Where the grounds are large and the crossing of specially prepared driveways interfere with the grading to induce a flow of surface water to the catch basin, a small water-way should be provided under it at proper intervals. This may be built of bricks, but still better, with a brick floor and an arch composed of an inverted U-shaped section, or sections, of cast iron an inch and a quarter thick. Ordinarily the space need not be over six inches high and eight to twelve inches wide. This form will be less liable to injury by driving over it; it will not be subject to displacement as if built of bricks, and may be more readily cleaned of ice and snow in winter. Catch basins should be covered with slightly arched cast iron gratings, the purpose of the arching being to prevent it from being easily clogged by bits of rubbish which may be washed to it by a heavy and sudden downpour of rain. Catch basins should be constructed of such dimensions that they need be cleaned out but twice a year, although by building them of double the capacity they may be only cleaned once a year, which had better be done in the summer or early autumn, before cold weather comes on, as a more convenient time than in the spring when snow is melting, the frost coming out of the ground, and the work becoming more disagreeable. As to the capacity of these catch basins, they should contain, up to the top of the bridgewall, about one cubic foot to every hundred square feet of yard surface to be drained. This will be amply sufficient for annual cleaning. These observations are intended to be practical. They are the result of experience as well as observation, and the more care and consideration that is given to the few matters to which attention is directed in this chapter, the less we shall be annoyed by the incidental and usually considered accidental expenses that so frequently cause much unexpected trouble and outlay in the regular course of the management of manufacturing plants. CHAPTER XVI MACHINE SHOP EQUIPMENT A General features. The special scope of this portion of the work. The usual errors. practical view of the subject. General requisites. Proper equipment for a medium class of work. A definite and comprehensive plan for manufacturing operations. The results of a lack of a proper plan. The business that "ought to pay" but does not. Too much conservatism. Seeing the end from the beginning. The only proper plan. Possible enlargements must be provided for. The "piecemeal" plan. Ill-considered and expensive alterations. The last state worse than the first. Better to make new things than patch up old ones. A complete and symmetrical whole. In the preceding chapters of this work, constituting Part First and under the general heading of Machine Shop Construction, we have carefully followed, step step, the process of planning and erecting a modern machine shop plant, giving special attention to all its parts, discussing the various plans and methods of construction, and describing the most approved forms of foundations, walls, roofs, floors, etc., and properly providing for the prime necessities of light, heat, ventilation, and power. We have given special attention to the requirements of manufacturing operations and so planned the entire plant as to bring its component parts into a proper relation to each other, even when confined to a very limited space upon which to build. land Ample provision has been made for all probable extensions and enlargements in the future that may be due to the possible increase of the business for which the plant is erected. There has been provided a simple and efficient means for the transportation of stock and material and the convenient handling of the same during the successive processes of manufacture. Some of the various mistakes and difficulties into which the builder is liable to fall by inconsiderate planning and execution of his work have been pointed out and commented upon. The endeavor has been made to lay all these matters before the prospective builder and the careful and studious reader as some of the results of years of practical experience, constant and conscientious study, and ample observation of the varied and complex phases of this interesting subject. Having thus carried forward the construction of the machine shop buildings of the model plant to completion, and having them adequately provided with power, light, heat, and ventilation, and thus ready for the next step in the process of making them ready for active and effective work, we will proceed with the duty of describing and illustrating their equipment with the proper machinery, tools, and appliances for accomplishing the contemplated work to be done. Machines should be so arranged in groups or departments as to best subserve the purpose intended, and to manufacture the product with the least cost for handling the materials in the various stages of their progress toward the completed product, and with the most efficient arrangement for supervising the work, and still to insure the desired standard of accuracy, finish, and thoroughness of the completed output. In considering the question of the proper equipment of a machine shop a great deal depends upon the character of the product which is to be turned. out. It may be that of heavy machinery requiring little or no machining except of surfaces in contact, as is the case with such work as sugar mill machinery, rolling mill work and similar product which will necessitate heavy castings and consequently a large proportion of machines for heavy planing, boring, drilling, tapping, and so on, as well as large erecting space and much use of the traveling crane and other forms of lifting devices. Again, it may be of a generally lighter kind of work, as for instance, steam engines of various sizes and similar work where much more finish as well as very accurate fitting is required. Or, it may be of machine tools, the larger of which will be similar to the engine work in many respects, while the smaller machines will require a large variety of machines both for general and special work and such as are capable of producing a large quantity of very accurate work even on rather large parts. The design and aim of this portion of our work is not to arrange and specify such an equipment as may be required for any certain kind or class of manufacture, or for any special line of sizes of machines, for that is manifestly impractical, but rather to suggest the proper selection and arrangement of the machines for a medium kind of work, on a practical plan which may be useful to those having charge of this class of mechanical engineering and be helpful in pointing out such machines as will be most economical in the production of certain classes of work in the more modern and up-to-date methods, and so grouping and arranging them as to make their management easy, practical, and profitable. In this connection it will not only be proper to offer some suggestions as to the class or type of machines best adapted for certain kinds of work, but also as to the methods of testing such machines to ascertain their fitness for the work to be done on them. |