overshot water wheel generator manufacturer

The overshot wheel is the most common wheel seen in North America. It is a gravity wheel. This means that it harnesses the force of gravity acting vertically on the water as it travels from the top to the bottom of the wheel. Properly designed for a particular site, and correctly timed, an overshot The overshot wheel is most effective when it turns as slowly as possible and can still handle the total flow of water available to it. The optimal rim speed should be only about 3 feet per second. The larger the wheel the slower it will need to turn. The incoming water must be traveling about three times the rim speed of the wheel so that it can fill the buckets effectively. This requires a foot or more of head above the wheel, usually controlled by a gate.

When the head, or fall of water was not sufficient for a large diameter overshot wheel, the breast wheel often is used. This is halfway between the overshot and undershot wheels. Water strikes the buckets of the breast wheel about midway between top and bottom, using the weight of the water for a 90 degree segment of arc. Their efficiency is far less than the overshot, which uses the weight of the water for a full 180 degrees.

This type of waterwheel relies on the flow of water, coming along the base flowing at a good rate of speed to push or thrust the waterwheel. This type of waterwheel is used on mills built on rivers or streams that do not have any height or (head). Undershot wheels are normally narrow and have to have the channel walls very close to the sides of the wheel to maximize the flow of water to pass through the wheels to generate power. This type of wheel is generally the least efficient type of wheel - usually in the 30-50% range. The exception to this is the Poncelet wheel that can get up to 80% efficiency if the channel is properly constructed and the buckets are designed right.

This type of waterwheel relies on the flow of water, generally in an open stream. This type of wheel is generally the least efficient type of wheel - usually in the 30-40% range. The exception to this is the Poncelet wheel that can get up to 80% efficiency if the channel is properly constructed and the buckets are designed right.

Many micro hydro electric generation strategies have evolved in recent years. Helical Ribbons, Under Water Blade Turbines, Tide and Wave action mechanical generators. Our approach is to simplify sustainable micro hydroelectric water wheel construction and improve the efficiency of energy generation. Our recent association with Ticho Industries in Italy has produced a new form of micro hydro waterwheels with a high efficiency electric generator mounted safely on the axle completely within the water wheel structure. This design simplifies micro hydro water wheel design for optimal water flow location mounting, system longevity, ease of maintenance and simplified electro mechanical connection. Our new design was created for city and rural stream based flows - including the outflows from major hydro electric dams, major navigation and irrigation dams, manufacturing and water treatment facilities.

To do this you will need to know two things, the quantity of water and the height of the water fall. From this you can determine the Horsepower at the axle of the waterwheel.

To get electricity out of a waterwheel you will have to gear the RPMs of the waterwheel (generally from 5-10 rpm”s up t0 500 - 1700 rpm’s) and then run it through a generator or a DC motor to charge a battery bank. This will generally cut your power at the axle HP by almost 1/3 to 1/2. A waterwheel is really designed to do mechanical work.

To establish if your site is suitable for generating electricity from a Poncelet Wheel you need to have flowing water and you need to know the three key components, which are WATER VELOCITY (in metres per second), AREA (in square metres) and HEAD (in metres).

The more flowing water you have, the more potential power you can generate. The Water Velocity can be estimated by recording how long (in seconds) a "floating object" (such as a ball) takes to travel over a given distance (in metres). Divide the distance by the time taken and you will have the Water Velocity (in metres per second).

The 4.1m diameter waterwheel is positioned in an existing water supply in one of the old wheel pits of the former gunpowder works, next to The Langdale Estate’s original turbine house which generated electricity for the estate in the 19th century.

The spokes, rims and buckets were all fabricated from 3mm pre-galvanised sheet finished with polyester powder coating. These lightweight components were easily and rapidly assembled using stainless steel nuts and bolts without the need for welding or any special tools on site. Only the wheel hub required welding and this was undertaken at our factory.

Delivery to site as a flat pack kit enabled it to be installed without the need for a large crane which would have been unable to travel down the narrow road to the site. This unique feature allows our overshot wheels to be installed in remote locations where there is restricted access.

Tests undertaken with Dr Paddy Quinlan of the University of Cumbria show that high mechanical efficiencies can be achieved from our overshot wheels. A water-to-wire efficiency of 65% was expected but the tests showed it is over 75%.

The waterwheel was funded through the University of Cumbria’s Renewable Energy Test and Education Centre (RETEC) with funding from Britain’s Energy Coast in partnership with the Nuclear Decommissioning Authority.

(This introductory overview to waterwheels is the first of a three-part series. The second installment [Issue No.17] will be about undershot and no-head wheels, and the third installment [Issue No. 18] will deal with overshot wheels. — Editor)

The creak of an old, wooden moss-covered wheel lazily driving a gristmill in a long lost past is how most people think of a small scale water power. Of course water power is old. Historical records put it at around 4000 years old. While that makes it an ancient technology, that doesn’t make it an antique technology. If you have ever considered windmills, think of a water wheel as a windmill that uses a fluid 824 times as dense. In other words, 824 times as powerful. On the negative side, you need access to a good stream, while the wind is everywhere. I am making this comparison to show that water power isn’t any more complicated than wind power to understand.

Waterwheels run because “gravity” causes a “mass” of water to fall some distance (HEAD). This energy is absorbed by the wheel to do work. There is more than one way to absorb the energy, so wheels have evolved into two classes:

Reaction, uses the moving water to create a pressure differential like an airplane wing. These are correctly called “turbine’s.” A propeller is the most common example of the type.

For this reason I recommendimpulse type water wheels. These function by transferring the momentum of the moving water to the machine. The energy transfer is similar to one billiard ball transferring its energy to another. Because of this, impulse wheels have a very high efficiency, and more importantly, have a constant efficiency over varying stream conditions.

On a small, variable stream (a typical home/farm stream) an impulse wheel can produce more than twice the kilowatt hours of a reaction wheel. Impulse wheels are available in several types, each designed for a specific type of stream.

