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Required CSC Infrastructure: Room/Building having a place of 100-150 Sq. Ft. Two PC's with UPS with 5 hours battery back-up or portable generator set. PC with licensed Operating System of Windows 7 or above. Two Printers. (Inkjet+ Laser) RAM having the minimum storage capacity of 2 GB Hard Disc Drive of at least 250 GB Digital Camera/ Web Cam Wired/ Wireless/V-SAT Connectivity Biometric/IRIS Authentication Scanner for Banking Services. CD/DVD Drive UPS Integration History The CSC project, which forms a strategic component of the National eGovernance Plan was approved in September 2006. It is also one of the approved projects under the Integrated Mission Mode Projects of the National eGovernance Plan.
"CSC e-Governance Services India Limited" incorporated on 16 July 2009. The implementation of the CSC would be done in a Public–private partnership (PPP) model whereby the total project cost of Rs. 57.42 billion, over 4 years, would be shared between Government(30% equal to Rs. 16.49billion) and private finances (70% equal to Rs. 40.93 billion). The split between central and state government would be Rs. 8.56 billion and Rs. 7.93 billion respectively. As of 31st Jan 2011, 88,689 CSCs have been rolled out in thirty-one States/UTs. 100% CSCs have been rolled out in 11 (Eleven) States (Chandigarh, Delhi, Goa, Gujarat, Haryana, Jharkhand, Kerala, Manipur, Pondicherry, Sikkim & Tripura).
More than 80% of the rollout has been completed in 6 States (Assam, Bihar, Madhya Pradesh, Meghalaya, Mizoram, and West Bengal). In about 6 States (Chhattisgarh, Himachal Pradesh, Maharashtra, Orissa, Tamil Nadu, and Uttarakhand) implementation of CSCs have crossed halfway mark (more than 50%). It is expected that the rollout of 100,000 CSCs would be completed by March 2011. Revenue support to Common Service Centres It is envisaged that G2Cservices may take longer to be operational, hence the SCA(Service Centre Agencies) are to be provided support in the form of “Guaranteed Provision of Revenue from Governmental Services” over a period of four years, once the CSCs are certified as operational by the SDA(State Designed Agency).
The amount of revenue support is proposed to be 33.33% of the normative value which works out to Rs. 3304/- per CSC per month. This support is to be shared by the Union and State Governments in equal ratio. However, the exact amount of support is to be arrived at through a ‘price discovery mechanism’ discovered through bids (not to exceed 50% of the normative value). See also Digital India India Portal Ministry of Electronics and Information Technology References Category: Digital India initiatives
Titanium hydride normally refers to the inorganic compound TiH2 and related nonstoichiometric materials. It is commercially available as a stable grey/black powder, which is used as an additive in the production of Alnico sintered magnets, in the sintering of powdered metals, the production of metal foam, the production of powdered titanium metal and in pyrotechnics. Production and reactions of TiH(2-x) In the commercial process for producing non-stoichiometric TiH(2-x), titanium metal sponge is treated with hydrogen gas at atmospheric pressure at between 300-500 °C. Absorption of hydrogen is exothermic and rapid, changing the color of the sponge grey/black. The brittle product is ground to a powder, which has a composition around TiH1.95.
In the laboratory, titanium hydride is produced by heating titanium powder under flowing hydrogen at 700 °C, the idealized equation being: Ti + H2 → TiH2 Other methods of producing titanium hydride include electrochemical and ball milling methods. Reactions TiH1.95 is unaffected by water and air. It is slowly attacked by strong acids and is degraded by hydrofluoric and hot sulfuric acids. It reacts rapidly with oxidising agents, this reactivity leading to the use of titanium hydride in pyrotechnics. The material has been used to produce highly pure hydrogen, which is released upon heating the solid starting at 300 °C.
Only at the melting point of titanium is dissociation complete. Titanium tritiide has been proposed for the long-term storage of tritium gas. Structure As TiHx approaches stoichiometry, it adopts a distorted body-centered tetragonal structure, termed the ε-form with an axial ratio of less than 1. This composition is very unstable with respect to partial thermal decomposition, unless maintained under a pure hydrogen atmosphere. Otherwise, the composition rapidly decomposes at room temperature until an approximate composition of TiH1.74 is reached. This composition adopts the fluorite structure, and is termed the δ-form, and only very slowly thermally decomposing at room temperature until an approximate composition of TiH1.47 is reached, at which point, inclusions of the hexagonal close packed α-form, which is the same form as pure titanium, begin to appear.
The evolution of the dihydride from titanium metal and hydrogen has been examined in some detail. α-Titanium has a hexagonal close packed (hcp) structure at room temperature. Hydrogen initially occupies tetrahedral interstitial sites in the titanium. As the H/Ti ratio approaches 2, the material adopts the β-form to a face centred cubic (fcc), δ- form, the H atoms eventually filling all the tetrahedral sites to give the limiting stoichiometry of TiH2. The various phases are described in the table below. If titanium hydride contains 4.0% hydrogen at less than around 40 °C then it transforms into a body-centred tetragonal (bct) structure called ε-titanium.
When titanium hydrides with less than 1.3% hydrogen, known as hypoeutectoid titanium hydride are cooled, the β-titanium phase of the mixture attempts to revert to the α-titanium phase, resulting in an excess of hydrogen. One way for hydrogen to leave the β-titanium phase is for the titanium to partially transform into δ-titanium, leaving behind titanium that is low enough in hydrogen to take the form of α-titanium, resulting in an α-titanium matrix with δ-titanium inclusions. A metastable γ-titanium hydride phase has been reported. When α-titanium hydride with a hydrogen content of 0.02-0.06% is quenched rapidly, it forms into γ-titanium hydride, as the atoms "freeze" in place when the cell structure changes from hcp to fcc.
γ-Titanium takes a body centred tetragonal (bct) structure. Moreover, there is no compositional change so the atoms generally retain their same neighbours. Hydrogen embrittlement titanium and titanium alloys The absorption of hydrogen and the formation of titanium hydride are a source of damage to titanium and titanium alloys (Ti /Ti alloys). This hydrogen embrittlement process is of particular concern when titanium and alloys are used as structural materials, as in nuclear reactors. Hydrogen embrittlement manifests as a reduction in ductility and eventually spalling of titanium surfaces. The effect of hydrogen is to a large extent determined by the composition, metallurgical history and handling of the Ti /Ti alloy.
CP-titanium (commercially pure: ≤99.55% Ti content) is more susceptible to hydrogen attack than pure α-titanium. Embrittlement, observed as a reduction in ductility and caused by the formation of a solid solution of hydrogen, can occur in CP-titanium at concentrations as low as 30-40 ppm. Hydride formation has been linked to the presence of iron in the surface of a Ti alloy. Hydride particles are observed in specimens of Ti /Ti alloys that have been welded, and because of this welding is often carried out under an inert gas shield to reduce the possibility of hydride formation. Ti /Ti alloys form a surface oxide layer, composed of a mixture of Ti(II), Ti(III) and Ti(IV) oxides, which offers a degree of protection to hydrogen entering the bulk.
The thickness of this can be increased by anodizing, a process which also results in a distinctive colouration of the material. Ti /Ti alloys are often used in hydrogen containing environments and in conditions where hydrogen is reduced electrolytically on the surface. Pickling, an acid bath treatment which is used to clean the surface can be a source of hydrogen. Uses Common applications include ceramics, pyrotechnics, sports equipment, as a laboratory reagent, as a blowing agent, and as a precursor to porous titanium. When heated as a mixture with other metals in powder metallurgy, titanium hydride releases hydrogen which serves to remove carbon and oxygen, producing a strong alloy.
