Motor-test blocks and chassis-assembling lines
A gray-iron foundry is not an automobile-body upholstering shop, and an automobile-upholstering shop is not a gas-engine assembling nor a chassis-assembling department. These assertions will be accepted by all without argument or demonstration. How, then, can the Ford engineers be expected to reduce labor-costs enormously in the gray-iron foundry, in the motor-assembling department , in the chassis-assembling department, and in the body-upholstering department, by use of one and the same mechanical element, a slowly-moving, endless chain?
|The Ford engineers certainly do make great labor reductions in the foundry, the machine shop, and in body-upholstering by simple endlesschain installations, because in all assembling operations it costs much less in labor-time expenditure to move an assembly in progress past fixed points of component supply than it costs to hold the assembly in progress stationary and bring the components to the one assembling location, and because the moving assembly gives more floor space for assemblers and hence permits the more minute subdividing of assembling operations. In the foundry, in ordinary practice, a poured mould is neither more nor less than an assembled unit, all assembling operations being performed in the one fixed location where the flask is first placed on the foundry floor. The sand is brought to the flask by hand and shovel, the pattern, gaggers, parting-sand, and cores are brought to the mould by hand and assembled, and, as the last operation, the melted metal, final component of this foundry assembled unit, is brought to the finished mould and poured into it.
The Ford four-cylinder en-bloc casting, the rough casting weighing 101 pounds, is made in this way at this time. The Westinghouse airbrake -cylinder mould is made and poured and shaken out on an intermittingly -moved endless train of cars (240 in number, if memory serves zone and over the shake-out gratings, as in the Westinghouse method.
The Ford moulding machines stand under sand chutes which are served by an endless chain of sand-distributing blades or pushers, slowly moving in troughs placed above the heads of the machine moulders.
The Ford gray-iron foundry is now installing a new core oven, served by two endless-chain lines, all as will be fully described in the chapter on the foundry, later in this book. The main themes of this chapter are the motor testing and chassis assembling; but the spectacle of the body-and-top chain-driven assembling led to a general survey of the Ford endless-chain assembling lines, which naturally recalled the Westinghouse endless-train air-brake-cylinder moulding and pouring, and so suggested the close analogy between machine-shop assembling and foundry moulding operations, notwithstanding the fact that foundry operations and machine-shop operations are so universally regarded as widely dissimilar.
Before following the chassis assembling in detail, however, further attention must be given to the motor block-test and the details of motor "running-in" on the block. These important operations conclude the motor assembly (which was described in the preceding chapter) and precede the delivery of the motor, with its motor-assembler's record, to the automobile-assembly line.
The Motor-Test Blocks
The motor blocks are nineteen in number at the date of this writing (June 1, 1914) and the day's motor production, whatever it may be, must be handled on the nineteen blocks. This number will soon be increased.
Each test-block consists of a Westinghouse direct-current shuntwound motor, constant speed, showing 20 horse power at 230 volts, 73 amperes and 750 revolutions per minute, equipped with Weston instruments and supported on a stand adapted to take the motor and hold the transmission shaft in line with the motor-armature shaft. The motor under test is placed on the block and driven at 750 revolutions per minute until the needle drops to a 20-ampere reading, this operation taking, say, from 3 to 5 minutes; each motor is given as much time on the block as may be, but the floor must be kept clear of untested motors. No motor is ever passed until it makes 750 revolutions per minute with 20 amperes of 230-volt current.
The head block-tester has one assistant, one tester to every testblock , and enough helpers to handle the motors on and off the testblocks . Each block-tester has an alphabetical steel stamp with his own individual letter, and marks a certain screw-head with hammer and letter stamp at the end of each test, and also paints one other certain screw-head red when a motor is passed from the test-block for use in the chassis-assembling line.
The block-tester examines the motor while on the block for all the possible imperfections enumerated in the list on the following page.
Imperfections discovered are noted in pencil, on small, white, stiff cards, using list terms, and a straight vertical pencil mark is made in the corresponding blank space at the left of the specified fault. One card is filled for each fault found, and all cards are fixed by one particular screw to the faulty motor, which is then sent to the motor-repairs department, working four men only, who are all-round machinists, and who take care of all the motor repairs when as many as 1,100 motors per day are being turned out.
