The new factory additions

The economic significance and effect of the general form and placing of work-shop floors is not yet so fully comprehended by industrial architects as to have evolved any one single form of factory building which has received widespread commendation and acceptance as the one and only best structure in points of low first cost, durability, convenience, and perfection of floor arrangements for housing workers and materials for the production of comparatively lightweight machines.

For the production of heavy machines, in which individual gray-iron components may weigh, say, from 100 pounds to 100 tons, handling of components is the principal thing to be considered; but few pieces, comparatively speaking, are to be turned out, and there is little room for novel improvements in design of the plant buildings.

The forge and foundries are likely to have contiguous placing, and as the massive components leave the loam mould or the steam hammer they move in stately procession down a wide middle way, with huge machine tools on either side, to the place of launching or railway shipment , assisted by rollers, railways, and traveling cranes as best may be, with no sojourn of finished components in finished stores, no rush requisitions for rough stores, no army of truckers and counters and inspectors dealing with rough-stores consignments received. Under these conditions the factory buildings must fit the work, so that the architect has little or no choice as to the forms of shop structures which are best suited to the form of expected production, since the form and weight of the product itself determine the shape of the structures best suited to house the industrial agents to be employed.

With light work, like the Ford car, where the heaviest rough-component weight is only about a hundred pounds and that of the lightest piece produced may be only a few grains (as is the case in the Ford shops at Highland Park), and where the business demands the placing of thou sands of workmen and very many workwomen, sexes separated, as closely together as possible on the factory floors—there is plenty of room for careful preliminary consideration and bold flights of invention in planning and designing the best possible factory building.

The Ford shop conditions when the Ford engineers began designing these new factory additions were highly satisfactory from a financial standpoint, but wholly unsatisfactory from the shop general-manager's position, as the factory production has been constantly below the product -purchasers' demands from the day that the small Ford car was first shown at Madison Square Garden. Every year saw the sales doubled or trebled, with the factory striving as best it might to meet the purchaser 's demands by adding to the factory plant and to the number of workers employed, with no time whatever for studious consideration of factory betterments and labor economizing.

There was not floor space enough; machine tools and factory departments were not placed as the management knew they should be, and more than a thousand men worked as truckers, pushers, and draggers engaged in needless handlings of materials and work in progress.

There was no relief in sight. The Ford sales system, including branch buildings and agencies scattered broadcast, it might be said, over the entire habitable face of the world, created a demand for the best low-priced car ever offered for sale, which the Ford car certainly was, and no one knew the ultimate Ford-car purchase volume.

Under these commercial conditions the first essential was abundant floor space, and the second indispensable requirement was for mechanical transportation inside the factory walls, to do away, in so far as might be, with hand trucking and hauling.

The old buildings had been equipped with monorail tracks and electric locomotives, together with a crane-way opening to most of the departments; but these devices could not reach the entire inter-department traffic, which was a constant and costly feature of the Ford-shops routine. The ground plan of the works was already large, necessitating long lines of travel which must be very much increased by the length of the new additions; and because of the great floor-space needed it was decided to give the additional buildings six floors in each, to make each of the floors 60 feet wide, and to extend them 908 feet to the eastward of the John R Street wall of the old shops, on the south or Manchester Avenue side. This would bring the eastern line of the additions about even with the eastern end of the foundry, which is next the railway on the north side of the Ford Motor Company's premises, and leave space for five more similar structures between the south line of the foundry and the north line of the two new buildings here under description— seven new buildings in all.

To meet the requirements of both rough-stores and finished-products handling, the plans included a railway track between each two of the new buildings, with two electric traveling cranes of 5-tons capacity each in each craneway, and they provided landing stages for each floor above the first, staggering the landings so that each one was fully open to crane service from overhead. The manufacturing departments were then so arranged that rough stores could be handled by the cranes directly to the top floors, and thence descend by gravity slides to floors below, so far as might be found feasible, so that the single product, the Ford motor car, might be finally assembled on a lower floor or floors, and be loaded directly on the railway freight cars, all with the least needless travel and handling that could be contrived.