References Category:Titanium compounds Category:Metal hydrides Category:Reducing agents Category:Pyrotechnic fuels
Swan neck may refer to: Objects Swan neck, a curved spout for dispensing beer Swan neck duct, an air duct with a large change in mean radius Swan-neck bottle, a type of ornamental glass bottle made in Iran Swan neck flask, laboratory glassware designed to slow down the motion of air Swan-necked pediment, a variation of an architectural element Swan neck spur, a style of equestrian riding boot spur Swan-neck tow ball, a type of trailer tow ball People Edith Swan-neck, the first wife or mistress of King Harold II of England Conditions Swan neck deformity, a deformity of the human finger
The columnar phase is a class of mesophases in which molecules assemble into cylindrical structures to act as mesogens. Originally, these kinds of liquid crystals were called discotic liquid crystals or bowlic liquid crystals because the columnar structures are composed of flat-shaped discotic or bowl-shaped molecules stacked one-dimensionally. Since recent findings provide a number of columnar liquid crystals consisting of non-discoid mesogens, it is more common now to classify this state of matter and compounds with these properties as columnar liquid crystals. Takuzo Aida and co-workers recently reported cyclic peptides that self-assemble into polar columnar organizations. These materials can be unidirectionally aligned over large areas by application of an external electric field.
Classes Columnar liquid crystals are grouped by their structural order and the ways of packing of the columns. Nematic columnar liquid crystals have no long-range order and are less organized than other columnar liquid crystals. Other columnar phases with long-range order are classified by their two-dimensional lattices: hexagonal, tetragonal, rectangular, and oblique phases. The discotic nematic phase includes nematic liquid crystals composed of flat-shaped discotic molecules without long-range order. In this phase, molecules do not form specific columnar assemblies but only float with their short axes in parallel to the director (a unit vector which defines the liquid-crystalline alignment and order).
Current topics of interest The first discotic liquid crystal was found in 1977 by the Indian researcher Sivaramakrishna Chandrasekhar. This molecule has one central benzene ring surrounded by six alkyl chains. Since then, a large number of discoid mesogenic compounds have been discovered in which triphenylene, porphyrin, phthalocyanine, coronene, and other aromatic molecules are involved. The typical columnar liquid-crystalline molecules have a pi-electron-rich aromatic core attached by flexible alkyl chains. This structure is attracting particular attention for potential molecular electronics in which aromatic parts transport electrons or holes and alkyl chains act as insulating parts. The advantages of liquid-crystalline conductors are their anisotropy, processibility, and self-healing characteristics for structural defects.
References David Dunmur & Tim Sluckin (2011) Soap, Science, and Flat-screen TVs: a history of liquid crystals, pp 258–62, Oxford University Press . Category:Liquid crystals
The French 75 mm field gun was a quick-firing field artillery piece adopted in March 1898. Its official French designation was: Matériel de 75mm Mle 1897. It was commonly known as the French 75, simply the 75 and Soixante-Quinze (French for "seventy-five"). The French 75 was designed as an anti-personnel weapon system for delivering large volumes of time-fused shrapnel shells on enemy troops advancing in the open. After 1915 and the onset of trench warfare, other types of battlefield missions demanding impact-detonated high-explosive shells prevailed. By 1918 the 75s became the main agents of delivery for toxic gas shells. The 75s also became widely used as truck mounted anti-aircraft artillery.
They were also the main armament of the Saint-Chamond tank in 1918. The French 75 is widely regarded as the first modern artillery piece. It was the first field gun to include a hydro-pneumatic recoil mechanism, which kept the gun's trail and wheels perfectly still during the firing sequence. Since it did not need to be re-aimed after each shot, the crew could reload and fire as soon as the barrel returned to its resting position. In typical use, the French 75 could deliver fifteen rounds per minute on its target, either shrapnel or melinite high-explosive, up to about away.
Its firing rate could even reach close to 30 rounds per minute, albeit only for a very short time and with a highly experienced crew. At the opening of World War I, in 1914, the French Army had about 4,000 of these field guns in service. By the end of the war about 12,000 had been produced. It was also in service with the American Expeditionary Forces (AEF), which had been supplied with about 2,000 French 75 field guns. Several thousand were still in use in the French Army at the opening of World War II, updated with new wheels and tires to allow towing by trucks rather than by horses.
The French 75 set the pattern for almost all early-20th century field pieces, with guns of mostly 75 mm forming the basis of many field artillery units into the early stages of World War II. It is not to be confused with the Schneider-manufactured modele 1907 and "modele 1912" made for the French cavalry and the export market, and its 1914 modification or the Saint-Chamond-Mondragón 75mm gun. Although the Schneider used the original French 75's ammunition, these privately manufactured Schneider guns were lighter, smaller, and mechanically different. Development The forerunner of the French 75 was an experimental 57 mm gun which was first assembled in September 1891 at the Bourges arsenal under the direction of a Captain Sainte-Claire Deville.
This 57 mm gun took advantage of a number of the most advanced artillery technologies available at the time: 1) Vieille's smokeless powder, which was introduced in 1884. 2) Self-contained ammunition, with the powder charge in a brass case which also held the shell. 3) An early hydro-pneumatic short recoil mechanism that was designed by Major Louis Baquet. 4) A rotating screw breech built under license from Thorsten Nordenfelt. The only major design difference between the 57 and 75 that would emerge was the recoil system. But even before the 57 entered testing, in 1890 General Mathieu, Director of Artillery at the Ministry of War, had been informed that Konrad Haussner, a German engineer working at the Ingolstadt arsenal, had patented an oil-and-compressed-air long-recoil system.
They also learned that Krupp was considering introducing the system after testing it. Krupp would later reject Haussner's invention, due to insoluble technical problems caused by hydraulic fluid leakage. In 1891 Haussner sold his patents to a firm named Gruson, which searched for potential buyers. After reviewing the blueprints in February 1892, the French artillery engineers advised that a gun should be produced without purchasing the Haussner invention. Accordingly, General Mathieu turned to Lt. Colonel Joseph-Albert Deport, at the time the Director of the Atelier de Construction de Puteaux (APX), and asked him whether he could construct a gun on the general principle of the Haussner long-cylinder recoil without infringing the existing patents.
After it was judged possible, a formal request was sent out on 13 July 1892. It took five more years under the overall leadership of Mathieu's successor, General Deloye, to perfect and finally adopt in March 1898 an improved and final version of the Deport 75 mm long-recoil field gun. Various deceptions, some of them linked to the Dreyfus Case which erupted in 1894, had been implemented by Deloye and French counter-intelligence to distract German espionage. The final experimental version of Deport's 75 mm field gun was tested during the summer of 1894 and judged very promising. Extensive trials, however, revealed that it was still prone to hydraulic fluid leakage from the long-recoil mechanism.
The Deport 75 was returned to Puteaux arsenal for further improvements. Hydraulic fluid leakage was typical of this experimental phase of artillery development during the 1890s, as Haussner and Krupp had previously experienced. In December 1894, Deport was passed over for promotion, and resigned to join "Chatillon-Commentry", a private armaments firm. Two young military engineers from Ecole Polytechnique, Captains Etienne Sainte-Claire Deville and Emile Rimailho, continued development and introduced an improved version in 1896. Their contribution was a leakproof hydro-pneumatic long-recoil mechanism which they named "Frein II" (Brake # II). A major improvement was the placement of improved silver-alloy rings on the freely moving piston which separated the compressed air and the hydraulic fluid inside the main hydro-pneumatic recoil cylinder.
