Misplaced Pages

#295704

57-565: The VK 45.01 (P) , also informally known as Tiger (P) or Porsche Tiger , was a heavy tank prototype designed by Porsche in Germany . With a dual engine gasoline-electric drive that was complex and requiring significant amounts of copper, it lost out to its Henschel competitor on trials, it was not selected for mass production and the Henschel design was produced as the Tiger I . Most of

114-508: A tank gun 's range, and sheer armour mass was no longer a guarantee of survivability against the largest HEAT warheads of tank guns or missiles. Chamberlain, Peter; Ellis, Chris (1981) [1969], British and American Tanks of World War II , Arco Publishing Background: History of the tank , Tank classification , Tanks in World War I Background: History of the tank , Tank classification , interwar period Background: History of

171-415: A ' brewery horse ' could produce 32,400 foot-pounds [43,929 J] per minute." James Watt and Matthew Boulton standardized that figure at 33,000 foot-pounds (44,742 J) per minute the next year. A common legend states that the unit was created when one of Watt's first customers, a brewer, specifically demanded an engine that would match a horse, and chose the strongest horse he had and driving it to

228-428: A 3-step speed switch took over the work. The electric motors transferred their power to a final drive with a ratio of 15: 1 directly to the drive wheels located at the rear. The fuel tanks carried 520 litres of petrol and allowed a driving range of 105 kilometers. Two compressed air tanks in the front crew compartment area assisted the driver during braking maneuvers. Unlike the Henschel design's mid-hull mounting for

285-429: A group of engineers modified a dynometer to be able to measure how much horsepower a horse can produce. This horse was measured to 5.7 hp (4.3 kW). When torque T is in pound-foot units, rotational speed N is in rpm , the resulting power in horsepower is The constant 5252 is the rounded value of (33,000 ft⋅lbf/min)/(2π rad/rev). When torque T is in inch-pounds, The constant 63,025

342-530: A healthy human can produce about 1.2 hp (0.89 kW) briefly (see orders of magnitude ) and sustain about 0.1 hp (0.075 kW) indefinitely; trained athletes can manage up to about 2.5 hp (1.9 kW) briefly and 0.35 hp (0.26 kW) for a period of several hours. The Jamaican sprinter Usain Bolt produced a maximum of 3.5 hp (2.6 kW) 0.89 seconds into his 9.58 second 100-metre (109.4 yd) sprint world record in 2009. In 2023

399-509: A heavy tank force and did not want to compromise its 4,800 km (3,000 miles) supply line to Europe. The M6 heavy tank was designed in 1940 but held few advantages over medium tanks and planned production of several thousand was stopped. The Anglo-American T14 heavy tank project started in 1941 did not deliver a pilot model until 1944. The US preferred to use tank destroyers (mobile but relatively lightly armoured vehicles) for anti-tank defence, and prior to 1944 there were few indications that

456-637: A larger arc. Heavy tank Heavy tanks achieved their greatest, albeit limited, success when fighting lighter tanks and destroying fortifications. Heavy tanks often saw limited combat in their intended roles, instead becoming mobile pillboxes or defensive positions, such as the German Tiger I and Tiger II designs, or the Russian KV and IS designs. Heavy tanks feature very heavy armor and weapons relative to lighter tanks. Many heavy tanks shared components with lighter tanks. For example,

513-529: A total of 12 individual wheels, 6 road wheels/axles, in 3 bogies. The wheels were not 'interleaved' like those of the Tiger I. The 57 to 59 tons combat weight in combination with 640 mm wide "slack-tracks" (KGS 62/640/130) using no return rollers, produced a ground pressure of about 1.06 kg / cm. The gasoline-electric drive specially developed by Ferdinand Porsche entered "uncharted territory" for road vehicles; this led to numerous development issues with

570-420: Is also used in many places to symbolize brake horsepower. Drawbar power (dbp) is the power a railway locomotive has available to haul a train or an agricultural tractor to pull an implement. This is a measured figure rather than a calculated one. A special railway car called a dynamometer car coupled behind the locomotive keeps a continuous record of the drawbar pull exerted, and the speed. From these,

627-463: Is equivalent to a boiler heat output of 33,469 Btu/h (9.809 kW). Present industrial practice is to define "boiler horsepower" as a boiler thermal output equal to 33,475 Btu/h (9.811 kW), which is very close to the original and revised definitions. Boiler horsepower is still used to measure boiler output in industrial boiler engineering in the US. Boiler horsepower is abbreviated BHP, which

