Line shaft

Four wool spinning machines driven by belts from an overhead lineshaft (Leipzig, Germany, circa 1925)

A line shaft is a power transmission system used extensively during the Industrial Revolution. Prior to the widespread use of electric motors small enough to be connected directly to each piece of machinery, line shafting was used to distribute power from a large central power source to machinery throughout an industrial complex. The central power source could be a water wheel or turbine, animal power, a stationary steam engine, a steam traction engine, a portable engine, or, in later years, a single large electric motor. Power was distributed from the shaft to the machinery by a system of belts,and pulleys.

History

Early version of line shafts date back into the 18th century, but truly came of age in the early 19th century industrialization and manufacturing. Line shafts were widely used in manufacturing, woodworking shops, machine shops, saw mills and grist mills.

Flat belt drive systems became popular in the UK from the 1870s, with the firms of J E Wood and W & J Galloway & Sons prominent in their introduction. Both of these firms manufactured stationary steam engines and the continuing demand for more power and reliability could be met not merely by improved engine technology but also improved methods of transferring power from the engines to the looms and similar machinery which they were intended to service. The use of flat belts was already common in the US but rare in Britain until this time. The advantages included less noise and less wasted energy in the friction losses inherent in the previously common drive shafts and their associated gearing. Also, maintenance was simpler and cheaper, and it was a more convenient method for the arrangement of power drives such that if one part were to fail then it would not cause loss of power to all sections of a factory or mill. These systems were in turn superseded in popularity by rope drive methods.

Line shafting fell out of favor in the early-to-mid 20th century with the widespread availability of electrical power and availability of compact electric motors. Such independent motors are far less maintenance intensive than maintaining a line shaft system. Those systems in place tended to be converted to power from a large internal combustion engine or large electric motor. Some systems were broken up with separate motors driving different parts of what was one system. Most systems were out of service by the mid-20th century and relatively few remain in the 21st century, even fewer in their original location and configuration.

Most paper machines used steam turbine -powered line shafts until the 1980s, since then many have been replaced with sectional electric drives.

Operation

Variable speed belt drive for a lathe. The fixed pulley on the upper shaft is driven at constant speed by a belt from the power source. The loose pulley ('idler') allows the machine to be stopped in isolation – necessary for changing speed. The stepped pulleys (left) provide three drive speeds for the machine tool (not shown), depending on which pair of pulleys is connected by the belt.

A typical line shaft would be suspended from the ceiling of one area and would run the length of that area. One pulley on the shaft would receive the power from the a parent line shaft elsewhere in the building. The other pulleys would supply power to pulleys on each individual machine or to subsequent line shafts. In manufacturing where there were a large number of machines performing the same tasks, the design of the system was fairly regular and repeated. In other applications such as machine and wood shops where there was a variety of machines with different orientations and power requirements, the system would appear erratic and inconsistent with many different shafting directions and pulley sizes. Shafts were usually horizontal and overhead but occasionally were vertical and could be underground. Shafts were usually rigid steel, made up of several parts bolted together at flanges. The shafts were suspended by hangers with bearings at certain intervals of length. The distance depended on the weight of the shaft and the number of pulleys. The shafts had to be kept aligned or the stress would overheat the bearings and could break the shaft. The bearings were usually friction type and had to be kept lubricated. Pulley lubricator employees were required in order to ensure that the bearings did not freeze or malfunction.

In the earliest applications power was transmitted between pulleys using loops of rope on grooved pulleys. This method is extremely rare today, dating mostly from the 18th century. Flat belts on flat pulleys or drums were the most common method during the 19th and early 20th centuries. The belts were generally tanned leather or cotton duck impregnated with rubber. Leather belts were fastened in loops with rawhide or wire lacing, lap joints and glue, or one of several types of steel fasteners. Cotton duck belts usually used metal fasteners or were melted together with heat. The leather belts were run with the hair side against the pulleys for best traction. The belts needed periodic cleaning and conditioning to keep them in good condition. Belts were often twisted 180 degrees per leg and reversed on the receiving pulley to cause the second shaft to rotate in the opposite direction.

