View allAll Photos Tagged headracing
Swan in the early morning light on the headrace canal of our power plant in my homeland. Actually just wanted to photograph the reflections - the swan was pure luck.
ALL RIGHT RESERVED
All material in my gallery MAY NOT be reproduced, copied, edited, published, transmitted or uploaded in any way without my permission.
Don't spam my photo thread! Comments with awards or photos will be removed!
Upstream end of the headrace for Cabe Mill, Eno River State Park.
Pentax K-1
SMC Pentax 1:3.5 35mm
Iridient Developer
A small tree on the levee of the headrace canal of our power plant in my homeland in front of rising thunderstorm clouds. Zero 2000, f 138, exposure time 45 sec., Ilford SFX + redfilter no. 29, processed with Ilford ID-11, solution 1:1, N-1, scanned with Nikon Supercoolscan 8000ED.
ALL RIGHT RESERVED
All material in my gallery MAY NOT be reproduced, copied, edited, published, transmitted or uploaded in any way without my permission.
Stand-alone maple tree with resting bench by the amper canal.
ALL RIGHT RESERVED
All material in my gallery MAY NOT be reproduced, copied, edited, published, transmitted or uploaded in any way without my permission.
Don't spam my photo thread! Comments with awards, photos or group logos will be removed!
The new headrace penstock snaking through the adaptive reuse project of an 1880s hydro-power tunnel.
The best I could do to save this image from flares and lens fog
nrhp # 13001166- The Potomac Mills was a mill complex located along the Potomac River roughly .5 miles (0.80 km) downriver of Shepherdstown. Built in 1826, the complex was originally used as a gristmill. In 1829, the mill began producing cement for the Chesapeake and Ohio Canal's construction. The factory continued to produce cement after the canal opened, and it shipped its product along the canal to other cities. Flooding and drought conditions in the 1880s led the mill to reduce its operations, and by 1901 the mill closed permanently.
The remaining buildings from the mill occupy an 18-acre (7.3 ha) site and are mostly in ruins. The buildings include the main mill building, several lime kilns, a headrace wall, and an office building. The stone foundation of the mill's dam, which extends across the river into Washington County, Maryland, is also still part of the site.[2] The mill site was added to the National Register of Historic Places on February 5, 2014.
from Wikipedia
The weir Glüder at the Wupper river downstream of Solingen-Burg. On the opposite bank is the intake for the headrace of the downstream hydropower plant and the fish migration facility.
Panoramic photo from 3 shots with the kit lens Olympus 12-50 mm and a ND 3.0 1000x neutral density filter.
Das Wupper-Wehr Glüder unterhalb von Solingen-Burg. Auf der gegenüberliegenden Seite liegt die Wasserfassung für das unterhalb liegende Wasserkraftwerk sowie die Fischaufstiegsanlage.
Panorama aus 3 Aufnahmen mit dem Kit-Objektiv Olympus 12-50 mm und einem ND 3.0 1000x Neutralgraufilter.
"This shift in *feeling* is an integral part of the tunnel and thus an important aspect of the integrity of the system."
1880s direct drive water power headrace, being reused for hydroelectric generation -- the newer penstock can be seen here on the floor of the old tunnel.
A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical shaft. Vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears; horizontal wheels usually directly drive their load.
A flowing stream was often dammed in order to maintain a steady supply of water for the mill; the dammed water would form a mill pond. A channel created for the water to follow while flowing to or from a water wheel is a mill race (also spelled millrace) or simply a "race", and is customarily divided into sections. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace. --from Wiki
Oil on canvas
127 x 127 cms
Last year's Glover Prize winner Robert O'Connor returned with an even stronger work than his "Somewhere on the midlands". A controversial "landscape" that featured a lamb roast on the pastures around Oatlands. To his credit, O'Connor admitted he was engaged in pranking the judges: francesvinall.wordpress.com/2020/03/07/i-was-trying-to-ta...
There is now quite a history of this in major Australian art and literary awards (judges beware, you are fair game). But to be fair to the Glover committee, Robert O'Connor was back again and deservedly selected in this year's finalists.
I personally love everything about this work. The allusions to Plato's famous cave analogy, the history of the Hydro Electric Commission (HEC), and the Poatina power station as it might appear abandoned in 50 years time. But of course, it is superb technical craftmanship.
As O'Connor himself says:
"Some see the land as something that only serves to be dug, cut, drilled, and exploited. It's okay though - the land will outlast us folk. She will heal and thrive, and the Poatina Headrace will resemble Claude Lorrain's 'Paysage de la Campagne' or Capriccio's 'Ruins with figures' or Claude Henri Watelet's 'Paysage' to the roaches, rats, and whatever else survives climate change."
Fine thoughts. I would just add that humans have survived far great levels of climate change in the past than we will ever go through in the near future. Remember the last Ice Age? Short historic memories our folk.
The archivist trying to describe this image provided an elaborate title "River, rocky bed, between wooded banks, weir seen from dumstream, mill wheel mill, outflow to left" I await an explanation for "Dumstream" and a virtual sticky bun for the best version!
The scene is wide and sylvan with an enormous mill building, probably a tidal river below the falls and a verdant river bank.
Where is/was it?
Photographers: Frederick Holland Mares, James Simonton
Contributor: John Fortune Lawrence
Collection: Stereo Pairs Photograph Collection
Date: between ca. 1860-1883
NLI Ref: STP_0735
You can also view this image, and many thousands of others, on the NLI’s catalogue at catalogue.nli.ie
The backwater as the Thames divides above the lock and weir at Goring on Thames in Oxfordshire. This was once the supply of water to the mill where it still rushes through the sluices to the wheel pit. Here, beside the boathouses lining the river bank, craft of all types are moored - now probably for the winter! In this view captured on a day in early October the lock keeper's cottage can be seen in the background.
A water wheel is a means of extracting power from the flow of water, that is hydropower.
A water wheel consists of a large wooden wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface.
A flowing stream was often dammed in order to maintain a steady supply of water for the mill; the dammed water would form a mill pond. A channel created for the water to follow while flowing to or from a water wheel is a mill race or simply a "race", and is customarily divided into sections. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace
Saint Marys Falls / Edison Sault hydropower plant (owned by Cloverland Electric Cooperative), Sault Ste. Marie, Michigan.
View of the power plant and the end of the Edison Sault Power Canal. The canal was excavated from September 1898 to June 1902. The canal is 2.24 miles (3.61 kilometers) long, 24 feet (7.3 meters) deep, 200-220 feet (60-67 meters) wide, and has a capacity of 30,000 cubic feet (850 cubic meters) of water per second.
The power plant was completed in 1902 in the Romanesque architectural style and built out of local red-brown sandstone, quarried from the construction of the power canal. It produces 26,000 kilowatts of power from 69 turbines.
The Hagen Open-air Museum (LWL-Freilichtmuseum Hagen – Westfälisches Landesmuseum für Handwerk und Technik; English: "LWL Open-air Museum Hagen – Westphalian State Museum for Craft and Technics") is a museum at Hagen in the southeastern Ruhr area, North Rhine-Westphalia, Germany. It was founded, together with the Detmold Open-air Museum, in 1960, and was first opened to the public in the early 1970s. The museum is run by the Landschaftsverband Westfalen-Lippe (LWL, regional authority for Westphalia and Lippe within North Rhine-Westphalia). It lies in the Hagen neighbourhood of Selbecke south of Eilpe in the Mäckingerbach valley.
The open-air museum brings a bit of skilled-trade history into the present, and it takes a hands-on approach. On its grounds stretching for about 42 ha, not only are urban and rural trades simply "displayed" along with their workshops and tools, but in more than twenty of the nearly sixty rebuilt workshops, they are still practised, and interested visitors can, sometimes by themselves, take part in the production.
As early as the 1920s, there were efforts by a group of engineers and historical preservationists to preserve technological monuments for posterity. The initiator, Wilhelm Claas, even suggested the Mäckingerbach valley as a good place for a museum to that end. The narrow valley was chosen, as wind, water and wood were the three most important location factors for industry in the 18th and 19th centuries.
In 1960, the Westphalian Open-Air Museum was founded, and thirteen years later, the gates opened to the public. Unlike most open-air museums, which show everyday life on the farm or in the country as it was in days gone by, the Hagen Open-Air Museum puts the history of these activities in Westphalia in the fore. From the late 18th century through the early years of the Industrial Revolution to the highly industrialized society emerging in the early 20th century, the visitor can experience the development of these trades and the industry in the region.
Crafts and trades demonstrated at the Westphalian Open-Air Museum include ropemaking, smithing, brewing, baking, tanning, printing, milling, papermaking, and much more. A favourite attraction is the triphammer workshop shown in the image above. Once the hammer is engaged, a craftsman goes to work noisily forging a scythe, passing it between the hammer and the anvil underneath in a process called peening.
