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important points that are apt to be neglected by the average architect in designing a garage or repair shop building will be considered first and then the equipment of tools, supplies, and special appliances necessary to furnish the repair shop in a first class manner will be discussed.
Requirements of Buildings Utilized.–Structures that have been used in another business do not always give full satisfaction when remodelled and equipped for motor car repairing. The one general fault all of these buildings have is inadequate lighting facilities, and they are seldom properly heated or ventilated. Large wooden structures formerly used for carriage or wagon shops, livery stables, etc., are often utilized, but these are invariably very inflammable, which alone should condemn them, even if the proper lighting and heating facilities were installed.
Many buildings have been erected for repair shops or garages that are lacking in conveniences not included because of lack of experience on the part of architects or builders, who do not understand the requirements of the repair business. These buildings obviously could be improved in arrangement and even in details of construction by those familiar with the restoration of automobiles and their component parts.
Any structure used for motor car housing or in repair work should be absolutely fireproof, which means that only materials having the desired qualities, such as steel, brick, stone or concrete be incorporated in the construction, with a minimum of wood. The building should not be more than two stories high, if the land is available, though large establishments in the heart of big cities will have to be three, four or five stories in height, depending upon the size of the lot available, the floor space needed and the prevailing prices of real estate. If it is to be operated in connection with a garage business on the same premises, the repair shop should be in the second story, the storage room on the ground floor.
In any event, the point of using natural to the exclusion of artificial light cannot be too firmly impressed on the builder. Mechanical work of all kinds demands the best of light, and in those buildings utilizing daylight in preference to electricity or other source of illumination, not only is the work carried out better, but a large item of expense, which must be included in the fixed charges of operation, is eliminated. The best construction, and one that has been demonstrated to be thoroughly practical in large, modern manufacturing establishments, is a steel framework, with concrete walls pierced by many large windows, and a sawtooth roof. The advantages of this construction over that using ordinary skylights is that the sun cannot shine in directly to interfere with the work, as the openings point toward the north, a stronger roof having more openings for light is obtained, and there is no possibility of water leaking in. What is most important in the northern states, the light will not be shut out as much by snow during the winter,
It is well to remember when planning large shops having more than two floors that high structures involve the use of power elevators, so the cars can be taken from one floor to the other, with increased overhead expense as it augments the cost of handling cars, either in repair work or storage for which no charge can be made the patron.
Lighting Methods.—The lighting problem can be viewed from two aspects: that of general illumination and the equally important one of individual lighting. For the former, powerful, though well diffused lights are wanted, these being placed high enough so they will be out of the way and yet give as much as possible the general effect of daylight. The amount of illumination needed varies with the different departments and the class of work carried on therein, but in making determinations it is always best to err on the excess side than to attempt to economize at the expense of the eyes of the workman. This is poor economy because it reacts directly upon the quality of the work turned out by the shop. In the car assembling or overhauling department, the general illumination should approximate about 120 candle power to every 200 square feet, while in a regular shop or room where the general lighting means is supplemented by individual lamps at vises and drop lights to carry to the cars themselves, the allowance of 100 candle power of general illumination to 300 square feet floor area will be found ample. Machine shop lighting should always be on a very liberal scale and should not only include good general illumination but individual lighting as well. The general practice in most shops is to use small units and plenty of them. Thirtytwo to sixty-four candle power lamps or other equivalent radiants are suspended over each machine tool where great accuracy of work is not essential, these including such appliances as shapers, planers, emery wheels, arbor presses, drilling machines, etc. On lathes, milling machines or grinders, where accurate cuts must be taken, the individual lamps should be supplemented by arc lights or powerful Tungsten lamp clusters, supported from the ceiling and well shaded to reflect the light where it is needed. One candle power per square foot floor area in addition to the individual lights, which should be at least 50 candle power over each tool designed for accurate work should be allowed in the machine shop.