At the date of this writing, August 25, 1914, two of the seven contemplated buildings are completed, the south building, on the Manchester Avenue north line, having a railway track on its north side only, and hence having crane service on the north side of its floors only; the next building to the north has a railway on each side and crane service to each side of its floors, and the first floor of each building is placed at the railway car floor level, so that the first-floor continuous platforms need no crane service. The cranes are in place and working and the ventilating and "air-conditioning" units are installed, but are not yet in operation.

A very important feature of the ventilating system is the avoidance of all air-pipes, gained by making all the inside floor-supporting columns hollow, with either one or two openings in each hollow column near the ceiling of each room, each column air-opening being covered by an individual damper. The hollow columns take air at about 1%-inches water-head pressure at the top, as supplied by eight "Sirocco" fan "airconditioning " units (American Blower Company's ventilating, heating and cooling system), the volume of air forced into each column being regulated by an individual damper, this air being delivered to each room with damper regulation for each opening of each column, so that the delivery of ventilating air can be so directed and apportioned as to obtain satisfactory circulation of ventilating air throughout the entire space enclosed by the building walls.

The upper view is taken looking west between the craneways of the north building, the lower is looking easterly on the Manchester Avenue side of the south building roof.

This novel scheme of hollow-column air distribution was fully worked out and drawings were made for the seven new buildings about two years before the construction of these two Ford factory additional buildings was begun. In the meantime this hollow-column air-distribution had been fully tried out in the new building of the Ford plant at Ford, Ontario, where it was found to give satisfaction in every particular, as first designed by the Ford engineers and architects. As the inside floor-supporting columns are spaced 20 feet center to center, the use of hollow columns as air distributors, each column air-delivery opening being covered by dampers so that the volume of air delivered at that point could be regulated to suit the requirements of ventilation, heating, and cooling in the most suitable and satisfactory manner, ensured the air circulation in every part of the entire factory building at the lowest possible cost in money and with highest possible economy of enclosed space.

The value of this hollow-column air distribution cannot be over-estimated , since a separate system of air pipes capable of furnishing equivalent air-distribution facilities would entail such added cost, such waste of floor space, and such architectural disfigurement as to prohibit its installation . The only obvious alternative is the forming of air passages in the thickness of the floor and walls, entailing impossible requirements for the preservation of needful structural strength, so that this novel conception of hollow-pillar air passages seems to be really the only practicable method by which a large factory building can be ideally cooled, warmed and ventilated.

The details of this new Ford system of ventilation combined with the American Blower air-conditioning and Sirocco-fan circulating will be given in detail later in this chapter.

Six floors. From railway track to top line of first floor, 3 feet 6 inches; top surface of first floor to top surface of second floor, 14 feet 4 inches; top of second to top of third, 12 feet; top of third to top of fourth, 12 feet; top of fourth to top of fifth, 12 feet; top of fifth to top of sixth, 12 feet.

Brick-work for all walls is carried on the concrete lintels over the windows. In general, the side walls are 8 1/2 inches thick and 42 inches high from the floor to the bottom of the window sash. The brick walls of the elevator shafts and the toilets are also carried on concrete beams to each floor and are 8 1/2 inches thick.

Floor Construction

Usual concrete flat slab, with mushroom-type pillars spaced 20 feet each way, floors reinforced with Cambria Steel Company's twisted square bars. The floor safe load is 200 pounds to the square foot, safety factor of 3.

Columns

The soil is 36 inches loam, then blue clay to limestone.

The column footings are about 13 feet square, with reinforced - concrete base extending about 5 feet below first floor. There are 175 columns on each floor of each building, spaced 20 feet each way.

All interior columns are hollow and serve as air passages; they take air from the top (see the detailed description of the ventilation) and deliver air through rectangular openings covered by dampers, the bottom of the opening being about 9 feet above the floor.

All columns on the first, second, third and fourth floors are steel lattice work covered with concrete, rectangular in form, corners being taken off. On the fifth and sixth floors the columns are round, and have thin sheet-metal air pipes inside and reinforced concrete outside.