These and other modifications achieved the desired result: the long-term retention of hydraulic fluid and compressed air inside the recoil system, even under the worst field conditions. Captain Sainte-Claire Deville also designed important additional features, such as a device for piercing the fuzes of shrapnel shells automatically during the firing sequence (an "automatic fuze-setter"), thus selecting the desired bursting distance. The independent sight had also been perfected for easy field use by the crews, and a nickel-steel shield was added to protect the gunners. The armored caissons were designed to be tilted in order to present the shells horizontally to the crews.
The wheel brakes could be swung under each wheel ("abattage"), and, together with the trail spade, they immobilized the gun during firing. The gun was officially adopted on 28 March 1898 under the name "Matériel de 75mm Mle 1897". The public saw it for the first time during the Bastille Day parade of 14 July 1899. Description of the hydro-pneumatic recoil mechanism The gun's barrel slid back on rollers, including a set at the muzzle, when the shot was fired. The barrel was attached near the breech to a piston rod extending into an oil-filled cylinder placed just underneath the gun.
When the barrel recoiled, the piston was pulled back by the barrel's recoil and thus pushed the oil through a small orifice and into a second cylinder placed underneath. That second cylinder contained a freely floating piston which separated the surging oil from a confined volume of compressed air. During the barrel's recoil the floating piston was forced forward by the oil, compressing the air even further. This action absorbed the recoil progressively as the internal air pressure rose and, at the end of recoil, generated a strong but decreasing back pressure that returned the gun forward to its original position.
The smoothness of this system had no equal in 1897, and for at least another ten years. Each recoil cycle on the French 75, including the return forward, lasted about two seconds, permitting a maximum attainable firing rate of about 30 rounds per minute. Ammunition At the beginning in 1914, the French 75 fired two main types of shells, both with high muzzle velocities (535 m/s for the shrapnel shell ) and a maximum range of 8,500 meters. Their relatively flat trajectories extended all the way to the designated targets. French 75 shells, at least initially in 1914, were essentially anti-personnel.
They had been designed for the specific purpose of inflicting maximum casualties on enemy troops stationing or advancing in the open. A impact-detonated, thin-walled steel, high-explosive (HE) shell with a time-delay fuze. It was filled with picric acid, known in France as "Melinite", used since 1888. The delay lasted five hundredths of a second, designed to detonate the shell in the air and at a man's height after bouncing forward off the ground. These shells were particularly destructive to men's lungs when exploding in their proximity. A time-fused shrapnel shell containing 290 lead balls. The balls shot forward when the fuse's timer reached zero, ideally bursting high above the ground and enemy troops.
During 1914 and 1915, the shrapnel shell was the dominant type of ammunition found in the French 75 batteries. However, by 1918, high-explosive shells had become virtually the sole type of 75mm ammunition remaining in service. Furthermore, several new shells and fuses were introduced due to the demands of trench warfare. A boat-tailed shell (with a superior ballistic coefficient) which could reach was also used during the latter part of the war. Every shell, whether it be a high-explosive or shrapnel shell, was fixed to a brass case which was automatically ejected when the breech was opened. Rapid fire capability The French 75 introduced a new concept in artillery technology: rapid firing without realigning the gun after each shot.
Older artillery had to be resighted after each shot in order to stay on target, and thus fired no more than two aimed shots per minute. The French 75 easily delivered fifteen aimed rounds per minute and could fire even faster for short periods of time. This rate of fire, the gun's accuracy, and the lethality of the ammunition against personnel, made the French 75 superior to all other regimental field artillery at the time. When made ready for action, the first shot buried the trail spade and the two wheel anchors into the ground, following which all other shots were fired from a stable platform.
Bringing down the wheel anchors tied to the braking system was called "abattage". The gun could not be elevated beyond eighteen degrees, unless the trail spade had been deeply dug into the ground; however, the 75 mm field gun was not designed for plunging fire. The gun could be traversed laterally 3 degrees to the sides by sliding the trail on the wheel's axle. Progressive traversing together with small changes in elevation could be carried out while continuously firing, called "fauchage" or "sweeping fire". A 4-gun battery firing shrapnel could deliver 17,000 ball projectiles over an area 100 meters wide by 400 meters long in a single minute, with devastating results.
Because of the gun's traversing ability, the greater the distance to the enemy concentration, the wider the area that could be swept. World War I service Each Mle 1897 75 mm field gun battery (4 guns) was manned by highly trained crews of 170 men led by 4 officers recruited among graduates of engineering schools. Enlisted men from the countryside took care of the 6 horses that pulled each gun and its first limber. Another 6 horses pulled each additional limber and caisson which were assigned to each gun. A battery included 160 horses, most of them pulling ammunition as well as repair and supply caissons.
The French artillery entered the war in August 1914 with more than 4,000 Mle 1897 75 mm field guns (1,000 batteries of 4 guns each). Over 17,500 Mle 1897 75 mm field guns were produced during World War I, over and above the 4,100 French 75s which were already deployed by the French Army in August 1914. All the essential parts, including the gun's barrel and the oleo-pneumatic recoil mechanisms were manufactured by French State arsenals: Puteaux, Bourges, Châtellerault and St Etienne. A truck-mounted anti-aircraft version of the French 75 was assembled by the automobile firm of De Dion-Bouton and adopted in 1913.
The total production of 75 mm shells during World War I exceeded 200 million rounds, mostly by private industry. In order to increase shell production from 20,000 rounds per day to 100,000 in 1915, the government turned to civilian contractors, and, as a result, shell quality deteriorated. This led to an epidemic of burst barrels which afflicted 75 mm artillery during 1915. Colonel Sainte-Claire Deville corrected the problem, which was due to microfissures in the bases of the shells, due to shortcuts in manufacturing. Shell quality was restored by September 1915, but never to the full exacting standards of pre-war manufacture.
The French 75 gave its best performances during the Battle of the Marne in August–September 1914 and at Verdun in 1916. At the time the contribution of 75 mm artillery to these military successes, and thus to the French victories that ensued, was seen as significant. In the case of Verdun, over 1,000 French 75s (250 batteries) were constantly in action, night and day, on the battlefield during a period of nearly nine months. The total consumption of 75 mm shells at Verdun during the period February 21 to September 30, 1916, is documented by the public record at the Service Historique de l'Armée de Terre to have been in excess of 16 million rounds, or nearly 70% of all shells fired by French artillery during that battle.
The French 75 was a devastating anti-personnel weapon against waves of infantry attacking in the open, as at the Marne and Verdun. However, its shells were comparatively light and lacked the power to obliterate trench works, concrete bunkers and deeply buried shelters. Thus, with time, the French 75 batteries became routinely used to cut corridors with high-explosive shells, across the belts of German barbed wire. After 1916, the 75 batteries became the carriers of choice to deliver toxic gas shells, including mustard gas and phosgene. The French Army had to wait until early 1917 to receive in numbers fast-firing heavy artillery equipped with hydraulic recoil brakes (e.g.
the 155 mm Schneider howitzer and the long-range Canon de 155mm GPF). In the meantime it had to do with a total of about four thousand de Bange 90 mm, 120 mm and 155 mm field and converted fortress guns, all without recoil brakes, that were effective but inferior in rate of fire to the more modern German heavy artillery. The excessive reliance on the 75 mm field gun, a doctrine developed by the General Staff during the pre-war years, cost hundreds of thousands of French lives that were lost during the unsuccessful Joffre offensives (Artois/Champagne) in 1915. World War II service Despite obsolescence brought on by new developments in artillery design, large numbers of 75s were still in use in 1939 (4,500 in the French army alone), and they eventually found their way into a number of unlikely places.
