The Moving Assembly Line Turns 100 (2013)

Summary

This month marks the official celebration of the world’s first moving assembly line. On Oct. 7, 1913, 140 assemblers stationed along a 150-foot chassis line at a Ford Motor Co. plant just north of Detroit stood in place as the work came to them. With the aid of three-wheeled dollies, chassis were pushed by hand along parallel rails embedded in the floor of the Highland Park plant. Six months earlier, Ford engineers had experimented with a movable line for assembling flywheel magnetos, a key component in the electrical system of the Model T. By raising the height of the assembly line, moving the magnetos with a continuous chain and lowering the number of operators to 14, the Ford engineers eventually achieved a daily output of 1,335 flywheel magnetos, which translated into five minutes per magneto vs. 20 minutes with a static assembly process. That success encouraged the engineers to experiment in other parts of the factory. The chassis line that debuted a century ago dramatically reduced Model T assembly time to less than three hours. In contrast, the traditional static assembly process took more than 12 hours. By December 1913, the line had doubled in length and 37 more assemblers were added to various workstations. Assembly time was further reduced by 20 minutes. In January 1914, Ford engineers ramped up a line that was equipped with an endless chain conveyor. Over the next four months, they raised, lowered, sped up and slowed down the assembly line. They also made numerous changes in workstation positions and the number of assemblers. Continuous improvement eventually whittled the time required for assembly to 93 minutes. By May 1914, when three parallel assembly lines were in operation on the ground floor of the Highland Park factory, assemblers were producing more than 1,200 chassis per eight-hour shift. The assembly process was methodically divided into 45 separate operations. That success prompted Ford engineers to expand their experiments. On June 1, 1914, f...