The column air-ways vary in diameter on each floor, being largest at the top, and smallest at the bottom. First-floor column air-ways are 12 inches in diameter; second floor, 13 inches; third floor, 14-inches; fourth floor; 16 inches; fifth floor, 17 inches, and the sixth-floor columns have air-ways 19 inches in diameter.

Roof

The flat roofs over the two buildings are reinforced-concrete, 83 1/2 inches thick, then cinders to obtain drainage slope, then 24-inch thick

ness of concrete, covered by tar and paper, all being of usual construction.

The craneways are covered by lantern roofs, the lantern sashes being hinged at the bottom to permit the tops of sashes to swing inward with fittings to retain sash positions. The craneway is roofed with wired glass so that in case of accident no glass can be dropped to craneway floor.

The roof has sky-lights next to the craneways, and each building has four pent-houses on the roof, housing the ventilating-system units.

From the pent-houses the ventilating air goes to the middle air passages on the roof, from which oblique laterals open into the tops of the hollow columns, all as clearly shown in the two roof pictures.

Doors

The craneways have structural-steel doors vertically sliding in guides, at the railway-track exits, in the east wall of the buildings. These heavy doors are counter-balanced by weights moving up and down in the hollow columns which form the door posts, and are electric motor raised and lowered.

The doors opening to Manchester Avenue are all alike, large double doors for goods entrance at the west, adjoined by six narrow doors for workmen's entrance to railed passages leading past the time clocks. These doors are under sky-lighted canopies.

Windows

The steel window-sashes are pivoted top and bottom to swing either way and so take advantage of natural air-currents, and are provided with fittings to retain the sash positions. The north craneway on the north side is lighted by sashes pivoted to swing on a middle horizontal axis which can be opened and retained in any position from the ground.

Architectural Ornamentation

The Manchester Avenue side of the south building is relieved by brickwork pylons, carried above the eave line and capped with concrete. Otherwise the building has no decorations.

Elevators, Stairways and Closets

Seven elevators, supplied by the Haughton Elevator Company, Toledo, Ohio, are placed. One on John R Street is used for male passengers as well as freight, and one, with access from Manchester Avenue, past the time clocks, is used for female passengers (workwomen) and freight.

Brick-work shafts take the elevator at the best, the stairway in the middle, and form closets at the east. See illustration. The closets are suction-fan ventilated, with exit to roof.

The stairway entrances are fire-protected by metallic curtains, rolled overhead and retained in position by a fusible section, so as to drop automatically in case of heat enough to melt the fusible metal.

The elevator gates, supplied by the Quincy Company, are operated by a hydraulic vertical cylinder with a rack and pinion movement, connected with a motor-current switch, so that the elevator platform cannot be moved until the gates are fully closed. These gates are peculiar, having lazy-tongs-guided, automatically-lifted bars at the bottom, all so as to give a predetermined head-room with the least possible vertical travel of the gate. These gate-bottom closing-bars were added to the regular Quincy gates by the Haughton Elevator Company, to make the gate close down to the floor with the gate-travel head-room available.

As the gates now are, they leave nothing to be desired, being fully auto matic, closing down to the floor and giving abundant head-room in restricted vertical travel space, holding the current away from the elevator platform motors until the gate is fully closed and being prompt and smooth in action.

The elevator platforms are 113 inches wide by 198 inches long, and can handle 2^-ton loads. All elevator service is both costly and dangerous , at its very best. These Ford new-building elevators are smoothrunning , speedy, and safe so far as an elevator can be made safe.

The gates are in every way satisfactory in action, and interlocking the gate action with a motor-current switch of its own, so that no current can reach the motor until after the gate is fully closed, does all that can be done to avoid accident. The gate is notable as closing close down to the floor, where it is most needed. See illustrations.