SECTION 10

#1732790139296

684-454: Is equivalent to a boiler heat output of 33,485 Btu/h (9.813 kW). A few years later in 1884, the ASME re-defined the boiler horsepower as the thermal output equal to the evaporation of 34.5 pounds per hour of water "from and at" 212 °F (100 °C). This considerably simplified boiler testing, and provided more accurate comparisons of the boilers at that time. This revised definition

741-484: Is in psi, and flow rate is in US gallons per minute. Drilling rigs are powered mechanically by rotating the drill pipe from above. Hydraulic power is still needed though, as 1 500 to 5 000 W are required to push mud through the drill bit to clear waste rock. Additional hydraulic power may also be used to drive a down-hole mud motor to power directional drilling . When using SI units, the equation becomes coherent and there

798-465: Is needed to pull a drawbar load of 2,025 pounds-force at 5 miles per hour? { P } h p = 2025 × 5 375 = 27. {\displaystyle \{P\}_{\mathrm {hp} }={\frac {2025\times 5}{375}}=27.} The constant 375 is because 1 hp = 375 lbf⋅mph. If other units are used, the constant is different. When using coherent SI units (watts, newtons, and metres per second), no constant

855-507: Is needed, and the formula becomes P = Fv . This formula may also be used to calculate the power of a jet engine, using the speed of the jet and the thrust required to maintain that speed. Example: how much power is generated with a thrust of 4000 pounds at 400 miles per hour? { P } h p = 4000 × 400 375 = 4266.7. {\displaystyle \{P\}_{\mathrm {hp} }={\frac {4000\times 400}{375}}=4266.7.} This measure

912-434: Is no dividing constant. where pressure is in pascals (Pa), and flow rate is in cubic metres per second (m ). Boiler horsepower is a boiler 's capacity to deliver steam to a steam engine and is not the same unit of power as the 550 ft lb/s definition. One boiler horsepower is equal to the thermal energy rate required to evaporate 34.5 pounds (15.6 kg) of fresh water at 212 °F (100 °C) in one hour. In

969-487: Is often assumed that heavy tanks suffered inferior mobility to medium tanks , this was not always the case, as many of the more sophisticated heavy tank designs featured advanced suspension and transmissions to counteract this drawback. As mentioned previously, heavy tanks are often extremely expensive and resource-intensive to produce and operate. The German Tiger I , for example, had similar speed and better terrain-handling characteristics when compared to its main competitor,

1026-513: Is ordinarily stated in watts or kilowatts. In the United States, the power output is stated in horsepower which, for this purpose, is defined as exactly 746 W. Hydraulic horsepower can represent the power available within hydraulic machinery , power through the down-hole nozzle of a drilling rig , or can be used to estimate the mechanical power needed to generate a known hydraulic flow rate. It may be calculated as where pressure

1083-743: Is the approximation of Assuming the third CGPM (1901, CR 70) definition of standard gravity , g n = 9.80665 m/s , is used to define the pound-force as well as the kilogram force, and the international avoirdupois pound (1959), one imperial horsepower is: Or given that 1 hp = 550 ft⋅lbf/s, 1 ft = 0.3048 m, 1 lbf ≈ 4.448 N, 1 J = 1 N⋅m, 1 W = 1 J/s: 1 hp ≈ 745.7 W The various units used to indicate this definition ( PS , KM , cv , hk , pk , k , ks and ch ) all translate to horse power in English. British manufacturers often intermix metric horsepower and mechanical horsepower depending on

1140-467: The Interwar period , these larger vehicles with stronger defensive and offensive capabilities became known as "heavy" tanks. Heavy tanks had gradually progressed from their trench warfare and bunker destroying role to dedicated anti-tank purposes by the onset of World War II . Heavy tanks saw limited deployment by France at the beginning of the war, and were only ever used in conflict by Nazi Germany and

1197-808: The T28 GMC and ' Tortoise ' had casement designs and weighed around 80 tonnes but did not enter service. The immediate post-war period saw the final fielding of heavy tanks, including the US M103 heavy tank , the British FV214 Conqueror , and the French ARL 44 (in very limited numbers for the ARL 44), all in response to the Soviet heavy tanks of the period . The largest tank guns were approaching maximum calibre whose shell could still be handled by

SECTION 20

#1732790139296

1254-592: The Tiger I , was adopted for production instead. The VK 45.01 (P) chassis was later chosen to be the basis of a new heavy Jagdpanzer (although designated a Panzerjäger ) which would eventually be called the Ferdinand and mount the new, longer, 88 mm Pak 43/2 . Only one tank went into service as a command tank in the Ferdinand ( Elefant ) unit, and served in Panzerjäger Abteilung 653. It