No-head: If you have a stream with an average velocity of 4 feet per second or higher (preferably higher), you can use a no-head water motor. These are a relatively new innovation. While they are somewhat inefficient compared to more traditional designs, they have the advantage that they do not need a dam of any sort. The time, expense and just plain hassles associated with building a dam make these designs very desirable. There are three choices:

A FITZ C-Rotor and the Scheider Lift Translator are autonomous generators, containing the wheel, generator, and regulator in a single unit. You just place one in a stream and connect the power cable to a load. Both designs are quite cost-effective as a personal power source.

Undershot wheels range from simple paddle wheels placed in a stream to Poncelot Wheels. They were developed in France during the 18th century. They are good for small to medium flows and heads from 1 foot to 12 feet. If properly designed, a Poncelot can be 85% efficient or more. Even an amateur-built wheel can be over 75% efficient.

Overshot wheels are the kind people associate with Currier & Ives engravings. While many were made of wood, after 1840 most were made of metal. For small streams and heads up to 25 feet, these are still the best choice for a home/farm user. The old FITZ I-X-L designed in 1862 was tested at the University of Wisconsin in 1913. It proved to be 93% efficient.

Crossflow turbines are incorrectly called a turbine since they work on the impulse principal. They can best be described as undershot wheels in a can. They are useful for small to large flows and heads from 10 feet to 100 feet. They are close tolerance devices so we wouldn’t recommend this design to an amateur builder unless you have some machining experience. A Pelton wheel is a high head variant of the crossflow, best used with heads of 50 feet or higher.

Surprisingly, wheel horsepower and efficiency are not the most important factors. This is because stream flows vary over the year. The best choice is the wheel that delivers 50% or more of the theoretical power of the stream. In other words, the total annual production should be at least HALF of the production you would get if the wheel ran at full power all year long.

For example, there are 8760 hours in a year. If you had a 100 kilowatt wheel, it should produce 438,000 kilowatt-hours annually. (100 KW * 8760 * 50%). If it doesn’t, you should use a smaller wheel. This isn’t as difficult to calculate as it sounds. Power available can be calculated as flow (in cubic feet per second) times head (in feet) divided by 11.8. This will give you power in kilowatts. Divide this answer by 0.746 to get horsepower.

Also remember a stream varies over the year. The most important thing to know for any waterwheel installation is how much water is available, and how much can you use. An oversized wheel is both inefficient and a waste of money. Plot the flows if you can, or get stream flow data from the U.S. Geological Survey. Usually a flow that is met or exceeded 25% of the time is a good flow to size your generator. While you may miss some power during spring floods, remember that they don’t occur often enough to justify the expense of a larger waterwheel.

When selecting a generator type, decide if you want AC or DC power. Will you co-generate with the electric company or go it alone? If your power plant is 25 kilowatts or larger, a self regulated AC system is the best. If it is smaller, or you want to supplement with wind power or photovoltaics, DC is the simplest to use. If you are co-generating, a simple AC induction system will work for any size power plant. This is the absolute least cost arrangement. Here is where the self-regulating characteristics of impulse wheels really pay off.

Impulse wheels turn slowly. This was one reason reaction turbines were invented. Today gearing is very reliable so it is no longer necessary to direct drive a generator. This also allows use of more efficient 4-pole (1800 rpm) generators. Any industrial enclosed drive will work. Do not use auto transmissions. They were never intended for continuous duty. The bearings and casing are too light unless you are making 10 kilowatts or less.

This is an overview of how waterwheels can be used for personal power plants. As in anything, attention to detail is what separates success from failure. Measure your stream carefully, and don’t over-estimate your power needs or building skills. Waterwheels are heavy industrial machines.

On the other hand, don’t under-estimate what one person looking to change their piece of the world can do. Before I bought the FITZ Waterwheel company, I had been through some hard times. Now 6 years later, I operate 1250 kilowatts of generators commercially, providing clean, environmentally safe power to over 1000 homes. I hope you have as much fun and satisfaction with your waterwheel, whatever the size.

Water wheel design has evolved over time with some water wheels oriented vertically, some horizontally and some with elaborate pulleys and gears attached, but they are all designed to do the same function and that is too, “convert the linear motion of the moving water into a rotary motion which can be used to drive any piece of machinery connected to it via a rotating shaft”.

Early Waterwheel Design were quite primitive and simple machines consisting of a vertical wooden wheel with wooden blades or buckets fixed equally around their circumference all supported on a horizontal shaft with the force of the water flowing underneath it pushing the wheel in a tangential direction against the blades.

These vertical waterwheels were vastly superior to the earlier horizontal waterwheel design by the ancient Greeks and Egyptians, because they could operate more efficiently translating the hydrokinetic energy of the moving water into mechanical power. Pulleys and gearing was then attached to the waterwheel which allowed a change in direction of a rotating shaft from horizontal to vertical in order to operate millstones, saw wood, crush ore, stamping and cutting etc.

Most Waterwheels also known as Watermills or simply Water Wheels, are vertically mounted wheels rotating about a horizontal axle, and these types of waterwheels are classified by the way in which the water is applied to the wheel, relative to the wheel’s axle. As you may expect, waterwheels are relatively large machines which rotate at low angular speeds, and have a low efficiency, due to losses by friction and the incomplete filling of the buckets, etc.

The action of the water pushing against the wheels buckets or paddles develops torque on the axle but by directing the water at these paddles and buckets from different positions on the wheel the speed of rotation and its efficiency can be improved. The two most common types of waterwheel design is the “undershot waterwheel” and the “overshot waterwheel”.

The Undershot Water Wheel Design, also known as a “stream wheel” was the most commonly used type of waterwheel designed by the ancient Greeks and Romans as it is the simplest, cheapest and easiest type of wheel to construct.

In this type of waterwheel design, the wheel is simply placed directly into a fast flowing river and supported from above. The motion of the water below creates a pushing action against the submerged paddles on the lower part of the wheel allowing it to rotate in one direction only relative to the direction of the flow of the water.

This type of waterwheel design is generally used in flat areas with no natural slope of the land or where the flow of water is sufficiently fast moving. Compared with the other waterwheel designs, this type of design is very inefficient, with as little as 20% of the waters potential energy being used to actually rotate the wheel. Also the waters energy is used only once to rotate the wheel, after which it flows away with the rest of the water.

