In railroading, the pilot is the device mounted at the front of a locomotive to deflect obstacles on the track that might otherwise derail the train. In addition to the pilot, small metal bars called life-guards, rail guards or guard irons are provided in front of the wheels, they knock away smaller obstacles lying directly on the running surface of the railhead. Fenced-off railway systems in Europe relied on those devices and did not use pilots, but that design is used in modern systems. Instead of a pilot, trams use. Objects lying on the tram track get hit by a sensor bracket, which triggers the lowering of a basket-shaped device to the ground, preventing the overrunning of the obstacles and dragging them along the road surface in front of the wheels. In snowy areas the pilot has the function of a snowplow; the pilot was invented by Charles Babbage in the 19th century, during his period of working for the Liverpool and Manchester Railway. However, Babbage's invention was not built, it is uncertain whether users were aware of Babbage's idea.
On a mainline locomotive, the pilot has to deflect an obstacle hit at speed. The locomotive should not lift on impact or the train will follow, the ideal is for a smooth structure so that the locomotive will not get caught and derailed; the typical shape is a blunt wedge, shallowly V-shaped in plan. In the days of steam locomotives, the front coupler was designed to swing out of the way so it could not get caught up. Early on, pilots were fabricated of bars mounted on a frame. Early diesel locomotives followed the same plan. Early shunting locomotives had a pilot with steps on it to allow yard workers to ride on the locomotive. In some countries, footboard pilots are outlawed for safety reasons, have been removed. Modern locomotives have front and rear platforms with safety rails where workers can ride. Most modern European rail vehicles must have pilots with snowplow rail guards by law; the required strength of the system is 30 kN in 50 kN near the rails. Modern US diesel locomotives have flatter, less wedge-shaped pilots, because a diesel locomotive has the cab near the front, the crew are vulnerable to impact from obstacles pushed up by the pilot.
To protect the crew and passengers, most modern locomotives and passenger cars have a device known as an anti-climber fitted above the coupler, designed to prevent colliding vehicles from travelling up over the frame and through the locomotive cab or passenger car. Where a pilot is not fitted, a different type of anti-climber may be used; this is to prevent one passenger car from telescoping in a collision. Bullbar Buffer stop Headstock "Notes and News: Pilot Engines and Present"; the Railway Magazine. Vol. 91 no. 556. Westminster: Railway Publishing Company. March–April 1945. Pp. 117–118. - describes seven other meanings of the word "pilot" used on Britain's railways. "Hubris and the Cowcatcher by John H. White Jr". Railroad History. Pflugerville, Texas: Railway & Locomotive Historical Society: 86–91. Fall–Winter 2016. - describes Lorenzo Davies, alleged inventor of the cowcatcher
Package cushioning is used to protect items during shipment. Vibration and impact shock during shipment and loading/unloading are controlled by cushioning to reduce the chance of product damage. Cushioning is inside a shipping container such as a corrugated box, it is designed to absorb shock by crushing and deforming, to dampen vibration, rather than transmitting the shock and vibration to the protected item. Depending on the specific situation, package cushioning is between 50 and 75 millimeters thick. Internal packaging materials are used for functions other than cushioning, such as to immobilize the products in the box and lock them in place, or to fill a void; when designing packaging the choice of cushioning depends on many factors, including but not limited to: effective protection of product from shock and vibration resilience resistance to creep – cushion deformation under static load material costs labor costs and productivity effects of temperature and air pressure on cushioning cleanliness of cushioning effect on size of external shipping container environmental and recycling issues sensitivity of product to static electricity Loose fill – Some cushion products are flowable and are packed loosely around the items in the box.
