--- In firstname.lastname@example.org
, "Tom" <tomandsue@...> wrote:
> And speaking of AT&T construction.....my Dad was a sales engineer, and previously lock designer and patent holder. He worked for Corbin Cabinet Lock, later merging with American Hardware, in their Corbin industrial hardware division. One of their huge clients was AT&T. I recall visiting some microwave sites as well as a few bunkers, and all had Corbin hardware, some with the large, jumbo cylinders which were used only in master and grand master key systems.
> Do any of you folks have any experience with the keying systems used by AT&T? Did someone way at the top have a 'grand master key' for all AT&T sites?
> I did see that much later many AT&T sites switched over to Best cylinders, with the interchangeable cores.
Snippet from message 3524:
"As one might expect, AT&T had good physical security at it's carrier
& MW stations; with windowless buildings,steel doors,reinforced
flanges over the strike,door alarms,and fenced enclosures around MW
Keys were were numbered, tightly controlled & common to a geographic
area, typically a "division"( usually 1 or more states).
For example Long Lines division 10(DC,MD,VA,WV) originally had
a "KL10" key for all K & L stations in those states;as MW stations
were established the key became a "Division 10" key.The tech's near
bordering states had access to the adjacent division's key
When a K station, L1/3 main station or MW station's door was opened
an alarm was sent to the CO with the alarm center(24/7); if no one
responded on the order wire , phone, or mobile radio within a few
minutes the local law enforcement was dispatched to investigate; also
if the responder was suspicious or unknown.
Interestingly the L1/3 & l4 repeater doors/manholes while locked,
were not alarmed,due to costs i'm sure.
MW stations usually had a perimeter fence with gates locked with a
seperately keyed "construction" padlock.
The locks were changed occasionally;once after the 1961 sabotage of 4
MW stations in Utah.