Another disadvantage of the undershot water wheel is that it requires large quantities of water moving at speed. Therefore, undershot waterwheels are usually situated on the banks of rivers as smaller streams or brooks do not have enough potential energy in the moving water.

One way of improving the efficiency slightly of an undershot waterwheel is to divert a percentage off the water in the river along a narrow channel or duct so that 100% of the diverted water is used to rotate the wheel. In order to achieve this the undershot wheel has to be narrow and fit very accurately within the channel to prevent the water from escaping around the sides or by increasing either the number or size of the paddles.

The Overshot Water Wheel Design is the most common type of waterwheel design. The overshot waterwheel is more complicated in its construction and design than the previous undershot waterwheel as it uses buckets or small compartments to both catch and hold the water.

These buckets fill with water flowing onto the wheel through a penstock design above. The gravitational weight of the water in the full buckets causes the wheel to rotate around its central axis as the empty buckets on the other side of the wheel become lighter.

This type of water wheel uses gravity to improve output as well as the water itself, thus overshot waterwheels are much more efficient than undershot designs as almost all of the water and its weight is being used to produce output power. However as before, the waters energy is used only once to rotate the wheel, after which it flows away with the rest of the water.

Overshot waterwheels are suspended above a river or stream and are generally built on the sides of hills providing a water supply from above with a low head (the vertical distance between the water at the top and the river or stream below) of between 5-to-20 metres. A small dam or weir can be constructed and used to both channel and increase the speed of the water to the top of the wheel giving it more energy but it is the volume of water rather than its speed which helps rotate the wheel.

Generally, overshot waterwheels are built as large as possible to give the greatest possible head distance for the gravitational weight of the water to rotate the wheel. However, large diameter waterwheels are more complicated and expensive to construct due to the weight of the wheel and water.

When the individual buckets are filled with water, the gravitational weight of the water causes the wheel to rotate in the direction of the flow of water. As the angle of rotation gets nearer to the bottom of the wheel, the water inside the bucket empties out into the river or stream below, but the weight of the buckets rotating behind it causes the wheel to continue with its rotational speed.

Once the bucket is empty of water it continues around the rotating wheel until it gets back up to the top again ready to be filled with more water and the cycle repeats. One of the disadvantages of an overshot waterwheel design is that the water is only used once as it flows over the wheel.

The Pitchback Water Wheel Design is a variation on the previous overshot waterwheel as it also uses the gravitational weight of the water to help rotate the wheel, but it also uses the flow of the waste water below it to give an extra push. This type of waterwheel design uses a low head infeed system which provides the water near to the top of the wheel from a pentrough above.

Unlike the overshot waterwheel which channelled the water directly over the wheel causing it to rotate in the direction of the flow of the water, the pitchback waterwheel feeds the water vertically downwards through a funnel and into the bucket below causing the wheel to rotate in the opposite direction to the flow of the water above.

Just like the previous overshot waterwheel, the gravitational weight of the water in the buckets causes the wheel to rotate but in an anti-clockwise direction. As the angle of rotation nears the bottom of the wheel, the water trapped inside the buckets empties out below. As the empty bucket is attached to the wheel, it continues rotating with the wheel as before until it gets back up to the top again ready to be filled with more water and the cycle repeats.

The difference this time is that the waste water emptied out of the rotating bucket flows away in the direction of the rotating wheel (as it has nowhere else to go), similar to the undershot waterwheel principal. Thus the main advantage of the pitchback waterwheel is that it uses the energy of the water twice, once from above and once from below to rotate the wheel around its central axis.

The result is that the efficiency of the waterwheel design is greatly increased to over 80% of the waters energy as it is driven by both the gravitaional weight of the incoming water and by the force or pressure of water directed into the buckets from above, as well as the flow of the waste water below pushing against the buckets. The disadvantage though of an pitchback waterwheel is that it needs a slightly more complex water supply arrangement directly above the wheel with chutes and pentroughs.

The Breastshot Water Wheel Design is another vertically-mounted waterwheel design where the water enters the buckets about half way up at axle height, or just above it, and then flows out at the bottom in the direction of the wheels rotation. Generally, the breastshot waterwheel is used in situations were the head of water is insufficient to power an overshot or pitchback waterwheel design from above.

The disadvantage here is that the gravitational weight of the water is only used for about one quarter of the rotation unlike previously which was for half the rotation. To overcome this low head height, the waterwheels buckets are made wider to extract the required amount of potential energy from the water.

Breastshot waterwheels use about the same gravitational weight of the water to rotate the wheel but as the head height of the water is around half that of a typical overshot waterwheel, the buckets are a lot wider than previous waterwheel designs to increase the volume of the water caught in the buckets.

The disadvantage of this type of design is an increase in the width and weight of the water being carried by each bucket. As with the pitchback design, the breastshot wheel uses the energy of the water twice as the waterwheel is designed to sit in the water allowing the waste water to help in the rotation of the wheel as it flows away down stream.

Historically water wheels have been used for milling flour, cereals and other such mechanical tasks. But water wheels can also be used for the generation of electricity, called a Hydro Power system.

By connecting an electrical generator to the waterwheels rotating shaft, either directly or indirectly using drive belts and pulleys, waterwheels can be used to generate power continuously 24 hours a day unlike solar energy. If the waterwheel is designed correctly, a small or “micro” hydroelectric system can produce enough electricity to power lighting and/or electrical appliances in an average home.

Look for Water wheel Generators designed to produce its optimum output at relatively low speeds. For small projects, a small DC motor can be used as a low-speed generator or an automotive alternator but these are designed to work at much higher speeds so some form of gearing may be required. A wind turbine generator makes an ideal waterwheel generator as it is designed for low speed, high output operation.

If there is a fairly fast flowing river or stream near to your home or garden which you can use, then a small scale hydro power system may be a better alternative to other forms of renewable energy sources such as “Wind Energy” or “Solar Energy” as it has a lot less visual impact. Also just like wind and solar energy, with a grid-connected small scale waterwheel designed generating system connected to the local utility grid, any electricity you generate but don’t use can be sold back to the electricity company.