The Hagen Westphalian Open-Air Museum is open from March or April until October.
A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical shaft. Vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears; horizontal wheels usually directly drive their load.
Water wheels were still in commercial use well into the 20th century, but they are no longer in common use. Prior uses of water wheels include milling flour in gristmills and grinding wood into pulp for papermaking, but other uses include hammering wrought iron, machining, ore crushing and pounding fiber for use in the manufacture of cloth.
Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race (also spelled millrace) or simply a "race", and is customarily divided into sections. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace.
John Smeaton's scientific investigation of the water wheel led to significant increases in efficiency in the mid to late 18th century and supplying much needed power for the Industrial Revolution.
Water wheels began being displaced by the smaller, less expensive and more efficient turbine developed by Benoît Fourneyron, beginning with his first model in 1827.[3] Turbines are capable of handling high heads, or elevations, that exceed the capability of practical-sized waterwheels.
The main difficulty of water wheels is their dependence on flowing water, which limits where they can be located. Modern hydroelectric dams can be viewed as the descendants of the water wheel, as they too take advantage of the movement of water downhill.
From the Power(full) family in Waterford to the Shannon Scheme’s great ending at Ardnacrusha, Co. Clare. We have visited here before, and this O’Dea image shows much of the superstructure of the power station.
+++ UPDATE +++
Thanks to Suck Diesel for the gem that Ardnacrusha was (briefly) the biggest hydro-electric station in the world, until that pesky Hoover Dam opened in 1930, and knocked Shannon off the top spot.
Photographer: James P. O'Dea
Collection: O’Dea Photograph Collection
Date: September 1951
NLI Ref.: ODEA 5/34
You can also view this image, and many thousands of others, on the NLI’s catalogue at catalogue.nli.ie
A fine Royal Plate from the Lawrence Collection for this Bank Holiday Monday, with the bridge and flour mills in Castletownroche, Co. Cork. It looks like quite a significant development with a fine headrace leading to the mill and a good natural fall to the right. Is this to join the no longer standing coterie, or by some miracle does it still survive?
Photographer: Robert French
Collection: Lawrence Photograph Collection
Date: Circa 1865-1914
NLI Ref: L_ROY_08596
You can also view this image, and many thousands of others, on the NLI’s catalogue at catalogue.nli.ie
A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical shaft. Vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears; horizontal wheels usually directly drive their load.
Water wheels were still in commercial use well into the 20th century, but they are no longer in common use. Prior uses of water wheels include milling flour in gristmills and grinding wood into pulp for papermaking, but other uses include hammering wrought iron, machining, ore crushing and pounding fiber for use in the manufacture of cloth.
Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race (also spelled millrace) or simply a "race", and is customarily divided into sections. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace
An old water wheel overgrown and seemingly lost at the rere of a terrace in the town of Moville, Co. Donegal was captured by Mr. French on a cabinet sized slide. It looks like the head of water is escaping off to the side but is that deliberate or due to neglect and decay? I suspect that this is one that is no longer standing!
Photographer: Robert French
Collection: Lawrence Photograph Collection
Date: Circa 1865 - 1914
NLI Ref: L_CAB_00618
You can also view this image, and many thousands of others, on the NLI’s catalogue at catalogue.nli.ie
nrhp # 13001166- The Potomac Mills was a mill complex located along the Potomac River roughly .5 miles (0.80 km) downriver of Shepherdstown. Built in 1826, the complex was originally used as a gristmill. In 1829, the mill began producing cement for the Chesapeake and Ohio Canal's construction. The factory continued to produce cement after the canal opened, and it shipped its product along the canal to other cities. Flooding and drought conditions in the 1880s led the mill to reduce its operations, and by 1901 the mill closed permanently.
The remaining buildings from the mill occupy an 18-acre (7.3 ha) site and are mostly in ruins. The buildings include the main mill building, several lime kilns, a headrace wall, and an office building. The stone foundation of the mill's dam, which extends across the river into Washington County, Maryland, is also still part of the site.[2] The mill site was added to the National Register of Historic Places on February 5, 2014.
from Wikipedia
A complicated system of buried canals, headraces, and tailrace tunnels honeycomb both sides of the river and powered the 19th century milling districts.
The system relied on three parts. “Headrace” tunnels diverted water from the river above the falls to the various mills. This water then gushed into a series of drop shafts.
This is Compton's Mill in Elk Lick Township, Somerset County, Pennsylvania. The mill was built in 1872 and operated by Samuel Compton. The headrace for the mill comes from the Tub Mill Run. It ran as an active flour mill until 1941.
Nikon D850 with a Nikkor 35mm F2.8 PC Shift Lens @ F11, ISO 64, 1/400th shutter speed. Oben tripod with Benro 3-way geared head.
The funicular in the headrace tunnel from Gletsch. This tunnel has a length of 2200 m and ends in Gletsch at 1750 m ü.M./5741 ft ASL. The diameter is 3.90 m and the slope about 13%. From this tunnel the distribution tunnels branch off to the turbine room. Switzerland, Sep 3, 2016. (20/20)
Sunset between the Brookfield natural gas-fired cogeneration power plant and the idle number six blast furnace of Essar Steel, Sault Ste. Marie steel plant. A three stop soft graduated neutral density filter (Singh-Ray) was used to balance the exposure.
nrhp # 13001166- The Potomac Mills was a mill complex located along the Potomac River roughly .5 miles (0.80 km) downriver of Shepherdstown. Built in 1826, the complex was originally used as a gristmill. In 1829, the mill began producing cement for the Chesapeake and Ohio Canal's construction. The factory continued to produce cement after the canal opened, and it shipped its product along the canal to other cities. Flooding and drought conditions in the 1880s led the mill to reduce its operations, and by 1901 the mill closed permanently.
The remaining buildings from the mill occupy an 18-acre (7.3 ha) site and are mostly in ruins. The buildings include the main mill building, several lime kilns, a headrace wall, and an office building. The stone foundation of the mill's dam, which extends across the river into Washington County, Maryland, is also still part of the site.[2] The mill site was added to the National Register of Historic Places on February 5, 2014.
from Wikipedia
A switch of the funicular in the access tunnel to the headrace tunnel. Switzerland, Sep 3, 2016. (18/20)
Practice. #WinFromWithin #Gatorade
#progrt #nwcup #portangeles #pnw #uci #usacycling #headracing #athlete #mtb #dh #bike #dh #cycling #sport #racing
85 Likes on Instagram
5 Comments on Instagram:
camm_gracce: thx I didn't know that was you in the picture!! #greatshot
alex__auger: Lies there were way more people waiting for the shuttle
neverridealone: ✌✌✌
mafonso: nice
gatoradeecuador: Amazing!
The access tunnel to the headrace tunnel. From here there is a funicular to Gletsch. Switzerland, Sep 3, 2016. (17/20)
The turbine room for two Pelton turbines. The lighted tunnels on the left are the distribution tunnels from the headrace tunnel. This cavern is located just under the old Furka-Oberalp railway mountain line. Switzerland, Sep 3, 2016. (11/20)
Water flows from the dam built across Kortright Creek through the Head Race into the Mill Pond to provide power for the Saw and Grist Mills. Goldenrod (Solidog canadensis) and wild purple Daisies (Osteospermum) grow alongside the race.
View from the Saul Canal National Historic Site, looking across the Brookfield Power head race (formerly Great Lakes Power), towards Essar Steel Algoma's steel plant (formerly Algoma Steel)- - -administration offices, various mills, and the Basic Oxygen Steel Plant. Thirty second exposure with a B+W ten stop solid neutral density filter (ND110) @ -10°C.
Caroline and Forbes St
1-16-2012
fredericksburg.patch.com/articles/embrey-power-station-a-...
The station was built of reinforced concrete and steel and was “powered by water from an underground headrace extending from the water power company canal. Six electrically operated gates at the Embrey Dam controlled by switches at the power plant regulated the flow of water into the canal.” Water was stored at the power plant in storage silos and forced into turbines “which turned like dynamos” to produce 3,000 kilowatts.
In 1923, the power station had 60 employees and provided electricity for 1,011 customers, according to the brochure. Three years later, the customer base had jumped to 2,000. That same year, 1926, Virginia Electric Power Company bought Gould’s power plants and extended its power lines between Fredericksburg and Richmond.
Hydroelectricity held sway in the Fredericksburg area until the 1960s, when VEPCO shut down the power stations because of low Rappahannock River water levels.
The old Embrey Power Plant now is a shell — a broken shell — of its former self. In the plant’s heyday, the area around it served as the city’s industrial hub, with mills dotting the Caroline Street landscape along the Rappahannock River.
Next to Old Mill Park and sandwiched between residential areas, the Embrey Power Plant stands isolated near a handful of other sites in the Historic Old Mill District. Time or fire has reduced all but one of the other historic structures to portions, foundations or wheel pits. The only other structure still standing is the vertical, stained concrete “ruins” of Myers & Brulle’s Germania Flour Mill.