A substantial number had been delivered to Poland in 1919–20, together with infantry ordnance, in order to fight in the Polish-Soviet War. They were known as 75mm armata wz.1897. In 1939 the Polish army had 1,374 of these guns, making it by far the most numerous artillery piece in Polish service. Some French guns were modernized between the wars, in part to adapt them for anti-tank fire, resulting in the Canon de 75 Mle 1897/33 which fired a high-explosive anti-tank shell. Many were captured by Germany during the Fall of France in 1940, in addition to Polish guns captured in 1939.
Over 3,500 were modified with a muzzle brake and mounted on a 5 cm Pak 38 carriage, now named 7.5 cm Pak 97/38 they were used by the Wehrmacht in 1942 as an emergency weapon against the Soviet Union's T-34 and KV tanks. Its relatively low velocity and a lack of modern armor-piercing ammunition limited its effectiveness as an anti-tank weapon. When the German 7.5 cm Pak 40 became available in sufficient numbers, most remaining Pak 97/38 pieces were returned to occupied France to reinforce the Atlantic Wall defenses or were supplied to Axis nations like Romania (PAK 97/38) and Hungary.
Non-modified remainders were used as second-line and coastal artillery pieces under the German designation 7.5 cm FK 231(f) and 7,5 cm FK 97(p). Romanian service Romania had a considerable number of World War I guns of 75 mm and 76.2 mm. Some models were modernized at Resita works in 1935 including French md. 1897. The upgrade was made with removable barrels. Several types of guns of close caliber were barreled to use the best ammunition available for 75 m m caliber which was explosive projectile model 1917 "Schneider". The new barrel was made of steel alloy with chrome and nickel with excellent mechanical resistance to pressure which allowed, after modifying the firing brake, the recovery arch and the sighting devices an increase of the range from 8.5 km to 11.2 km and a rate of fire of 20 rounds/minute.
During World War 2 these guns also used Costinescu 75 mm anti-tank round. These upgraded field guns were used in all infantry divisions in World War II. British service In 1915 Britain acquired a number of "autocanon de 75 mm mle 1913" anti-aircraft guns, as a stopgap measure while it developed its own anti-aircraft alternatives. They were used in the defence of Britain, usually mounted on de Dion motor lorries using the French mounting which the British referred to as the "Breech Trunnion". Britain also purchased a number of the standard 75 mm guns and adapted them for AA use using a Coventry Ordnance Works mounting, the "Centre Trunnion".
At the Armistice there were 29 guns in service in Britain. In June 1940, with many British field guns lost in the Battle of France, 895 M1897 field guns and a million rounds of ammunition were purchased from the US Army. For political purposes, the sale to the British Purchasing Commission was made through the US Steel Corporation. The basic, unmodified gun was known in British service as "Ordnance, QF, 75mm Mk 1", although many of the guns were issued to units on converted or updated mountings. They were operated by field artillery and anti-tank units. Some of the guns had their wheels and part of their carriages cut away so that they could be mounted on a pedestal called a "Mounting, 75mm Mk 1".
These weapons were employed as light coastal artillery and were not declared obsolete until March 1945. During World War II, the British also received the American half-track M3 Gun Motor Carriage under Lend Lease terms and used these in Italy and Northern Europe until the end of the war as fire support vehicles in Armored Car Regiments. US service The US Army adopted the French 75 mm field gun during World War I and used it extensively in battle. The US designation of the basic weapon was 75 mm Gun M1897. There were 480 American 75 mm field gun batteries (over 1,900 guns) on the battlefields of France in November 1918.
Manufacture of the French 75 by American industry began in the spring of 1918 and quickly built up to an accelerated pace. Carriages were built by Willys-Overland, the hydro-pneumatic recuperators by Singer Manufacturing Company and Rock Island Arsenal, the cannon itself by Symington-Anderson and Wisconsin Gun Company. American industry built 1,050 French 75s during World War I, but only 143 had been shipped to France by 11 November 1918; most American batteries used French-built 75s in action. The first US artillery shots in action in World War I were fired by Battery C, 6th Field Artillery on October 23, 1917 with a French 75 named "Bridget" which is preserved today at the United States Army Ordnance Museum.
During his service with the American Expeditionary Forces, Captain (and future U.S. President) Harry S. Truman commanded a battery of French 75s. By the early 1930s, the only US artillery units that remained horse-drawn were those assigned to infantry and cavalry divisions. During the 1930s, most M1897A2 and A3 (French made) and M1897A4 (American made) guns were subsequently modernized for towing behind trucks by mounting on the modern carriage M2A3 which featured a split trail, pneumatic rubber tires allowing towing at any speed, an elevation limit increased to 45 degrees, and traverse increased to 30 degrees left and right. Along with new ammunition, these features increased the effective range and allowed the gun to be used as an anti-tank gun, in which form it equipped the first tank destroyer battalions.
In 1941 these guns became surplus when were replaced by the M2A1 105 mm M101 split-trail Howitzer and were removed from their towed carriages and installed on the M3 Half-Track as the M3 Gun Motor Carriage (GMC). M3 GMCs were used in the Pacific theater during the Battle for the Philippines and by Marine Regimental Weapons Companies until 1944. The M3 GMC also formed the equipment of the early American Tank Destroyer Battalions during operations in North Africa and Italy and continued in use with the British in Italy and in small numbers in Northern Europe until the end of the war.
Many others were used for training until 1942. The 75mm M2 and M3 tank guns of the M3 Lee and M4 Sherman Medium tanks, the 75mm M6 tank gun of the M24 Chaffee light tank and the 75mm gun of the -G and -H subtypes of the B-25 Mitchell bomber all used the same ammunition as the M1897. The 75mm Pack Howitzer M1 used the same projectiles fired from a smaller 75x272R case. Contemporary usage The Canon de 75 modèle 1897 is still used in France as a saluting gun. When the French Army discarded its 105 HM2 howitzers to replace them with MO-120-RT mortars, only 155mm artillery pieces remained, for which no blank cartridges were available.
The Army then recommissioned two Canon de 75 modèle 1897, then located at the Musée de l'Artillerie de Draguignan. They are used for State ceremonies. Variants and derivatives Naval and coastal artillery The French Navy adopted the 75mm modèle 1897 for its coastal batteries and warships The 75mm modèle 1897–1915 was placed on SMCA modèle 1925 mountings with a vertical elevation of -10 to +70° and a 360° rotation. This allowed it to be used in an anti-aircraft role. New 75 mm guns were developed specifically for anti-aircraft use. The '75 mm modèle 1922', '75 mm modèle 1924' and '75 mm modèle 1927' of 50 calibre were developed from the 62.5 calibre '75 mm Schneider modèle 1908' mounted on the Danton-class battleships.