In the next tutorial about Hydro Energy, we will look at the different types of turbines available which we could attach to our waterwheel design for hydro power generation. For more information about Waterwheel Design and how to generate your own electricity using the power of water, or obtain more hydro energy information about the various waterwheel designs available, or to explore the advantages and disadvantages of hydro energy, then Click Here to order your copy from Amazon today about the principles and construction of waterwheels which can be used for generating electricity.

The path that the water takes through a turbine and the general layout is often used for classification, like tangential-flow, radial-flow cross-flow and axial-flow. Below are the various categories of ‘water driven prime mover that can be used to convert the ‘potential energy’ in a river or stream into usable ‘mechanical’ or ‘electrical’ energy. This section continues with information on what types of turbine are suitable in various sites and applications.

Gravity devices are those where any kinetic energy present at the entry of the device is either minimal or lost in turbulence and does nor contribute measurably to the output of the device. Such devices include most waterwheel types, Archimedes screws (where the outer case rotates with the flutes); Hydrodynamic screws (as used for sewage pumping and now being used in reverse as low-head prime-movers); Norias (more commonly used for raising water) and consist of a string of buckets like an overshot waterwheel attached to form a chain, and positive displacement devices or hydraulic engines.

Impulse turbines are those where the potential energy in a ‘head of water’ is largely converted into kinetic energy at a nozzle or spout. The simplest of such devices is the Gharat or Norse Wheel (where the conversion to kinetic energy takes place in an open flume). The more conventional devices harness the potential energy in a pipeline or penstock that terminates in a nozzle. The flow path through the turbine is usually used to describe the specific device, namely, tangential-flow, radial-flow, cross-flow, axial-flow or mixed-flow. Specific turbine designers have been associated with most of these devices, though confusion can result because they often designed several different types of device (The Pelton Waterwheel Company also made cased reaction turbines, Herschel pre dates Jonval’s patent that was the precursor of the Turgo Impulse wheel, a single nozzle version developed by Gilkes. Donat Banki, a Hungarian was also making cross-flow turbines many years before Mitchell and Ossburger came on the scene.

Reaction turbines are those where the turbine runner is usually completely flooded and the transfer of energy from the water to the turbine runner is achieved by a combination of reaction and/or lift. Some designs of cross-flow turbine in common use a combination of impulse and reaction. Reaction turbines have had a more complex development, with many designers and factories adding features such as movable ‘wicket gates’ that resulted in Francis’s name becoming the tag by which this group of turbines are now known. The Kaplan turbine developed in the 1930s is a sophisticated variable geometry version of the ‘propeller turbine’ that as its name suggests is similar to a ship’s propeller in a housing. Halfway between these types is the single regulated propeller turbine, where either the runner blades or the ‘guide vanes’ (wicket gates) are adjustable.

Free-stream devices encompass large slow running wheels and turbines, some of which are being tried out for marine energy applications. Like wind turbines, the power delivered increases as a cube of the velocity, such that a doubling of the velocity gives an eight fold increase in power output. The devices themselves are very large and slow running and only have very specialised applications for extracting small amounts of power from bank-side locations on very large rivers.

High head sites with over 20 metres of fall, where the water is conveyed directly to the turbine in a pipe (penstock) or via an open canal followed by a piped section, generally use impulse turbines. The reason is that high head sites are usually subject to significant changes in water flow and reaction turbines like the Francis are not able to cope with such variations. Silt in the water can also cause a lot of damage to Francis turbines that is expensive to repair.

One of the most successful high head turbines was developed in California during the gold rush from a device referred to as a ‘hurdy gurdy’ that was basically a cartwheel with buckets around the periphery. A carpenter by the name of Lester Pelton came up with the now familiar double bucket shape and went on to found ‘The Pelton Watewheel Company’ of San Francisco. The bucket design was later improved by Doble who joined the company as an engineer in 1899. Doble’s improvement is the central cut-out in the bucket that prevents the water jet from first striking the back of the bucket and wasting energy. www.oldpelton.net. Today, similar machines are operating from over 1000 metres of fall and generating up to 100MW of power.

A simple weir is all that is required to divert the stream into the penstock (pipeline) via a de-silting chamber to remove any sand. Water storage may be included if the terrain allows and if it is advantageous to generate more power for short periods or where it is necessary to store water for generation when flows are very low. A low-pressure pipe or open canal may also be used to reduce to overall cost if it allows a short steep decent to the powerhouse using less high-pressure pipe.

Pelton turbines are efficient over a very wide range of flows but at lower heads the speed is too low for belt drives, so we reduce the pitch circle and modify the bucket shape to increase the specific speed. The jets may have plain nozzles or adjustable spear valves to adjust the water consumption to the available stream flow. It is usual with larger machines to have ‘deflectors’ that divert the water away from the runner for controlling the speed without altering the water flow. They can also be used for emergency shutdown.

Turgo Impulse turbines, the name given by Gilkes of Kendal, is a ‘jet supplied impulse turbine’ that has its origins back in the early 19c when Herschel and Jonval and latterly Gunthers of Oldham made similar turbines. The ‘Turgo’ with one or more jets is often used for lower heads where it is necessary to keep the shaft speed up for direct driving the generator. A two jet ‘Turgo’ runs at about twice the RPM of an equivalent four jet pelton, and the runner is significantly smaller but the efficiency is a little lower.

For thousands of years waterpower has been harnessed for milling and pumping water. In the Developing World many are still in daily use, but in Western Countries they have usually fallen into disrepair as a result of competition from diesel and electric power. In the U.K. there were over 70,000 working mills at the end of the 18th century and now there are a few hundred. These mills fall into a number of categories that will determine their suitability for redevelopment.

The waterwheels that were used on these sites in the U.K. are usually of the Roman or horizontal shaft type, though the vertical shaft type is much more common in Mediterranean and Asian countries. Depending on the fall of water available, the horizontal wheels are classified into ‘Overshot’, ‘Breast-shot’, ‘Back-shot’ and ‘Under-shot’. With the exception of projects to restore a mill to its original design, or where the visual appearance is important to maintain, only the overshot wheel is suitable for a new power generation projects.