The future of the Embrey plant is cloudy at best. C & G Investment Properties LLC, headed by former Spotsylvania supervisor and businessman Hugh Cosner, owns the property. There had been talk about turning the place into a waterfront restaurant, but that idea seems to have drifted away.
So for the near, and perhaps distant, future it appears the Embrey Power Station will remain a hollowed-out husk. Instead of diners, its only regular visitors will be vagrants with beer cans and spray paint and the flock of geese that meanders up and down the Rappahannock, stopping to enjoy the field next to the station and drift in the secluded water running beneath the vacant building.
A watermill or water mill is a mill that utilizes hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may be comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills.
One major way to classify watermills is by wheel orientation (vertical or horizontal), one powered by a vertical waterwheel through a gearing mechanism, and the other equipped with a horizontal waterwheel without such a mechanism. The former type can be further divided, depending on where the water hits the wheel paddles, into undershot, overshot, breastshot and pitchback (backshot or reverse shot) waterwheel mills. Another way to classify water mills is by an essential trait about their location: tide mills use the movement of the tide; ship mills are water mills onboard (and constituting) a ship.
CLASSICAL ANTIQUITY
Hellenistic engineers invented the two main components of watermills, the waterwheel and toothed gearing, and were, along with the Romans, the first to operate undershot, overshot and breastshot waterwheel mills.
The earliest evidence of a water-driven wheel is probably the Perachora wheel (3rd century BC), in Greece. The earliest written reference is in the technical treatises Pneumatica and Parasceuastica of the Greek engineer Philo of Byzantium (c. 280−220 BC). The British historian of technology M.J.T. Lewis has shown that those portions of Philo of Byzantium's mechanical treatise which describe water wheels and which have been previously regarded as later Arabic interpolations, actually date back to the Greek 3rd-century BC original. The sakia gear is, already fully developed, for the first time attested in a 2nd-century BC Hellenistic wall painting in Ptolemaic Egypt.
Lewis assigns the date of the invention of the horizontal-wheeled mill to the Greek colony of Byzantium in the first half of the 3rd century BC, and that of the vertical-wheeled mill to Ptolemaic Alexandria around 240 BC.
The Greek geographer Strabon reports in his Geography a water-powered grain-mill to have existed near the palace of king Mithradates VI Eupator at Cabira, Asia Minor, before 71 BC.
The Roman engineer Vitruvius has the first technical description of a watermill, dated to 40/10 BC; the device is fitted with an undershot wheel and power is transmitted via a gearing mechanism. He also seems to indicate the existence of water-powered kneading machines.
The Greek epigrammatist Antipater of Thessalonica tells of an advanced overshot wheel mill around 20 BC/10 AD. He praised for its use in grinding grain and the reduction of human labour:
Hold back your hand from the mill, you grinding girls; even if the cockcrow heralds the dawn, sleep on. For Demeter has imposed the labours of your hands on the nymphs, who leaping down upon the topmost part of the wheel, rotate its axle; with encircling cogs, it turns the hollow weight of the Nisyrian millstones. If we learn to feast toil-free on the fruits of the earth, we taste again the golden age.
The Roman encyclopedist Pliny mentions in his Naturalis Historia of around 70 AD water-powered trip hammers operating in the greater part of Italy. There is evidence of a fulling mill in 73/4 AD in Antioch, Roman Syria.
It is likely that a water-powered stamp mill was used at Dolaucothi to crush gold-bearing quartz, with a possible date of the late 1st century to the early 2nd century. The stamps were operated as a batch of four working against a large conglomerate block, now known as Carreg Pumpsaint. Similar anvil stones have been found at other Roman mines across Europe, especially in Spain and Portugal.
The 1st-century AD multiple mill complex of Barbegal in southern France has been described as "the greatest known concentration of mechanical power in the ancient world". It featured 16 overshot waterwheels to power an equal number of flour mills. The capacity of the mills has been estimated at 4.5 tons of flour per day, sufficient to supply enough bread for the 12,500 inhabitants occupying the town of Arelate at that time. A similar mill complex existed on the Janiculum hill, whose supply of flour for Rome's population was judged by emperor Aurelian important enough to be included in the Aurelian walls in the late 3rd century.
A breastshot wheel mill dating to the late 2nd century AD was excavated at Les Martres-de-Veyre, France.
The 3rd-century AD Hierapolis water-powered stone sawmill is the earliest known machine to incorporate a crank and connecting rod mechanism. Further sawmills, also powered by crank and connecting rod mechanisms, are archaeologically attested for the 6th-century water-powered stone sawmills at Gerasa and Ephesus. Literary references to water-powered marble saws in what is now Germany can be found in Ausonius 4th-century poem Mosella. They also seem to be indicated about the same time by the Christian saint Gregory of Nyssa from Anatolia, demonstrating a diversified use of water-power in many parts of the Roman Empire.
The earliest turbine mill was found in Chemtou and Testour, Roman North Africa, dating to the late 3rd or early 4th century AD. A possible water-powered furnace has been identified at Marseille, France.
Mills were commonly used for grinding grain into flour (attested by Pliny the Elder), but industrial uses as fulling and sawing marble were also applied.
The Romans used both fixed and floating water wheels and introduced water power to other provinces of the Roman Empire. So-called 'Greek Mills' used water wheels with a horizontal wheel (and vertical shaft). A "Roman Mill" features a vertical wheel (on a horizontal shaft). Greek style mills are the older and simpler of the two designs, but only operate well with high water velocities and with small diameter millstones. Roman style mills are more complicated as they require gears to transmit the power from a shaft with a horizontal axis to one with a vertical axis.
Although to date only a few dozen Roman mills are archaeologically traced, the widespread use of aqueducts in the period suggests that many remain to be discovered. Recent excavations in Roman London, for example, have uncovered what appears to be a tide mill together with a possible sequence of mills worked by an aqueduct running along the side of the River Fleet.
In 537 AD, ship mills were ingeniously used by the East Roman general Belisarius, when the besieging Goths cut off the water supply for those mills. These floating mills had a wheel that was attached to a boat moored in a fast flowing river.
MIDDLE AGES
At the time of the compilation of the Domesday Book (1086), there were 5,624 watermills in England alone, only 2% of which have not been located by modern archeological surveys. Later research estimates a less conservative number of 6,082, and it has been pointed out that this should be considered a minimum as the northern reaches of England were never properly recorded. In 1300, this number had risen to between 10,000 and 15,000. By the early 7th century, watermills were well established in Ireland, and began to spread from the former territory of the empire into the non-romanized parts of Germany a century later. Ship mills and tide mill were introduced in the 6th century.
TIDE MILLS
In recent years, a number of new archaeological finds has consecutively pushed back the date of the earliest tide mills, all of which were discovered on the Irish coast: A 6th-century vertical-wheeled tide mill was located at Killoteran near Waterford. A twin flume horizontal-wheeled tide mill dating to c. 630 was excavated on Little Island. Alongside it, another tide mill was found which was powered by a vertical undershot wheel. The Nendrum Monastery mill from 787 was situated on an island in Strangford Lough in Northern Ireland. Its millstones are 830mm in diameter and the horizontal wheel is estimated to have developed 7–8 hp at its peak. Remains of an earlier mill dated at 619 were also found at the site.
SURVEY OF INDUSTRIAL MILLS
In a 2005 survey the scholar Adam Lucas identified the following first appearances of various industrial mill types in Western Europe. Noticeable is the preeminent role of France in the introduction of new innovative uses of waterpower. However, he has drawn attention to the dearth of studies of the subject in several other countries.
ANCIENT CHINA
The waterwheel was found in China from 30 AD onwards, when it was used to power trip hammers, the bellows in smelting iron, and in one case, to mechanically rotate an armillary sphere for astronomical observation (see Zhang Heng). Although Joseph Needham speculates that the water-powered millstone could have existed in Han China by the 1st century AD, there is no sufficient literary evidence for it until the 5th century. In 488 AD, the mathematician and engineer Zu Chongzhi had a watermill erected which was inspected by Emperor Wu of Southern Qi (r. 482–493 AD). The engineer Yang Su of the Sui Dynasty (581–618 AD) was said to operate hundreds of them by the beginning of the 6th century. A source written in 612 AD mentions Buddhist monks arguing over the revenues gained from watermills. The Tang Dynasty (618–907 AD) 'Ordinances of the Department of Waterways' written in 737 AD stated that watermills should not interrupt riverine transport and in some cases were restricted to use in certain seasons of the year. From other Tang-era sources of the 8th century, it is known that these ordinances were taken very seriously, as the government demolished many watermills owned by great families, merchants, and Buddhist abbeys that failed to acknowledge ordinances or meet government regulations. A eunuch serving Emperor Xuanzong of Tang (r. 712–756 AD) owned a watermill by 748 AD which employed five waterwheels that ground 300 bushels of wheat a day. By 610 or 670 AD, the watermill was introduced to Japan via Korean Peninsula. It also became known in Tibet by at least 641 AD.