The stairways have low risers, concrete treads, and substantial pipe-rail protection. The closets are as well fitted as in ordinary hotels, are ventilated by ample-capacity suction-fans, and the bowls are separated by slate partitions of good height, giving color enough of privacy to satisfy in some degree the demands of user's reasonable self-respect, being in this particular in strong contrast to the conditions commonly found in ordinary factory practice.

Women Workers' Rooms

The arrangement and fittings of the women workers ' rooms are well shown in the illustrations. The rest room is open to any women at any time, with the forewomen's permission . The wash-room and clothes rack are reasonably convenient, all fully as good as the women workers are likely to have in their homes.

The women's workrooms (see illustration) are as good in points of light and ventilation as the best business offices in the best New York City office buildings. This photograph was taken before the white curtains, sliding on overhead rods, were in place. The wages of these women workers run from 32 to 62*^ cents per hour, from $2.66 to $5.00 for an 8-hour day, and many of them are in the $5.00 class. Such labor conditions as these should give the management untroubled slumbers and freedom from worry.

The Cranes

The craneways and cranes are the dominating features of these new Ford plant buildings, and taken in connection with the staggered landing stages give this building the best installation of crane service within the writer's knowledge. The second, third, fourth and fifth floors have each thirty-seven landing stages, and the sixth floor has twenty-nine.

The north building floors have twice as many landing stages as the south building, because the north building is served from both craneways while the south building is served from one craneway only. Landing stages are cantilever platforms of reinforced concrete , 10 feet long and projecting 6 feet into the craneway space, with pipe railing at ends and chain lengthwise in front. The landing stages are staggered so as to each have clear head-room up to the cranes.

Each craneway is served by two cranes, 5tons capacity each, supplied by the Whiting Foundry Equipment Company , Harvey, Illinois.

The extreme lift of the crane-hook is about 75 feet, the crane track being placed 80 feet above the railway track. This 75foot lift gives opportunity for undesirable sway of crane loads suspended by a single cable. To avoid load swaying, two cable drums are placed side by side in each crane unit, as long as the frame work permits, and each cable drum or windlass is spiral-grooved righthand at one end and left-hand at the other end; four lifting cables are used for each crane, the cable ends being fixed to the out ends of the right-hand and left-hand windlass spirals. This gives the crane load a four-cable suspension, with cables most widely separated at low-load position, and approaching each other as the load is lifted, all so that sway of crane load becomes impossible. This converging four-cable load suspension is a new feature in traveling crane construction, original with the Ford engineers, and is of great working value, as sway of the crane load would lead to marked inconvenience and delay of the crane service. See page 403. The cranes are modern construction, electric of course, having all gears enclosed, all in most striking contrast to the mechanically operated traveling cranes which were once regarded as such triumphs of factory-equipment engineering.

Artificial Lighting

The floors are lighted by about two thousand ceiling-placed reflectors and clusters, each cluster made up of four 60-watt tungsten lamps, having individual switches concealed in the pillars. Clusters supplied by the Western Electric Company.

Each craneway will have fourteen 5,000 candle-power quartz lamps, spaced 60 feet apart, placed in the roof peak, 76 feet above the ground, supplied by the Cooper Hewitt Company.

Fire Protection

These buildings have no partition walls, being everywhere open and without hiding places. The concrete construction is non-inflammable so that the fire danger is from the contents, not from the containing structure. The stairways and elevators, as already noted, have rolling metal curtains, fusible-metal retained in lifted positions, and automatically dropped when surrounding temperature melts the fusible metal retertion.

These buildings are equipped with fire-extinguishers supplied by Childs, of Utica, New York, four hundred and sixty-two extinguishers of 3-gallons capacity being distributed through the buildings, while seven of the Childs wheeled fire-extinguishers, 40-gallons capacity each, are stationed at suitable points on the floors.

These brief general specifications, sketchy and meager as space available compels them to be, will, nevertheless, when read in connection with the many illustrations given, enable the reader to obtain a fair idea of these remarkable new factory buildings, which certainly appear to be the very best that can be done with a multinoored structure, up to the ventilation, heating and cooling requirements, which are so fully met that the ventilating system may deservedly be termed ideal.