1311-616: The VK 30.01 (P) medium tank, Porsche's medium tank prototype, and adapted parts used on it for the new tank. The new Porsche tank, designated the VK 45.01 (P) was to be powered by twin V-10 air cooled Porsche Type 101 gasoline engines which were mounted to the rear of the tank. Each of the twin engines would then drive a separate generator , one for either side of the tank, which would then power each of two electric motors , one powering each track from

1368-485: The imperial horsepower as in "hp" or "bhp" which is about 745.7 watts , and the metric horsepower as in "cv" or "PS" which is approximately 735.5 watts. The term was adopted in the late 18th century by Scottish engineer James Watt to compare the output of steam engines with the power of draft horses . It was later expanded to include the output power of other power-generating machinery such as piston engines , turbines , and electric motors . The definition of

1425-781: The kilowatt as the official power-measuring unit in EEC directives. Other names for the metric horsepower are the Italian cavallo vapore (cv) , Dutch paardenkracht (pk) , the French cheval-vapeur (ch) , the Spanish caballo de vapor and Portuguese cavalo-vapor (cv) , the Russian лошадиная сила (л. с.) , the Swedish hästkraft (hk) , the Finnish hevosvoima (hv) ,

1482-501: The 1926 Iowa State Fair , they reported that the peak power over a few seconds has been measured to be as high as 14.88 hp (11.10 kW) and also observed that for sustained activity, a work rate of about 1 hp (0.75 kW) per horse is consistent with agricultural advice from both the 19th and 20th centuries and also consistent with a work rate of about four times the basal rate expended by other vertebrates for sustained activity. When considering human-powered equipment ,

1539-861: The Estonian hobujõud (hj) , the Norwegian and Danish hestekraft (hk) , the Hungarian lóerő (LE) , the Czech koňská síla and Slovak konská sila (k or ks ), the Serbo-Croatian konjska snaga (KS) , the Bulgarian конска сила , the Macedonian коњска сила (KC) , the Polish koń mechaniczny (KM) ( lit.   ' mechanical horse ' ), Slovenian konjska moč (KM) ,

1596-639: The Soviet IS series . Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther , for example, was a "medium" tank that outweighed most Allied "heavy" tanks. American forces rarely fielded heavy tanks, as they still held on to the infantry-support doctrine like the British; in addition, the Americans recognized the logistical and mobility issues that came with possessing

1653-432: The US M103 heavy tank shared many components with the lighter Patton tank , including transmission and engine. As a result, they tend to be either underpowered and comparatively slow, or have engine and drive train reliability issues. In case of an entirely new design development, which was the case with the German Tiger I , designs often became needlessly complex and costly, resulting in low production numbers. Although it

1710-557: The US M4 Sherman was outclassed in terms of armor and weapons by German heavy tanks which were few in number. Near the end of World War II, a few early model M26 Pershings were sent to Europe to gain combat experience. Aside from these the closest the Americans came to putting a heavy tank into service were up-armored M4 Sherman "Jumbos" which were used as assault guns . Both the US and UK developed very well-armoured and armed tanks intended for assaulting heavily defended areas -

1767-565: The USSR from about 1943 to the war's end. This tank type remained a decisive factor in the early years of the Cold War. The purpose of heavies would not change until their replacement by the main battle tank . Often referred to as MBTs, these designs effectively filled all roles required by armies, thus rendering more specialized designs obsolete. The first British tank, the Mark I of World War I,

VK 45.01 (P) - Misplaced Pages Continue

1824-667: The Ukrainian кінська сила (к. с.) , the Romanian cal-putere (CP) , and the German Pferdestärke (PS) . In the 19th century, revolutionary-era France had its own unit used to replace the cheval vapeur (horsepower); based on a 100 kgf ⋅m/s standard, it was called the poncelet and was abbreviated p . Tax or fiscal horsepower is a non-linear rating of a motor vehicle for tax purposes. Tax horsepower ratings were originally more or less directly related to

1881-500: The already produced chassis were rebuilt as Elefant Panzerjäger tank destroyers. On 26 May 1941, Henschel and Porsche were asked to submit designs for a 45-ton heavy tank capable of mounting the high velocity 8.8 cm Kwk 36 L/56 gun which was derived from the German 88 mm Flak 37 antiaircraft gun . Both the Henschel and Porsche tanks were to be fitted with the same turret supplied by Krupp . The Porsche company worked on updating