ANCIENT INDIA
According to Greek historical tradition, India received water-mills from the Roman Empire in the early 4th century AD when a certain Metrodoros introduced "water-mills and baths, unknown among them [the Brahmans] till then".
ISLAMIC WORLD
Muslim engineers adopted the Greek watermill technology from the Byzantine Empire, where it had been applied for centuries in those provinces conquered by the Muslims, including modern-day Syria, Jordan, Israel, Algeria, Tunisia, Morocco, and Spain (see List of ancient watermills).
The industrial uses of watermills in the Islamic world date back to the 7th century, while horizontal-wheeled and vertical-wheeled watermills were both in widespread use by the 9th century. A variety of industrial watermills were used in the Islamic world, including gristmills, hullers, sawmills, shipmills, stamp mills, steel mills, sugar mills, and tide mills. By the 11th century, every province throughout the Islamic world had these industrial watermills in operation, from al-Andalus and North Africa to the Middle East and Central Asia. Muslim and Middle Eastern Christian engineers also used crankshafts and water turbines, gears in watermills and water-raising machines, and dams as a source of water, used to provide additional power to watermills and water-raising machines. Fulling mills, and steel mills may have spread from Al-Andalus to Christian Spain in the 12th century. Industrial watermills were also employed in large factory complexes built in al-Andalus between the 11th and 13th centuries.
The engineers of the Islamic world used several solutions to achieve the maximum output from a watermill. One solution was to mount them to piers of bridges to take advantage of the increased flow. Another solution was the shipmill, a type of watermill powered by water wheels mounted on the sides of ships moored in midstream. This technique was employed along the Tigris and Euphrates rivers in 10th-century Iraq, where large shipmills made of teak and iron could produce 10 tons of flour from corn every day for the granary in Baghdad.
PERSIA
More than 300 watermills were at work in Iran till 1960. Now only a few are still working. One of the famous ones is the water mill of Askzar and the water mill of the Yazd city, still producing flour.
OPERATION
Typically, water is diverted from a river or impoundment or mill pond to a turbine or water wheel, along a channel or pipe (variously known as a flume, head race, mill race, leat, leet, lade (Scots) or penstock). The force of the water's movement drives the blades of a wheel or turbine, which in turn rotates an axle that drives the mill's other machinery. Water leaving the wheel or turbine is drained through a tail race, but this channel may also be the head race of yet another wheel, turbine or mill. The passage of water is controlled by sluice gates that allow maintenance and some measure of flood control; large mill complexes may have dozens of sluices controlling complicated interconnected races that feed multiple buildings and industrial processes.
Watermills can be divided into two kinds, one with a horizontal water wheel on a vertical axle, and the other with a vertical wheel on a horizontal axle. The oldest of these were horizontal mills in which the force of the water, striking a simple paddle wheel set horizontally in line with the flow turned a runner stone balanced on the rynd which is atop a shaft leading directly up from the wheel. The bedstone does not turn. The problem with this type of mill arose from the lack of gearing; the speed of the water directly set the maximum speed of the runner stone which, in turn, set the rate of milling.
Most watermills in Britain and the United States of America had a vertical waterwheel, one of four kinds: undershot, breast-shot, overshot and pitchback wheels. This vertical produced rotary motion around a horizontal axis, which could be used (with cams) to lift hammers in a forge, fulling stocks in a fulling mill and so on.
MILLING CORN
However, in corn mills rotation about a vertical axis was required to drive its stones. The horizontal rotation was converted into the vertical rotation by means of gearing, which also enabled the runner stones to turn faster than the waterwheel. The usual arrangement in British and American corn mills has been for the waterwheel to turn a horizontal shaft on which is also mounted a large pit wheel. This meshes with the wallower, mounted on a vertical shaft, which turns the (larger) great spur wheel (mounted on the same shaft). This large face wheel, set with pegs, in turn, turned a smaller wheel (such as a lantern gear) known as a stone nut, which was attached to the shaft that drove the runner stone. The number of runner stones that could be turned depended directly upon the supply of water available. As waterwheel technology improved mills became more efficient, and by the 19th century, it was common for the great spur wheel to drive several stone nuts, so that a single water wheel could drive as many as four stones. Each step in the process increased the gear ratio which increased the maximum speed of the runner stone. Adjusting the sluice gate and thus the flow of the water past the main wheel allowed the miller to compensate for seasonal variations in the water supply. Finer speed adjustment was made during the milling process by tentering, that is, adjusting the gap between the stones according to the water flow, the type of grain being milled, and the grade of flour required.
In many mills (including the earliest) the great spur wheel turned only one stone, but there might be several mills under one roof. The earliest illustration of a single waterwheel driving more than one set of stones was drawn by Henry Beighton in 1723 and published in 1744 by J. T. Desaguliers.
OVERSHOT AND PITCHBACK MILLS
The overshot wheel was a later innovation in waterwheels and was around two and a half times more efficient than the undershot. The undershot wheel, in which the main water wheel is simply set into the flow of the mill race, suffers from an inherent inefficiency stemming from the fact that the wheel itself, entering the water behind the main thrust of the flow driving the wheel, followed by the lift of the wheel out of the water ahead of the main thrust, actually impedes its own operation. The overshot wheel solves this problem by bringing the water flow to the top of the wheel. The water fills buckets built into the wheel, rather than the simple paddle wheel design of undershot wheels. As the buckets fill, the weight of the water starts to turn the wheel. The water spills out of the bucket on the down side into a spillway leading back to river. Since the wheel itself is set above the spillway, the water never impedes the speed of the wheel. The impulse of the water on the wheel is also harnessed in addition to the weight of the water once in the buckets. Overshot wheels require the construction of a dam on the river above the mill and a more elaborate millpond, sluice gate, mill race and spillway or tailrace.
An inherent problem in the overshot mill is that it reverses the rotation of the wheel. If a miller wishes to convert a breastshot mill to an overshot wheel all the machinery in the mill has to be rebuilt to take account of the change in rotation. An alternative solution was the pitchback or backshot wheel. A launder was placed at the end of the flume on the headrace, this turned the direction of the water without much loss of energy, and the direction of rotation was maintained. Daniels Mill near Bewdley, Worcestershire is an example of a flour mill that originally used a breastshot wheel, but was converted to use a pitchback wheel. Today it operates as a breastshot mi
Larger water wheels (usually overshot steel wheels) transmit the power from a toothed annular ring that is mounted near the outer edge of the wheel. This drives the machinery using a spur gear mounted on a shaft rather than taking power from the central axle. However, the basic mode of operation remains the same; gravity drives machinery through the motion of flowing water.
Toward the end of the 19th century, the invention of the Pelton wheel encouraged some mill owners to replace over- and undershot wheels with Pelton wheel turbines driven through penstocks.
TIDE MILLS
A different type of watermill is the tide mill. This mill might be of any kind, undershot, overshot or horizontal but it does not employ a river for its power source. Instead a mole or causeway is built across the mouth of a small bay. At low tide, gates in the mole are opened allowing the bay to fill with the incoming tide. At high tide the gates are closed, trapping the water inside. At a certain point a sluice gate in the mole can be opened allowing the draining water to drive a mill wheel or wheels. This is particularly effective in places where the tidal differential is very great, such as the Bay of Fundy in Canada where the tides can rise fifty feet, or the now derelict village of Tide Mills in the United Kingdom. A working example can be seen at Eling Tide Mill.
Run of the river schemes do not divert water at all and usually involve undershot wheels the mills are mostly on the banks of sizeable rivers or fast flowing streams. Other watermills were set beneath large bridges where the flow of water between the stanchions was faster. At one point London bridge had so many water wheels beneath it that bargemen complained that passage through the bridge was impaired.
CURRENT STATUS
By the early 20th century, availability of cheap electrical energy made the watermill obsolete in developed countries although some smaller rural mills continued to operate commercially later throughout the century. A few historic mills such as the Newlin Mill and Yates Mill in the US and The Darley Mill Centre in the UK still operate for demonstration purposes. Small-scale commercial production is carried out in the UK at Daniels Mill, Little Salkeld Mill and Redbournbury Mill.
Some old mills are being upgraded with modern hydropower technology, such as those worked on by the South Somerset Hydropower Group in the UK.
In some developing countries, watermills are still widely used for processing grain. For example, there are thought to be 25,000 operating in Nepal, and 200,000 in India. Many of these are still of the traditional style, but some have been upgraded by replacing wooden parts with better-designed metal ones to improve the efficiency. For example, the Centre for Rural Technology in Nepal upgraded 2,400 mills between 2003 and 2007.
