History of the Lock: England
Welcome back to the History of the Lock series. As we have seen in previous articles there is quite a rich and colorful history presented in the lock, the locksmith and each of their respective developments. Over time locks have progressed a great deal from much needed, but basic, forms of protection to those advanced, secure and ever evolving ones that we see and utilize all around us today. From the early pin tumbler to the keyless entry lock, the elaborate knot to the deadbolt, warded locks and their current models to VAT systems, we see a constant and interesting evolution of one of the most important inventions known to man, the lock.
We begin this part of the series with England. Being one of the more industrialized nations of Europe locks were in high demand with little in the way of progress being made in lock protection. A trio of clever minds in lock design in England were Joseph Bramah, Robert Barron and Jeremiah Chubb.
Joseph Bramah wrote the thesis "A Dissertation on the Construction of Locks" and exposed a great many of the flaws found in locks of his current day, so called "thief proof" locks. This thesis made clear the ease which these locks could be picked by a criminal with any knowledge or training in keys and locks or a specialist with adequate skills. Bramah found one tumbler lock to be in good form but noticed a glaring fault: when this lock was in the locked position the levers gave away the flaw to its design which were its uneven edges at the bottom. Therefore a key coated with material such as wax could inserted into the lock and a new key created from this. Showing the bottom edges of the levers displayed the depths needed to make the new key. Bramah surmised the lever bottoms should be cut unevenly, thus creating and patenting in 1798 a barrel shaped lock which used multiple sliders that were aligned with corresponding notching at the barrel of its key.
It was Robert Barron's lock that Joseph Bramah pointed out was a good, but flawed lock. Barron's lock, which added a tumbler to the current locks of the day was more secure than the others (and remains the basic design for lever tumbler locks today) and also used wards. However, he also added a series of level tumblers which were acted upon by a single step of the key, stopping the bolt movement if the tumbler was not raised to the correct height of the key. While this improved upon the previous tumbler locks of the time he added six double lever actions to his lock thinking it would make it almost impossible to open with the proper key. While ingenious in design at the time, as we see, he was wrong.
Another lock that had multiple enhancements over Barron's lock was Jeremiah Chubb's four level tumbler rim lock, called a detector lock. Built with a detector level to alert if the lock had been tampered with it also came with a metal drape which fell over the keyhole as the lock began turning. Chubb's lock received praise throughout the locksmith industry and has been considered one of the greats in the history of locks.