Safes: 3 Major Historical Developments

If you have ever seen a Robin Hood movie (animated or not), you may have noticed that when Robin robbed from the Sheriff of Nottingham, the gold was often kept in a wood box that was bound with iron straps. These were called strong boxes, and are the precursor to modern day safes. It seems rather obvious that a wood box has limited security potential, and offers almost no protection against fire, but it wasn't until the late 1700's that we started seeing serious efforts in what would become modern day safes. Let's take a look at three of the these developments.

The first, and probably most obvious upgrade was in the late 1700's. Though cast iron strong boxes may have been around on a limited basis, in the 1780's they became more widespread as iron became less expensive. They were commonly seen in the homes of the wealthy upper class in England. The term safes was not yet in use, so at this point they were called iron chests. These chests were about 1/2" to 1" thick and were cast in one piece. Doors were cast also from one piece and of similar thickness to the body.

But iron chests and the old strong boxes were specifically designed against theft, not for fire protection. It wasn't until the 1800's that manufacturers started to make safes to protect against heat and fire. It is in the quest to protect against fire that we see the second major development in safes.

One of the first fire resistant patents was filed by Richard Scott in 1801, but there is no evidence that he used it. Others were also working on fire resistant security boxes, with the idea to have multiple layers of metal with slow conducting materials between layers.

It was Thomas Milner, a tinsmith from England who developed in the 1820's a safe that was composed of two thin sheets of strong tin plate, with a layer of sawdust mixed with alum sandwiched between the tin. When the safe was exposed to fire, the alum melted which resulted in the sawdust being dampened. The wet sawdust stopped the conduction of heat to the inside of the safe. Though fire resistant, it was not very secure against burglary.

Over the next decade, the wood based insulating material evolved several times until in the 1840's when Daniel Fitzgerald discovered how to use a liquid form of plaster of Paris for insulation between heavy iron plates. This was called the "Salamander Safe" (after the amphibian that in folklore is said to be able to survive a fire). The only problem that was discovered was that items inside the safe became damp. With a few small changes in the composition of the plaster, the problem was solved. This innovation is credited with a lot of success in protecting valuables during fires in the nineteenth century.

The third major development of safes came with an improvement in burglary protection during the 1840's (around the time that the term "safe" came into use).  During this decade, and from a few different sources, we saw the development of diagonal bolt systems for locks, the use of strong plate iron, and drill protection used around the locks of safes. All of these made safes harder to break into, which became big public sport among safe manufacturers of this time period.

Safes have definitely come a long way from the original wood strong box. These three major break through in its development are the building blocks to the modern safe, in which we still see innovation and improvements today.