WIKIPEDIA
Number Seven blast furnace and mills, Essar Steel Algoma, Sault Ste. Marie, Ontario, as seen from the Sault Canal. 30 second exposure with a polarizer and 10 stop neutral density filter- - -B+W ND110.
A complicated system of buried canals, headraces, and tailrace tunnels honeycomb both sides of the river and powered the 19th century milling districts.
The system relied on three parts. “Headrace” tunnels diverted water from the river above the falls to the various mills. This water then gushed into a series of drop shafts.
Number six blast furnace on a cold January morning (-20°C). A two stop graduated neural density filter, hard (Singh Ray), was used to balance the exposure.
nrhp # 13001166- The Potomac Mills was a mill complex located along the Potomac River roughly .5 miles (0.80 km) downriver of Shepherdstown. Built in 1826, the complex was originally used as a gristmill. In 1829, the mill began producing cement for the Chesapeake and Ohio Canal's construction. The factory continued to produce cement after the canal opened, and it shipped its product along the canal to other cities. Flooding and drought conditions in the 1880s led the mill to reduce its operations, and by 1901 the mill closed permanently.
The remaining buildings from the mill occupy an 18-acre (7.3 ha) site and are mostly in ruins. The buildings include the main mill building, several lime kilns, a headrace wall, and an office building. The stone foundation of the mill's dam, which extends across the river into Washington County, Maryland, is also still part of the site.[2] The mill site was added to the National Register of Historic Places on February 5, 2014.
from Wikipedia
A watermill or water mill is a mill that utilizes hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may be comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills.
One major way to classify watermills is by wheel orientation (vertical or horizontal), one powered by a vertical waterwheel through a gearing mechanism, and the other equipped with a horizontal waterwheel without such a mechanism. The former type can be further divided, depending on where the water hits the wheel paddles, into undershot, overshot, breastshot and pitchback (backshot or reverse shot) waterwheel mills. Another way to classify water mills is by an essential trait about their location: tide mills use the movement of the tide; ship mills are water mills onboard (and constituting) a ship.
CLASSICAL ANTIQUITY
Hellenistic engineers invented the two main components of watermills, the waterwheel and toothed gearing, and were, along with the Romans, the first to operate undershot, overshot and breastshot waterwheel mills.
The earliest evidence of a water-driven wheel is probably the Perachora wheel (3rd century BC), in Greece. The earliest written reference is in the technical treatises Pneumatica and Parasceuastica of the Greek engineer Philo of Byzantium (c. 280−220 BC). The British historian of technology M.J.T. Lewis has shown that those portions of Philo of Byzantium's mechanical treatise which describe water wheels and which have been previously regarded as later Arabic interpolations, actually date back to the Greek 3rd-century BC original. The sakia gear is, already fully developed, for the first time attested in a 2nd-century BC Hellenistic wall painting in Ptolemaic Egypt.
Lewis assigns the date of the invention of the horizontal-wheeled mill to the Greek colony of Byzantium in the first half of the 3rd century BC, and that of the vertical-wheeled mill to Ptolemaic Alexandria around 240 BC.
The Greek geographer Strabon reports in his Geography a water-powered grain-mill to have existed near the palace of king Mithradates VI Eupator at Cabira, Asia Minor, before 71 BC.
The Roman engineer Vitruvius has the first technical description of a watermill, dated to 40/10 BC; the device is fitted with an undershot wheel and power is transmitted via a gearing mechanism. He also seems to indicate the existence of water-powered kneading machines.
The Greek epigrammatist Antipater of Thessalonica tells of an advanced overshot wheel mill around 20 BC/10 AD. He praised for its use in grinding grain and the reduction of human labour:
Hold back your hand from the mill, you grinding girls; even if the cockcrow heralds the dawn, sleep on. For Demeter has imposed the labours of your hands on the nymphs, who leaping down upon the topmost part of the wheel, rotate its axle; with encircling cogs, it turns the hollow weight of the Nisyrian millstones. If we learn to feast toil-free on the fruits of the earth, we taste again the golden age.
The Roman encyclopedist Pliny mentions in his Naturalis Historia of around 70 AD water-powered trip hammers operating in the greater part of Italy. There is evidence of a fulling mill in 73/4 AD in Antioch, Roman Syria.
It is likely that a water-powered stamp mill was used at Dolaucothi to crush gold-bearing quartz, with a possible date of the late 1st century to the early 2nd century. The stamps were operated as a batch of four working against a large conglomerate block, now known as Carreg Pumpsaint. Similar anvil stones have been found at other Roman mines across Europe, especially in Spain and Portugal.
The 1st-century AD multiple mill complex of Barbegal in southern France has been described as "the greatest known concentration of mechanical power in the ancient world". It featured 16 overshot waterwheels to power an equal number of flour mills. The capacity of the mills has been estimated at 4.5 tons of flour per day, sufficient to supply enough bread for the 12,500 inhabitants occupying the town of Arelate at that time. A similar mill complex existed on the Janiculum hill, whose supply of flour for Rome's population was judged by emperor Aurelian important enough to be included in the Aurelian walls in the late 3rd century.
A breastshot wheel mill dating to the late 2nd century AD was excavated at Les Martres-de-Veyre, France.
The 3rd-century AD Hierapolis water-powered stone sawmill is the earliest known machine to incorporate a crank and connecting rod mechanism. Further sawmills, also powered by crank and connecting rod mechanisms, are archaeologically attested for the 6th-century water-powered stone sawmills at Gerasa and Ephesus. Literary references to water-powered marble saws in what is now Germany can be found in Ausonius 4th-century poem Mosella. They also seem to be indicated about the same time by the Christian saint Gregory of Nyssa from Anatolia, demonstrating a diversified use of water-power in many parts of the Roman Empire.
The earliest turbine mill was found in Chemtou and Testour, Roman North Africa, dating to the late 3rd or early 4th century AD. A possible water-powered furnace has been identified at Marseille, France.
Mills were commonly used for grinding grain into flour (attested by Pliny the Elder), but industrial uses as fulling and sawing marble were also applied.
The Romans used both fixed and floating water wheels and introduced water power to other provinces of the Roman Empire. So-called 'Greek Mills' used water wheels with a horizontal wheel (and vertical shaft). A "Roman Mill" features a vertical wheel (on a horizontal shaft). Greek style mills are the older and simpler of the two designs, but only operate well with high water velocities and with small diameter millstones. Roman style mills are more complicated as they require gears to transmit the power from a shaft with a horizontal axis to one with a vertical axis.
Although to date only a few dozen Roman mills are archaeologically traced, the widespread use of aqueducts in the period suggests that many remain to be discovered. Recent excavations in Roman London, for example, have uncovered what appears to be a tide mill together with a possible sequence of mills worked by an aqueduct running along the side of the River Fleet.
In 537 AD, ship mills were ingeniously used by the East Roman general Belisarius, when the besieging Goths cut off the water supply for those mills. These floating mills had a wheel that was attached to a boat moored in a fast flowing river.
MIDDLE AGES
At the time of the compilation of the Domesday Book (1086), there were 5,624 watermills in England alone, only 2% of which have not been located by modern archeological surveys. Later research estimates a less conservative number of 6,082, and it has been pointed out that this should be considered a minimum as the northern reaches of England were never properly recorded. In 1300, this number had risen to between 10,000 and 15,000. By the early 7th century, watermills were well established in Ireland, and began to spread from the former territory of the empire into the non-romanized parts of Germany a century later. Ship mills and tide mill were introduced in the 6th century.
TIDE MILLS
In recent years, a number of new archaeological finds has consecutively pushed back the date of the earliest tide mills, all of which were discovered on the Irish coast: A 6th-century vertical-wheeled tide mill was located at Killoteran near Waterford. A twin flume horizontal-wheeled tide mill dating to c. 630 was excavated on Little Island. Alongside it, another tide mill was found which was powered by a vertical undershot wheel. The Nendrum Monastery mill from 787 was situated on an island in Strangford Lough in Northern Ireland. Its millstones are 830mm in diameter and the horizontal wheel is estimated to have developed 7–8 hp at its peak. Remains of an earlier mill dated at 619 were also found at the site.
SURVEY OF INDUSTRIAL MILLS
In a 2005 survey the scholar Adam Lucas identified the following first appearances of various industrial mill types in Western Europe. Noticeable is the preeminent role of France in the introduction of new innovative uses of waterpower. However, he has drawn attention to the dearth of studies of the subject in several other countries.