This list of motor repairs is long because it includes every fault which has been so far discovered in any Ford "Model T" motor. Each day's report of motor repairs is sent by the head motor assembler to the machine-shop superintendent. After repairing, the motor goes back to the tester, with its fault-cards, is placed on the block and given another trial, and so on until the motor shows no faults. By applying test certification marks to two specified bolt heads, finishing record-spots on motor castings is avoided; also, if the two specified screws should be removed, no one could be sure the motor had been tested, as it would then be without test certification marks.
Triplicate sheet, Form No. 386, printed in black, on one side only, as shown on the next page, thin paper, three colors, size 9 3/4 inches wide by 8 1/2 inches high. Filled by head of motor assembling, one original and two carbon copies. The green original is placed by the head assembler in a heavy envelope, wired to the pedal, and goes with the motor to the chassis-assembling line.
The yellow carbon is filled by the head assembler and also placed in the envelope wired to pedal, going with the motor to the chassis-assembling line. The white carbon is filled and filed by the head motor assembler as his own record of production.
All of these motor-assembly triplicate record forms are numbered in red, in numerical sequence, as are also the automobile-assembly records described near the end of this chapter, and to be more fully explained by an examination of the Ford sales and shipping practice.
Ford Special Nut-Brace
The Ford shops have brought out no end of original small tools and fixtures, and a considerable number of highly original machine-tools, but this is the only hand-tool involving notable invention that has so far been brought to my attention in the Ford assembling.
In case of placing a free-body-fit bolt, the head of the bolt must be held while the nut is turned on and forced to place. With ordinary wrenches, the assembler holds the head from turning with one wrench, held in one hand, and turns the nut home with another wrench, worked by his other hand—a slow operation at best, and, in many cases, very difficult because of obstructions which prevent ready access to the bolthead while turning the nut to place.
With the special brace (page 135), which has a solid nose fitted to the nut at N, a block, S B, fitted to slide on the brace-body, B B, with an off-set extension, fixed to S B, reaching outward beyond N and then bent inward and ending in the head-holder, H H, concentric with B B and N, the bolt-seating operation becomes easy and rapid.
The bolt-bead and nut are shown as holding the plates P, PI, together, the plates being cut away to show the bolt. An open coilspring , S, is placed between S B and N. With the bolt in the holes in P, PI, and the nut carried in N, S B is pushed towards N until HII can be slipped over the bolt-head; then S B is released, S pulls H onto the bolt-head, and the assembler then has both hands free to run the nut home by operating the brace in the usual manner.
Three of these bolt-head-holding nut-braces are used on each automobile assembling line, nine braces in all, saving three men on each line, $15 per 8-hour day, or $45 per day on the three assembling lines, which is a large interest on the brace cost.
Ford Chassis Assembling
The Ford chassis assembling in moving lines affords a highly impressive spectacle to beholders of every class, technical or non-technical. Long lines of slowly moving assemblies in progress, busy groups of successive operators, the rapid growth of the chassis as component after component is added from the overhead sources of supply, and, finally the instant start into self-moving power—these excite the liveliest interest and admiration in all who witness for the first time this operation of bringing together the varied elements of the new and seemingly vivified creation, on the three Ford chassis assembling lines where over 1,200 have been put together and driven out of doors into John R Street in one single 8-hour day.
Chassis Assembling in Chain-Driven Lines
Up to August, 1913, the Ford chassis was assembled in one location. First the front and rear axles were laid on the floor, then the chassis frame with springs in place was assembled with the axles, next the wheels were placed on the axles, and the remaining components were successively added to complete the chassis. All components needed to make up one chassis had to be brought by hand to each chassis-assembling location. This routine of stationary chassis assembling was, in September , 1913, worked with two lines of assembling-floor space, 600 feet long, 12 feet chassis-to-chassis centers, 50 assembling locations in each 600foot line, 100 cars in process of assembling in the two lines. Working in this routine 600 men were employed, 500 being assemblers who were supplied with components by 100 men acting as component carriers.