Overshot waterwheels are the most fish-friendly and able to handle leaves and sticks. A similar device is the Noria or chain wheel, which has the disadvantage of potential more maintenance, but it runs faster, is more efficient and easier to install than an overshot waterwheel.

The power available is a function of the head and flow so building a large wheel will only increase the cost and reduce the shaft speed but not increase the power. Major components in the cost are the primary gearbox and the material required in the construction of the wheel itself. We are happy to build any type of waterwheel, but the cost is likely to be significantly greater than that of an equivalent turbine, when you take the gearing and installation costs into consideration. There are no short cuts with waterwheels and the engineering has to be good, on account of the high torque in the low speed drive.

Mills with ponds are seldom suitable for redevelopment for anything other than a few kilowatts because the water flow is obviously too little to sustain the mill on a continuous basis, and it is much too expensive to install a wheel or turbine that can only be operated for a few hours a day. In some cases the ponds were only used in the summer months when the water was low, but today we are looking to the higher winter flow for the bulk of the power that can be used for heating. There is always a loss of head into and out of the pond, but this may be recoverable with a turbine installation.

Mills with leats, lades or channels take their water from a water course along the side of a valley at a gradient that is usually less than one in five hundred. At a suitable point when enough fall can be achieved in one place, the mill is built. The only limitations to future development are the actual head and flow available. Since there was a mill there anyway there should be enough power for domestic purposes. Improvements to the leat and head are usually possible but are very site specific. Modern mini excavators make leat widening and maintenance much easier than when the mills were first built.

Mills on weirs or with short wide diversion channels present the most difficult challenge for the developer. The available head may only be a metre or so and the flow required to generate useful amounts of power will be several cubic metres of water per second. The undershot waterwheels that were originally used at these sites are totally redundant on account of their high cost and low efficiency. The exact layout of the site becomes increasingly important with the lower falls, because access for excavators and to install the large items of equipment is more difficult.

Open flume installations are the most usual for the very low head sites, and employ fixed geometry propeller turbines on account of their simple construction and high ‘specific speed’. The more complex variable ‘Kaplan’ type turbines are not economic for these small schemes and it is easier to achieve ‘flow control’ by installing more than one machine or by running until the water has fallen by say 100mm and then switching off automatically until it has come up again. This latter system can be used for heating

Tubular turbines of the propeller type can be used for mill sites with a higher head, typically those that originally employed ‘Overshot’ waterwheels. Many different arrangements are possible to suite existing civil works but the main compromise arises from their inflexible performance. If the mill is only extracting a small percentage of the available water from the main river, then there is no problem. If however the water flow reduces below that which is required to supply the turbine, either water storage, another smaller turbine or a change in turbine speed will be required.

Low cost open impulse turbineshave been developed by us, primarily for projects in the Developing World. Installed outside the mill house like a waterwheel, it is an economic alternative for smaller domestic sites here in the U.K. They cannot be used with a draft tube since the runner is open to the atmosphere but the installation and maintenance is much simpler. The valve control shaft is extended through the mill house wall to an operating lever on the ,inside or a simple open shoot conveys the water directly to the runner in the manner of the old ‘flutter wheels’ used in the USA in the 19c. Installation work is usually kept to a minimum and may be in an old waterwheel pit or even behind an existing wheel under the launder. A vertical shaft version like the Indian Gharat can produce considerably more power by increasing the entry area, whilst maintaining its self-cleaning characteristics.

Portable turbines are highly adaptable and be assembled on site in a few hours. Applications include ‘Rural Development’, camping and field hospitals. Typical outputs range from 200 watts to 50 kW. The inlet works are prefabricated and the pipeline is either flexible polyethylene or ‘lay-flat’ coiled pipe. The whole unit can be built into a trailer or air-portable unit for rapid deployment in the field. The buckets that are divided along their centre line by a splitter ridge, turn the jet of water that is directed at them, through 1800 so that the energy is transferred efficiently to the shaft.

Turbines that are suitable for a particular type of site and turbines that are suitable for particular type of application are referred to as ‘groups’. Hence you can have a group of ‘Hillstream’ turbines for upland sites, or a group of ‘Agricultural’ turbines for agricultural applications. The site may be defined topographically as an upland or ‘Hillstream’ site, or as a lowland or ‘Millstream’ site. Each of these groups I then divided into two sub-groups depending on the actual site layout and general features. The ‘Hillstream’ group is comprised of vertical and horizontal shaft impulse turbines that may be either direct drive, belt drive or overhung from the generator. The application for the plant may be to generate electricity, mechanically power machinery or pump water for irrigation or for a drinking water supply. The application will also have a bearing on the materials, the sophistication, the governing system and the general build.

Water Power, when properly developed, is the most faithful, the mostwonderful power in the world. A water wheel will run day in and day out,year in and year out, with practically no care and attention and will furnishelectric light and power, pump water and drive machinery.

There are three principal kinds of Water Wheels;-the Overshoot, the Turbine,and the Impulse. Each type of Wheel has its own particular use and is suitedto its own particular conditions.

The proper selection of the Water Wheel is the most important part of aWater Power Plant. We have known business which have failed because theOwners did not select the right kind of Water Wheel to drive their machinery.

It is not only vital that the proper type of Water Wheel be selected butalso the proper size of that particular type. In these matters our Engineersare expert.

Believing that you will be more interested in seeing the actual resultsobtained on Water Power work than in a technical description of these installations,we are showing you in out Catalogue photographs of Plants which we haveinstalled and which are in operation at the present time. Also, we are showingsome illustrations of general layouts of Plants.

It is not always necessary to have a Water-fall as shown on the oppositepage to develop Water Power. We often utilize the rapids or the gentle slopein a stream.

When selecting a Water Power to use commercially or a Country Estate witha Water Power on it, it is to the Owner"s advantage to have an experiencedHydraulic Engineer examine the Water Power and advise him what it is worthbefore he buys. We shall be pleased to send an Engineer to do this for you.

We plan, manufacture, and install Water Wheels; plan and construct completeHydro-Electric Plants, including dams, flumes, power houses, Water Wheels,and electrical equipment, also complete Water Wheel Pumping Plants and ElectricPumping Plants.