The box is closed to tighten the pack. This includes expanded polystyrene foam pieces, similar pieces made of starch-based foams, common popcorn; the amount of loose fill material required and the transmitted shock levels vary with the specific type of material. Paper – Paper can be manually or mechanically wadded up and used as a cushioning material. Heavier grades of paper provide more weight-bearing ability than old newspapers. Creped cellulose wadding is available. Corrugated fiberboard pads – Multi-layer or cut-and-folded shapes of corrugated board can be used as cushions; these structures are designed to crush and deform under shock stress and provide some degree of cushioning. Paperboard composite honeycomb structures are used for cushioning. Foam structures – Several types of polymeric foams are used for cushioning; the most common are: Expanded Polystyrene, polypropylene and polyurethane. These can be molded engineered sheets which are cut and glued into cushion structures. Convoluted foams sometimes used.
Some degradable foams are available. Foam-in-place is another method of using polyurethane foams; these fill the box encapsulating the product to immobilize it. It is used to form engineered structures. Molded pulp – Pulp can be molded into shapes suitable for cushioning and for immobilizing products in a package. Molded pulp is recyclable. Inflated products – Bubble wrap consists of sheets of plastic film with enclosed “bubbles” of air; these sheets can be wrapped around items to be shipped. A variety of engineered inflatable air cushions are available. Note that inflated air pillows used for void-fill are not suited for cushioning. Other – Several other types of cushioning are available including suspension cushions, thermoformed end caps, various types of shock mounts. Proper performance of cushioning is dependent on its proper use, it is best to use a trained packaging engineer, reputable vendor, consultant, or independent laboratory. An engineer needs to know the severity of shock to protect against.
This can be based on an existing specification, published industry standards and publications, field studies, etc. Knowledge of the product to be packaged is critical. Field experience may indicate the types of damage experienced. Laboratory analysis can help quantify the fragility of the item reported in g's. Engineering judgment can be an excellent starting point. Sometimes a product can be made more rugged or can be supported to make it less susceptible to breakage; the amount of shock transmitted by a particular cushioning material is dependent on the thickness of the cushion, the drop height, the load-bearing area of the cushion. A cushion must deform under shock for it to function. If a product is on a large load-bearing area, the cushion may not deform and will not cushion the shock. If the load-bearing area is too small, the product may “bottom out” during a shock. Engineers use “cushion curves” to choose the best thickness and load-bearing area for a cushioning material. Two to three inches of cushioning are needed to protect fragile items.
Cushion design requires care to prevent shock amplification caused by the cushioned shock pulse duration being close to the natural frequency of the cushioned item. The process for vibration protection involves similar considerations as that for shock. Cushions can be thought of as performing like springs. Depending on cushion thickness and load-bearing area and on the forcing vibration frequency, the cushion may 1) not have any influence on input vibration, 2) amplify the input vibration at resonance, or 3) isolate the product from the vibration. Proper design is critical for cushion performance. Verification and validation of prototype designs are required; the design of a package and its cushioning is an iterative process involving several designs, redesigns, etc. Several published package testing protocols are available to evaluate the performance of a proposed package. Field performance should be monitored for feedback into the design process. D1596 Standard Test Method for D
Rail transport is a means of transferring of passengers and goods on wheeled vehicles running on rails known as tracks. It is commonly referred to as train transport. In contrast to road transport, where vehicles run on a prepared flat surface, rail vehicles are directionally guided by the tracks on which they run. Tracks consist of steel rails, installed on ties and ballast, on which the rolling stock fitted with metal wheels, moves. Other variations are possible, such as slab track, where the rails are fastened to a concrete foundation resting on a prepared subsurface. Rolling stock in a rail transport system encounters lower frictional resistance than road vehicles, so passenger and freight cars can be coupled into longer trains; the operation is carried out by a railway company, providing transport between train stations or freight customer facilities. Power is provided by locomotives which either draw electric power from a railway electrification system or produce their own power by diesel engines.
Most tracks are accompanied by a signalling system. Railways are a safe land transport system. Railway transport is capable of high levels of passenger and cargo utilization and energy efficiency, but is less flexible and more capital-intensive than road transport, when lower traffic levels are considered; the oldest known, man/animal-hauled railways date back to the 6th century BC in Greece. Rail transport commenced in mid 16th century in Germany in the form of horse-powered funiculars and wagonways. Modern rail transport commenced with the British development of the steam locomotives in the early 19th century, thus the railway system in Great Britain is the oldest in the world. Built by George Stephenson and his son Robert's company Robert Stephenson and Company, the Locomotion No. 1 is the first steam locomotive to carry passengers on a public rail line, the Stockton and Darlington Railway in 1825. George Stephenson built the first public inter-city railway line in the world to use only the steam locomotives all the time, the Liverpool and Manchester Railway which opened in 1830.