Ford New Building Work-Shop Suitability

Beyond all question, these new Ford-factory additions give the workmen and workwomen therein housed ideal work-hour conditions. The lighting is, perhaps, the very best that can be obtained from the sun's rays in a multifloored building, floors 60 feet wide, and the night lighting is made as good as can be by placing of a great number of electric lamp clusters, each cluster provided with an individual switchjso that lighting any one location need not waste current by turning on lamps where illumination is not needed. Light is the first essential of low laborcost factory production. How the last generation of factory managers (previous to those of the present hour) could have ever accepted the bat-and-mole twilights of our first large American factory buildings is a question which no living person can answer, though perhaps we of today should keep our mouths shut about machine-shop lighting so long as we tolerate the present practice of overhead counter-shaft placing and belt-driving of machine tools—but that is another story.

Certainly these new Ford shops are the best day-lighted of any shop floors within my observations. The heating, cooling, and ventilation are the best so far made public; pure, cool drinking-water is close at hand everywhere in these new buildings, the floors are swept continuously ; the closets are sanitary and decent, and the stairways are well railed, easy rising, and have good fire-protection, double landings for each flight, and are as safe as any stairway can be made.

These conditions and provisions leave nothing but materials and work-in-progress handling and transportation to consider before these new buildings can be awarded first position among the multifloored factory structures of the whole world. The craneways, the staggered landing stages, and the seven elevators were placed to make electricity do as much of the lifting (inseparable from the multifloored factory) as is possible, and the absolutely novel feature of the four converging crane-load lifting cables was originated by the Ford engineers to prevent completely all swaying of crane loads, and also to locate the crane windlass pull infallibly in a truly vertical line above the load, so that no lengthwise dragging of the crane load need ever occur, and in practice never does occur. The chain hook is brought exactly to the load center, and the load is lifted in a vertical line and with absolute steadiness which is not affected by horizontal crane travel.

It is very doubtful if successful and altogether satisfactory use of a 70-foot traveling-crane-lift could have been had with free pendulum suspension of the crane load, while with the four-converging-cables load-suspension there is only the very short pendulum from the crane hook to the bottom of the load platform possible, so that load-sway consideration becomes negligible.

These Whiting Company cranes make a 70-foot lift in 35 seconds, and 800 feet of horizontal travel in 95 seconds, and travel in both vertical and horizontal directions can be made simultaneously after the load is above the freight-car tops.

Merchandise Purchasing and Receiving

The Ford Company, when making 1,000 cars per day, purchases about $8,000,000 value of merchandise each month and receives and unloads about 100 railway freight cars daily, delivering merchandise from all points of the compass. Some of the shipments to the Ford Company are made by water. The Highland Park plant is about 6 miles north of Detroit city hall, and about 6 1/2 miles north of the boat docks and the railway freight houses. The Detroit belt-line railway bounds the north side of the Highland Park realty, making this road the best line of city transit.

The "Trap" Cars

The Ford Company has five motor trucks of 3-tons capacity, four supplied by the Kelly Springfield Motor Truck Company and one by Grabrowski, all of which are giving satisfactory service, three being in use all the time. There are also three Ford motor-car chassis "haulers" —regular Ford chassis, save that a large rear-axle gear housing is fitted to take a strongly geared low speed, in use at the Highland Park plant.

These little "haulers" have an astonishing road adhesion, without the use of rear-axle load-boxes, so that one of them pulls a freight car with 20 or 25 tons load along the Belt line tracks or takes a train of loaded monorail wheeled platforms to any accessible point on the shops' first floors.

To obtain omnibus transportation by Belt line, one 3-ton motor truck works downtown, taking Ford freight from the steamboat wharves and from other railway freight houses to the Michigan Central freight yards, where that road furnishes about three "trap" cars per day to the Ford Company, these trap cars being loaded with freight collected by motor truck from other transportation lines, and with the Ford city-purchased supplies, and sent to Highland Park via Belt line.

