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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