This section is from the "Modern Machine Shop Construction, Equipment, And Management" book, by Oscar E. Perrigo. Also see Amazon: Modern Machine Shop Construction, Equipment, And Management.
In all cases the wall should be frequently leveled crosswise, as well as lengthwise, to insure a fair horizontal bearing for all the bricks, as even a slight inclination greatly endangers the strength of the wall.
The roof1 proper should be supported by trusses at each division or bay, and connected by purlins, all securely braced; by which construction lightness, combined with great strength and ample elasticity, is secured. For a covering, wood may be used and covered with roofing tin which should be always protected by a good coating of mineral paint.
The covering may be of corrugated iron, although this has the very serious objection of moisture condensing on its underside and dripping into the interior of the building. This may be wholly prevented by laying on a couple of thicknesses of tar paper, or other paper impervious to water, and as a protection against fire from the underside of the tar paper, first laying two thicknesses of asbestos paper. These four layers of paper are supported by galvanized wire netting, tightly stretched over the purlin supports.
This is probably the best form of roof covering yet devised for the roofs of manufacturing buildings, and with brick walls, truss roof, and covering as described the building is practically fire-proof.
Referring to Fig. 4, the machine shop is seen to be constructed with a central portion 40 feet wide and covered by a traveling crane, giving a clear height of 40 feet beneath it. This crane is supported by wide plate girders resting on the main columns, and runs the entire length of the machine shop. It may be operated by belting and gearing, but preferably by electricity, as the necessary power is much more readily transmitted to any point in the length of the building by conducting wires and a suitable trolley than by means of shafts and belts with their attendant expense and annoyance.
On each side of the central portion of the building are wings 30 feet wide, extending the whole length of the structure, and built in two floors, the upper one, or gallery, being used for light machinery. It extends across the front end, both as a means of conveniently connecting the two galleries and of affording a platform for transferring stock, materials, or machines to and from the ground floor by the traveling crane.
1The roof designs shown are substantially those adopted by the Berlin Construction Co., New Britain, Conn.
Fig. 4. Cross Section through Machine Shop.
The lower member of the roof truss is of latticed form, to give the required strength for supporting the lines of shafting. The floors of the galleries are supported by girders, upon which floor joists are supported, and to the under side of which the line-shaft hangers are attached.
The side walls are built 20 inches thick for the first story, or 16 feet, and 16 inches thick for the remainder of the height, and are strengthened by buttresses of 8 inches projection and 24 inches wide. Each bay, or division, is 18 feet 3 inches centers, and the side wall is pierced for two windows on each floor, each window being 4 feet wide; the lower ones 10 feet, and the upper ones 9 feet high.
Above the wing roofs is a monitor roof construction having another series of windows 5 feet high, extending the entire length of the building and separated one from the other only by about 12 inches, thus giving ample light to the central portion of the building. Every alternate sash is pivoted so as to be opened for ventilation.
The roof is constructed as has already been described, with an outward covering of corrugated iron, and has a pitch of 3 1/2 inches to the foot, as have the roofs of all the buildings of the plant. The form of truss is the usual one, as shown in the engravings.
The foundry is built on a plan similar to that of the machine shop, with a central part 35 feet wide and side wings 25 feet wide each. On the cupola side the wing proper is extended 30 feet further, to furnish accommodations for the cupola platform, chipping, core, and flask rooms. See Figs. 5 and 6.
Fig. 5. Cross Section through Foundry, Cupola Platform, etc.
The central part of the foundry is covered by a traveling crane supported by plate girders resting on the main columns and having a clear space of 30 feet beneath it, while the side wings are 20 feet in the clear. The operations of the foundry do not require this height, but it is very desirable to have ample space for the steam and gases, incident to "shaking out" the flasks after pouring off, thus adding much to the comfort of the men.
To further facilitate the exit of these gases, the upper windows 5 feet in height, opening over the roofs of the side wings, are all made with pivoted sashes, so as to be readily opened when necessary.
The bays or divisions between columns are 18 feet 6 inches centers. The side walls are 20 inches thick, strengthened by buttresses of 4 inches projection and 18 inches wide, and each bay is provided with two windows 4 feet wide and 12 feet high, affording ample light to the side wings and, by the aid of the ventilator windows in the monitor roof construction, completely lighting the whole interior.
The lower member of the roof trusses for the side wings is of latticed form to afford sufficient strength for supporting the cranes, and for trolley hoists at any point where they may be needed.
The cupola platform construction is shown in cross-section in Fig. 5 and at right angles with this in Fig. 6. A floor supported by suitable timbers forms the cupola platform proper. This may be constructed entirely of iron, if desired, in order to lessen the liability to damage by fire. The platform should be covered with sheet iron, at least in the immediate vicinity of the cupolas, and should be placed at a proper height to suit the cupolas used. It may be reached by way of an elevator carrying one of the yard tram cars, as will be described hereafter in another chapter.
The forge shop is built much heavier in proportion to its size than the other buildings, on account of the strains and shocks caused by heavy hammers and drop presses. It is 50 feet wide, 80 feet long, and 18 feet high in the clear, and no columns or other obstructions interfere with the free working. The roof girders are strongly built and thoroughly braced, and the lower member made in latticed form for supporting the usual overhead work of the shop as shown in Fig. 7.
Fig. 6. Section through Cupola Platform at Right Angles to Fig. 5.