Merchandise to be delivered to the north and south craneway located midway of the old shop floors is unloaded at the "Dock" at that craneway north end. Foundry supplies are unloaded by a Shaw gantry crane working along the foundry north side, and by a flat-car crane working on the tracks east of the foundry. Supplies which go first to the smithy and the heat-treating buildings are unloaded on the platform of the first track south of those structures, and about thirty-five cars are unloaded daily from the new building craneway tracks.

Sequence of Freight-Car Placing

It is of course needful that incoming freight cars should be placed in proper sequence on the tracks where they are to be unloaded. The Ford Company owns no switch engine; hence the received-cars switching and sequence placing is done by the Belt line, in the night time mainly, according to instructions given to the Highland Park yard-master by a Ford official, who first inspects the lading of cars as received and then gives written directions to the yard-master as to car placing for unloading.

The trap cars are always placed to enter craneways first, from the east, so as to stand for unloading at the craneways' west ends. Both the 3-ton motor trucks and the Ford haulers can enter the new buildings' ground floors from the John R Street level: About 90 per cent of the lading of the thirty-five cars daily unloaded in the craneways is delivered to various locations on the new buildings' twelve floors, the other tenth part being placed on the monorail wheeled platforms, which may be pulled, singly or made up in trains, by the Ford haulers, which are so small and handy that they can travel readily on the first floors of either the old or the new Ford buildings.

Floor Bridges

The new buildings extend 910 feet eastward of the John R Street east line. The railway tracks enter the craneways from the east end and extend westward on a sunken track, to bring the car floors level with the building first floor, for a length of 830 feet, to the buffers which stand 80 feet east of the new buildings' west end wall, thus making each floor west end 80 feet east and west by 200 feet north and south. Three elevators are placed along the south line of the north craneway, and three along the south line of the south craneway.

Bridges 20 feet wide connect the third, fourth, fifth and sixth north and south floors at the middle of the craneway length, while the eastern ends of the fourth, fifth and sixth floors are connected by bridges 10 feet wide, and an elevated bridge, 6 feet wide, is placed at the east ends of the third floors.

This arrangement gives about 2 miles length of floor 60 feet wide, all this floor being paying-load surface, save the space taken by the elevator, stairway, and closet shafts.

Rough Stores to Top, Finished Product at Bottom

I The practice of taking rough stores to the top of a multifloored factory building and dropping finished components to the completedproduct bottom-floor delivery is well known, though by no means commonly adopted, and is unquestionably the best possible procedure, as any other scheme must of necessity involve detail routing of lines both up and down. Hence, it is better to begin manufacture by transporting rough stores to the top floor, and routing the lines of descent so that components meet at convenient assembly points and the finishedproduct assembling ends at the shipping room.

Present Use of New Building Floors

These new buildings have been available for work use since about August 20,1914, and are now devoted mainly to body painting and top making, body and top assembling on a moving-assembly line 360 feet long, and to finished-components storage close to the boxing and shipping department, which loads all finished components, or "repairs" shipments, on freight cars in the north craneway.

It is not certain that the best arrangement for stock-received storing in the new building has yet been found, but the present department placing has effected a saving of about 200 men in merchandise-received handling. The body wood-working machinery is now being installed on the north-building top floor, and lumber dry-kilns are nearing completion east of the new building, where the craneway rail tracks (which are depressed inside the buildings) rise to the Belt line grade; this permits unloading of lumber directly into the dry kilns, and reloading it on freight cars after kiln drying, to go into the craneways to be lifted up to the top-floor body wood-shaping department.

These new buildings are so vastly better in every way than the old plant buildings that they are regarded by Ford officials as wholly above criticism in any direction, and will certainly appreciably lessen the labor cost of the yearly production of 300,000 cars, which is the figure now set by Henry Ford, who has very decidedly advanced his ideas since, in the not so very old Piquette Street days, he said he would rest satisfied when he could turn out 20 Ford cars per day, six days in the week.