About April 1, 1913, the first sliding assembling line, used for assembling the Ford fly-wheel magneto, was placed in work and immediately showed a large reduction in assembling labor-cost. Consequently , the possibility of lowering chassis-assembling costs by introducing the moving assembling line for chassis assembling became a matter of discussion among the Ford engineers.
In the month of August, 1913 (the dull season) 250 assemblers, with a stationary assembling location for each chassis, the assemblers being served by 80 component carriers, worked 9 hours per day for 26 days to turnout 6,182 chassis assemblies. Total labor hours 330 X 9x26 = 77,220 hours, giving 12 hours and 28 minutes for labor time on each chassis , about as good as was ever done with stationary chassis assembling.
The assembling line was long—600 feet—but even at that did not give room enough, and 12 1/2 hours of labor time seemed altogether too much for one chassis. It was in the dull season, and an experiment was made with rope and windlass traction on a moving assembly line 250 feet long. Six assemblers traveled with the chassis as it was slowly pulled along the floor by the rope and windlass past stationary means of component supply, and the chassis-assembling time was reduced to 5 hours and 50 minutes of one man's time, over 50 per cent saving.
October 7, 1913, on a moving-assembly line 150 feet long, with no helpers, components being piled at suitable locations, 140 assemblers in the line completed 435 chassis assemblies in one 9-hour day, 2 hours and 57 minutes of one man's time for each chassis assembling.
The assembling line was lengthened by degrees to 300 feet, giving the men more room, and on December 1,1913,177 assemblers working 9 hours turned out 606 completed chassis assemblies, about 2 hours 38 minutes of one man's time to each chassis.
December 30, 1913, working two assembling lines, 191 men completed 642 chassis assemblies in one 9-hour day, a little less than 2 hours 40 minutes of one man's time for each chassis, the cars being pushed along by hand. January 14, 1914, one assembling line was endless-chain driven, with favorable results.
January 19, four chassis-assembling lines were worked, only one line being chain-driven. The wheels were put on as soon as the axles and the chassis frames were assembled, and the assemblies in progress ran with their front wheels on the floor and their hind wheels carried in 3-wheeled cradles, used to give easy placing of the rear wheels on the motor-starting drive at the end of the line.
February 27, 1914, the first high line of rails with chain drive was used. The chassis slid on its axles as pulled by the chain, and the wheels were applied only a short distance before the motor-starting was reached. This first high line was made with rails 26 3/4 inches above the shop floor, and at once showed great advantages, the best time for one chassis assembling being only 84 minutes, while the worst time was 2 hours. Two other high lines were soon installed, 24 1/2 inches high, with chain drives; tall men worked on the line 26 3/4 inches high, and short men on the other two lines, 24 1/2 inches high.
The Ford engineers make a point of "man-high" work placing, having learned that any stooping position greatly reduces the workman's efficiency. The differing heights of the chassis-assembling high lines are believed to be decidedly advantageous.
On these three high lines, on April 30, 1914, 1,212 chassis assemblies were completed in one 8-hour day, each chassis being assembled in 1 hour 33 minutes of one man's time, as against 12 hours 28 minutes, the best time with stationary chassis assembling, September, 1913—93 minutes as against 728 minutes—and it must be borne in mind that the September, 1913, Ford practice in chassis assembling was fully abreast of the best known in the trade. Very naturally this unbelievable reduction in chassis-assembling labor costs gave pause to the Ford engineering staff, and led to serious search for other labor-reduction opportunities in the Ford shops, regardless of precedents and traditions of the trade at large.
The chassis was not completed when it ran out into John R Street, and the first practice was to let the driver run the chassis up and down until he thought best to abandon it to the motor inspector and the rearaxle inspector, and to return to the end of the assembling lines for another chassis to drive out into John R Street. The bodies were allowed to slide down an incline from the second floor, and were then dragged along the pavement by one man and stood on end in a bunch south of the chute.
When the assembly was completed on the John R pavement, and had been inspected by the motor inspector and the rear-axle inspector, it was again boarded by a driver and taken to the bunch of bodies, where four men lifted a body into place on the chassis, and the completed automobile assembly was then driven to the shipping-clerk's office, between the railway tracks, ready for shipment.