Field artillery canon de 75 mm mle 1897 modifié 1938 motorized artillery variant with wooden wheels replaced by metallic wheels with tyres, altered shield Mountain gun canon de 75 M(montagne) modèle 1919 Schneider canon de 75 M(montagne) modèle 1928 Anti-aircraft autocanon de 75 mm mle 1913 self-propelled anti-aircraft variant, on De Dion-Bouton chassis using Canon de 75 antiaérien mle 1913-1917. canon de 75 mm contre-aéroplanes sur plateforme mle 1915 static anti-aircraft variant on rotating platform canon de 75 mm contre-aéroplanes mle 1917 anti-aircraft variant on 1-axle trailer with stabilizer legs. Anti-tank Canon de 75 mm mle 1897 modifié 1933 similar shield and wheels as the standard version, but split-trail carriage allowing 58° traverse.
Used in the anti-tank role 7.5 cm Pak 97/38 Several thousand captured French guns were modified by the Germans during World War II as makeshift anti-tank guns, by adding a Swiss-designed muzzle brake and mounting it on German-built carriages. See also French 75 (cocktail) – cocktail named for the gun United States home front during World War I Notes References [Detailed history.] http://www.1939.pl/uzbrojenie/polskie/artyleria/a_75mm_wz97/index.html External links Manual For The Battery Commander. 75-mm Gun. FROM "L'ECOLE DU COMMANDANT DU BATTERIE, I PARTIE, CANON 75", Of THE FRENCH ARTILLERY SCHOOL, OF DECEMBER, 1916, CORRECTED TO MARCH, 1917. Translated to English and republished by US Army War College 1917 Notes on the French 75-mm Gun.
US Army War College. October 1917 Range tables for French 75-/mm Gun Model 1897 Firing tables 75 Millimeter Gun Material Model of 1897 M1 (French). Pages 80–93 in "Handbook of artillery : including mobile, anti-aircraft and trench matériel (1920)" United States. Army. Ordnance Dept, May 1920 United States War Department. TM 9-305 Technical Manual 75-MM Gun Matériel, M1897 and Modifications. 31 March 1941 List and pictures of World War I surviving 75 mm Mle 1897 guns Canon de 75 Modèle 1897 Photos of a reproduction or restored US M1918 limber for the 75 mm gun M1897 with all accoutrements Category:World War I guns Category:World War I field artillery of France Category:World War I artillery of the United States Category:75 mm artillery Category:World War II weapons of France Category:Articles containing video clips
Raymond Tripier (1838–1916) was a French physician and pathologist. From 1858 to 1862 he worked as interne des hôpitaux in Lyon, afterwards supporting his doctorate in Paris (1863) with a dissertation on spontaneous arterio-venous aneurysms of the aorta and superior vena cava, "De l'anéurysme artério-veineux spontané de l'aorte et de la veine cave supérieure". In 1866 he became médecin des hôpitaux in Lyon, and from 1884 to 1908 was chair of pathological anatomy to the Faculté de Médecine. He was a patron of the arts, after retiring from teaching he devoted his time to museum work in Lyon. Written works He is remembered for his studies of cardiovascular and respiratory diseases, Etudes anatomo-cliniques; coeur, vaisseaux, poumons (Anatomo-clinical studies of the heart, vessels and lungs, 1909).
Another principal work of his was a treatise on pathological anatomy titled Traité d’Anatomie Pathologique Générale (1904). Other noted writings by Tripier include: La fiévre typhoide traitée par les bains froids, with Léon Bouveret, 1886 (Typhoid fever: treatment by cold baths). Die Kaltwasserbehandlung des Typhus, with Léon Bouveret, 1889 Rôle de la péritonite sous-hépatique dans la pathogenie des hernies abdominales, with Jean Paviot, 1909 (Role of subhepatic peritonitis in the pathogenesis of abdominal hernias). Instinct et intelligence comme fonction synthétique de l'organisme humain pour sa conservation applications pratiques aux diverses phases de l'existence, 1911 (Instinct and intelligence: a synthetic function of the human organism for its preservation: practical applications in various phases of life).
Considérations pratiques sur l'art, les artistes, les musées: peinture et sculpture, 1913. References IDREF.fr (biographical information) Category:French pathologists Category:University of Lyon faculty Category:1838 births Category:1916 deaths
Cai Lun (; ; c. 48–121 CE), courtesy name Jingzhong (敬仲), was a Chinese eunuch, inventor, and politician of the Han dynasty. He is traditionally regarded as the inventor of paper and the papermaking process, in forms recognizable in modern times as paper (as opposed to papyrus). Although early forms of paper had existed in China since the 2nd century BCE, he was responsible for the first significant improvement and standardization of papermaking by adding essential new materials into its composition. Cai Lun served in the court of Emperor He of Han (reigned 88–106), who granted him an aristocratic title and great wealth, and the court of Empress Deng Sui who is considered the first to champion the use of paper.
Cai was a supporter of Empress Dou and played a part in the death of her rival Consort Song. In CE 121, Emperor An of Han (reigned 106 to 125), a grandson of Consort Song, gave commands for the imprisonment of Cai Lun. Cai Lun committed suicide by poison before the imperial order could be carried out. Cai was later revered in Chinese ancestor worship. Fei Zhu of the later Song Dynasty (960–1279) wrote that a temple in honor of Cai Lun had been erected in Chengdu. Invention of paper Cai Lun (蔡伦) was born in Guiyang (modern day Leiyang, Hunan) during the Eastern Han Dynasty to a low class merchant family.
After castration followed by serving as a court eunuch from CE 75, he was given several promotions under the rule of Emperor He of Han. In CE 89, he was promoted with the title of Shang Fang Si, an office in charge of manufacturing instruments and weapons; he also became a Regular Palace Attendant (中常侍). He was involved in palace intrigue as a supporter of Empress Dou, and in the death of her romantic rival, Consort Song. After the death of Empress Dou in CE 97, he became an associate of Consort Deng Sui. In 105 CE, Cai invented the composition for paper along with the papermaking process—though he may have received the credit for an invention by someone from a lower class.
There is also a legend that says Cai received inspiration for making paper from watching paper wasps make their nests. Tools and machinery of papermaking in modern times may be more complex, but they still employ the ancient technique of felted sheets of fiber suspended in water, draining of the water, and then drying into a thin matted sheet. For this invention Cai would be world-renowned posthumously, and even in his own time he was given recognition for his invention. A part of his official biography written later in China read thus (Wade–Giles spelling): As listed above, the papermaking process included mostly mulberry and other barks, hemp, rags, and fishing net; his exact formula has been lost.
Emperor He was pleased with the invention and granted Cai an aristocratic title and great wealth. In CE 121, Consort Song's grandson Emperor An of Han assumed power after Empress Deng's death and Cai was ordered to report to prison. Before he was to report, he committed suicide by drinking poison after taking a bath and dressing in fine silk robes. Cai was later revered in Chinese ancestor worship. Fei Zhu of the later Song Dynasty (960–1279) wrote that a temple in honor of Cai Lun had been erected in Chengdu, where several hundred families involved in the papermaking industry traveled five miles (8 km) from the south to come and pay respects.
Influence The creator of this extremely important invention is only somewhat known outside East Asia. After Cai invented the papermaking process in 105, it became widely used as a writing medium in China by the 3rd century. It enabled China to develop its civilization (through widespread literature and literacy) much faster than it had with earlier writing materials (primarily bamboo and silk, the latter of which was a more expensive medium). By the 600s, China's papermaking technique had spread to Korea, Vietnam, and Japan. In CE 751, some Chinese papermakers were captured by Arabs after Tang troops were defeated in the Battle of Talas River.