ANCIENT CHINA
The waterwheel was found in China from 30 AD onwards, when it was used to power trip hammers, the bellows in smelting iron, and in one case, to mechanically rotate an armillary sphere for astronomical observation (see Zhang Heng). Although Joseph Needham speculates that the water-powered millstone could have existed in Han China by the 1st century AD, there is no sufficient literary evidence for it until the 5th century. In 488 AD, the mathematician and engineer Zu Chongzhi had a watermill erected which was inspected by Emperor Wu of Southern Qi (r. 482–493 AD). The engineer Yang Su of the Sui Dynasty (581–618 AD) was said to operate hundreds of them by the beginning of the 6th century. A source written in 612 AD mentions Buddhist monks arguing over the revenues gained from watermills. The Tang Dynasty (618–907 AD) 'Ordinances of the Department of Waterways' written in 737 AD stated that watermills should not interrupt riverine transport and in some cases were restricted to use in certain seasons of the year. From other Tang-era sources of the 8th century, it is known that these ordinances were taken very seriously, as the government demolished many watermills owned by great families, merchants, and Buddhist abbeys that failed to acknowledge ordinances or meet government regulations. A eunuch serving Emperor Xuanzong of Tang (r. 712–756 AD) owned a watermill by 748 AD which employed five waterwheels that ground 300 bushels of wheat a day. By 610 or 670 AD, the watermill was introduced to Japan via Korean Peninsula. It also became known in Tibet by at least 641 AD.
ANCIENT INDIA
According to Greek historical tradition, India received water-mills from the Roman Empire in the early 4th century AD when a certain Metrodoros introduced "water-mills and baths, unknown among them [the Brahmans] till then".
ISLAMIC WORLD
Muslim engineers adopted the Greek watermill technology from the Byzantine Empire, where it had been applied for centuries in those provinces conquered by the Muslims, including modern-day Syria, Jordan, Israel, Algeria, Tunisia, Morocco, and Spain (see List of ancient watermills).
The industrial uses of watermills in the Islamic world date back to the 7th century, while horizontal-wheeled and vertical-wheeled watermills were both in widespread use by the 9th century. A variety of industrial watermills were used in the Islamic world, including gristmills, hullers, sawmills, shipmills, stamp mills, steel mills, sugar mills, and tide mills. By the 11th century, every province throughout the Islamic world had these industrial watermills in operation, from al-Andalus and North Africa to the Middle East and Central Asia. Muslim and Middle Eastern Christian engineers also used crankshafts and water turbines, gears in watermills and water-raising machines, and dams as a source of water, used to provide additional power to watermills and water-raising machines. Fulling mills, and steel mills may have spread from Al-Andalus to Christian Spain in the 12th century. Industrial watermills were also employed in large factory complexes built in al-Andalus between the 11th and 13th centuries.
The engineers of the Islamic world used several solutions to achieve the maximum output from a watermill. One solution was to mount them to piers of bridges to take advantage of the increased flow. Another solution was the shipmill, a type of watermill powered by water wheels mounted on the sides of ships moored in midstream. This technique was employed along the Tigris and Euphrates rivers in 10th-century Iraq, where large shipmills made of teak and iron could produce 10 tons of flour from corn every day for the granary in Baghdad.
PERSIA
More than 300 watermills were at work in Iran till 1960. Now only a few are still working. One of the famous ones is the water mill of Askzar and the water mill of the Yazd city, still producing flour.
OPERATION
Typically, water is diverted from a river or impoundment or mill pond to a turbine or water wheel, along a channel or pipe (variously known as a flume, head race, mill race, leat, leet, lade (Scots) or penstock). The force of the water's movement drives the blades of a wheel or turbine, which in turn rotates an axle that drives the mill's other machinery. Water leaving the wheel or turbine is drained through a tail race, but this channel may also be the head race of yet another wheel, turbine or mill. The passage of water is controlled by sluice gates that allow maintenance and some measure of flood control; large mill complexes may have dozens of sluices controlling complicated interconnected races that feed multiple buildings and industrial processes.
Watermills can be divided into two kinds, one with a horizontal water wheel on a vertical axle, and the other with a vertical wheel on a horizontal axle. The oldest of these were horizontal mills in which the force of the water, striking a simple paddle wheel set horizontally in line with the flow turned a runner stone balanced on the rynd which is atop a shaft leading directly up from the wheel. The bedstone does not turn. The problem with this type of mill arose from the lack of gearing; the speed of the water directly set the maximum speed of the runner stone which, in turn, set the rate of milling.
Most watermills in Britain and the United States of America had a vertical waterwheel, one of four kinds: undershot, breast-shot, overshot and pitchback wheels. This vertical produced rotary motion around a horizontal axis, which could be used (with cams) to lift hammers in a forge, fulling stocks in a fulling mill and so on.
MILLING CORN
However, in corn mills rotation about a vertical axis was required to drive its stones. The horizontal rotation was converted into the vertical rotation by means of gearing, which also enabled the runner stones to turn faster than the waterwheel. The usual arrangement in British and American corn mills has been for the waterwheel to turn a horizontal shaft on which is also mounted a large pit wheel. This meshes with the wallower, mounted on a vertical shaft, which turns the (larger) great spur wheel (mounted on the same shaft). This large face wheel, set with pegs, in turn, turned a smaller wheel (such as a lantern gear) known as a stone nut, which was attached to the shaft that drove the runner stone. The number of runner stones that could be turned depended directly upon the supply of water available. As waterwheel technology improved mills became more efficient, and by the 19th century, it was common for the great spur wheel to drive several stone nuts, so that a single water wheel could drive as many as four stones. Each step in the process increased the gear ratio which increased the maximum speed of the runner stone. Adjusting the sluice gate and thus the flow of the water past the main wheel allowed the miller to compensate for seasonal variations in the water supply. Finer speed adjustment was made during the milling process by tentering, that is, adjusting the gap between the stones according to the water flow, the type of grain being milled, and the grade of flour required.
In many mills (including the earliest) the great spur wheel turned only one stone, but there might be several mills under one roof. The earliest illustration of a single waterwheel driving more than one set of stones was drawn by Henry Beighton in 1723 and published in 1744 by J. T. Desaguliers.
OVERSHOT AND PITCHBACK MILLS
The overshot wheel was a later innovation in waterwheels and was around two and a half times more efficient than the undershot. The undershot wheel, in which the main water wheel is simply set into the flow of the mill race, suffers from an inherent inefficiency stemming from the fact that the wheel itself, entering the water behind the main thrust of the flow driving the wheel, followed by the lift of the wheel out of the water ahead of the main thrust, actually impedes its own operation. The overshot wheel solves this problem by bringing the water flow to the top of the wheel. The water fills buckets built into the wheel, rather than the simple paddle wheel design of undershot wheels. As the buckets fill, the weight of the water starts to turn the wheel. The water spills out of the bucket on the down side into a spillway leading back to river. Since the wheel itself is set above the spillway, the water never impedes the speed of the wheel. The impulse of the water on the wheel is also harnessed in addition to the weight of the water once in the buckets. Overshot wheels require the construction of a dam on the river above the mill and a more elaborate millpond, sluice gate, mill race and spillway or tailrace.
An inherent problem in the overshot mill is that it reverses the rotation of the wheel. If a miller wishes to convert a breastshot mill to an overshot wheel all the machinery in the mill has to be rebuilt to take account of the change in rotation. An alternative solution was the pitchback or backshot wheel. A launder was placed at the end of the flume on the headrace, this turned the direction of the water without much loss of energy, and the direction of rotation was maintained. Daniels Mill near Bewdley, Worcestershire is an example of a flour mill that originally used a breastshot wheel, but was converted to use a pitchback wheel. Today it operates as a breastshot mi
Larger water wheels (usually overshot steel wheels) transmit the power from a toothed annular ring that is mounted near the outer edge of the wheel. This drives the machinery using a spur gear mounted on a shaft rather than taking power from the central axle. However, the basic mode of operation remains the same; gravity drives machinery through the motion of flowing water.
Toward the end of the 19th century, the invention of the Pelton wheel encouraged some mill owners to replace over- and undershot wheels with Pelton wheel turbines driven through penstocks.
TIDE MILLS
A different type of watermill is the tide mill. This mill might be of any kind, undershot, overshot or horizontal but it does not employ a river for its power source. Instead a mole or causeway is built across the mouth of a small bay. At low tide, gates in the mole are opened allowing the bay to fill with the incoming tide. At high tide the gates are closed, trapping the water inside. At a certain point a sluice gate in the mole can be opened allowing the draining water to drive a mill wheel or wheels. This is particularly effective in places where the tidal differential is very great, such as the Bay of Fundy in Canada where the tides can rise fifty feet, or the now derelict village of Tide Mills in the United Kingdom. A working example can be seen at Eling Tide Mill.
Run of the river schemes do not divert water at all and usually involve undershot wheels the mills are mostly on the banks of sizeable rivers or fast flowing streams. Other watermills were set beneath large bridges where the flow of water between the stanchions was faster. At one point London bridge had so many water wheels beneath it that bargemen complained that passage through the bridge was impaired.