Efficiency Requisites of Factory Ventilation

Efficiency is the watch-word and war-cry of modern industrial equipment and organization. Our immediate predecessors in manufacturing were descendants of the blacksmiths, wagon-makers and the saw-mill men, and thought they did extremely well in the way of factory building when they placed a rain-proof roof over their workers and lighted the floors with few windows of small area, though the factory was inefficiently warmed and no attempt was made towards cooling, with no adequate sanitary provisions and wholly accidental ventilation.

Now we are fully aware that the factory building must be sanitary, must give the fullest possible admission of daylight, must have artificial lighting so good that the setting of the sun does not darken the factory , must give each and every worker ready access to pure drinking water, and, last and most important of all efficiency demands, must supply workrooms with an abundance of pure air, heated or cooled as the temperature of the changing seasons of the year may require; and that this abundant pure-air supply, warmed or cooled as may be needful, must be in constant circulation and must be always in process of purification and renewal, if the maximum efficiency of the factory workers is to be obtained—and without maximum labor efficiency, no factory of today can hope for marked commercial success.

To obtain pure air throughout large workrooms some means of effecting constant air circulation, constant admission of fresh air, and efficient washing of all air, together with needful heating or cooling of the air before sending it into the factory workrooms, must be provided.

Where the factory is large a great volume of air must be in constant motion, in constant process of washing, heating or cooling, and must be so supplied as to circulate constantly through every portion of every room in the factory building.

One of the very best ventilation systems ever installed in any factory building is that placed by the American Blower Company in these two large new factory buildings of the Ford Motor Company, at their Highland Park plant, Michigan.

These buildings as already described are each 842 feet long by 60 feet wide, have six floors, are 77 feet high, have 687,500 square feet of working floor area, and enclose 11,200,000 cubic feet of space.

Air Volume Per Minute

Eight " Sirocco " fans having rotors 72 inches diameter, 36 inches face and turned at 218 revolutions per minute, are placed, one in each of eight pent-houses, equally spaced on the roof of the new buildings.

Each rotor has 64 blades and when driven at 218 turns will deliver 56,000 cubic feet of air at about 1 3/4-inches water-column pressure. Hence, if some method of air-piping can be found which will permit the distribution of air throughout the buildings without exceeding the air pressure specified, = 1 3/4 water-column inches, then, dividing 11,200,000 cubic feet of building enclosed space by 448,000 cubic feet of air delivered per minute gives about 25 minutes as the time demanded for an entire change of all the air within the factory walls, if the air supply to the fans is taken wholly from the outside.

Source of Air-Supply

Provisions are made for supplying air to the fans wholly from the outside or wholly from the craneways, or partly from each source. If air to the fans is taken from outside of the building only, then temperature modifications of the entire contained air. volume must be made once in each 25 minutes; if the air to the fans is taken from the craneways only, then after the building interior is once warmed, only a comparatively small additional heating need thereafter be imparted to the fan air-supply to keep the factory temperature at, say, 65 to 70 degrees F., throughout the entire working day.

Air taken from above the roof would be almost perfectly pure, and it seems quite likely that labor efficiency would be so much increased by an entire change.of air once in 25 minutes as to pay for the increased airheating cost when the factory required heating. Of course, during the warmer months, when the factory demanded cooling effect, the air would be taken from the outside, and would be delivered to the factory at "wet-bulb" temperature, which is about 72 degrees F. for Detroit.

"Conditioning" the Air

By the ventilating methods employed the fan supply of air is first drawn past an assemblage of vertical pipes supplied with water at predetermined pressure, these pipes being fitted with a sufficient number of individual atomizers to maintain a heavy mist in the air which passes through the washing chamber. On the fan side of the washing chamber the air first meets closely spaced vertical plates set at a small angle to the direct line of air travel; these plates are constantly wet, and the inclination forces the air against them so that all dust particles contained by the passing air are certain to be collected on these many vertical plates, which do not, however, deprive the air of its surplus moisture.