With steam engines, one could construct mainline railways, which were a key component of the Industrial Revolution. Railways reduced the costs of shipping, allowed for fewer lost goods, compared with water transport, which faced occasional sinking of ships; the change from canals to railways allowed for "national markets" in which prices varied little from city to city. The spread of the railway network and the use of railway timetables, led to the standardisation of time in Britain based on Greenwich Mean Time. Prior to this, major towns and cities varied their local time relative to GMT; the invention and development of the railway in the United Kingdom was one of the most important technological inventions of the 19th century. The world's first underground railway, the Metropolitan Railway, opened in 1863. In the 1880s, electrified trains were introduced, leading to electrification of tramways and rapid transit systems. Starting during the 1940s, the non-electrified railways in most countries had their steam locomotives replaced by diesel-electric locomotives, with the process being complete by the 2000s.
During the 1960s, electrified high-speed railway systems were introduced in Japan and in some other countries. Many countries are in the process of replacing diesel locomotives with electric locomotives due to environmental concerns, a notable example being Switzerland, which has electrified its network. Other forms of guided ground transport outside the traditional railway definitions, such as monorail or maglev, have been tried but have seen limited use. Following a decline after World War II due to competition from cars, rail transport has had a revival in recent decades due to road congestion and rising fuel prices, as well as governments investing in rail as a means of reducing CO2 emissions in the context of concerns about global warming; the history of rail transport began in the 6th century BC in Ancient Greece. It can be divided up into several discrete periods defined by the principal means of track material and motive power used. Evidence indicates that there was 6 to 8.5 km long Diolkos paved trackway, which transported boats across the Isthmus of Corinth in Greece from around 600 BC.
Wheeled vehicles pulled by men and animals ran in grooves in limestone, which provided the track element, preventing the wagons from leaving the intended route. The Diolkos was in use for over 650 years, until at least the 1st century AD; the paved trackways were later built in Roman Egypt. In 1515, Cardinal Matthäus Lang wrote a description of the Reisszug, a funicular railway at the Hohensalzburg Fortress in Austria; the line used wooden rails and a hemp haulage rope and was operated by human or animal power, through a treadwheel. The line still exists and is operational, although in updated form and is the oldest operational railway. Wagonways using wooden rails, hauled by horses, started appearing in the 1550s to facilitate the transport of ore tubs to and from mines, soon became popular in Europe; such an operation was illustrated in Germany in 1556 by Georgius Agricola in his work De re metallica. This line used "Hund" carts with unflanged wheels running on wooden planks and a vertical pin on the truck fitting into the gap between the planks to keep it going the right way.
The miners called the wagons Hunde from the noise. There are many references to their use in central Europe in the 16th century; such a transport system was used by German miners at Cal
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is rather referred to as multiple units, motor coaches, railcars or power cars. Traditionally, locomotives pulled trains from the front. However, push-pull operation has become common, where the train may have a locomotive at the front, at the rear, or at each end; the word locomotive originates from the Latin loco – "from a place", ablative of locus "place", the Medieval Latin motivus, "causing motion", is a shortened form of the term locomotive engine, first used in 1814 to distinguish between self-propelled and stationary steam engines. Prior to locomotives, the motive force for railways had been generated by various lower-technology methods such as human power, horse power, gravity or stationary engines that drove cable systems. Few such systems are still in existence today. Locomotives may generate their power from fuel, or they may take power from an outside source of electricity.
