Tann Banker’s Cash Safe
Overall thickness 7 inches. Thickness in front of vital parts 4 1/4 inches. The outer door-plate, edges of door and lockchamber, all 1/2 inch thick steel, are welded into one unit, and the door is constructed with the following successive lines of defence:— Siemens Martin tough steel, 1/2 inch thick, on the outside. Hard blowpipe resisting non-conducting Adamantium (which has been certified by Kirkaldys, the testing engineers, to have a crushing strength of 11,200 lbs. per sq. inch), 1 3/4 inches thick, reinforced with strong expanded steel. Drillproof anti-blowpipe Tannalloy, 11 inches thick. Siemens Martin tough steel, 1/4 inch thick. Compound drillproof unbreakable steel, 1/4 inch thick, in front of lockwork. Lockchamber 2 1/4 inches thick. Fire resisting chamber, 1 inch thick, containing John Tann's moisture generating non-conducting composition (see the booklet "Scientific Protection against Loss by Fire").
LOCK & BOLT MECHANISM
The door is secured by bright-drawn steel bolts, 11 inches diameter, passing through the solid-flange lockchamber into the welded frame of the body. The back of the door is secured by a continuous 1 1/4 inches steel tongue-bar which protects the whole length of the door. The boltwork is controlled by two John Tann unpickable 10-lever locks (with stainless steel keys in duplicate) or by keyless combination locks, as may be desired.
The drawers, cupboards or other interior fittings, as required, are strongly constructed of heavy-gauge steel and are secured by strong 6-lever locks, with stainless steel keys in duplicate.
ANTI-BLOWPIPE & ANTI-EXPLOSIVE (RELOCKING) DEVICES
In connection with each lock the lockchamber is fitted with John Tann's patent tested Anti-blowpipe and Anti-explosive (Relocking) Devices, by
means of which the bolts are held and doubly secured, even if the locks are entirely destroyed or removed by means of any kind of thermic appliance, by high explosives, or by a combination of these with other methods of attack. As a result of the operation of these devices, it is necessary to destroy practically the whole door to gain entry, instead of merely having to cut out or destroy the locks. See certificates of tests by Curtis's and Harvey (now Imperial Chemical Industries) and the British Oxygen Company.
The whole of the body and back is of solid anti-blowpipe drill-proof, impact-proof, and fire-resisting construction 5 inches thick. This construction has an outer body of Siemens Martin tough steel plate 1 inch thick, bent cold under hydraulic pressure at all twelve corners and welded into one complete and jointless member. The next line of defence is a 3 inch thickness of hard blowpipe-resisting non-conducting Adamantium, which has been certified by Kirkaldys, the testing engineers, to have a crushing strength of 11,200 lbs. per sq. inch. reinforced with strong expanded steel. The next line of defence is a 1 inch thickness of anti‑blowpipe drillproof Tannalloy and within this is a chamber, 1 1/4 inches thick, containing the fire-resisting composition (see the booklet "Scientific Protection against Loss by Fire".)
The safe is normally finished in silver-grey enamel, with chromium plated handles and other furniture.