s techniques developed. In 1818 Jeremiah Chubb patented a "detector lock" based on levers, which would not open if someone tried to pick it. In 1848, Linus Yale patented the Yale compact cylinder lock, based on ancient Egyptian pin-tumbler locks. This design was improved by his son, also named Linus and the Yale lock is now one of the most commonly used domestic locks.
As safes became more difficult to crack, thieves resorted to terrorising bank staff to open them and to counter this; James Sargent, inventor of the key-changeable, combination lock in 1857, introduced a time-lock mechanism, patented in 1873.
By the twentieth century, advances in steel production led to a decrease in the incidence of safe-cracking. Safes could now be manufactured by bending a single piece of steel up to 12mm thick, producing the rounded edges familiar today. Explosives were more commonly used to open such safes and by the 1930s, safes were protected by "anti-blowpipe" technology.
By the 1940s, with former servicemen familiar with cutting torches, the 1930s designs were not sufficient to repel the post-war increase in burglaries, although in 1945 the contents of a safe only 300m from the centre of the atomic blast at Hiroshima survived intact.
Today safes incorporate torch- and drill-resistant materials and even concrete. In 1997 a Home Office report found that attacks on banks decreased by 46% in 1994 and by a further 19% in 1995, proof of the legacy of improvements in security and a comforting thought next time you use your door key in the door lock cylinder of your front door. |