It is common to classify locomotives by their source of energy. The common ones include: A steam locomotive is a locomotive whose primary power source is a steam engine; the most common form of steam locomotive contains a boiler to generate the steam used by the engine. The water in the boiler is heated by burning combustible material – coal, wood, or oil – to produce steam; the steam moves reciprocating pistons which are connected to the locomotive's main wheels, known as the "drivers". Both fuel and water supplies are carried with the locomotive, either on the locomotive itself or in wagons called "tenders" pulled behind; the first full-scale working railway steam locomotive was built by Richard Trevithick in 1802. It was constructed for the Coalbrookdale ironworks in Shropshire in the United Kingdom though no record of it working there has survived. On 21 February 1804, the first recorded steam-hauled railway journey took place as another of Trevithick's locomotives hauled a train from the Pen-y-darren ironworks, in Merthyr Tydfil, to Abercynon in South Wales.
Accompanied by Andrew Vivian, it ran with mixed success. The design incorporated a number of important innovations including the use of high-pressure steam which reduced the weight of the engine and increased its efficiency. In 1812, Matthew Murray's twin-cylinder rack locomotive Salamanca first ran on the edge-railed rack-and-pinion Middleton Railway. Another well-known early locomotive was Puffing Billy, built 1813–14 by engineer William Hedley for the Wylam Colliery near Newcastle upon Tyne; this locomotive is the oldest preserved, is on static display in the Science Museum, London. George Stephenson built Locomotion No. 1 for the Stockton and Darlington Railway in the north-east of England, the first public steam railway in the world. In 1829, his son Robert built The Rocket in Newcastle-upon-Tyne. Rocket was entered into, won, the Rainhill Trials; this success led to the company emerging as the pre-eminent early builder of steam locomotives used on railways in the UK, US and much of Europe.
The Liverpool and Manchester Railway, built by Stephenson, opened a year making exclusive use of steam power for passenger and goods trains. The steam locomotive remained by far the most common type of locomotive until after World War II. Steam locomotives are less efficient than modern diesel and electric locomotives, a larger workforce is required to operate and service them. British Rail figures showed that the cost of crewing and fuelling a steam locomotive was about two and a half times larger than the cost of supporting an equivalent diesel locomotive, the daily mileage they could run was lower. Between about 1950 and 1970, the majority of steam locomotives were retired from commercial service and replaced with electric and diesel-electric locomotives. While North America transitioned from steam during the 1950s, continental Europe by the 1970s, in other parts of the world, the transition happened later. Steam was a familiar technology that used widely-available fuels and in low-wage economies did not suffer as wide a cost disparity.
It continued to be used in many countries until the end of the 20th century. By the end of the 20th century the only steam power remaining in regular use around the world was on heritage railways. Internal combustion locomotives use an internal combustion engine, connected to the driving wheels by a transmission, they keep the engine running at a near-constant speed whether the locomotive is stationary or moving. Kerosene locomotives use kerosene as the fuel, they were the world's first oil locomotives, preceding diesel and other oil locomotives by some years. The first known kerosene locomotive was a draisine built by Daimler in 1887. A kerosene locomotive was built in 1894 by the Priestman Brothers of Kingston upon Hull for use on Hull docks; this locomotive was built using a 12 hp double-acting marine type engine, running at 300 rpm, mounted on a 4-wheel wagon chassis. It was only able to haul one loaded wagon at a time, due to its low power output, was not a great success; the first successful kerosene locomotive was "Lachesis" built by Richard Hornsby & Sons Ltd. and delivered to Woolwich Arsenal railway in 1896.
The company built a series of kerosene locomotives between 1896 and 1903, for use by the British military. Petrol locomotives use petrol as their fuel. Most petrol locomotives built were petrol-mechanical, using a mechanical transmission to deliver the power output of the engine t
A coupling is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, is as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together; the equipment that connects the couplings to the rolling stock is known as the draft gear or draw gear. The different types of coupling do not always have formal or official names, which makes descriptions of the couplings in use on any railway system problematic; the basic type of coupling on railways following the British tradition is the buffer and chain coupling. A large chain of three links connects hooks on the adjoining wagons; these couplings were made more regular. Buffers on the frame of the wagon absorbed impact loads; the simple chain could not be tensioned and this slack coupling allowed a lot of back-and-forth movement and banging between vehicles. Acceptable for mineral wagons, this gave an uncomfortable ride for passenger coaches, so the chain was improved by replacing the centre link with a turnbuckle that draws the vehicles together, giving the screw coupling.