1938-403: The crew, even using awkward two-part ammunition (separate projectile and propellant case, similar to battleship guns), which greatly slowed their rate of fire. Thanks to improved shell designs and fire control technology improving accuracy, postwar medium tanks were catching up to heavy tanks in firepower. The tactical value of heavy tanks thus declined to the point that no new designs were fielded;

1995-429: The drive system. The two air-cooled 15-litre V-10 engines designated Porsche Type 101 , which were each coupled with a Siemens-Schuckert 500 kVA generator , generated the necessary electric power to operate each of the two Siemens 230 kW (312.7 PS ) individual-output electric motors driving the rear sprockets. In this drive system, a mechanical power transmission system and gearbox could be omitted, since now

2052-666: The early days of steam use, the boiler horsepower was roughly comparable to the horsepower of engines fed by the boiler. The term "boiler horsepower" was originally developed at the Philadelphia Centennial Exhibition in 1876, where the best steam engines of that period were tested. The average steam consumption of those engines (per output horsepower) was determined to be the evaporation of 30 pounds (14 kg) of water per hour, based on feed water at 100 °F (38 °C), and saturated steam generated at 70 psi (480 kPa). This original definition

2109-530: The engine's bore size, number of cylinders, and a (now archaic) presumption of engine efficiency. As new engines were designed with ever-increasing efficiency, it was no longer a useful measure, but was kept in use by UK regulations, which used the rating for tax purposes . The United Kingdom was not the only country that used the RAC rating; many states in Australia used RAC hp to determine taxation. The RAC formula

2166-499: The engine. The situation persisted for several generations of four- and six-cylinder British engines: For example, Jaguar's 3.4-litre XK engine of the 1950s had six cylinders with a bore of 83 mm (3.27 in) and a stroke of 106 mm (4.17 in), where most American automakers had long since moved to oversquare (large bore, short stroke) V8 engines . See, for example, the early Chrysler Hemi engine . The power of an engine may be measured or estimated at several points in

2223-731: The heavily armed mediums came to be known as the main battle tank (MBT). Doctrine held that less expensive self-propelled artillery could serve in the infantry support role. The weight of MBTs quickly increased during the Cold War , and most third generation MBTs including the M1 Abrams , Challenger 2 , Leopard 2 , Merkava , Arjun MBT , and Type 99 have weights similar to those of 1950s heavy tanks. Older heavy tanks with steel armour were rendered obsolete by anti-tank guided missiles and high-explosive anti-tank (HEAT) ammunition. The much more flexible missiles are effective at ranges beyond

2280-534: The increasing demands of the U-boat fleet (which used very similar diesel-electric transmissions , which worked perfectly well); while it was easy enough to obtain quality copper to build a single prototype, once series production began, this became more difficult. These problems, and the fact that trials proved the tank to be less maneuverable than its competitor, were the reason why Henschel's identically armed and more conventional VK 45.01 (H) H1 prototype, which became

2337-454: The limit. In that legend, Watt accepted the challenge and built a machine that was actually even stronger than the figure achieved by the brewer, and the output of that machine became the horsepower. In 1993, R. D. Stevenson and R. J. Wassersug published correspondence in Nature summarizing measurements and calculations of peak and sustained work rates of a horse. Citing measurements made at

VK 45.01 (P) - Misplaced Pages Continue

2394-512: The origin of the engine in question. DIN 66036 defines one metric horsepower as the power to raise a mass of 75 kilograms against the Earth's gravitational force over a distance of one metre in one second: 75 kg × 9.80665 m/s × 1 m / 1 s = 75  kgf ⋅m/s = 1 PS. This is equivalent to 735.49875 W, or 98.6% of an imperial horsepower. In 1972, the PS was replaced by

2451-670: The power generated can be calculated. To determine the maximum power available, a controllable load is required; it is normally a second locomotive with its brakes applied, in addition to a static load. If the drawbar force ( F ) is measured in pounds-force (lbf) and speed ( v ) is measured in miles per hour (mph), then the drawbar power ( P ) in horsepower (hp) is { P } h p = { F } l b f { v } m p h 375 . {\displaystyle \{P\}_{\mathrm {hp} }={\frac {\{F\}_{\mathrm {lbf} }\{v\}_{\mathrm {mph} }}{375}}.} Example: How much power