Where electric current is available the most suitable lamp from the viewpoint of steadiness, quality, and intensity of light is the incandescent filament lamp using the Tungsten alloy illuminating element. The flaming arc is an economical light, but it is far from being steady and its color is such that it is hard to discover fine lines or colors having a bluish tinge. The fluctuation in an arc light and even the clicking of the regulating mechanism may become very annoying when engaged in fine work: Many garage and repair shop proprietors in small towns where there is no central lighting plant find it desirable and economical to generate their own current by any one of the many small individual lighting units sold for this purpose using a gas or gasoline engine as power. The electric current reduces the fire risk and as it is the most convenient form of energy for generating power to operate machine tools, the installation of individual lighting plants is justified by the many advantages accruing from the use of electric current.
Where electricity is not available it is rarely possible to find either coal or water gas such as generated by a public service corporation. In many small, isolated communities it may be necessary to use acetylene gas generated on the premises. Some favor kerosene or gasoline vapor lamps in which incandescent mantles are employed. One popular lamp in the rural sections which burns oil under air pressure producing a Bunsen flame capable of heating the usual incandescent thorium mantle is called the “Washing
ton" lamp and is a very economical method of lighting. It is apparent that any system of illumination that involves the use of a naked flame introduces an item of fire risk that is very undesirable in a building where the fumes of gasoline are present.
Electricity is not only the safest method of lighting but the Tungsten lamp is the nearest to sunlight of the artificial radiants. Where electricity is available it will be poor economy to use other means of lighting, except for general illumination as by groups of incandescent mantle gas lamps. For individual lighting the electric lamp is the most suitable because it is safe, compact, clean, does not give out much heat, is portable and can be used in any position. There is no other means of artificial lighting that permits one to obtain all of these desirable requirements in combination. Considering the relative cost of the various methods of lighting, the following table, based on the cost per 100 normal candle hours, will prove useful:
Cents Washington light
0.238 Flaming electric arc
0.381 Mercury vapor lamp
0.595 Incandescent gas light
0.595 Incandescent petroleum light
0.714 Direct current electric arc
0.942 Osram, zircon and tungsten lamp
1.190 Kerosene burner
1.666 The writer has frequently noticed the use of poor droplights in garages which are not only undesirable because of the physical discomfort entailed by the action of the electric current upon the human system, but also because of the liability of fire. The wire and sockets of these lamps are subjected to very severe treatment and they soon cause trouble where a cheap equipment has been provided, because the insulation of the wire deteriorates and will cause a short circuit whenever it comes in contact with the metal part of the frame or of the various parts of the human system which will provide a path to the ground for the current. Where a current of 110 volts is used, there is no danger of severe or permanent injuries because of contact with such a “live wire,” but the sensation is decidedly unpleasant, to say the least. Cases have
been observed by the writer where a fire has been caused because of such defective insulation of the wire. One case in particular has been distinctly impressed on his mind because he was in a pit beneath a car at the time of the fire. A helper was washing the mechanism with gasoline, preparatory to an overhauling, and plenty of vapor filled the air. A partly bare spot on one of the wires became crossed with the frame work of the car and the brilliant spark resulting ignited the gasoline immediately. The car and pit were in flames and had it not been for the presence of mind of another mechanic with a chemical extinguisher in dealing with the blaze before it assumed dangerous proportions, the results might have been more serious.
In figuring on a droplight equipment, the best material should be obtained. It is a "penny wise, pound foolish” policy to use materials for which the only recommendation is cheapness. The wire should be provided with a very heavy insulation, and need not be very flexible. Beware of lamp cord, as it is of no value for use under severe conditions. The best and heaviest sockets should be used. The writer would advise the use of some that had either a very heavy porcelain or hard rubber insulation around them. Then comes the choice of proper cages or shields and handles. There are cages now marketed that are of heavy construction, the wire of which they are composed being nearly an eighth of an inch in diameter. These will prove to be the cheapest in the end. In assembling, it will be found best to wind plenty of electrical tape around the wires for the entire length of the drop. This not only serves as an additional insulator, but takes much of the wear that would otherwise come upon the insulation of the wire proper, and it may be easily renewed when it shows signs of wear. It will be found well to solder all the connections at the socket and rosette, as there is nothing more disconcerting, when a difficult or tedious job of fitting or adjusting is being performed, than to have a “winking” light to work with, which is liable to fail at the time it is needed most. Heating and Ventilation.
It is very important that the workrooms should be kept at comfortable temperature during cold weather. About 75 degrees Fahrenheit is usually considered correct,