SAFES AND VAULTS. I. BURGLAR-PROOF CONSTRUCTION.—The highest skill of the safe maker is now devoted to the construction of strong-rooms and vaults for banks and safe deposit companies.
Safe-de posit and Bank Vaults.—Fig. I represents a front elevation of a structure in tended to be proof against not only fire and burglars, but the depredations of a riotous mob.
A steel vault is provided with an outside wall of stone or brick, 2 ft. in thickness and laid up in cement ; the vault rests upon a foundation especially prepared for it, and is usually erected within and apart from the walls of the edifice in which it is located, so that it may be patrolled on all its sides by watchmen, or by an armed force, should necessity require. When the space within a building to be occupied by the vault is contracted, a fire-proof composition, 6 in. thick, sustained within an iron shell or cladding, is sometimes substituted for the thicker wall of stone or brick.
The architectural design of these structures may be severely plain, as shown in the en graving, or may be embellished with brick and terra cotta, or by cast-iron base moldings and pediment when the outside wall or cladding is of iron.
Fig. 2 represents. however, the plan of a medium cost vault, and shows the steel walls surrounded by brick work, together with the entrance, which consists of a steel vestibule with inner folding-doors and a single outer door. Many safe-deposit vaults are built with two openings or entrances instead of one. The number of patrons to be accommodated ren ders it desirable to use one set of doors as an entrance, and the second set of doors as a means of departure from the vault.
There is, however, another and far more important reason for the use of two openings. Untold expense and annoyance would be entailed upon the patrons and officials of a safe deposit or bank vault should the locking mechanism of the doors become disarranged over night, and thereby prevent access to the vault at the regular hour for opening up for business in the morning, as might happen, despite all reasonable care. if but one entrance is provided. That the locks on both sets of entrances, where two openings are provided, should cause trouble at the same moment is a contingency so remote as to be removed from the necessity for consideration. The vaults of the Marvin Safe Co. are constructed in the following manner : A corner section of the walls of the vault is shown in Fig. 3, together with the junction of the walls with the vestibule ; the jamb and a part of the left-hand folding inner door : and the jamb and a part of the outer or main door. The outer frame of the vault is made of 6 x 6 x 1 in. angles of welded chrome steel and iron, bent and welded at the corners to form tripod sections. The panels formed by this frame are filled in with plates of the same material and thickness. All edges of the angles and plates are rabbeted one-half their thick. ness, and with 4- in. lap, and engage with similar rabbets wherever plates and angles abut each other. The second layer is formed of plates of welded chrome steel and iron rin in thickness. All the corners of the second layer are formed of angles wrought from the plates. The plates of the second layer are placed at right angles to those of the outer layer, and are secured to the latter with welded steel and iron counter-sunk bolts in. in diameter and spaced not more than 10 in. from centers. These bolts pass through the second layer into but not through the outer layer, the purpose being to " blind" all fastenings on the surface. The third and fourth layers are also of fin, welded chrome steel, and iron, turned at the corners to form angles. The third layer is placed at right angles to the second layer, and secured thereto with the welded steel and iron bolts, which pass through tire third layer, and are tapped into the full thickness of the second layer. The fourth layer parallels
the second layer, and is bolted to the third layer by the s-in. welded steel and iron bolts passing through the fourth layer. The fifth or final layer is of Bes semer steel plates, in. in thickness, cured to the fourth layer by similar bolts to those used in the preceding layers. The total thickness is 3 in., but the thick ness is varied by the addition to, or reduced by taking from. the number of plates or layers in the vault, according to the de gree of security desired. The vestibule is constructed of the same material and in the same manner as the body of the vault, except that in most cases its thick ness is inereaeed t in. over that of the vault itself The vestibule is usually escoped into the vault, as shown, and is joined to the walls of the vault with re versed angles, as shown. The outer or main door is usually made 5 in. thick, of alternate layerr of the live-ply welded chrome an I iron, as shown, secured together with the welded steel and iron belts, pleee I at average distances of 8 in. from centers, and great care being observed, as in bolting the layers of the vault. that no two hosts align each other. The bolt frame is of steel, forged into a continuous frame. and secured to the inner edge of the door by conical bolts, made of the best wrought iron, with the conical parts of hardened welded chrome steel and iron. These bolts start with and extend through the sixth, seventh, and eighth layers into and through the bolt frame. The inner doors are made folding, as shown in Fig. 2, and the right-hand door overlaps and interlocks with the left-hand. These dt,ors are usually made 31. to 4 in. in thickness of mate rials, and put together in the same manner as already described for the outer door. Through the bolt frame of the outer door extend not less than twenty-four round revolving steel bolts, each 2 in. in diameter. They are checked by the time-lock and by two four-wheel combination locks, so ar ranged as to require that both locks must be unlocked before the bolts can be retracted. They are further ar ranged so that, if desired, one of the locks will release the bolt-work. Each inner door is fitted with not less than sixteen round revolving bolts, in. in diameter, also checked by two four wheel combination locks, so arranged that one lock, at least, on each door must be unlocked before the bolt-work of either door can be retracted. The lock and holt-work spindles are of steel, in conical sections, closely ground to fit, and packed so as to be absolutely proof against the introduction of ex plosives. They can be neither driven in or drawn out, and by reason of their peculiar construction do not develop the structural weakness which appears in former methods of spindle construction. In addition to the locks on both the outer and inner doors, each door is equipped with a gravity device, to operate the instant tLe locks are forced from the inner surfece of the doors, so that the doors will remain locked or fastened, even though the locks themselves should by any means be driven from their fastenings. All the doors are hung to compound hinges with a vertical part and two cross-arms. They operate in an anti-friction or ball-bearing cup, and are so arranged that th sag of the door may be easily taken up. The finish of the locks, bolt frames, and bolt-work is very elaborate, and is protected from rust and dust by being enclosed be hind plate-glass doors, hung to the inside of the bolt frames. The day gate is usually hung back of the vesti bule doors, and is made of polished steel vertical bars, with flat polished frames and cross-bars. tipped with polished brass ornaments. It is hung to gravity hinges, and is fitted with a key-lock and lock-guard plate.