It does not matter to us how small or how large an installation may be.We take the same pleasure and interest in installing the smallest WaterWheel Pumping Plant as we do the largest Hydro-Electric Plant.

Overshoot Water Wheels are used on ordinary streams from 6 inches to12 feet in width, and with falls from 4 feet to 60 feet in height. All creeks,except the very largest should have Overshoot Water Wheels installed onthem.

An Overshoot Water Wheel derives its power from the weight of the water,which falls into the buckets on the rim of the Wheel, and exerts its poweron the Wheel by leverage.

Our modern Copper-bearing Iron Overshoot Water Wheels, electrically weldedthroughout, are the finest Overshoot Water Wheels yet built. In the past,Iron Overshoot Wheels were built by riveting pieces of metal together. Thousandsof rivet holes were punched in the metal, which weakened it. Due to thestrains set up in the Wheel, many rivets became loose, and the Wheel beganto spurt water through the open holes in the metal. Also, often the metalcracked along the rivet line. Our Welded Water Wheels are a solid pieceof metal which cannot break or leak. All the parts of our Welded Wheelsare so joined together that they have the strength of a latticed girder.

The buckets of our Wheels are so designed that they carry all the wateralmost to the extreme bottom of the Wheel before it is spilled into thetail-race. With this type of bucket, not a drop of water falls on the Wheelthat does not do its work and deliver its power to the shaft, which transmitsit to the generator, pump, or machinery.

We not only planned and installed the Water Wheel, but also furnished andinstalled all the shafting and gearing, all the burr stones, and the flourmaking machinery within the Mill, and turned the Plant over to Mr. Fordcomplete and in operation.

The Hoops were made of one board, and the wooden screw jack was cut froma piece of apple wood before the days of iron screw jacks. The bins, wherethe whole wheat and buckwheat flour and the water ground corn meal are stored,are shown in the right foreground.

A 1 1/2- inch pipe of water flowing from a spring, which drives the 30foot diameter by 1 foot wide Overshoot Water Wheel and pumps water to a20,00 gallon reservoir on top of a hill at Andorra Nurseries, Chestnut Hill,Philadelphia, Pennsylvania. From the reservoir the water is distributedunder high pressure to all parts of the Nursery.

Later, we increased the flow of the spring so it would supply a Water Businessin Philadelphia, as well as operate the Wheel and furnish the water forthe Nursery.

The Water Wheel has operated continuously for four years without attention,except new grease on the ball bearings every six months, and an occasionaloiling and new leathers for the pump.

Overshoot Water Wheel, 17 feet in diameter by 6 feet wide, driving Hydro-ElectricPlant of Mr. R. S. Ward at his Willowemoc Creek Fish Hatchery, DeBruce,Sullivan County, New York.

The Water Wheel furnishes all of the electric light and power for the Hatchery,which includes operating a large refrigerating plant that freezes the foodfor the fish. It also furnishes light and power for the Country Home ofHonorable Charles B. Ward and Debruce Inn, which are nearby. Besides lightand power, the Plant furnishes heat for the buildings in the winter.

A welded Water Wheel is a solid piece of metal. There are no seams or holesto leak and rust as in riveted Wheels. The space within a welded Wheel betweenthe spokes runs perfectly dry.

Because all of the water from the stream falls into the buckets of a weldedWheel and cannot get out but must give up its power to the Wheel, a weldedWater Wheel is more efficient than a riveted Wheel.

Many of our our customers ask us if we are going to spoil the beauty oftheir streams when we develop their Water Powers. We have never yet spoiledthe beauty of a stream. There are always means of utilizing Water Powerswithout detracting from the beauty of streams.

The above photograph shows a stream where the Water Power has been developedby us, and no one would ever know any water had been taken from the streamor that a pipe line had been used to carry the water to the Water Wheel.The pipe line is under the rocks in the middle of the stream.

Our Overshoot Water Wheel, 11 feet in diameter and 1 1/2 feet wide, at theJohn C. Campbell Folk School, Brasston, North Carolina, solved the problemof pumping spring water to a high reservoir. A shaft further utilizes thatpower for a saw, lathe, and sander in the Wood-Working Shop.

Turbine Water Wheels are used where the flow of water are very large,such as rivers or very large creeks. They should never be used on smallstreams, because it takes too much water to run them. Where a heavy flowof water is available, they will operate efficiently.

Turbine Water Wheels utilize a fall of from 4 feet to several hundred feet,but they are used principally for heads under 100 feet with large flows.Single Turbines will develop from 2 to 50,000 horse power.

A Turbine Water Wheel develops power by the pressure of the water againstthe blades of the Turbine, which forces it around. All the working mechanismof a Turbine is under water and cannot be seen.

There are both Vertical and Horizontal Turbine Water Wheels, and it dependsupon the conditions prevailing at that particular power site as to whichkind of Turbine should be used. The selection of the Turbine should be leftto our Engineer.

Vertical Turbine Installed in a wooden penstock. The water enters the Turbinethrough the vanes just above the floor and leaves through the circular openingsat the bottom. In going through the Turbine the water presses against theblades of the Turbine and turns it around and thus gives up its power tothe Turbine.

From the jaw coupling at the top of the Turbine, a shaft is carried upwardsand the power is taken off the vertical shaft, either with gears or a pulley.Often the generator itself is attached to the vertical shaft.

The smaller coupling at the left of the center of the Turbine is for attachingthe gate rod, which extends upwards and generally has a hand wheel on top.By means of the hand wheel the gates of the Turbine are opened and closed.

Horizontal Turbine, which will drive a generator, pump or other machineryfrom the Turbine shaft. Often the generator is connected directly to theshaft itself.

The water enters the Turbine through the opening at the center of the pictureand leaves the Turbine through the openings pointing downward between theI-beams. A pipe brings the water to the Turbine and another takes it away.The latter is generally short and is called a "draft tube." Thepipes are not shown in the illustration.

A Vertical Turbine installed in a concrete penstock. At the top of the verticalshaft a pair of bevel gears transmit the power to a horizontal shaft, fromwhich it is transmitted to a generator, pump or line shaft by a pulley andbelt.

