![Mill engine at full chat](https://upload.wikimedia.org/wikipedia/commons/2/2b/Mill_engine_at_full_chat._-_geograph.org.uk_-_682452.jpg)
A rope drive is a form of
belt drive, used for mechanical power transmission.
Rope drives use a number of circular section
rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similar ...
s, rather than a single
flat
Flat or flats may refer to:
Architecture
* Flat (housing), an apartment in the United Kingdom, Ireland, Australia and other Commonwealth countries
Arts and entertainment
* Flat (music), a symbol () which denotes a lower pitch
* Flat (soldier), ...
or
vee belt.
Multiple rope drive
The first multiple rope drive was a 9-rope drive of 200
bhp
BHP Group Limited (formerly known as BHP Billiton) is an Australian multinational mining, metals, natural gas petroleum public company that is headquartered in Melbourne, Victoria, Australia.
The Broken Hill Proprietary Company was founded ...
produced by
Combe Barbour for their Falls Foundry, Belfast, in 1863.
James Combe experimented first with circular ropes laid from leather strips, then from
manila hemp
Manila hemp, also known as abacá, is a type of buff-colored fiber obtained from ''Musa textilis'' (a relative of edible bananas), which is likewise called Manila hemp as well as abacá. It is mostly used for pulping for a range of uses, inclu ...
.
The idea of using rope drives had arisen from his earlier, 1856, experiments in using a rope drive together with an expanding
vee pulley, as part of a
Van Doorne or
Variomatic
Variomatic is the continuously variable transmission (CVT) of the Dutch car manufacturer DAF, originally developed by Hub van Doorne. It is a stepless, fully-automatic transmission, consisting of a V-shaped drive-belt, and two pulleys, each o ...
transmission.
Combe Barbour were makers of
textile machinery
Textile Manufacturing or Textile Engineering is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful goods ...
and differential speed gearing was often needed as part of the spinning process, where one shaft could be smoothly adjusted to run slightly faster or slower than another.
Usage
Rope drives were most widely used for power-transmission in mills and factories, where a single
mill engine would have a large rope drive to each floor, where
lineshaft
A line shaft is a power-driven rotating shaft for power transmission that was used extensively from the Industrial Revolution until the early 20th century. Prior to the widespread use of electric motors small enough to be connected directly to e ...
s across each floor distribute power to the individual machines. These multiple rope drives replaced the earlier technique of a vertical
wrought iron
Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it a wood-like "grain" ...
shaft with bevel gears at each floor. They remained in use for as long as mills were driven by central steam engines, rather than individual electric motors.
Some were used with early electric motors, where these were large single motors driving a whole floor of machinery. A 1907 installation at
Droylesden split the output of one motor between two floors with two new rope drives.
Rope drives were rarely used in the internal-combustion era, although some were used with
gas engines running on
producer gas. A Yorkshire mill converted to use a 1,000 hp
Allen Allen, Allen's or Allens may refer to:
Buildings
* Allen Arena, an indoor arena at Lipscomb University in Nashville, Tennessee
* Allen Center, a skyscraper complex in downtown Houston, Texas
* Allen Fieldhouse, an indoor sports arena on the Unive ...
diesel engine in 1938, and retained the rope drives.
Shaft drives had often used gearing from the engines to increase their speed, and thus their power transmission. This was avoided for rope drives, as the rope's maximum useful speed could be achieved from the engine's flywheel and flexibility of the ropes led to backlash in the gearing.
Power
Power transmitted was typically 50 bhp per rope, for ropes working at 5,000 feet / minute.
Groups of ropes could drive different floors and they also allowed individual ropes to be replaced separately, and without losing all power to a mill floor after a rope breakage.
US practice sometimes used a single rope, looped between floors and tensioned by an idler pulley, but this system was not used in the UK and each loop was tensioned between its two pulleys by one of them being movable. Rope drives were also cheaper than belts - around a quarter of the price.
Factory power distribution
The rope drives were placed in a large diagonal shaft at the side of the building, usually windowless and distinctively visible from outside the building.
Rope drives required a larger such shaft than comparable belt or shaft drives. As the open shaft represented a channel for transmitting fires, unlike the narrow holes of a shaft drive, it needed careful fireproofing from the loom floors.
It was sometimes arranged for large drives that the engine drove a set of horizontal ropes to a pulley on a
layshaft or 'second motion shaft' alongside the engine house, then diagonally up through the shaft.
References
{{Reflist, refs=
[{{Book-Hills-Power from Steam, pages=209–212 ]
[{{Cite web
, title=Combe Barbour
, website= Grace's Guide
, url=https://www.gracesguide.co.uk/Combe_Barbour
]
[{{Cite journal
, title=Notes on the Introduction and Development of Rope Driving
, date=7 August 1896
, journal= The Engineer
, pages=130–131
, url=https://www.gracesguide.co.uk/Special:MemberUsers?file=1/14/Er18960807.pdf
]
[{{Cite journal
, title=Visits to Works (Excursions) in the Belfast area
, journal= Proc. Inst. Mech. Eng.
, date=1876
, page=392
]
[{{Cite book
, title=The Textile Mill Engine
, volume=1
, first=George , last=Watkins
, year=1970
, isbn=0-7153-4983-X
, publisher=David & Charles
, ref={{harvid, Watkins, Vol 1, 1970
, page=12
]
[{{Cite book
, title=The Textile Mill Engine
, volume=2
, first=George , last=Watkins
, year=1971
, isbn=0-7153-5253-9
, publisher=David & Charles
, ref={{harvid, Watkins, Vol 2, 1971
, pages=102–105
]
*
Rope-Driving a treatise on the transmission of power by means of fibrous ropes''. Flather, John Joseph. 1895.
Mechanical power transmission