HISTORYOFLOCKS • 61
A German rim deadlock with dual bolts operated independently but with the same key via different chambers.
A Victorian dispatch box, this one marked‘ First Lord of the Treasury’- the Prime Minister-( believed to be Gladstone’ s). Note: these boxes are invariably very tattered but much cherished.
The same lock with the cap dislodged to show the keyway access to the lower chamber at 90 ° from the upper keyway.
hole, pins in the inner chamber had to correctly line up and / or be depressed by the key when rotation of the circular plate would allow locking / unlocking. The top chamber was very often engraved with a warning and offering a reward to anyone being asked to make a key.
Marr introduced a double chamber for safe locks early in the 19th century. The top chamber, incorporating conventional pocketed levers, access to the lower
A typical Marr safe lock with vertical access to the top chamber.
Top chamber with cap removed, protected with levers; the lower key hole blocked.
A ministerial dispatch box lock with its distinctive keyway, which was invariably different to the lower chamber keyway.
chamber was protected with a shutter. Additionally, the lower chamber was protected with both pocketed levers and a detector. The upper and lower chambers were operated with different keys providing both dual control and resistance to being compromised with Hobbs type instruments.
Finally the Tann‘ Nozle’( no, Nozle is not misspelt) patent of 18 ** shows how an old idea is reinvented to counter evolving threats. The key was inserted into the nozle and turned counter-clockwise a quarter turn and then pushed into the lower chamber and operated the lock in the normal way. The main purpose of the first chamber was to trap black powder – the idea being that insufficient powder could be introduced to cause any damage.
The modern locksmith, by at least being aware of early principals, can reinvent or reapply past ideas to solve problems and counter new threats. Chubb, for instance, added a chamber to their custodial locks to trap the malicious insertion of‘ foreign bodies’ deliberately to disable the lock.
The first chamber exposed showing the reward notice which reads:“ If anyone apply for a key inform a secretary of state & you shall receive £ 50”. Note the horizontal keyway. The key enters the upper chamber vertically, enters the lower chamber horizontally after a clockwise rotation of 90 °, turned a further180 ° to withdraw it from the lower chamber, after which it’ s returned to a vertical position to remove from the upper chamber.
Tann’ s nozle patent in a safe lock configuration.
Top chamber unlocked now exposing the lower chamber key hole. |
Lower chamber with levers and a detector protecting the main bolt. |
Brian Morland, curator of The History of Locks Museum’ s Heritage Collection of locks and keys, welcomes comments and corrections on historical aspects of locks and keys. Brian can be contacted by email: brian @ emorlands. com |
Rear view of the cap showing how the key enters and withdraws the lower chamber horizontally. |
The solid lock body with very little space for black powder; even if it could inserted past the nozle. |
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LOCKSMITHJOURNAL. CO. UK | MAR / APR 2018 Sponsored by Lockex 2018- Security & Fire Safety |
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