steel and has a removable interchangeable core. The lock uses
the standard government keyway
Medeco cylinder. It can be serviced and rapidly rekeyed. The
shackle is completely armored
and guarded. Even the Medeco
cylinder is protected by hardened
armor. I was told by a very reliable source that these locks were
used around missile silos. The
other high security locks were
mainly made to lock up ammunition storage sites. Figures 22 and
23, show the Hi-Shear lock.
Most of the high security
locks that have been discussed
were made for the government.
They can afford the incredible
prices such locks demand. What
does industry use for high security? A good starting place is Best
Best has made several very
good high security locks in the
past. Unfortunately they have
dropped the locks from their catalog. The Best lock in figure 24,
is a good quality lock and meets
the definition of high security in
all areas except cylinder drilling
(core). Steel pins can be added
to the combinating of the core,
but the core can still be drilled,
only slower. The core can also be
pulled out. It is quite exposed.
The Best lock in figure 25, is
quite massive and seems to have
solved the problem of drilling the
Note the special core double
control lug construction and the
armored steel plate that is held in
by the core.
This has been a semi-chrono-
logical order of the development
of US high security locks. Noth-
ing very impressive has been
offered except for the Medeco
mechanism. The fact that US lock
companies had to re-brand Eng-
lish locks and use their mecha-
nisms is a good indication of how
far we are behind European high
security locks. European high
security locks will be the subject
of a future article. Perhaps the
need for true high security locks
is greater in Europe than it is in
About the Author: Robert
Dix is President of the “American
Lock Collectors Association” and is
the Editor of the “Journal of Lock
Collecting,” a bi-monthly publication of the American Lock Collectors Association. He has also been
inducted into the “Lock Collectors
Hall of Fame, and is a leading
authority of antique and collectable locks.
You can contact him at:
25. BEST high security lock.
20. Ingersoll mechanism.
21. Chubb mechanism.
22. Hi-shear padlock with spare
23. Rear view.
24. A guarded shackle BEST lock.