The water comes to the Turbine through a steel pipe that is not shown inthe illustration, and leaves the Turbine through the short draft tube andconcrete flume at the bottom.

Impulse Water Wheels are used where the Water falls are very high from100 to several thousand feet in height. They utilize flows of water froma stream 4 inches wide to 8 or 10 feet wide. Where the streams are wider,two or more Impulse Wheels are used. An Impulse Wheel will develop froma fraction of the horse power to several thousand horse power.

Impulse Wheels are generally used in mountainous countries. They are simplein construction and small in size compared with the power that they produce,and can easily be carried over the mountains to the location where theyare to be installed.

In an Impulse Wheel, the water comes out of a nozzle, like a fire nozzle,and strikes small cups on the rim of the wheel, and the force of the waterstriking these buckets turns the Wheel. The principle on which the ImpulseWheel operates it shown in the illustration below.

The Water Wheel is 24 inches in diameter. The case is in two parts and theupper part can be removed, which gives easy access to the Wheel and thenozzle.

General view of installation of an Impulse Water Wheel. The long pipe linecarries the water from the top of the hill to the Wheel in the house inthe valley below. It looks like an incline railroad up a mountainside.

A notch is cut in a board of ample size to carry the full flow of thestream and the board is placed across the stream so that all of the waterhas a free fall through the notch. The bottom of the notch is made exactlylevel.

Six to eight feet up stream from the board a stake is driven into the wateruntil the top of the stake is on a level with the bottom of the notch. Thedepth of the water is then measured on this stake and with this measurementand the width of the notch our Engineers can calculate the flow of the stream.

In the photograph a man is shown measuring down the top of the stake, whichis under the water. The stake shown in the photograph is not the one towhich he is measuring, but only a guard stake.

It is necessary to cut off all the flow of water underneath the weir andthis is often very difficult to do, especially where the flow of water inthe stream is large.

First of all, send to us for a Hydraulic Engineer. Here is where youmake the first great saving. Our charges for an expert Engineer are veryreasonable. A Water Power Development requires a specialist, an Engineerwho understands hydraulics, Water Wheels, pipe lines, and the constructionof dams and power houses. The advice of our experienced Engineer keep youform making costly mistakes in this highly specialized work.

Our Engineer will take accurate measurements of the fall and flow of yourStream and will advise you definitely how much power can be developed. Also,he will lay out your Plant for you, show you where the dam and power houseshould be places, advise you whether it is better to lead the water to theWater Wheel through an open race or a pipe line, and go over with you manyother important points regarding your installation.

From the data which he gathers, we will submit to you a full written report,covering in detail the amount of power which you can develop, the propersize and kind of Water Wheel to install, and the cost of dam, power house,electrical equipment and transmission line.

Power wheels, the overshot in particular, benefits from several often overlooked design features. Operational reliability and ruggedness are very high in a practical installation, the overshot tolerates heavily silted waters, flood debris, rocks, rubbish and outright vandalism. The high rotational inertia and increased static torque create a self cleaning mechanism that breaks tangled fishing lines and carrier bags. Fish and all aquatic life are completely unaffected and water quality may be slightly improved.

The overshot and midshot wheels are very much more efficient than often stated, indeed the overshotis the most efficient energy extractor for limited applications. We make hese to any size; Our Ultra Ultra low head midshots operate in impossibly low head situations finding great favour with utilities and agencies for continuous small or transient high power demands.

We have solutions to address the specific needs applicable to domestic, water, communications and environmental management. Our special purpose team can engineer power solutions for all load demands, try our team of hardened optimists before giving up on your project ! 01525 874226

A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets arranged on the outside rim forming the driving car. Water wheels were still in commercial use well into the 20th century but they are no longer in common use. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre 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. 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.

Waterwheels were used for various purposes from agriculture to metallurgy in ancient civilizations spanning the Hellenistic Greek world, Rome, China and India. Waterwheels saw continued use in the Post-classical age, like the Middle Ages of Europe and the Islamic Golden Age, but also elsewhere. In the mid to late 18th century John Smeaton"s scientific investigation of the water wheel led to significant increases in efficiency supplying much needed power for the Industrial Revolution.turbine, developed by Benoît Fourneyron, beginning with his first model in 1827.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.

Overshot and backshot water wheels are typically used where the available height difference is more than a couple of meters. Breastshot wheels are more suited to large flows with a moderate head. Undershot and stream wheel use large flows at little or no head.

There is often an associated millpond, a reservoir for storing water and hence energy until it is needed. Larger heads store more gravitational potential energy for the same amount of water so the reservoirs for overshot and backshot wheels tend to be smaller than for breast shot wheels.

Overshot and pitchback water wheels are suitable where there is a small stream with a height difference of more than 2 metres (6.5 ft), often in association with a small reservoir. Breastshot and undershot wheels can be used on rivers or high volume flows with large reservoirs.

Stream wheels are cheaper and simpler to build and have less of an environmental impact, than other types of wheels. They do not constitute a major change of the river. Their disadvantages are their low efficiency, which means that they generate less power and can only be used where the flow rate is sufficient. A typical flat board undershot wheel uses about 20 percent of the energy in the flow of water striking the wheel as measured by English civil engineer John Smeaton in the 18th century.

Stream wheels mounted on floating platforms are often referred to as hip wheels and the mill as a ship mill. They were sometimes mounted immediately downstream from bridges where the flow restriction of the bridge piers increased the speed of the current.

An undershot wheel is a vertically mounted water wheel with a horizontal axle that is rotated by the water from a low weir striking the wheel in the bottom quarter. Most of the energy gain is from the movement of the water and comparatively little from the head. They are similar in operation and design to stream wheels.

The word breastshot is used in a variety of ways. Some authors restrict the term to wheels where the water enters at about the 10 o’clock position, others 9 o’clock, and others for a range of heights.

The small clearance between the wheel and the masonry requires that a breastshot wheel has a good trash rack ("screen" in British English) to prevent debris from jamming between the wheel and the apron and potentially causing serious damage.