CURRENT STATUS
By the early 20th century, availability of cheap electrical energy made the watermill obsolete in developed countries although some smaller rural mills continued to operate commercially later throughout the century. A few historic mills such as the Newlin Mill and Yates Mill in the US and The Darley Mill Centre in the UK still operate for demonstration purposes. Small-scale commercial production is carried out in the UK at Daniels Mill, Little Salkeld Mill and Redbournbury Mill.
Some old mills are being upgraded with modern hydropower technology, such as those worked on by the South Somerset Hydropower Group in the UK.
In some developing countries, watermills are still widely used for processing grain. For example, there are thought to be 25,000 operating in Nepal, and 200,000 in India. Many of these are still of the traditional style, but some have been upgraded by replacing wooden parts with better-designed metal ones to improve the efficiency. For example, the Centre for Rural Technology in Nepal upgraded 2,400 mills between 2003 and 2007.
WIKIPEDIA
A watermill or water mill is a mill that utilizes hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may be comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills.
One major way to classify watermills is by wheel orientation (vertical or horizontal), one powered by a vertical waterwheel through a gearing mechanism, and the other equipped with a horizontal waterwheel without such a mechanism. The former type can be further divided, depending on where the water hits the wheel paddles, into undershot, overshot, breastshot and pitchback (backshot or reverse shot) waterwheel mills. Another way to classify water mills is by an essential trait about their location: tide mills use the movement of the tide; ship mills are water mills onboard (and constituting) a ship.
CLASSICAL ANTIQUITY
Hellenistic engineers invented the two main components of watermills, the waterwheel and toothed gearing, and were, along with the Romans, the first to operate undershot, overshot and breastshot waterwheel mills.
The earliest evidence of a water-driven wheel is probably the Perachora wheel (3rd century BC), in Greece. The earliest written reference is in the technical treatises Pneumatica and Parasceuastica of the Greek engineer Philo of Byzantium (c. 280−220 BC). The British historian of technology M.J.T. Lewis has shown that those portions of Philo of Byzantium's mechanical treatise which describe water wheels and which have been previously regarded as later Arabic interpolations, actually date back to the Greek 3rd-century BC original. The sakia gear is, already fully developed, for the first time attested in a 2nd-century BC Hellenistic wall painting in Ptolemaic Egypt.
Lewis assigns the date of the invention of the horizontal-wheeled mill to the Greek colony of Byzantium in the first half of the 3rd century BC, and that of the vertical-wheeled mill to Ptolemaic Alexandria around 240 BC.
The Greek geographer Strabon reports in his Geography a water-powered grain-mill to have existed near the palace of king Mithradates VI Eupator at Cabira, Asia Minor, before 71 BC.
The Roman engineer Vitruvius has the first technical description of a watermill, dated to 40/10 BC; the device is fitted with an undershot wheel and power is transmitted via a gearing mechanism. He also seems to indicate the existence of water-powered kneading machines.
The Greek epigrammatist Antipater of Thessalonica tells of an advanced overshot wheel mill around 20 BC/10 AD. He praised for its use in grinding grain and the reduction of human labour:
Hold back your hand from the mill, you grinding girls; even if the cockcrow heralds the dawn, sleep on. For Demeter has imposed the labours of your hands on the nymphs, who leaping down upon the topmost part of the wheel, rotate its axle; with encircling cogs, it turns the hollow weight of the Nisyrian millstones. If we learn to feast toil-free on the fruits of the earth, we taste again the golden age.
The Roman encyclopedist Pliny mentions in his Naturalis Historia of around 70 AD water-powered trip hammers operating in the greater part of Italy. There is evidence of a fulling mill in 73/4 AD in Antioch, Roman Syria.
It is likely that a water-powered stamp mill was used at Dolaucothi to crush gold-bearing quartz, with a possible date of the late 1st century to the early 2nd century. The stamps were operated as a batch of four working against a large conglomerate block, now known as Carreg Pumpsaint. Similar anvil stones have been found at other Roman mines across Europe, especially in Spain and Portugal.
The 1st-century AD multiple mill complex of Barbegal in southern France has been described as "the greatest known concentration of mechanical power in the ancient world". It featured 16 overshot waterwheels to power an equal number of flour mills. The capacity of the mills has been estimated at 4.5 tons of flour per day, sufficient to supply enough bread for the 12,500 inhabitants occupying the town of Arelate at that time. A similar mill complex existed on the Janiculum hill, whose supply of flour for Rome's population was judged by emperor Aurelian important enough to be included in the Aurelian walls in the late 3rd century.
A breastshot wheel mill dating to the late 2nd century AD was excavated at Les Martres-de-Veyre, France.
The 3rd-century AD Hierapolis water-powered stone sawmill is the earliest known machine to incorporate a crank and connecting rod mechanism. Further sawmills, also powered by crank and connecting rod mechanisms, are archaeologically attested for the 6th-century water-powered stone sawmills at Gerasa and Ephesus. Literary references to water-powered marble saws in what is now Germany can be found in Ausonius 4th-century poem Mosella. They also seem to be indicated about the same time by the Christian saint Gregory of Nyssa from Anatolia, demonstrating a diversified use of water-power in many parts of the Roman Empire.
The earliest turbine mill was found in Chemtou and Testour, Roman North Africa, dating to the late 3rd or early 4th century AD. A possible water-powered furnace has been identified at Marseille, France.
Mills were commonly used for grinding grain into flour (attested by Pliny the Elder), but industrial uses as fulling and sawing marble were also applied.
The Romans used both fixed and floating water wheels and introduced water power to other provinces of the Roman Empire. So-called 'Greek Mills' used water wheels with a horizontal wheel (and vertical shaft). A "Roman Mill" features a vertical wheel (on a horizontal shaft). Greek style mills are the older and simpler of the two designs, but only operate well with high water velocities and with small diameter millstones. Roman style mills are more complicated as they require gears to transmit the power from a shaft with a horizontal axis to one with a vertical axis.
Although to date only a few dozen Roman mills are archaeologically traced, the widespread use of aqueducts in the period suggests that many remain to be discovered. Recent excavations in Roman London, for example, have uncovered what appears to be a tide mill together with a possible sequence of mills worked by an aqueduct running along the side of the River Fleet.
In 537 AD, ship mills were ingeniously used by the East Roman general Belisarius, when the besieging Goths cut off the water supply for those mills. These floating mills had a wheel that was attached to a boat moored in a fast flowing river.
MIDDLE AGES
At the time of the compilation of the Domesday Book (1086), there were 5,624 watermills in England alone, only 2% of which have not been located by modern archeological surveys. Later research estimates a less conservative number of 6,082, and it has been pointed out that this should be considered a minimum as the northern reaches of England were never properly recorded. In 1300, this number had risen to between 10,000 and 15,000. By the early 7th century, watermills were well established in Ireland, and began to spread from the former territory of the empire into the non-romanized parts of Germany a century later. Ship mills and tide mill were introduced in the 6th century.
TIDE MILLS
In recent years, a number of new archaeological finds has consecutively pushed back the date of the earliest tide mills, all of which were discovered on the Irish coast: A 6th-century vertical-wheeled tide mill was located at Killoteran near Waterford. A twin flume horizontal-wheeled tide mill dating to c. 630 was excavated on Little Island. Alongside it, another tide mill was found which was powered by a vertical undershot wheel. The Nendrum Monastery mill from 787 was situated on an island in Strangford Lough in Northern Ireland. Its millstones are 830mm in diameter and the horizontal wheel is estimated to have developed 7–8 hp at its peak. Remains of an earlier mill dated at 619 were also found at the site.
SURVEY OF INDUSTRIAL MILLS
In a 2005 survey the scholar Adam Lucas identified the following first appearances of various industrial mill types in Western Europe. Noticeable is the preeminent role of France in the introduction of new innovative uses of waterpower. However, he has drawn attention to the dearth of studies of the subject in several other countries.
ANCIENT CHINA
The waterwheel was found in China from 30 AD onwards, when it was used to power trip hammers, the bellows in smelting iron, and in one case, to mechanically rotate an armillary sphere for astronomical observation (see Zhang Heng). Although Joseph Needham speculates that the water-powered millstone could have existed in Han China by the 1st century AD, there is no sufficient literary evidence for it until the 5th century. In 488 AD, the mathematician and engineer Zu Chongzhi had a watermill erected which was inspected by Emperor Wu of Southern Qi (r. 482–493 AD). The engineer Yang Su of the Sui Dynasty (581–618 AD) was said to operate hundreds of them by the beginning of the 6th century. A source written in 612 AD mentions Buddhist monks arguing over the revenues gained from watermills. The Tang Dynasty (618–907 AD) 'Ordinances of the Department of Waterways' written in 737 AD stated that watermills should not interrupt riverine transport and in some cases were restricted to use in certain seasons of the year. From other Tang-era sources of the 8th century, it is known that these ordinances were taken very seriously, as the government demolished many watermills owned by great families, merchants, and Buddhist abbeys that failed to acknowledge ordinances or meet government regulations. A eunuch serving Emperor Xuanzong of Tang (r. 712–756 AD) owned a watermill by 748 AD which employed five waterwheels that ground 300 bushels of wheat a day. By 610 or 670 AD, the watermill was introduced to Japan via Korean Peninsula. It also became known in Tibet by at least 641 AD.
