National Geographic : 1923 Oct
388 THE NATIONAL GEOGRAPHIC MAGAZINE success of the automotive industry. With out it motor cars would certainly be be yond the means of millions of persons who now own them. In the early days they were largely made by hand. To S daytheuseofapaintbrushorapair of spanners, the movement of a lever, or the holding of an electric wrench repre sents about the limit of handwork in motor-car manufacture. That precision tools are superior to human senses in automobile making has been strikingly demonstrated. O CLIPPING MINUTES IN MOTOR MAKING I O In the early days the material for the assembly of a car was simply dumped to a gether in a space on the floor where the S automobile was to be set up. Then the 2 Ford iMotor Company thought to try out the overhead trolley system used by the Chicago packers and a division of labor. One man could assemble a flywheel < magneto in twenty minutes. When the moving line was installed and divided into twenty-nine operations, the time was cut S down to less than fourteen minutes. By raising the height of the line eight inches, % uC so as to save stooping, the time was re duced to seven minutes. Other experi ments reduced the time to five minutes. ,z In 1913, 9 hours and 54 minutes were required to assemble a motor in the Ford u plant. Six months later the time had Been reduced to 5 hours and 56 minutes. S By early methods 12 hours and 28 min utes was the time required to assemble a chassis. Then the idea was evolved of towing the chassis down a 250-foot line with a rope attached to a windlass. Six assemblers walked down the line, picking I Q up parts from various piles and attach - ing them as the car moved. This speeded t up the assembly to 5 hours and 50 min utes. By placing the work waist-high and I", bringing the speed of the conveyor to the most effective point, the time of assembly was reduced to I hour and 33 minutes. It was quite a task to determine at what speed each conveyor should move so as to give each workman ample time to do his bit properly and yet economize every second. The flywheel magneto assembly line was tried at sixty feet a minute, and that proved too fast. Eighteen feet per minute proved too slow. Forty-four feet finally proved to be the correct velocity.