Pulleys were constructed of wood, iron, steel or a combination thereof. Varying sizes of pulleys were used in conjunction to change the speed of rotation. For example a 40" pulley at 100 rpm would turn a 20" pulley at 200 rpm. Pulleys solidly attached to the shaft could be combined with adjacent pulleys that turned freely on the shaft (idlers). In this configuration the belt could be maneuvered onto the idler to stop power transmission or onto the solid pulley to convey the power. This arrangement was often used near machines to provide a means of shutting the machine off when not in use. Usually at the last belt feeding power to a machine, a pair of stepped pulleys could be used to give a variety of speed settings for the machine.

Occasionally gears were used between shafts to change speed rather than belts and different sized pulleys, but this seems to have been relatively uncommon.

Early Examples

Jedediah Strutt, North Mill at Belper in 1819, showing vertical shaft leading from the 18 feet (5.5 m) waterwheel, to horizontal drive shafts running the length of each floor on each floor

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In an early example, Jedediah Strutt's water-powered cotton mill, North Mill in Belper, built in 1776, all the power to operate the machinery came from a 18 feet (5.5 m) water wheel.

Preservation

A number of line shaft systems still exist.

Original systems

United Kingdom

• Stott Park Bobbin Mill, Cumbria, England – (???)
• Tees Cottage Pumping Station, near Darlington, County Durham, England – (complete original maintenance workshop in working order)
• Shelsley Watermill, Shelsley Walsh, Worcester, UK – (partially operable - grain mill)

United States

• Austin Organs. Hartford, CT
• East Broad Top Railroad and Coal Company. Rockhill Furnace, PA – (partially operable - machine shop, sheet metal shop, wood shop, blacksmiths shop, foundry)
• Empire Mine State Park machine Shop, Grass Valley, CA – (??? - machine tools)
• Hagley Museum, Wilmington, DE
• Hanford Mills Museum, East Meredith, NY – (???)
• Longleaf Lumber Company/Southern Forest Heritage Museum, Longleaf, LA – (partially operable - machine tools, sawmill)
• Sierra Railroad Shops/Railtown 1897 State Historic Park, Jamestown, CA – (operable - machine tools, blacksmith shop)
• Mingus Mill, Great Smokey Mountains National Park, SC – (partially operable - grain mill)
• Slater Mill Historic Site, Pawtucket, RI – (???)
• Thomas Edison National Historical Park, West Orange, NJ – (??? - Machine Tools)
• Cruiser Olympia, Philadelphia, PA – (operational machine shop)
• W J Doran Company, Waupaca, WI – (fully operational - machine tools)

Reconstructed or demonstration systems

United States

• Smithsonian Institution, Arts and Industries Building, Washington DC – (machine tools)
• White River Valley Antique Association, Enora, IN – (machine and woodworking tools)
• Denton Farmpark, Denton, NC – (machine tools)
• Cincinnati History Museum, Cincinnati, OH – (machine tools)
• Henry Ford Museum and Greenfield Village, Dearborn, MI – (machine tools)
• Molly Kathleen Mine, Clear Creek, CO – (sawmill)
• Boott Mills, Lowell, MA – (power cotton looms)
• Silver Dollar City, Branson, MO – (woodworking tools and bakery machinery)
• Tuckahoe Steam & Gas Association, Easton, MD – (machine tools)
• Virginia Historical Society, Richmond, VA

See also

• Lineshaft roller conveyor – uses a long shaft to drive a series of rollers

References

Notes

Bibliography

• Falconer, Keith (2001). "Derwent Valley Textile Mills". Industrial Archaeology Review. Leicester: Belper North Mill Trust: 99. ISSN 0309-0728. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Hills, Richard Leslie (1989), Power from Steam: A History of the Stationary Steam Engine, Cambridge University Press, p. 244, ISBN 052145834X, 9780521458344, retrieved January 2009 {{citation}}: Check |isbn= value: invalid character (help); Check date values in: |accessdate= (help); Invalid |ref=harv (help)CS1 maint: extra punctuation (link)
• Nasmith, Joseph (1895), Recent Cotton Mill Construction and Engineering, London: John Heywood, p. 284, ISBN 1-4021-4558-6, retrieved March 2009 {{citation}}: Check date values in: |accessdate= (help)

External links

Media related to Line shafts at Wikimedia Commons

• Line Shaft Pulleys and Belting – 1906 treatise on the engineering aspects of belt drives – Warning: webpage has background music (scroll to end to pause)