History of Locks
This 19th century example , cast in brass , also supplied with a keyhole drop ; both features increase its ‘ harsh environment ’ qualities .
An interesting adaptation where Polheim style discs rotate to allow a heel and toe action to release the shackle as it its pulled to disengage ; very good ‘ hash environment ’ qualities .
Polhiem continues to inspire , this lock , first introduced in c2000 , continues to be used to secure US government facilities , particularly perimeter gates . It ’ s made of stainless steel with various shackle options . a large padlock using Hr . Christopher Polhem ’ s design , and in addition to this there were two other kinds of padlocks , one which used a key , and also the usual kind .” There were also several kinds of anvils and swages to make the bolts on the locks . A swage hammer was also used to stamp and edge plates and dishes .
4 ) The “ steelyard ” works , which was operated only occasionally , and then by the locksmith , “ because the man who had been employed there previously had lost his eyesight .
5 ) A clockworks , with nine workmen .
The original Polhem design of the 1720s . The tail is attached to the shackle which retains it , other versions are found without the tail which allows complete shackle removal .
6 ) A tin plating works which produced parts and other things from forged sheet iron .
In addition Polhem was engaged in many civil engineering projects like mining equipment and locks ( for ships ). It ’ s his padlocks though that will interest readers here .
The freezing conditions of the Northern latitudes required additional considerations to be taken into account . Polhem dispensed with springs altogether and created circular levers . These circular levers were pierced in the middle with an aperture to accept the key with faces
This Russian version also incorporated fixed wards between the discs and a swing type shackle .
This style is typical of the type produced in America and Canada by colonisation from northern Europe . that controlled the rotation of the disc , thus disengaging them from the shackle to unlock or bringing them back to secure the shackle ; this dispensed with the need for springing making it the first harsh environment padlock and at the same time greatly improved security . The style was adopted in many countries and regions and even taken to the New World . Polhem ’ s name may have been lost in the mists of time but the lock became known as the Scandinavian style with many countries and regions developing their own styles . Immigrants to the New World took the idea with them creating their own style . In fact the Finnish Abloy classic style improved on Polhems idea by adding a side bar . Since then many lockmakers have been inspired by Polhem to this day whenever a ‘ harsh environment ’ lock is required . Few knew of this idea at the time in the more temperate regions of Europe .
The world had to wait until the last quarter of the 18th century when the industrial revolution was in full swing and another inspired inventor this time from the UK raised the bar with an inspired security principle again inspiring lock makers everywhere – watch out for Part 2 of this article .
Brian Morland , curator of the MLA Heritage Room , HoL Archive and the HoL 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
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