The techniques of papermaking then spread to the West. When paper was first introduced to Europe in the 12th century, it gradually revolutionized the manner in which written communication could be spread from region to region. Along with contact between Arabs and Europeans during the Crusades (with the essential recovery of ancient Greek written classics), the widespread use of paper aided the foundation of the Scholastic Age in Europe. Notes References Sources Category:48 births Category:121 deaths Category:1st-century Chinese people Category:2nd-century Chinese people Category:Chinese inventors Category:Chinese politicians who committed suicide Category:Han dynasty eunuchs Category:Han dynasty politicians Category:Inventors who committed suicide Category:Male suicides Category:Papermakers Category:Papermaking in China Category:People from Leiyang Category:Suicides by poison
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truck. They subsequently fell from use due to advances in poppet-valve technology, including sodium cooling, and the Knight system double sleeve engine's tendency to burn a lot of lubricating oil or to seize due to lack of it. The Scottish Argyll company used its own, much simpler and more efficient, single sleeve system (Burt-McCollum) in its cars, a system which, after extensive development, saw substantial use in British aircraft engines of the 1940s, such as the Napier Sabre, Bristol Hercules, Centaurus, and the promising but never mass-produced Rolls-Royce Crecy, only to be supplanted by the jet engines.
Description A sleeve valve takes the form of one or more machined sleeves. It fits between the piston and the cylinder wall in the cylinder of an internal combustion engine, where it rotates and/or slides. Ports (holes) in the side of the sleeves come into alignment with the cylinder's inlet and exhaust ports at the appropriate stages in the engine's cycle. Types of sleeve valve The first successful sleeve valve was patented by Charles Yale Knight, and used twin alternating sliding sleeves. It was used in some luxury automobiles, notably Willys, Daimler, Mercedes-Benz, Minerva, Panhard, Peugeot and Avions Voisin. Mors adopted double sleeve-valve engines made by Minerva.
The higher oil consumption was heavily outweighed by the quietness of running and the very high mileages without servicing. Early poppet-valve systems required decarbonization at very low mileages. The Burt-McCollum sleeve valve was named for the two inventors who applied for similar patents within a few weeks of each other. The Burt system was an open sleeve type, driven from the crankshaft side, while the McCollum design had a sleeve in the head and upper part of the cylinder, and a more complex port arrangement (Source: 'Torque Meter' Magazine, AEHS). The design that entered production was more 'Burt' than 'McCollum.'
It was used by the Scottish company Argyll for its cars, and was later adopted by Bristol for its radial aircraft engines. It used a single sleeve which rotated around a timing axle set at 90 degrees to the cylinder axis. Mechanically simpler and more rugged, the Burt-McCollum valve had the additional advantage of reducing oil consumption (compared to other sleeve valve designs), while retaining the combustion chambers and big, uncluttered, porting area possible in the Knight system. A small number of designs used a "cuff" sleeve in the cylinder head instead of the cylinder proper, providing a more "classic" layout compared to traditional poppet valve engines.
This design also had the advantage of not having the piston within the sleeve, although in practice this appears to have had little practical value. On the downside, this arrangement limited the size of the ports to that of the cylinder head, whereas in-cylinder sleeves could have much larger ports. Advantages/disadvantages Advantages The main advantages of the sleeve-valve engine are: High volumetric efficiency due to very large port openings. Sir Harry Ricardo also demonstrated better mechanical and thermal efficiency. The size of the ports can be readily controlled. This is important when an engine operates over a wide RPM range, since the speed at which gas can enter and exit the cylinder is defined by the size of the duct leading to the cylinder, and varies according to the cube of the RPM.
In other words, at higher RPM the engine typically requires larger ports that remain open for a greater proportion of the cycle; this is fairly easy to achieve with sleeve valves, but difficult in a poppet valve system. Good exhaust scavenging and controllable swirl of the inlet air/fuel mixture in single-sleeve designs. When the intake ports open, the air/fuel mixture can be made to enter tangentially to the cylinder. This helps scavenging when exhaust/inlet timing overlap is used and a wide speed range required, whereas poor poppet valve exhaust scavenging can dilute the fresh air/fuel mixture intake to a greater degree, being more speed dependent (relying principally on exhaust/inlet system resonant tuning to separate the two streams).
Greater freedom of combustion chamber design (few constraints other than the spark plug positioning) means that fuel/air mixture swirl at top dead centre (TDC) can also be more controlled, allowing improved ignition and flame travel which, as demonstrated by H. Ricardo, allows at least one extra unit of compression ratio before detonation, compared with the poppet valve engine. The combustion chamber formed with the sleeve at the top of its stroke is ideal for complete, detonation-free combustion of the charge, as it does not have to contend with compromised chamber shape and hot exhaust (poppet) valves. No springs are involved in the sleeve valve system, therefore the power needed to operate the valve remains largely constant with the engine's RPM, meaning that the system can be used at very high speeds with no penalty for doing so.
A problem with high-speed engines that use poppet valves is that as engine speed increases, the speed at which the valve moves also has to increase. This in turn increases the loads involved due to the inertia of the valve, which has to be opened quickly, brought to a stop, then reversed in direction and closed and brought to a stop again. Large poppet valves that allow good air-flow have considerable mass and require a strong spring to overcome their inertia when closing. At higher engine speeds, the valve spring may be unable to close the valve before the next opening event, resulting in a failure to completely close.
This effect, called valve float, can result in the valve being struck by the top of the rising piston. In addition, camshafts, push-rods, and valve rockers can be eliminated in a sleeve valve design, as the sleeve valves are generally driven by a single gear powered from the crankshaft. In an aircraft engine, this provided desirable reductions in weight and complexity. Longevity, as demonstrated in early automotive applications of the Knight engine. Prior to the advent of leaded gasolines, poppet-valve engines typically required grinding of the valves and valve seats after 20,000 to 30,000 miles (32,000 to 48,000 km) of service.
Sleeve valves did not suffer from the wear and recession caused by the repetitive impact of the poppet valve against its seat. Sleeve valves were also subjected to less intense heat build-up than poppet valves, owing to their greater area of contact with other metal surfaces. In the Knight engine, carbon build-up actually helped to improve the sealing of the sleeves, the engines being said to "improve with use", in contrast to poppet valve engines, which lose compression and power as valves, valve stems, and guides wear. Due to the continuous motion of the sleeve (Burt-McCollum type), the high wear points linked to poor lubrication in the TDC/BDC (bottom dead centre) of piston travel within the cylinder are suppressed, so rings and cylinders lasted much longer.
The cylinder head is not required to host valves, allowing the spark plug to be placed in the best possible location for efficient ignition of the combustion mixture. For very big engines, where flame propagation speed limits both size and speed, the swirl induced by ports, as described by Harry Ricardo can be an additional advantage. In his research with two-stroke single sleeve valve compression ignition engines, Harry Ricardo proved that an open sleeve was feasible, acting as a second annular piston with 10% of the central piston area, that transmitted 3% of the power to the output shaft through the sleeve driving mechanism.
This highly simplifies construction, as the 'junk head' is no longer needed. Lower operating temperatures of all power-connected engine parts, cylinder and pistons. Harry Ricardo showed that as long as the clearance between sleeve and cylinder is adequately settled, and the lubricating oil film is thin enough, sleeves are 'transparent to heat'. Continental in the United States conducted extensive research in single sleeve valve engines, pointing out that they were eventually of lower production cost and easier to produce. However, their aircraft engines soon equaled the performance of single-sleeve-valve engines by introducing improvements such as sodium-cooled poppet valves, and it seems also that the costs of this research, along with the October 1929 crisis, led to the Continental single-sleeve-valve engines not entering mass production.