Breastshot wheels are less efficient than overshot and backshot wheels but they can handle high flow rates and consequently high power. They are preferred for steady, high-volume flows such as are found on the Fall Line of the North American East Coast. Breastshot wheels are the most common type in the United States of America

A vertically mounted water wheel that is rotated by water entering buckets just past the top of the wheel is said to be overshot. The term is sometimes, erroneously, applied to backshot wheels, where the water goes down behind the wheel.

A typical overshot wheel has the water channeled to the wheel at the top and slightly beyond the axle. The water collects in the buckets on that side of the wheel, making it heavier than the other "empty" side. The weight turns the wheel, and the water flows out into the tail-water when the wheel rotates enough to invert the buckets. The overshot design is very efficient, it can achieve 90%,

Nearly all of the energy is gained from the weight of water lowered to the tailrace although a small contribution may be made by the kinetic energy of the water entering the wheel. They are suited to larger heads than the other type of wheel so they are ideally suited to hilly countries. However even the largest water wheel, the Laxey Wheel in the Isle of Man, only utilises a head of around 30 m (100 ft). The world"s largest head turbines, Bieudron Hydroelectric Power Station in Switzerland, utilise about 1,869 m (6,132 ft).

Overshot wheels require a large head compared to other types of wheel which usually means significant investment in constructing the headrace. Sometimes the final approach of the water to the wheel is along a flume or penstock, which can be lengthy.

A backshot wheel (also called pitchback) is a variety of overshot wheel where the water is introduced just before the summit of the wheel. In many situations, it has the advantage that the bottom of the wheel is moving in the same direction as the water in the tailrace which makes it more efficient. It also performs better than an overshot wheel in flood conditions when the water level may submerge the bottom of the wheel. It will continue to rotate until the water in the wheel pit rises quite high on the wheel. This makes the technique particularly suitable for streams that experience significant variations in flow and reduces the size, complexity, and hence cost of the tailrace.

The direction of rotation of a backshot wheel is the same as that of a breastshot wheel but in other respects, it is very similar to the overshot wheel. See below.

Some wheels are overshot at the top and backshot at the bottom thereby potentially combining the best features of both types. The photograph shows an example at Finch Foundry in Devon, UK. The head race is the overhead timber structure and a branch to the left supplies water to the wheel. The water exits from under the wheel back into the stream.

A special type of overshot/backshot wheel is the reversible water wheel. This has two sets of blades or buckets running in opposite directions so that it can turn in either direction depending on which side the water is directed. Reversible wheels were used in the mining industry in order to power various means of ore conveyance. By changing the direction of the wheel, barrels or baskets of ore could be lifted up or lowered down a shaft or inclined plane. There was usually a cable drum or a chain basket on the axle of the wheel. It is essential that the wheel have braking equipment to be able to stop the wheel (known as a braking wheel). The oldest known drawing of a reversible water wheel was by Georgius Agricola and dates to 1556.

The earliest waterwheel working like a lever was described by Zhuangzi in the late Warring States period (476-221 BC). It says that the waterwheel was invented by Zigong, a disciple of Confucius in the 5th century BC.Chinese of the Eastern Han Dynasty were using water wheels to crush grain in mills and to power the piston-bellows in forging iron ore into cast iron.

In the text known as the Xin Lun written by Huan Tan about 20 AD (during the usurpation of Wang Mang), it states that the legendary mythological king known as Fu Xi was the one responsible for the pestle and mortar, which evolved into the tilt-hammer and then trip hammer device (see trip hammer). Although the author speaks of the mythological Fu Xi, a passage of his writing gives hint that the water wheel was in widespread use by the 1st century AD in China (Wade-Giles spelling):

Fu Hsi invented the pestle and mortar, which is so useful, and later on it was cleverly improved in such a way that the whole weight of the body could be used for treading on the tilt-hammer (tui), thus increasing the efficiency ten times. Afterwards the power of animals—donkeys, mules, oxen, and horses—was applied by means of machinery, and water-power too used for pounding, so that the benefit was increased a hundredfold.

In the year 31 AD, the engineer and Prefect of Nanyang, Du Shi (d. 38), applied a complex use of the water wheel and machinery to power the bellows of the blast furnace to create cast iron. Du Shi is mentioned briefly in the Hou Han Shu) as follows (in Wade-Giles spelling):

In the seventh year of the Chien-Wu reign period (31 AD) Tu Shih was posted to be Prefect of Nanyang. He was a generous man and his policies were peaceful; he destroyed evil-doers and established the dignity (of his office). Good at planning, he loved the common people and wished to save their labor. He invented a water-power reciprocator (shui phai) for the casting of (iron) agricultural implements. Those who smelted and cast already had the push-bellows to blow up their charcoal fires, and now they were instructed to use the rushing of the water (chi shui) to operate it ... Thus the people got great benefit for little labor. They found the "water(-powered) bellows" convenient and adopted it widely.

Water wheels in China found practical uses such as this, as well as extraordinary use. The Chinese inventor Zhang Heng (78–139) was the first in history to apply motive power in rotating the astronomical instrument of an armillary sphere, by use of a water wheel.mechanical engineer Ma Jun (c. 200–265) from Cao Wei once used a water wheel to power and operate a large mechanical puppet theater for the Emperor Ming of Wei (r. 226–239).

The ancient Greeks invented the waterwheel independently and used it in nearly all of the forms and functions described above, including its application for watermilling.Hellenistic period between the 3rd and 1st century BC.

The compartmented water wheel comes in two basic forms, the wheel with compartmented body (Latin tympanum) and the wheel with compartmented rim or a rim with separate, attached containers.sakia gear.

The earliest literary reference to a water-driven, compartmented wheel appears in the technical treatise Pneumatica (chap. 61) of the Greek engineer Philo of Byzantium (ca. 280−220 BC).Parasceuastica (91.43−44), Philo advises the use of such wheels for submerging siege mines as a defensive measure against enemy sapping.dry docks in Alexandria under the reign of Ptolemy IV (221−205 BC).papyri of the 3rd to 2nd century BC mention the use of these wheels, but don"t give further details.Ancient Near East before Alexander"s conquest can be deduced from its pronounced absence from the