This procedure afforded plenty of gaps and vacancies for discretionary proceedings on the part of all the men working outside under the head assembler. The next radical improvement was made by laying down the angle-iron John R street track, running southward from the exit door, under the body-chute and something more than a chassis
length to the south of the chute; and the chute itself was presently equipped with a car-body handling rig, not regarded as the final thing, but serving to place a body on the chassis with one handling only. The ground plan of the three chassis-assembling lines inside the shop, and of the John R street track, is given to scale on this page and the numerous illustrations in half-tone will give the reader a fair idea of the chassisassembling procedure.
It must be clearly understood that the moving-assembly speed is varied to suit exactly each individual assembling job. As each operation is performed while the work passes slowly across the station occupied by each assembler or assembling gang, the time of transit past this station must be sufficient for good work and no more. The first assembling line established in the Ford shops (for the magneto) was originally speeded at 60 inches per minute, which proved much too fast. The next speed tried, 18 inches per minute, was found to be as much too slow. The third guess, 44 inches per minute, answered so well that it is yet retained.
This view is at the north end of the chain-driven chassis-and-springs assembling line, on which the chassis frames are carried to the south for various operations after the frames are mounted on the springs
The dash-assembly line travels 72 inches per minute; the front axle assembling line 189 inches per minute, and the body-and-top assembling line 144 inches per minute. The speed of the chassis-assembling line is 72 inches (6 feet) per minute, i The work is so divided among the assemblers that each operation is performed in 7 minutes and 36 seconds, turning out 300 complete chassis assemblies on each chassis-assembling line in 8 hours of working time, save in case of operations 1 and 2.
- 1. Three men; one press man and two chassis-frame handlers. Fix 4 mud-guard brackets, 2 on each side, to the chassis frame, 600 in 8 hours.
- 2. Six men. On moving line, fix rear spring to chassis frame, 600 in 8 hours. Operations 1 and 2 are on a side line, work moving from north to south, and this side line turns out 600 chassis frames with 4 mudguard brackets and rear springs in place in 8 hours, enough to supply two lines of automobile assemblers, work moving from south to north, each line turning out 300 automobile assemblies in 8 hours. The Ford Highland Park shops on June 11,1914, were turning out 600 automobiles per day, and about 400 more per day were assembled at the various Ford branches, making about 1,000 new Ford automobiles assembled per day. To assemble more than 600 automobiles per day, two presses and 18 men are worked in operations 1 and 2, and three automobile-assembling lines are worked. The high production and the record at that date were 1,212 automobiles assembled in one 8-hour day at the Highland Park plant. From operation 2, all operations are performed on two automobileassembling lines simultaneously, same number of men and same operations on each line, assemblies moving from south to north. Operations performed and men used on one automobile assembling line only, here follow.
- 3. Three men. Two men place and fix the rear axle, connecting the rear spring to the rear-axle spring shackles; one man working simultaneously with the other two places and fixes the front-axle assembly under the chassis frame.
- 4. Two men. One completes the fixing of front axle, places the two combined lamp - brackets and front mud-guards, and catches nuts on, while the other man places and fixes the mud-guard bracket truss-rods.
- 5. Two men. Place nuts on truss-rods. Place and fix control-lever rock-shaft.
- 6. One man. Fixes front spring, tightens nuts, and puts in 4 split pins.
- 7. Two men. Complete fixing of combined front fender-irons and lamp brackets.
- 7 1/2. Place one gallon of gasoline in the gasoline tank, on gasoline tank bridge.
- 8. Two men. Place gasoline tank and fix same, also place gasoline feed-pipe. The tank receives one gallon of gasoline before leaving the gasoline tank bridge.
- 9. One man. With hard-grease syringe ("dope gun") injects 4 pounds of heavy grease into the bevel gear and differential housing . Also places 1 pound heavy grease in universal-joint globe housing.
- 10. Two men. Place motor and connect the universal joint of propeller shaft to the change-gear shaft.