A book (Continental! Its Motors and Its People, W. Wagner, 1983. ) on Continental engines reports that General Motors had conducted tests with single sleeve valve engines, rejecting this kind of arrangement, and, according to M. Hewland (Car & Driver, July 1974) also Ford around 1959. Most of these advantages were evaluated and established during the 1920s by Roy Fedden and Harry Ricardo, possibly the sleeve valve engine's greatest advocate. He conceded that some of these advantages were significantly eroded as fuels improved up to and during World War II and as sodium-cooled exhaust valves were introduced in high-output aircraft engines.
Disadvantages A number of disadvantages plagued the single sleeve valve: Perfect, even very good, sealing is difficult to achieve. In a poppet valve engine, the piston possesses piston rings (at least three and sometimes as many as eight) which form a seal with the cylinder bore. During the "breaking in" period (known as "running-in" in the UK) any imperfections in one are scraped into the other, resulting in a good fit. This type of "breaking in" is not possible on a sleeve-valve engine, however, because the piston and sleeve move in different directions and in some systems even rotate in relation to one another.
Mike Hewland claimed the run-in time for rings in his SSV designs was 10 hrs. Unlike a traditional design, the imperfections in the piston do not always line up with the same point on the sleeve. In the 1940s this was not a major concern because the poppet valve stems of the time typically leaked appreciably more than they do today, so that oil consumption was significant in either case. To one of the 1922–1928 Argyll single sleeve valve engines, the 12, a four-cylinder 91 cu. in. (1,491 cc) unit, was attributed an oil consumption of one gallon for 1,945 miles, and 1,000 miles per gallon of oil in the 15/30 four-cylinder 159 cu.
in. (2,610 cc). Mike Hewland claimed in 1974 that the progress in lubricating oils, materials, and machining had solved the oil thirst problem, his experimental 500 cc single cylinder engines using less oil than their contemporary poppet valve 'competitors'. Some proposed an added ring in the base of the sleeve, between sleeve and cylinder wall. Single-sleeve-valve engines had a reputation of being much less smoky than the Daimler with engines of Knight double-sleeve engines counterparts. The high oil consumption problem associated with the Knight double sleeve valve was fixed with the Burt-McCollum single sleeve valve, as perfected by Bristol. The models that had the complex 'junk head' installed a non-return purging valve on it; as liquids cannot be compressed, the presence of oil in the head space would result in problems.
Mike Hewland, after adding an expander ring that worked in reserve, found the oil consumption of his single sleeve valve engines was half that of a similar poppet valve engine. 'In this engine all we really have to lubricate is the crankshaft, the rest seems to lubricate itself' (C&D, Jul 1974). At top dead centre (TDC), the single-sleeve valve rotates in relation to the piston. This prevents boundary lubrication problems, as piston ring ridge wear at TDC and bottom dead centre (BDC) does not occur. The Bristol Hercules time between overhauls (TBO) life was rated at 3,000 hours, very good for an aircraft engine, but not so for automotive engines.
Sleeve wear was located primarily in the upper part, inside the 'junk head'. An inherent disadvantage is that the piston in its course partially obscures the ports, thus making it difficult for gases to flow during the crucial overlap between the intake and exhaust valve timing usual in modern engines. Mike Hewland admitted this was a problem at speeds above 10,000 rpm in his engines aimed at racing, but in the middle range, SSV was always better than a poppet valve engine. The 1954 printing of the book by Harry Ricardo The High-Speed Internal Combustion Engine, and also some patents on sleeve valve production, point out that the available zone for ports in the sleeve depends on the type of sleeve drive and bore/stroke ratio; Ricardo tested successfully the 'open sleeve' concept in some two-stroke, compression ignition engines.
It not only eliminated the head rings, but also allowed a reduction in height of the engine and head, thus reducing frontal area in an aircraft engine, the whole circumference of the sleeve being available for exhaust port area, and the sleeve acting in phase with the piston forming an annular piston with an area around 10% of that of the piston, that contributed to some 3% of power output through the sleeve driving mechanism to the crankshaft. The German-born engineer Max Bentele, after studying a British sleeve valve aero engine (probably a Hercules), complained that the arrangement required more than 100 gearwheels for the engine, too many for his taste.
A serious issue with large single-sleeve aero-engines is that their maximum reliable rotational speed is limited to about 3,000 RPM, but the M Hewland car engine was raced above 10,000 rpm without toil. Improved fuel octanes, above about 87 RON, have assisted poppet-valve engines’ power output more than to the single-sleeve engines’. The increased difficulty with oil consumption and cylinder-assembly lubrication was reported as never having been solved in series-produced engines. Railroad and other large single sleeve-valve engines emit more smoke when starting; as the engine reaches operating temperature and tolerances enter the adequate range, smoke is greatly reduced. For two-stroke engines, a three-way catalyst with air injection in the middle was proposed as best solution in a SAE Journal article around the year 2000.
Some (Wifredo Ricart, Alfa-Romeo) feared the build-up of heat inside the cylinder, however Ricardo proved that if only a thin oil film is retained and working clearance between the sleeve and the cylinder barrel was kept small, moving sleeves are almost transparent to heat, actually transporting heat from upper to lower parts of the system. If stored horizontally, sleeves tend to become oval, producing several types of mechanical problems. To avoid this, special cabinets were developed to store sleeves vertically. Equivalent implementations of modern variable valve timing and variable lift are impossible due to the fixed sizes of the port holes and essentially fixed rotational speed of the sleeves.
It may theoretically be possible to alter the rotational speed through gearing that is not linearly related to the engine speed, however it seems this would be impractically complex even compared to the complexities of modern valve control systems. History Charles Yale Knight In 1901 Knight bought an air-cooled, single-cylinder three-wheeler whose noisy valves annoyed him. He believed that he could design a better engine and did so, inventing his double sleeve principle in 1904. Backed by Chicago entrepreneur L.B. Kilbourne, a number of engines were constructed, followed by the "Silent Knight" touring car, which was shown at the 1906 Chicago Auto Show.
Knight's design had two cast-iron sleeves per cylinder, one sliding inside the other with the piston inside the inner sleeve. The sleeves were operated by small connected rods actuated by an eccentric shaft. They had ports cut out at their upper ends. The design was remarkably quiet, and the sleeve valves needed little attention. It was, however, more expensive to manufacture due to the precision grinding required on the sleeves' surfaces. It also used more oil at high speeds and was harder to start in cold weather. Although he was initially unable to sell his Knight Engine in the United States, a long sojourn in England, involving extensive further development and refinement by Daimler supervised by their consultant Dr Frederick Lanchester, eventually secured Daimler and several luxury car firms as customers willing to pay his expensive premiums.
He first patented the design in England in 1908. The patent for the US was granted in 1910. As part of the licensing agreement, "Knight" was to be included in the car's name. Six-cylinder Daimler sleeve valve engines were used in the first British tanks in WW1, up to and including the Mark IV. As a result of the tendency of the engines to smoke and hence give away the tank positions, Harry Ricardo was brought in, and devised a new engine which replaced the sleeve valve starting with the Mark V tank.