2508-485: The rear drive sprocket. But the engines and drive train were generally new and unorthodox designs for a tank (other than some brief experiments in the very early years), and due to being underdeveloped were prone to break down or require frequent maintenance. It was also difficult for the Third Reich to obtain additional amounts of quality copper to build whole new fleets of vehicles with electric drives in addition to

2565-474: The significantly lighter Panzer IV medium tank. However, low reliability and limited resources meant that just 1,347 were produced, compared to roughly 8,800 Pz.Kpfw. IV. The origins of the class date to World War I and the first tank designs, which were intended to operate in close concert with infantry . Virtually all early tanks possessed thick armor to allow them to survive in no man's land . As lighter and more maneuverable designs were introduced during

2622-423: The size of the engine; but as of 2000, many countries changed over to systems based on CO 2 emissions, so are not directly comparable to older ratings. The Citroën 2CV is named for its French fiscal horsepower rating, "deux chevaux" (2CV). Nameplates on electrical motors show their power output, not the power input (the power delivered at the shaft, not the power consumed to drive the motor). This power output

2679-515: The tank , Tank classification , Tanks in the Cold War Background: History of the tank , Tank classification Horsepower#Metric horsepower (PS, cv, hk, pk, ks, ch) Horsepower ( hp ) is a unit of measurement of power , or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are

2736-502: The transmission of the power from its generation to its application. A number of names are used for the power developed at various stages in this process, but none is a clear indicator of either the measurement system or definition used. In general: All the above assumes that no power inflation factors have been applied to any of the readings. Engine designers use expressions other than horsepower to denote objective targets or performance, such as brake mean effective pressure (BMEP). This

2793-422: The turret, the VK 45.01 (P) had its Krupp-designed turret mounted at the front. The turret, which mounted the 8.8 cm KwK 36 and a 7.92 mm MG 34 coaxial machine gun , was essentially the same Krupp design also used for Henschel's contract-winning VK45.01(H) prototype design. The first eight turrets produced had lower sides and a flat roof with raised centre section to allow the gun to be depressed through

2850-685: The unit varied among geographical regions. Most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on 1 January 2010, the use of horsepower in the EU is permitted only as a supplementary unit. The development of the steam engine provided a reason to compare the output of horses with that of the engines that could replace them. In 1702, Thomas Savery wrote in The Miner's Friend : The idea

2907-609: Was 12 feet (3.7 m) in radius; therefore, the horse travelled 2.4 × 2π × 12 feet in one minute. Watt judged that the horse could pull with a force of 180 pounds-force (800 N). So: Engineering in History recounts that John Smeaton initially estimated that a horse could produce 22,916 foot-pounds (31,070 J) per minute. John Desaguliers had previously suggested 44,000 foot-pounds (59,656 J) per minute, and Thomas Tredgold suggested 27,500 foot-pounds (37,285 J) per minute. "Watt found by experiment in 1782 that

SECTION 50

#1732790139296

2964-538: Was deployed in April 1944 and lost that subsequent July. The VK 45.01 (P)'s chassis and many of the Elefant's components were later used in developing the VK 45.02 (P) prototype heavy tank. Ferdinand Porsche developed the spring rod roller carriage; there were 6 road wheels, each road wheel formed of an inner and outer paired wheel per axle. The six paired road wheels were divided into three 2-axle bogies per side, for

3021-439: Was designed under the British infantry tank concept, which is similar to the heavy tank, having thick armour and tending to weigh more than their other tanks. However, it is usually considered separate because infantry tanks generally had less firepower, with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II , as well as

3078-546: Was instituted by the Royal Automobile Club and was used to denote the power of early 20th-century British cars. Many cars took their names from this figure (hence the Austin Seven and Riley Nine), while others had names such as "40/50 hp", which indicated the RAC figure followed by the true measured power. Taxable horsepower does not reflect developed horsepower; rather, it is a calculated figure based on

3135-533: Was introduced to break through German defensive lines of trenches and barbed wire . When lighter, faster tanks were introduced, the larger tanks were classified as heavy. The French Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1 , T-35 , and KV-1 . The Matilda II

3192-420: Was later used by James Watt to help market his improved steam engine. He had previously agreed to take royalties of one-third of the savings in coal from the older Newcomen steam engines . This royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a minute). The wheel

3249-420: Was sometimes applied in British colonies as well, such as Kenya (British East Africa) . where Since taxable horsepower was computed based on bore and number of cylinders, not based on actual displacement, it gave rise to engines with "undersquare" dimensions (bore smaller than stroke), which tended to impose an artificially low limit on rotational speed , hampering the potential power output and efficiency of

#295704