Mass production

Sometimes production in series has obvious benefits, as is the case with this 5-sickle casting mold from the Bronze Age on show at a museum in Yekaterinburg, Russia.

This woodcut from 1568 shows the left printer removing a page from the press while the one at right inks the text-blocks. Such a duo could reach 14,000 hand movements per working day, printing around 3,600 pages in the process.[3]

Standardized parts and sizes and factory production techniques were developed in pre-industrial times; before the invention of machine tools the manufacture of precision parts, especially metal ones, was very labor-intensive.

Crossbows made with bronze parts were produced in China during the Warring States period. The Qin Emperor unified China at least in part by equipping large armies with these weapons, which were equipped with a sophisticated trigger mechanism made of interchangeable parts.[4] The Terracotta Army guarding the Emperor's necropolis is also believed to have been created through the use of standardized molds on an assembly line.[5][6]

In ancient Carthage, ships of war were mass-produced on a large scale at a moderate cost, allowing them to efficiently maintain their control of the Mediterranean.[7] Many centuries later, the Republic of Venice would follow Carthage in producing ships with prefabricated parts on an assembly line: the Venetian Arsenal produced nearly one ship every day in what was effectively the world's first factory, which at its height employed 16,000 people.[8][9]

The invention of movable type has allowed for documents such as books to be mass produced. The first movable type system was invented in China by Bi Sheng,[10] during the reign of the Song Dynasty, where it was used to, among other things, issue paper money.[11] The oldest extant book produced using metal type is the Jikji, printed in Korea in the year 1377.[12] Johannes Gutenberg, through his invention of the printing press and production of the Gutenberg Bible, introduced movable type to Europe. Through this introduction, mass production in the European publishing industry was made commonplace, leading to a democratization of knowledge, increased literacy and education, and the beginnings of modern science.[13]

Jean-Baptiste de Gribeauval, a French artillery engineer, introduced the standardization of cannon design in the mid-18th century. He developed a 6-inch (150 mm) field howitzer whose gun barrel, carriage assembly and ammunition specifications were made uniform for all French cannons. The standardized interchangeable parts of these cannons down to the nuts, bolts and screws made their mass production and repair easier than before.

In the Industrial Revolution, simple mass production techniques were used at the Portsmouth Block Mills in England to make ships' pulley blocks for the Royal Navy in the Napoleonic Wars. It was achieved in 1803 by Marc Isambard Brunel in cooperation with Henry Maudslay under the management of Sir Samuel Bentham.[14] The first unmistakable examples of manufacturing operations carefully designed to reduce production costs by specialized labour and the use of machines appeared in the 18th century in England.[15]

A pulley block for rigging on a sailing ship. By 1808, annual production in Portsmouth reached 130,000 blocks.

The Navy was in a state of expansion that required 100,000 pulley blocks to be manufactured a year. Bentham had already achieved remarkable efficiency at the docks by introducing power-driven machinery and reorganising the dockyard system. Brunel, a pioneering engineer, and Maudslay, a pioneer of machine tool technology who had developed the first industrially practical screw-cutting lathe in 1800 which standardized screw thread sizes for the first time which in turn allowed the application of interchangeable parts, collaborated on plans to manufacture block-making machinery. By 1805, the dockyard had been fully updated with the revolutionary, purpose-built machinery at a time when products were still built individually with different components.[14] A total of 45 machines were required to perform 22 processes on the blocks, which could be made into one of three possible sizes.[14] The machines were almost entirely made of metal thus improving their accuracy and durability. The machines would make markings and indentations on the blocks to ensure alignment throughout the process. One of the many advantages of this new method was the increase in labour productivity due to the less labour-intensive requirements of managing the machinery. Richard Beamish, assistant to Brunel's son and engineer, Isambard Kingdom Brunel, wrote:

So that ten men, by the aid of this machinery, can accomplish with uniformity, celerity and ease, what formerly required the uncertain labour of one hundred and ten.[14]

By 1808, annual production from the 45 machines had reached 130,000 blocks and some of the equipment was still in operation as late as the mid-twentieth century.[14][16] Mass production techniques were also used to rather limited extent to make clocks and watches, and to make small arms, though parts were usually non-interchangeable.[2] Though produced on a very small scale, Crimean War gunboat engines designed and assembled by John Penn of Greenwich are recorded as the first instance of the application of mass production techniques (though not necessarily the assembly-line method) to marine engineering.[17] In filling an Admiralty order for 90 sets to his high-pressure and high-revolution horizontal trunk engine design, Penn produced them all in 90 days. He also used Whitworth Standard threads throughout.[18] Prerequisites for the wide use of mass production were interchangeable parts, machine tools and power, especially in the form of electricity.