Among the companies using Knight's technology were Avions Voisin, Daimler (1909–1930s) including their V12 Double Six, Panhard (1911–39), Mercedes (1909–24), Willys (as the Willys-Knight, plus the associated Falcon-Knight), Stearns, Mors, Peugeot, and Belgium's Minerva company that was forced to stop their sleeve-valve line of engines as a result of the limitations imposed on them by the winners of WWII, some thirty companies in all. Itala also experimented with rotary and sleeve valves in their 'Avalve' cars. Upon Knight's return to America he was able to get some firms to use his design; here his brand name was "Silent Knight" (1905–1907) — the selling point was that his engines were quieter than those with standard poppet valves.
The best known of these were the F.B. Stearns Company of Cleveland, which sold a car named the Stearns-Knight, and the Willys firm which offered a car called the Willys-Knight, which was produced in far greater numbers than any other sleeve-valve car. Burt-McCollum The Burt-McCollum sleeve valve, having its name from the surnames of the two engineers that patented the same concept with weeks of difference, Peter Burt and James Harry Keighly McCollum, patent applications are of August 6 and June 22, 1909, respectively, both engineers hired by the Scottish car maker Argyll, consisted of a single sleeve, which was given a combination of up-and-down and partial rotary motion.
It was developed in about 1909 and was first used in the 1911 Argyll car. The initial 1900 investment in Argyll was £15,000 and building the magnificent Scotland plant cost £500,000 in 1920. It is reported that litigation by the owners of the Knight patents cost Argyll £50,000, perhaps one of the reasons for the temporary shutdown of their plant. Another car maker that used the Argyll SSV patents, and others of their own (patent GB118407), was Piccard-Pictet (Pic-Pic); Louis Chevrolet and others founded Frontenac Motors in 1923 with the aim of producing an 8-L SSV engined luxury car, but this never reached production for reasons connected to the time limits to the Argyll patents in the USA.
The greatest success for single sleeve valves (SSV) was in Bristol's large aircraft engines, it was also used in the Napier Sabre and Rolls-Royce Eagle engines. The SSV system also reduced the high oil consumption associated with the Knight double sleeve valve. Barr and Stroud Ltd of Anniesland, Glasgow, also licensed the SSV design, and made small versions of the engines that they marketed to motorcycle companies. In an advertisement in Motor Cycle magazine in 1922 Barr & Stroud promoted their 350cc sleeve valve engine and listed Beardmore-Precision, Diamond, Edmund, and Royal Scot as motorcycle manufacturers offering it. This engine had been described in the March edition as the 'Burt' engine.
Grindlay-Peerless started producing a SSV Barr & Stroud engined 999cc V-twin in 1923. and later added a 499cc single SSV as well as the 350cc. Vard Wallace, known for his aftermarket forks for motorcycles, presented in 1947 drawings of a Single Cylinder, Air-Cooled, 250 cc SSV engine. Some small SSV auxiliary boat engines and electric generators were built in the UK, prepared for burning 'paraffin' from start, or after a bit of heat-up with more complex fuels. (Petter Brotherhood, Wallace. 'The Engineer', Dec 9, 1921, pg 618) A number of sleeve valve aircraft engines were developed following a seminal 1927 research paper from the RAE by Harry Ricardo.
This paper outlined the advantages of the sleeve valve and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp (1,100 kW). Napier and Bristol began the development of sleeve-valve engines that would eventually result in limited production of two of the most powerful piston engines in the world: the Napier Sabre and Bristol Centaurus. The Continental Motors Company, around the years of the Great Depression, developed prototypes of single sleeve-valve engines for a range of applications, from cars to trains to airplanes, and thought that production would be easier, and costs would be lower, than its counterpart poppet valve engines.
Due to the financial problems of Continental, this line of engines never entered production. ('Continental! Its motors and its people', William Wagner, Armed Forces Journal International and Aero Publishers, 1983, ) Potentially the most powerful of all sleeve-valve engines (though it never reached production) was the Rolls-Royce Crecy V-12 (oddly, using a 90-degree V-angle), two-stroke, direct-injected, turbocharged (force-scavenged) aero-engine of 26.1 litres capacity. It achieved a very high specific output, and surprisingly good specific fuel consumption (SFC). In 1945 the single-cylinder test-engine (Ricardo E65) produced the equivalent of 5,000 HP (192 BHP/Litre) when water injected, although the full V12 would probably have been initially type rated at circa .
Sir Harry Ricardo, who specified the layout and design goals, felt that a reliable 4,000 HP military rating would be possible. Ricardo was constantly frustrated during the war with Rolls-Royce's (RR) efforts. Hives & RR were very much focused on their Merlin, Griffon then Eagle and finally Whittle's jets, which all had a clearly defined production purpose. Ricardo and Tizard eventually realized that the Crecy would never get the development attention it deserved unless it was specified for installation in a particular aircraft but by 1945, their "Spitfire on steroids" concept of a rapidly climbing interceptor powered by the lightweight Crecy engine had become an aircraft without a purpose.
Following World War II, the sleeve valve became utilised less, Roy Fedden, very early involved in the S-V research, built some flat-six single sleeve-valve engines intended for general aviation around 1947; after this, just the French SNECMA produced some SSV engines under Bristol license that were installed in the Noratlas transport airplane, also another transport aircraft, the Azor built by the Spanish CASA installed SSV Bristol engines post-WWII. Bristol sleeve valve engines were used however during the post-war air transport boom, in the Vickers Viking and related military Varsity and Valetta, Airspeed Ambassador, used on BEA's European routes, and Handley Page Hermes (and related military Hastings), and Short Solent airliners and the Bristol Freighter and Superfreighter.
The Centaurus was also used in the military Hawker Sea Fury, Blackburn Firebrand, Bristol Brigand, Blackburn Beverly and the Fairey Spearfish. The poppet valve's previous problems with sealing and wear had been remedied by the use of better materials and the inertia problems with the use of large valves were reduced by using several smaller valves instead, giving increased flow area and reduced mass, and the exhaust valve hot spot by Sodium-cooled valves. Up to that point, the single sleeve valve had won every contest against the poppet valve in comparison of power to displacement. The difficulty of Nitride hardening, then finish-grinding the sleeve valve for truing the circularity, may have been a factor in its lack of more commercial applications.
The Knight-Argyll Patent Case When the Argyll car was launched in 1911, the Knight and Kilbourne Company immediately brought a case against Argyll for infringement of their original 1905 patent. This patent described an engine with a single moving sleeve, whereas the Daimler engines being built at the time were based on the 1908 Knight patent which had engines with two moving sleeves. As part of the litigation an engine was built according to the 1905 specification and developed no more than a fraction of the rated RAC horsepower. This fact coupled with other legal and technical arguments led the judge to rule, at the end of July 1912, that the holders of the original Knight patent could not be supported in their claim that it gave them master rights encompassing the Argyll design.
Costs of litigation against claims by Knight patent holders seem having substantially contributed to bankrupt of Argyll in Scotland. Modern usage The sleeve valve has begun to make something of a comeback, thanks to modern materials, dramatically better engineering tolerances and modern construction techniques, which produce a sleeve valve that leaks very little oil. However, most advanced engine research is concentrated on improving other internal combustion engine designs, such as the Wankel. Mike Hewland with his assistant John Logan, and also independently Keith Duckworth, experimented with a single-cylinder sleeve-valve test engine when looking at Cosworth DFV replacements. Hewland claimed to have obtained from a 500 cc single-cylinder engine, with a specific fuel consumption of 177-205 gr/HP/hr (0.39 - 0.45 lb/HP/hr), the engine being able to work on creosote, and with no specific lubrication supply for the sleeve.