TANN LIST L
FIRE, FALL AND BURGLAR RESISTING ANTI-BLOWPIPE SAFES
These Safes have been designed as a result of the recent successful burglaries by the use of the oxy-acetylene cutting blow-pipe and of circular cutters. They provide at moderate cost complete protection against either of these appliances and against high explosives, such as gelignite, as used by burglars to destroy the locks of safes of various types.
1 inch thick, consisting of an outer body of Siemens Martin tough steel plate, 3/8in. thick, bent solid at all 12 corners under a hydraulic pressure of 250 tons, an inner body of John Tann's compound drill-proof unbreakable ,two-ply steel plate 3/8in. thick, and a 1/4in. thickness of blowpipe-resisting copper between them. The special copper plate placed between the steel plates is quite impenetrable by the oxy-acetylene cutting blowpipe, owing to the high conductivity of the copper and to the speed with which the heat of the blowpipe is dissipated over a plate of this size and thickness. As a consequence, the heat cannot be sufficiently concentrated at any point for the blowpipe to have effect. For effective protection against the blowpipe it is essential that the copper plate be not less than 1/4in. thick.
The compound steel is impenetrable by drilling, chipping, or cutting tools. The drillproof face of this steel is placed immediately behind the blowpipe-resisting copper, so as to resist penetration of the copper itself by drills or by chipping or cutting tools. In attempting so to penetrate this copper, the point of the drill reaches this drill-proof face, and is stopped, before the copper is completely penetrated, the point of the drill or tool being destroyed. .
BACK OF SAFE
1 inch thick, of similar construction to the body, is inserted from the front and riveted to the inside face of back flange of body, and is immovable.
FRONT OF SAFE
Strengthened by a solid frame welded into one piece. This is riveted to the inside of front flange of body and greatly enhances the power of the safe to resist wedging.
Constructed similarly to the body, but with extra thicknesses of Siemens Martin tough steel plate and compound drill-proof unbreakable steel plate, so that the thickness in front of the locks is 2 3/8 ins.
Constructed of steel T bars, 4in. x 4in. x 1/2in., through which the sliding lock-bolts pass and shoot behind the welded frame on body.
ANTI-BLOWPIPE AND ANTI-EXPLOSIVE DEVICES
As an extra precaution, the lock-chamber is fitted, in connection with each lock, with John Tann's Patent Tested Anti-Explosive and Anti-Blowpipe Devices, by means of which the bolts are held secure even if both locks are entirely destroyed or removed by means of the oxy-acetylene blowpipe, by high explosives, or by a combination of these with other methods of attack. As a result of these devices, it is necessary, in order to gain entry, to destroy practically the whole door by means of the blowpipe or similar apparatus, instead of merely having to cut out or destroy the locks in order to open the door.
Compound drill-proof unbreakable stranded rivets, put in under a hydraulic pressure of 30 tons to each rivet, are used in attaching the lock-chamber to the door and also in the construction of the body.
The bolts are secured by two of John Tann's Patent " Reliance " Unpickable gunpowder-proof bank locks. Each lock is supplied with duplicate keys.
BACK OF DOOR
Secured by John Tann's continuous tongue bar, which shuts behind the welded frame on body and protects the whole length of the door.
Filled with John Tann's patent moisture-generating non-conducting fire-resisting mineral composition.