- 11. Two men. Line up mud-guard brackets. Tighten rear-spring perch nuts and place the cotter pins in same.
- 12. One man. Places spark plugs. Fixes same.
- 13. One man. Seats and caps motor front-support and wires 2 cap screws.
- 14. Two men. Fix globe housing to end of transmission case, place 2 bolts and 2 cap screws.
- 15. One man. Put cotter pins in the nuts placed in operation 14 and wire the cap-screw heads placed in the same operation.
- 16. Two men. Place and fix the 2 rear crank-case bracket bolts and 2 bolts with split pins.
- 17. One man. Places 4 grease cups, 2 in universaljoint casings and 2 in rearaxle gear housings.
- 18. Two men. Place dash assembly. Place 4 bolts.
- 19. One man. Places muffler and fixes exhaust pipe, also replaces rear-axle bevel-gear housing greaseplug , after first making certain that grease has been properly supplied. 20. One man. Nails name plate on dash board.
- 21. One man. Adjusts pedals travel.
- 22. One man. Fixes steering-column end to chassis frame.
- 23. One man. Places and fixes commutator.
- 24. One man. Places acetylene-gas pipe and its supporting bracket inside chassis frame.
- 25. Two men. Place split pins in fender and lamp-bracket bolt nuts; also put split pins in 4 dash-board bottom holding-bolt nuts.
- 26. Two men. Place and fix motor-hood clips and hood "blocks" (wood-strips) and connect the spark-plug wires.
- 27. One man. Places radiator support and spring studs and nuts, and places split pins in nuts.
- 28. One man. Tightens and pins muffler-fixing bolt nuts.
- 29. One man. Secures gasoline feed-pipe to carburetor; also connects brake-rod.
- 30. Two men. Place motor pans, one on each side, under chassis frame, and pan-holding bolts and nuts.
- 31: Four men. Tighten motor-pan-bolt nuts and place split pins in same.
- 32. One man. Pins steering-gear bracket nut, and adjusts sparktime.
- 33. Two men. Put on wheels, place wheel nuts.
- 34. One man. Connects carburetor "pull rod" (gives more or less gasoline) and adjusts the carburetor, and turns on the gasoline.
- 35. Three men; one head checker and 2 checkers, one on each side, also act as inspectors. Record chassis numbers and car numbers, fill blank records in record sheets, Form 14. The third man is record inspector, and filler of his own number record book; superior to the two checkers.
- 36. One man. Caps steering connecting-rod globe end, places 2 cap bolts, places nuts and pins them.
- 37. One man. Connects magneto wire, and paints bolts and nuts on right side of chassis.
- 38. One man. Places radiator and its water connection and top stay-rod, and places carburetor priming rod.
- 39. One man. Tightens radiator water connection.
- 40. One man. Places nuts and split pins, radiatorsupport studs.
- 41. One man. In pit, caps front-axle radius-rod globe, and puts on two stud nuts and wires same.
- 42. One man. Paints bolts and nuts on left side of chassis and radiator.
- 43. One man. Final inspector , tags defects.
- 44. Two men. Fill radiator with water, handle starting weight lever on rear axle, and lift rear wheels ofTstarting friction-wheels and attach exhaust hose.
- 45. One man. Driver, drives car on to John R street line.
The John R Street Track
In regular course of events the chassis is driven from the motorstarting drive at the north end of the assembling line, through the door to John R street, directly on to the John R street track, and is there left by its driver, who walks back into the shop and takes out the next chassis which has had its motor started. The John R street track was not placed until after the need for it was plainly apparent.
Body at top right, on chute platform, ready to go down the chute, endless-belt control by man at lever at extreme right of platform . Two handlers on top of platform to left of the lever man are ready to start the next body down the chute. Near the foot of the chute, under the rocking gallows frame, two men, one on each side of body, are making slings, hung from the gallows cross-bar, fast to the body. The chassis stands at the left, ready to take the body. The man on the box, at right gallows upright, controls the movement of the gallows frame. The man at left gallows upright stands ready to direct the body when launched.