ANCIENT INDIA
According to Greek historical tradition, India received water-mills from the Roman Empire in the early 4th century AD when a certain Metrodoros introduced "water-mills and baths, unknown among them [the Brahmans] till then".
ISLAMIC WORLD
Muslim engineers adopted the Greek watermill technology from the Byzantine Empire, where it had been applied for centuries in those provinces conquered by the Muslims, including modern-day Syria, Jordan, Israel, Algeria, Tunisia, Morocco, and Spain (see List of ancient watermills).
The industrial uses of watermills in the Islamic world date back to the 7th century, while horizontal-wheeled and vertical-wheeled watermills were both in widespread use by the 9th century. A variety of industrial watermills were used in the Islamic world, including gristmills, hullers, sawmills, shipmills, stamp mills, steel mills, sugar mills, and tide mills. By the 11th century, every province throughout the Islamic world had these industrial watermills in operation, from al-Andalus and North Africa to the Middle East and Central Asia. Muslim and Middle Eastern Christian engineers also used crankshafts and water turbines, gears in watermills and water-raising machines, and dams as a source of water, used to provide additional power to watermills and water-raising machines. Fulling mills, and steel mills may have spread from Al-Andalus to Christian Spain in the 12th century. Industrial watermills were also employed in large factory complexes built in al-Andalus between the 11th and 13th centuries.
The engineers of the Islamic world used several solutions to achieve the maximum output from a watermill. One solution was to mount them to piers of bridges to take advantage of the increased flow. Another solution was the shipmill, a type of watermill powered by water wheels mounted on the sides of ships moored in midstream. This technique was employed along the Tigris and Euphrates rivers in 10th-century Iraq, where large shipmills made of teak and iron could produce 10 tons of flour from corn every day for the granary in Baghdad.
PERSIA
More than 300 watermills were at work in Iran till 1960. Now only a few are still working. One of the famous ones is the water mill of Askzar and the water mill of the Yazd city, still producing flour.
OPERATION
Typically, water is diverted from a river or impoundment or mill pond to a turbine or water wheel, along a channel or pipe (variously known as a flume, head race, mill race, leat, leet, lade (Scots) or penstock). The force of the water's movement drives the blades of a wheel or turbine, which in turn rotates an axle that drives the mill's other machinery. Water leaving the wheel or turbine is drained through a tail race, but this channel may also be the head race of yet another wheel, turbine or mill. The passage of water is controlled by sluice gates that allow maintenance and some measure of flood control; large mill complexes may have dozens of sluices controlling complicated interconnected races that feed multiple buildings and industrial processes.
Watermills can be divided into two kinds, one with a horizontal water wheel on a vertical axle, and the other with a vertical wheel on a horizontal axle. The oldest of these were horizontal mills in which the force of the water, striking a simple paddle wheel set horizontally in line with the flow turned a runner stone balanced on the rynd which is atop a shaft leading directly up from the wheel. The bedstone does not turn. The problem with this type of mill arose from the lack of gearing; the speed of the water directly set the maximum speed of the runner stone which, in turn, set the rate of milling.
Most watermills in Britain and the United States of America had a vertical waterwheel, one of four kinds: undershot, breast-shot, overshot and pitchback wheels. This vertical produced rotary motion around a horizontal axis, which could be used (with cams) to lift hammers in a forge, fulling stocks in a fulling mill and so on.
MILLING CORN
However, in corn mills rotation about a vertical axis was required to drive its stones. The horizontal rotation was converted into the vertical rotation by means of gearing, which also enabled the runner stones to turn faster than the waterwheel. The usual arrangement in British and American corn mills has been for the waterwheel to turn a horizontal shaft on which is also mounted a large pit wheel. This meshes with the wallower, mounted on a vertical shaft, which turns the (larger) great spur wheel (mounted on the same shaft). This large face wheel, set with pegs, in turn, turned a smaller wheel (such as a lantern gear) known as a stone nut, which was attached to the shaft that drove the runner stone. The number of runner stones that could be turned depended directly upon the supply of water available. As waterwheel technology improved mills became more efficient, and by the 19th century, it was common for the great spur wheel to drive several stone nuts, so that a single water wheel could drive as many as four stones. Each step in the process increased the gear ratio which increased the maximum speed of the runner stone. Adjusting the sluice gate and thus the flow of the water past the main wheel allowed the miller to compensate for seasonal variations in the water supply. Finer speed adjustment was made during the milling process by tentering, that is, adjusting the gap between the stones according to the water flow, the type of grain being milled, and the grade of flour required.
In many mills (including the earliest) the great spur wheel turned only one stone, but there might be several mills under one roof. The earliest illustration of a single waterwheel driving more than one set of stones was drawn by Henry Beighton in 1723 and published in 1744 by J. T. Desaguliers.
OVERSHOT AND PITCHBACK MILLS
The overshot wheel was a later innovation in waterwheels and was around two and a half times more efficient than the undershot. The undershot wheel, in which the main water wheel is simply set into the flow of the mill race, suffers from an inherent inefficiency stemming from the fact that the wheel itself, entering the water behind the main thrust of the flow driving the wheel, followed by the lift of the wheel out of the water ahead of the main thrust, actually impedes its own operation. The overshot wheel solves this problem by bringing the water flow to the top of the wheel. The water fills buckets built into the wheel, rather than the simple paddle wheel design of undershot wheels. As the buckets fill, the weight of the water starts to turn the wheel. The water spills out of the bucket on the down side into a spillway leading back to river. Since the wheel itself is set above the spillway, the water never impedes the speed of the wheel. The impulse of the water on the wheel is also harnessed in addition to the weight of the water once in the buckets. Overshot wheels require the construction of a dam on the river above the mill and a more elaborate millpond, sluice gate, mill race and spillway or tailrace.
An inherent problem in the overshot mill is that it reverses the rotation of the wheel. If a miller wishes to convert a breastshot mill to an overshot wheel all the machinery in the mill has to be rebuilt to take account of the change in rotation. An alternative solution was the pitchback or backshot wheel. A launder was placed at the end of the flume on the headrace, this turned the direction of the water without much loss of energy, and the direction of rotation was maintained. Daniels Mill near Bewdley, Worcestershire is an example of a flour mill that originally used a breastshot wheel, but was converted to use a pitchback wheel. Today it operates as a breastshot mi
Larger water wheels (usually overshot steel wheels) transmit the power from a toothed annular ring that is mounted near the outer edge of the wheel. This drives the machinery using a spur gear mounted on a shaft rather than taking power from the central axle. However, the basic mode of operation remains the same; gravity drives machinery through the motion of flowing water.
Toward the end of the 19th century, the invention of the Pelton wheel encouraged some mill owners to replace over- and undershot wheels with Pelton wheel turbines driven through penstocks.
TIDE MILLS
A different type of watermill is the tide mill. This mill might be of any kind, undershot, overshot or horizontal but it does not employ a river for its power source. Instead a mole or causeway is built across the mouth of a small bay. At low tide, gates in the mole are opened allowing the bay to fill with the incoming tide. At high tide the gates are closed, trapping the water inside. At a certain point a sluice gate in the mole can be opened allowing the draining water to drive a mill wheel or wheels. This is particularly effective in places where the tidal differential is very great, such as the Bay of Fundy in Canada where the tides can rise fifty feet, or the now derelict village of Tide Mills in the United Kingdom. A working example can be seen at Eling Tide Mill.
Run of the river schemes do not divert water at all and usually involve undershot wheels the mills are mostly on the banks of sizeable rivers or fast flowing streams. Other watermills were set beneath large bridges where the flow of water between the stanchions was faster. At one point London bridge had so many water wheels beneath it that bargemen complained that passage through the bridge was impaired.
CURRENT STATUS
By the early 20th century, availability of cheap electrical energy made the watermill obsolete in developed countries although some smaller rural mills continued to operate commercially later throughout the century. A few historic mills such as the Newlin Mill and Yates Mill in the US and The Darley Mill Centre in the UK still operate for demonstration purposes. Small-scale commercial production is carried out in the UK at Daniels Mill, Little Salkeld Mill and Redbournbury Mill.
Some old mills are being upgraded with modern hydropower technology, such as those worked on by the South Somerset Hydropower Group in the UK.
In some developing countries, watermills are still widely used for processing grain. For example, there are thought to be 25,000 operating in Nepal, and 200,000 in India. Many of these are still of the traditional style, but some have been upgraded by replacing wooden parts with better-designed metal ones to improve the efficiency. For example, the Centre for Rural Technology in Nepal upgraded 2,400 mills between 2003 and 2007.
WIKIPEDIA