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The History of Locks (Part One): Invention

22/02/2018 An ancient oriental door with old lock.

Proverbially, invention is the daughter of necessity. When the need arises, an invention is sought that will solve a problem and satisfy the need. The history of the invention of locks contains within it a mystery. How and why were lock and key systems developed independently in various parts of the world around the same time?

The Wealth of Agriculture 

From around 10,000BC there was a global shift as the human populations of Asia, Northern Africa and Southern Europe ceased to be hunter gatherers and started being farmers. The hunter gatherer had no need of a lock and key because they carried everything with them as they followed migratory patterns of animals. The wealth created by the development of agriculture led to settled communities and the division of labour. A primitive class system developed and the wealthy had to protect their grain stores from the less well-off.

Necessity is the Mother of Invention

The ‘need’ therefore was the need to limit access to stores and it appeared in all countries that had developed agriculture. The solution was a lock and key system and, although different materials and designs were used in their development in different regions, fascinatingly they all followed the same simple principles.

The Principles of Locking

All these historical lock systems had three components: a fastening device, an obstacle and an opening device. The fastening device was, more often than not, a simple sliding bolt. The obstacle prevents the bolt from sliding back. The opening device removes the obstacle allowing the bolt to be slid back and the door to be opened. If you’re interested, this academic paper delivered to the International Symposium on the History of Machines and Mechanisms goes into considerable more detail (starting from page 42).

Regional Differences

In the west, our mechanical locks tended to use wards or tumblers as the obstacle. In China, they preferred a splitting-spring. The earliest surviving lock for which we have archaeological evidence is an Ancient Egyptian wooden lock. A modern pin-tumbler cylinder lock works on exactly the same principle as this earliest of locks – albeit with some refinements that make them more secure: like the use of metal rather than wood. A wooden lock is always going to be susceptible to brute force or, if that proves insufficient, fire.

That’s a brief survey of the invention of the lock. There’s much more to be said on the history of locks, so we’ve called this blog post ‘part one’ and we’ll be revisiting the topic with a continuation in a few weeks.

At PT Lock and Safe, we’ve turned our fascination with locks and puzzles into a thriving locksmith business. If you are in the Norfolk area and you find yourself locked out of your home or car, call us on 01603 812613.

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