Continuing the discussion of alarm contacts, here are some images that show methods other than using the bolts.
Above: an emergency door at the Colorado National Bank (probably Remington Sherman ca. 1915), this image just barely shows some switch contacts at the top. This is a lug-type (bayonet?) door so the lug rotates into the switch assembly instead of pressing radially into it.
Above: a door at the former San Francisco city/county treasury not only shows busbar-type wiring under the glass, notice the flat 4-contact panel at the top of the door and the corresponding plate affixed to the frame. These are inside the vault when the door is closed which seems better than arrangements that are on the outside.
Above, the Metals Sports Bar & Grill (formerly Metals Bank and Trust Company) in Butte, Montana. A 5-contact panel is at the top of the door, on the inside.
Above, 14 Wall Street in New York shows a round 5-pin contact but here it’s on the outside when the door is closed. Depending on how the alarm circuitry is designed and implemented, this seems less secure than inside designs.
Above, Alamo National Bank next to the Drury Plaza in San Antonio, Texas. Save this image and view it outside your browser at full size (2048×1347). Aside from the very interesting boltwork notice the round 4-pin contact at the top of both doors, on the outside when closed. Also notice the bolt roller bearings but only on some bolts, not all of them. It has elements of both Hollar and HHM doors with a more modern finish. There is a builder’s plate on the middle ring at the top but I can’t read it. Any thoughts on who made this impressive door?
