Steve48 wroteThank you for that, actually rather glad my safe doesn’t have one then. Although in use commercially it makes sense. Which would then be followed by a replacement safe presumably.
Steve, in fact your safe does not require a relocking device anyway. With 4 way boltwork such as yours if a high explosive charge is sufficient to remove the lock entirely the surrounding boltwork and operating follower will be so distorted and disconnected as to preclude release. In such circumstances I have never known the perpetrator to spend any subsequent time attempting to release the mechanism. That was why my presence was required and to remove any remaining explosive substances.
As far as I can gather, the Ratner Safe Company was the first to use a device specifically to relock the boltwork if the keylock was destroyed by high explosives inserted into the lock. In 1913 they fitted a ‘dead’ device which they called the ‘safety bolt’ which was attached by a wire held by compression under the lock until the lock was removed.
This was significantly improved in 1918 by a swivelling rocker bolt operated in conjunction with the unlocking of the keylock. When locked, the ‘safety bolt’ blocked any movement of the boltwork, in other words, it was ‘live’.
The attached illustration shows the boltcase mechanism of the Grade 3 Ratner which had 1 dead (at the bottom) and the live at the top blocking the boltwork even before the lock had been blown off,
In such a small safe it had been of necessity that the dead device was in too close proximity to the force of the explosion and rendered inoperative. This applies to most of the safes of today but since explosives are most unlikely to be used (apart from gas attacks on ATMs) it is unlikely they will ever be asked to perform.
In most cases when the live relocker was released the safe doors were removed for repair and have of occassion been subjected to a second attempt - also unsuccessful.
1952.
Some more trivia: London Trades Directories.
1870 Safe Makers - Samuel Whitfield & Son, 97 Cheapside.
1900 Fireproof Box Makers - Fred.Whitfield, 11& 12 St Andrews Hill, EC
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