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.
Heat may be applied by a steam coil as shown in Fig. 112, or hot air may be admitted from the regular air pipes of the heating system. The degree of heat should not be high as the seasoning process is apt to be too much hurried and so produce an unnecessary number of "season checks" by drying and consequently shrinking the outer portion of the lumber before the center has the opportunity to contract with it. Some have advocated the plan of standing the lumber on end, and then turning it "end for end" once a week. This causes an unnecessary amount of labor. If the lumber is placed in the racks as shown, it will not be necessary to even turn it over, provided too high a temperature is not maintained. The necessity for a dry room is apparent from the fact that it is very difficult to obtain properly kiln-dried lumber fit to put into pattern work, whatever price we are willing to pay for it. And unless we dry it ourselves we are never sure of its condition. Patterns are too expensive to take any chances of improperly seasoned lumber. For convenience in passing lumber to and from the dry room, a trap door, as shown in Fig. 111, may be made in the floor of the loft. Pattern lumber may be delivered on the machine shop floor, passed to the gallery by the traveling crane, then up through this trap door to the dry room. After it is properly dried, it may be passed back to the pattern shop in the same way. Or, it may be passed in through the trap door over the pig iron storage space, and thence into the pattern shop.
The pattern storage room is a continuation of the pattern shop, a door 8 feet wide giving ample access to it. In the inner corner, next to the pattern shop, is a trap door 4 feet by 8, opening over the pig iron storage space, and at the other end of the room is a trap door 4 × 10 feet, opening over the flask room of the foundry. Over this trap door is a quick-acting hoist by which patterns may be readily lowered to the foundry, or brought back to the pattern storage room. This room is amply lighted so that patterns may be easily found, stored, or taken from the shelves as needed.
The system of storing patterns is upon a series of shelves arranged so as to form alcoves connecting with a wide passageway in the center, the pattern racks being placed with the end against the wall, and regularly between the windows. Opposite the broad spaces in the walls where the pilasters are located, and space between windows is wider, the pattern racks are made of double width, and are used for the storage of larger patterns, which may be more conveniently stored on very broad shelves. Should the patterns be generally of small size, so as to make narrower shelves advisable, the racks may be all made of single width and located without regard to the windows. In this case they are placed two feet from the wall. In the arrangement shown, the single racks have shelves 4×18 feet, and in the double racks the shelves are 9 × 18 feet. Thus the latter style will accommodate patterns from four to nine feet in length.
Fig. 111. Plan of Loft over Pattern Shop.
Fig. 112. Dry Room for Pattern Lumber.
At the end of the pattern storage room, next to the foundry, a space is left clear for the care and storage of patterns too large for placing upon the shelves. It will, of course, be understood that in every shop special arrangements must be made for the care of patterns peculiar to the kind of work done, and that the arrangement here given is only such as may be useful in a general way, and that it is subject to whatever modification may be necessary to suit individual conditions. For instance, if there are many heavy patterns like lathe beds, planer beds, or engine beds, etc., it will be necessary to provide a larger space for them, and also to arrange for readily lifting and moving them. A convenient method is to suspend an I-beam overhead, and upon this to run a trolley with a chain or rope hoist, by means of which the patterns can be picked up and moved wherever they are wanted. These may be put up with branches and switches, so as to cover any desired space.
If these large patterns are placed entirely upon the floor they will occupy too much valuable space. They may be arranged in this manner: One bed pattern may lie upon strips not less than an inch thick laid on the floor. Over this pattern are placed two or more trestles, high enough to clear it. Upon these a second pattern may be placed. Over this place still higher trestles, and upon them support a third pattern, and so on. The advantage of this method is that the patterns may be always kept in good condition and "out-of-wind," while if, as is often done, strips are laid upon one pattern, and another pattern supported upon it, there is a strong probability that it will be marred and injured, or warped out of shape.
Various forms of racks, both self-supporting and attached to the building, have been devised. The common form used to be that of supporting the shelves by a series of posts placed four to eight feet apart, and spiking to these horizontal strips, upon which the boards or planks forming the shelves were placed. Frequently a strip three or four inches high was placed around the shelves to prevent the patterns from falling off. This made a receptacle for dust and dirt which was not only disagreeable but difficult to get rid of. In this form of racks the numerous uprights obscured a good deal of light, and were very much in the way of conveniently handling patterns.