A simplified version of this, quicker to attach and detach, still used three links but with the centre link given a T-shaped slot. This could be turned lengthwise to lengthen it, allowing coupling turned vertically to the shorter slot position, holding the wagons more together. Higher speeds associated with fully-fitted freight made the screw-tensioned form a necessity; the earliest'dumb buffers' were fixed extensions of the wooden wagon frames, but spring buffers were introduced. The first of these were stiff cushions of leather-covered horsehair steel springs and hydraulic damping; this coupling is still widespread. The link-and-pin coupling was the original style of coupling used on North American railways. After most railroads converted to semi-automatic Janney couplers, the link-and-pin survived on forestry railways. While simple in principle, the system suffered from a lack of standardisation regarding size and height of the links, the size and height of the pockets; the link-and-pin coupler consisted of a tube-like body.
During coupling, a rail worker had to stand between the cars as they came together and guide the link into the coupler pocket. Once the cars were joined, the employee inserted a pin into a hole a few inches from the end of the tube to hold the link in place; this procedure was exceptionally dangerous and many brakemen lost fingers or entire hands when they did not get them out of the way of the coupler pockets in time. Many more were killed as a result of being crushed between cars or dragged under cars that were coupled too quickly. Brakemen were issued with heavy clubs that could be used to hold the link in position, but many brakemen would not use the club, risked injury; the link-and-pin coupler proved unsatisfactory because: It made a loose connection between the cars, with too much slack action. There was no standard design, train crews spent hours trying to match pins and links while coupling cars. Crew members had to go between moving cars during coupling, were injured and sometimes killed.
The links and pins were pilfered due to their value as scrap metal, resulting in substantial replacement costs. John H. White suggests that the railroads considered this to be more important than the safety issue at the time. Railroads progressively began to operate trains that were heavier than the link-and-pin system could cope with. An episode of the 1958 television series Casey Jones was devoted to the problems of link-and-pin couplings. To avoid the safety issues, Karl Albert director at the Krefeld Tramway, developed the Albert coupler during 1921, a key and slot coupler with two pins. Cars to be coupled were pushed together, both couplings moving to the same side. One pin was inserted the cars were pulled to straighten the coupling and the other pin inserted; this operation required less exact shunting. Due to the single-piece design, only minimal slack was possible; the system became quite popular with narrow gauge lines. During the 1960s most cities replaced them with automatic couplers.
But in modern cars, Albert couplers get installed as emergency couplers for towing a faulty car. The link and pin was replaced in North American passenger car usage during the latter part of the 19th century by the assemblage known as the Miller Platform, which included a new coupler called the Miller Hook; the Miller Platform was used for several decades before being replaced by the Janney coupler. Norwegian couplings consist of a central buffer with a mechanical hook that drops into a slot in the central buffer. There may be a U-shaped securing latch on the opposite buffer, fastened over the top of the hook to secure it; the Norwegian is found only on narrow gauge railways of 1,067 mm, 1,000 mm or less, such as the Isle of Man Railway, Western Australian Government Railways, the Ffestiniog Railway and the Welsh Highland Railway where low speeds and reduced train loads allow a simpler system. The Norwegian coupler allows sharper curves than the buffer-and-chain, an advantage on those railways.