To separate the air from its water carried in suspension, three sets of vertical metal plates, inclined to the direct line of air movement and hooked on their fan-ward vertical edges, are placed in the air-to-fan way; the first row is spaced much closer than the second row of these vertical "eliminators" (see sectional plan of "conditioning" elements) and the second row is closer spaced than the third row, while angles and hooksides are changed in each row of water detrainers, all so that the air is freed from water in suspension before it meets the "Vento" heating stacks in its way to the fan. These Vento heating stacks are composed of flat, hollow, gray-iron sections, each one carrying on its flat sides a great number of closely placed lozengeshaped hollow projections; these studded and hollow flat sections are placed vertically, with their edges toward the air current, and are filled inside with hot water or steam to heat the air as it passes through the vast number of narrow and crooked passages before it reaches the fans. Each One of the eight Ford-building ventilating units nas nine sec- tions deep of 72-inch Vento heaters piled two stacks high, and presents a total heating surface of 10,250 square feet to the air passing to each fan.

It is the intention to use hot water supplied from the water-jackets of the gas-engine sides of the new "Gasteam" power units which are expected to drive the Ford shops in the near future, but for immediate use a battery of steam boilers is now being placed near the eastern end of these new buildings to supply heat until the "Gasteam" motors begin working.

From the fans the thoroughly washed and cooled or heated air goes to the hollow columns, as previously specified, past individual dampers which regulate the volume of air delivered to each air release opening throughout the entire heating, cooling, and ventilating system of the buildings. The roof air-passages have brick-work walls with 4-inch air spaces between walls and the enclosed sheet-metal air passages, and are covered with cinders, tar and gravel, making these roof-ducts nearly non-conductors of heat.

Each one of the eight fans is driven by a 40 horse-power electric motor, supplied by the Westinghouse Electric Company, but the actual driving of each rotor at 218 turns requires only about 28 horse-power.

The Sirocco fan is capable of delivering air at the pressure of a 40-inch water column if desired, so that the air pressure specified, equal to that of a 124-inch water column, is easy work on the machine. It will be understood, of course, that greater pressures of delivered air require increased power, and increased stability of rotor construction.

It will be observed that the purity of the air depends entirely on the efficient action of the water atomizers fitted to the vertical water pipes which are shown herewith in section. Dirt contained in the water collects, of course, at the very narrow annular opening where the water leaves the pipes and strikes the concave surface of the atomizer head. This dirt can be instantly dislodged by increasing the discharge annulus area. To flush all of the atomizers of one unit instantly and at once, the atomizer-head stems are spring-pressed to close the annulus, and screw-adjusted to open the annulus to deliver water suitably, and each atomizing head stem has a small diameter piston fixed to it, the piston being so seated in its cylinder that pressure on one side of the piston will compress the stem spring and push the atomizer wide open.

These atomizer piston cylinders are piped to hydrant water-pressure, all so that by simply turning on the hydrant water all the atomizers of one unit are flushed at one time, and as soon as the hydrant water is shut off, the atomizers are automatically spring-returned to their original adjustments.

The heating efficiency of the Vento stack is obviously high, since all the heat delivered by the stack must be infallibly imparted to the passing air, as there is no other conductor by which it can be carried out of the system.

The entire water-washing system is placed over a water-tight pan; the air-washing system requires the circulation of 270 gallons of water per minute, at a pressure of 50 inches of water column. This water circulation is made automatically regulating by the water-piping arrangement, and the water circulation is effected by a centrifugal pump driven by a 10 horse-power electric motor.

This admirable ventilating and air purifying and heating and cooling system is illustrated by pictures prepared especially for this account, which show its extreme simplicity and ease of control, the clever atomizer -flushing device, which makes the air-cleansing and the air-cooling certain, being especially commendable, as a less ready and certain atomizer flushing and atomizer automatic returai to original adjustment might easily lead to wholly unsatisfactory operation of the entire airpurifying system.

Taken as a whole, this combination of the air-conditioning and circulating system with the hollow-column circulation of the air throughout the entire factory seems to leave nothing whatever to be desired in the way of perfectly satisfactory heating, cooling, and ventilating, and this perfection of factory air-supply cannot possibly fail to affect most favorably factory labor-efficiency, both of officials and hand workers.