The early practice included a run up and down John R street at discretion of the driver, who did not leave the car until he saw fit to do so. The consequence was, that with new cars coming out of the shop door at 40-second intervals , the street was filled with cars running up and down in no regular sequence and with a considerable waste of the time of the drivers, as was shown by the fact that six drivers were taken off as soon as the John R street track began to be used. The John R track also cleaned up the traffic congestion at that point, and the placing of idlers on ball bearings at one point in the John R street track made the rear-axle running inspection possible without taking the cars off the track and placing the rear-axle housings on small wooden horses so that the rear axle could be motordriven without moving the chassis. These idlers in the John R street track at once showed their value by almost entirely clearing that thoroughfare of all new cars save those on the track itself.
A very considerable list of chassis-assembling operations, performed formerly between the shop door whence the cars came out and the body chute, are now performed on the John R street track, with that notable time-saving which always followed keeping work line is used when haste is important, the slow line when there is plenty of time defined line and thus leaving as little as possible to the whim or choice of the individual workman.
As soon as a chassis is driven onto the John R track the clutch is adjusted so that, with the motor running, the chassis will "creep" at something less than walking pace along the unobstructed track, southward toward the body chute. The man who tightens the clutch also throttles the motor to low speed.
Next the water connection to the radiator is made tight, if it shows any leak. Then the top nut of the steering shaft, which holds the hand-wheel, is put on, after inspection to make sure that the hand-wheel key is in place. This is followed by careful carburetor adjusting. The Ford cars are equipped about half and half with Holly and Kingston carburetors.
Next the motor inspector, who must be an expert and must hear well, puts the motor through its paces, and if he detects any fault the chassis is taken out of the line and goes to the "Hospital," across the street, where the motor is made to run right or is exchanged for one that does run right. The Ford en-bloc cylinders castings are piled in the open air for 30 days to "season" before machining, but may develop leaks when placed in actual work in spite of the shop hydraulic test, and the highly specialized motor inspectors can rightly interpret every sound made by a running motor, and so are able to locate accurately the point where any abnormal sound originates.
Finally, the hind wheels of the chassis are brought to stand on four flanged-sleeve ball-bearing idlers and the rear axle is run at various speeds and its noises are carefully noted. Here, again, experience and quick hearing are indispensable. The rear axle makes but little noise and the inspector must be able to locate certainly the cause of any unusual sound.
The rear-axle inspection takes place under the body chute, and when everything is right the chassis runs to the south end of the chute and has a body placed on it, and is then ready to be driven out to the shipping platform.
The illustration on page 152 gives an excellent idea of the orderly conditions secured by the present methods. Anyone who saw John R street in the strenuous days preceding the installation of the track will appreciate thoroughly the improvement in methods represented by this item alone.
Every motor has an individual number, as each chassis and body have, but these two numbers are not the same in any one car, and it is needful the factory should have a record of the number of the motor and of the chassis and the body which are assembled together to form one complete automobile.
Triplicate Form No. 14, printed on thin paper in' three colors, is filled by the head of the chassis assembling, one original and two carbon copies being made. It carries the entire specifications of an automobile on a sheet 9% inches wide by 8*4 inches high. Use of the green original; after the dash assembly is fixed to the chassis, the motor-assembly record envelope (Form 386) is removed from the pedal and fixed to the steering wheel. The green original automobile record is placed in the same envelope. The yellow carbon also is placed in this envelope with the green original. The white carbon is filed by the head automobile assembler as his own record of production.
Daily "Car" Report
"Car" here signifies either a chassis without a body, or a chassis with a body making the assembly a complete automobile. The word "Decked," in this form, signifies "Body on Chassis." "L.H.R." means left-hand control, regular. "L.H.M." means left-hand control, metric (for foreign trade). "R.H.R." means right-hand control, regular. "R.H.M." means right-hand control, metric. "L.H. 60 ins." means left-hand control, 60-inches gauge, for southern trade. This Form 842, a single sheet of thin white paper, printed in black, 8 1/2 inches wide by 5 1/4 inches high, constituting the chassis-assembler's daily report to the machine-shop superintendent, is filled daily by the head of the chassis-assembling department and by him sent to the machine -shop superintendent, who files it in his office, as his own record of production.