On railway lines where rolling stock always points the same way, the mechanical hook may be provided only on one end of each wagon. The hand brake handles may be on one side of the wagons only. Norwegian couplings are not strong, may be supplemented by auxiliary chains. Not all Norwegian couplings are compatible with one another as they vary in height and may or may not be limited
Buffers and chain coupler
Buffers and chain coupler is the standard train coupling system used in Europe, outside the former Soviet Union. It is occasionally used outside Europe; the vehicles are coupled by hand using a hook and links with a turnbuckle that draws the vehicles together. In Britain, this is called a screw coupling. Vehicles have buffers, one at each corner on the ends, which are pulled together and compressed by the coupling device; this arrangement limits the slack in lessens shunting shocks. By contrast, the semi-automatic Janney coupler requires comparatively jarring encounters in order to engage the coupling fully; the earliest buffers were fixed extensions of the wagon frames, but spring buffers were introduced. The standard type of coupling on railways following the British tradition is the buffer and chain coupling used on the pioneering Planet class locomotive of the Liverpool and Manchester Railway of 1830; these couplings were made more regular. This coupling is still the standard in European countries.
Coupling is done by a worker. First he winds the turnbuckle to the loose position, he can hang the chain on the hook. After hanging the chain on the towing hook the turnbuckle handle is stowed on the idle hook to prevent damage to itself, the vehicle, or the brake pipes. Only shunting is permitted with a dangling chain. Disconnected brake pipes must be stowed on dummy connectors, to allow proper operation of the brakes; the hooks and chain hold the carriages together, while the buffers keep the carriages from banging into each other so that no damage is caused. The buffers can be spring-loaded; that means. The other benefit compared with automatic couplers is that its lesser slack causes smaller forces on curves; the disadvantage is the smaller mass of the freight that can be hauled by chain couplers. Early rolling stock was fitted with a pair of auxiliary chains as a backup if the main coupling failed; this made sense before the fitting of continuous fail-safe braking systems. On railways where rolling stock always pointed the same way, the chain might be mounted at one end only, as a small cost and weight saving measure.
On German and Scandinavian railways, the left buffer is flatter than the right one, more rounded. This provides better contact between the buffers than would be the case if both buffers were rounded. A peculiarly British practice was the "loose-coupled" freight train, operated by the locomotive crew and a'Guard' at the rear of the train, the successor to the brakesman of earlier times; this train type used three-link chain couplings for traction and side buffers to accept pushing forces: since such trains were not fitted with an automatic through-train braking system there were no pipes to connect between the vehicles. The last vehicle of the train was a ballasted guard's van with its brakes controllable by a handwheel convenient for the guard. The'slack' between vehicles was convenient when starting heavy trains with a low-powered locomotive on the level or a rising gradient. On the driver's command the guard would apply his brake as hard as possible; the driver would gently reverse to close up the wagons onto their buffers.
The locomotive was driven ahead and it could pick up the load, wagon by wagon, thus giving an easy start up the gradient. Wagons of that era didn't have roller bearings and the grease-lubricated bearings had considerable resistance to start moving on a cold day, so starting wagon-by-wagon reduced the traction force required from the locomotive; the downside of this convenience was that the guard could get badly thrown about as the train changed speed due to the inter-wagon gaps opening or closing. In the worst case these jerks could cause a derailment. A skilled guard would observe or listen to his train and apply or release his brake to keep the last few couplings reasonably taught and act as a shock-absorber; the same effect was seen when the route changed gradient, when going over a hill the rear of the train would catch up with the wagons held back by the locomotive, the guard could minimize this. This working of the brake was why the guard was required to prove his route knowledge, same as the driver, before being in charge of a heavy train.
Such trains were phased out in the 1970s. An improvement on this is the "Instanter" coupling, in which the middle link of a three link chain is specially triangular shaped so that when lying "prone" it provides enough slack to make coupling possible, but when this middle link is rotated 90 degrees the length of the chain is shortened, reducing the amount of slack without the need to wind a screw; the closeness of the coupling allows the use of inter-vehicle pipes for train brakes. Three-link and Instanter couplings can be operated from the side of the wagons using a shunter's pole and are safer when shunting work is under way; the screw-adjustable coupler can be connected by a shunter's pole once it has been unscrewed. Ordinary chain couplings have been superseded by screw or buck-eye couplers in UK freight trains today. On some narrow-gauge lines in Europe and on the
Hydraulics is a technology and applied science using engineering and other sciences involving the mechanical properties and use of liquids. At a basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, cover concepts such as pipe flow, dam design and fluid control circuitry; the principles of hydraulics are in use in the human body within the vascular system and erectile tissue. Free surface hydraulics is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, lakes and seas, its sub-field open-channel flow studies the flow in open channels. The word "hydraulics" originates from the Greek word ὑδραυλικός which in turn originates from ὕδωρ and αὐλός.