Some of the organizational management concepts needed to create 20th-century mass production, such as scientific management, had been pioneered by other engineers (most of whom are not famous, but Frederick Winslow Taylor is one of the well-known ones), whose work would later be synthesized into fields such as industrial engineering, manufacturing engineering, operations research, and management consultancy. Although after leaving the Henry Ford Company which was rebranded as Cadillac and later was awarded the Dewar Trophy in 1908 for creating interchangeable mass-produced precision engine parts, Henry Ford downplayed the role of Taylorism in the development of mass production at his company. However, Ford management performed time studies and experiments to mechanize their factory processes, focusing on minimizing worker movements. The difference is that while Taylor focused mostly on efficiency of the worker, Ford also substituted for labor by using machines, thoughtfully arranged, wherever possible.

In 1807, Eli Terry was hired to produce 4,000 wooden movement clocks in the Porter Contract. At this time, the annual yield for wooden clocks did not exceed a few dozen on average. Terry developed a milling machine in 1795, in which he perfected Interchangeable parts. In 1807, Terry developed a spindle cutting machine, which could produce multiple parts at the same time. Terry hired Silas Hoadley and Seth Thomas to work the Assembly line at the facilities. The Porter Contract was the first contract which called for mass production of clock movements in history. In 1815, Terry began mass-producing the first shelf clock. Chauncey Jerome, an apprentice of Eli Terry mass-produced up to 20,000 brass clocks annually in 1840 when he invented the cheap 30-hour OG clock.[19]

The United States Department of War sponsored the development of interchangeable parts for guns produced at the arsenals at Springfield, Massachusetts and Harpers Ferry, Virginia (now West Virginia) in the early decades of the 19th century, finally achieving reliable interchangeability by about 1850.[2] This period coincided with the development of machine tools, with the armories designing and building many of their own. Some of the methods employed were a system of gauges for checking dimensions of the various parts and jigs and fixtures for guiding the machine tools and properly holding and aligning the work pieces. This system came to be known as armory practice or the American system of manufacturing, which spread throughout New England aided by skilled mechanics from the armories who were instrumental in transferring the technology to the sewing machines manufacturers and other industries such as machine tools, harvesting machines and bicycles. Singer Manufacturing Co., at one time the largest sewing machine manufacturer, did not achieve interchangeable parts until the late 1880s, around the same time Cyrus McCormick adopted modern manufacturing practices in making harvesting machines.[2]

Mass production of Consolidated B-32 Dominator airplanes at Consolidated Aircraft Plant No. 4, near Fort Worth, Texas, during World War II.

During World War II, The United States mass-produced many vehicles and weapons, such as ships (i.e. Liberty Ships, Higgins boats ), aircraft (i.e. North American P-51 Mustang, Consolidated B-24 Liberator, Boeing B-29 Superfortress), jeeps (i.e. Willys MB), trucks, tanks (i.e. M4 Sherman) and M2 Browning and M1919 Browning machine guns. Many vehicles, transported by ships have been shipped in parts and later assembled on-site.[20]

For the ongoing energy transition, many wind turbine components and solar panels are being mass-produced.[21][22][23] Wind turbines and solar panels are being used in respectively wind farms and solar farms.

In addition, in the ongoing climate change mitigation, large-scale carbon sequestration (through reforestation, blue carbon restoration, etc) has been proposed. Some projects (such as the Trillion Tree Campaign) involve planting a very large amount of trees. In order to speed up such efforts, fast propagation of trees may be useful. Some automated machines have been produced to allow for fast (vegetative) plant propagation.[24]Also, for some plants that help to sequester carbon (such as seagrass), techniques have been developed to help speed up the process .[25]

Mass production benefited from the development of materials such as inexpensive steel, high strength steel and plastics. Machining of metals was greatly enhanced with high-speed steel and later very hard materials such as tungsten carbide for cutting edges.[26] Fabrication using steel components was aided by the development of electric welding and stamped steel parts, both which appeared in industry in about 1890. Plastics such as polyethylene, polystyrene and polyvinyl chloride (PVC) can be easily formed into shapes by extrusion, blow molding or injection molding, resulting in very low cost manufacture of consumer products, plastic piping, containers and parts.

