Fig. 220. - Section New York Life Building.
Bearing Plates. - Wherever iron or wooden posts, columns or girders rest on brickwork, a cast iron or stone bearing plate should be used to distribute the concentrated weight over a safe area of the mason work. Several failures in buildings have resulted from carelessness in this particular. Rules for proportioning the size of bearing plates are given in the Architects' and Builders' Pocket Book.
Cast Iron Skewbacks for Brick Arches. - Wherever segmental arches are used over doors or windows, without ample abutments. cast iron skewbacks, connected by iron rods of proper size, should be used to take up the thrust of the arch, as shown in Fig. 224.
Shutter Eyes. - All fireproof doors and shutters in brick or stone walls should have hinges made of 2 x ¾-inch flat iron bars, welded around a ¾-inch diameter pin working in a cast iron shutter eye built into the wall. For brick walls the shape shown at a, Fig. 225, is about the best for the eyes, although for very heavy doors or shutters the strength of the face should be increased by having another web. For stone walls the shape shown at b should be used. The thickness of the metal is generally made ¼ of an inch.
Door Guards and Bumpers. - It is a good idea to protect the brick jambs of the carriage doors in stables by bumpers, which are rounded projections on the corners extending 12 to 18 inches above the ground and about 8 inches beyond the wall and jamb, so that if the carriage wheel strikes the bumper the hub will not scratch the brick jamb. Such bumpers may be made either of some hard stone or of iron.
Fig. 222. - Section Through Top of Bays.
Fig. 223 - Plan of Piers and Mullions in Alley and Light Court, New York Life Building, Chicago.
The jambs of the exterior doors to freight elevators and of the delivery and receiving doorways in mercantile buildings should also be protected for a height of 4 or 5 feet above the sill by iron guards, to prevent the brickwork being broken by boxes, trucks, etc. Such guards are generally made of cast iron about ½ inch thick, as castings-can more easily be fastened to the wall than plate iron. The castings, or plates, should be made with lugs on the inside pierced with holes for clamping them securely to the brickwork as the wall is built. Fig. 226 shows a section of one of the alley piers of the New
York Life Building, Chicago, and the manner in which the iron guards are attached to the brickwork. A similar arrangement can be adapted to any door jamb. In Chicago it is quite common to protect the bottoms of the piers on the alleys in this way to prevent injury to the walls from passing teams.