Early uses of water power date back to Mesopotamia and ancient Egypt, where irrigation has been used since the 6th millennium BC and water clocks had been used since the early 2nd millennium BC. Other early examples of water power include the Qanat system in ancient Persia and the Turpan water system in ancient Central Asia; the Greeks constructed sophisticated water and hydraulic power systems. An example is the construction by Eupalinos, under a public contract, of a watering channel for Samos, the Tunnel of Eupalinos. An early example of the usage of hydraulic wheel the earliest in Europe, is the Perachora wheel; the construction of the first hydraulic automata by Ctesibius and Hero of Alexandria is notable. Hero describes a number of working machines using hydraulic power, such as the force pump, known from many Roman sites as having been used for raising water and in fire engines; the Persians constructed an intricate system of water mills and dams known as the Shushtar Historical Hydraulic System.
The project, commenced by Achaemenid king Darius the Great and finished by a group of Roman engineers captured by Sassanian king Shapur I, has been referred to by UNESCO as "a masterpiece of creative genius." They were the inventors of the Qanat, an underground aqueduct. Several of Iran's large, ancient gardens were irrigated thanks to Qanats. In ancient China there was Sunshu Ao, Ximen Bao, Du Shi, Zhang Heng, Ma Jun, while medieval China had Su Song and Shen Kuo. Du Shi employed a waterwheel to power the bellows of a blast furnace producing cast iron. Zhang Heng was the first to employ hydraulics to provide motive power in rotating an armillary sphere for astronomical observation. In ancient Sri Lanka, hydraulics were used in the ancient kingdoms of Anuradhapura and Polonnaruwa; the discovery of the principle of the valve tower, or valve pit, for regulating the escape of water is credited to ingenuity more than 2,000 years ago. By the first century AD, several large-scale irrigation works had been completed.
Macro- and micro-hydraulics to provide for domestic horticultural and agricultural needs, surface drainage and erosion control and recreational water courses and retaining structures and cooling systems were in place in Sigiriya, Sri Lanka. The coral on the massive rock at the site includes cisterns for collecting water. Large ancient reservoirs of Sri Lanka are Kalawewa, Parakrama Samudra, Tisa Wewa, Minneriya In Ancient Rome, many different hydraulic applications were developed, including public water supplies, innumerable aqueducts, power using watermills and hydraulic mining, they were among the first to make use of the siphon to carry water across valleys, used hushing on a large scale to prospect for and extract metal ores. They used lead in plumbing systems for domestic and public supply, such as feeding thermae. Hydraulic mining was used in the gold-fields of northern Spain, conquered by Augustus in 25 BC; the alluvial gold-mine of Las Medulas was one of the largest of their mines. It was worked by at least 7 long aqueducts, the water streams were used to erode the soft deposits, wash the tailings for the valuable gold content.
In 1619 Benedetto Castelli, a student of Galileo Galilei, published the book Della Misura dell'Acque Correnti or "On the Measurement of Running Waters", one of the foundations of modern hydrodynamics. He served as a chief consultant to the Pope on hydraulic projects, i.e. management of rivers in the Papal States, beginning in 1626. Blaise Pascal studied fluid hydrodynamics and hydrostatics, centered on the principles of hydraulic fluids, his discovery on the theory behind hydraulics led to the invention of the hydraulic press by Joseph Bramah, which multiplied a smaller force acting on a smaller area into the application of a larger force totaled over a larger area, transmitted through the same pressure at both locations. Pascal's law or principle states that for an incompressible fluid at rest, the difference in pressure is proportional to the difference in height and this difference remains the same whether or not the overall pressure of the fluid is changed by applying an external force.
This implies that by increasing the pressure at any point in a confined fluid, there is an equal increase at every other point in the containe