An influential article that helped to frame and popularize the 20th century's definition of mass production appeared in a 1926 Encyclopædia Britannica supplement. The article was written based on correspondence with Ford Motor Company and is sometimes credited as the first use of the term.[2]

Electrification of factories began very gradually in the 1890s after the introduction of a practical DC motor by Frank J. Sprague and accelerated after the AC motor was developed by Galileo Ferraris, Nikola Tesla and Westinghouse, Mikhail Dolivo-Dobrovolsky and others. Electrification of factories was fastest between 1900 and 1930, aided by the establishment of electric utilities with central stations and the lowering of electricity prices from 1914 to 1917.[27]

Electric motors were several times more efficient than small steam engines because central station generation were more efficient than small steam engines and because line shafts and belts had high friction losses.[28][29] Electric motors also allowed more flexibility in manufacturing and required less maintenance than line shafts and belts. Many factories saw a 30% increase in output simply from changing over to electric motors.

Electrification enabled modern mass production, as with Thomas Edison's iron ore processing plant (about 1893) that could process 20,000 tons of ore per day with two shifts, each of five men. At that time it was still common to handle bulk materials with shovels, wheelbarrows and small narrow-gauge rail cars, and for comparison, a canal digger in previous decades typically handled five tons per 12-hour day.

The biggest impact of early mass production was in manufacturing everyday items, such as at the Ball Brothers Glass Manufacturing Company, which electrified its mason jar plant in Muncie, Indiana, U.S., around 1900. The new automated process used glass-blowing machines to replace 210 craftsman glass blowers and helpers. A small electric truck was used to handle 150 dozen bottles at a time where previously a hand truck would carry six dozen. Electric mixers replaced men with shovels handling sand and other ingredients that were fed into the glass furnace. An electric overhead crane replaced 36 day laborers for moving heavy loads across the factory.[30]

According to Henry Ford:[31]

The provision of a whole new system of electric generation emancipated industry from the leather belt and line shaft, for it eventually became possible to provide each tool with its own electric motor. This may seem only a detail of minor importance. In fact, modern industry could not be carried out with the belt and line shaft for a number of reasons. The motor enabled machinery to be arranged in the order of the work, and that alone has probably doubled the efficiency of industry, for it has cut out a tremendous amount of useless handling and hauling. The belt and line shaft were also tremendously wasteful – so wasteful indeed that no factory could be really large, for even the longest line shaft was small according to modern requirements. Also high speed tools were impossible under the old conditions – neither the pulleys nor the belts could stand modern speeds. Without high speed tools and the finer steels which they brought about, there could be nothing of what we call modern industry.

The assembly plant of the Bell Aircraft Corporation in 1944. Note parts of overhead crane at both sides of photo near top.

Mass production was popularized in the late 1910s and 1920s by Henry Ford's Ford Motor Company,[32] which introduced electric motors to the then-well-known technique of chain or sequential production. Ford also bought or designed and built special purpose machine tools and fixtures such as multiple spindle drill presses that could drill every hole on one side of an engine block in one operation and a multiple head milling machine that could simultaneously machine 15 engine blocks held on a single fixture. All of these machine tools were arranged systematically in the production flow and some had special carriages for rolling heavy items into machining position. Production of the Ford Model T used 32,000 machine tools.[33]

The process of prefabrication, wherein parts are created separately from the finished product, is at the core of all mass-produced construction. Early examples include movable structures reportedly utilized by Akbar the Great,[34] and the chattel houses built by emancipated slaves on Barbados.[35] The Nissen hut, first used by the British during World War I, married prefabrication and mass production in a way that suited the needs of the military. The simple structures, which cost little and could be erected in just a couple of hours, were highly successful: over 100,000 Nissen huts were produced during World War I alone, and they would go on to serve in other conflicts and inspire a number of similar designs.[36]

Following World War II, in the United States, William Levitt pioneered the building of standardized tract houses in 56 different locations around the country. These communities were dubbed Levittowns, and they were able to be constructed quickly and cheaply through the leveraging of economies of scale, as well as the specialization of construction tasks in a process akin to an assembly line.[37] This era also saw the invention of the mobile home, a small prefabricated house that can be transported cheaply on a truck bed.

In the modern industrialization of construction, mass production is often used for prefabrication of house components.[38]