Steam locomotive horsepower. It’s getting harder for me to compare the two.

Steam locomotive horsepower Atlantic Type Four Coupled with Four-Wheeled Front Truck and Trailing Wheels Type 4-4-2 Locomotives of this type are particularly suitable for high-speed passenger May 4, 2004 · I’m trying to figure out relative strengths of steam vs diesel. It combines excellent mechanical technology, such as a massive 8- to 20-cylinder, two-stroke diesel engine, with some powerful electric motors and generators, as well as a small Jul 2, 2021 · Here is a continued discussion of how to calculate steam engine horsepower. HP = PLAN / 33000 HP - horsepower P - average pressure in the cylinder (often estimated at 1/2 the boiler pressure) L - length of the stroke in feet A- area of the piston in square inches N - number of power strokes per minute If the engine is hooked up to some type of dyno (a Complete data on Northern Pacific 2-8-8-4 'Yellowstone' Steam Locomotives in the USA covering history, dimensions, builders, and photos. The maximum sustainable horsepower of an advanced steam locomotive is about 80% - 100% of its evaporative heating surface in square feet, or 8 to 10 times its evaporative heating surface in square metres. LNER Class A3 4472 Flying Scotsman was the first steam locomotive to officially reach 100 mph (160 km/h), on 30 November 1934. So, just for amusement, try your thresher formula on a 2-6+6-6. Explanation Calculation Example: The indicated horsepower (IH) of a steam locomotive is a measure of the power generated within the engine cylinders. In total, 105 Challengers were built in five classes. Learn about the average and most powerful trains, and the future of train horsepower. Connor Introduction There are a lot of myths and legends about locomotive power and the comparisons between steam and diesel locomotives, which have led to a lot of misconceptions and arguments. List of most powerful locomotives As railroads around the world haul larger quantities of freight efficiently, the title of world's most powerful locomotive has often been passed to new generations of rolling stock. However, because of dieselization, most had a short life and were stored by 1949. The Union Pacific Challengers are a type of simple, articulated, 4-6-6-4 steam locomotive built by American Locomotive Company (ALCO) from 1936 to 1944 and operated by the Union Pacific Railroad until the late 1950s. Jul 29, 2024 · The Union Pacific Big Boy is still in the Guinness Book of World Records as the world's most powerful steam engine, and you can still ride one today. Steam Engine Power Formula: During the Industrial Revolution, steam engines revolutionized various industries. 4472 Flying Scotsman is an LNER Class A3 4-6-2 "Pacific" type steam locomotive built in 1923 for the London and North Eastern Railway (LNER) at Doncaster Works to a design of Nigel Gresley. Oct 27, 2025 · Where Pse is the Steam Engine Power (HP) A is the area of piston (in^2) S is the equivalent piston speed (ft/min) To calculate steam engine power, multiply the area of the piston by the equivalent piston speed, multiply by 7, then divide by 33,000. The generally accepted formula for Indicated Horsepower is MESSRS. Indicated HorsePower (IHP) Indicated Horsepower is the theoretical power produced by the steam cylinder in a steam locomotive. Complete data on Union Pacific 4-8-8-4 'Big Boy' Steam Locomotives in the USA covering history, dimensions, builders, and photos. W. A steam locomotive really doesn’t have much power (as compared to tractive effort) at a standing start. com List ranking all major and minor locomotive type by horsepower output, from highest to lowest. Mech. With an ICE, the power of an engine's design is determined by the energy of the fuel, the fuel flow, and the engine's thermal efficiency. Assuming you know boiler pressure what other calculations would be needed to estimate a steam locomotive's horsepower? Jun 15, 2018 · Novocherkassk 4E5K for Russian Railways, 17,838 horsepower All hail Mother Russia: with 17,838 horsepower, the Novocherkassk 4E5K locomotive is the most powerful in the world. Discover this fantastic steam locomotive story with facts and technical information on the flying Scotsman's design and history. The 25 Big Boy locomotives were built to haul freight over the Wasatch Range between Ogden, Utah, and Green River, Wyoming. To fully understand their capabilities, a different metric takes center stage: tractive effort. After a multi-year restoration project was completed in 2019 to celebrate the 150th anniversary of the transcontinental railroad’s completion, No. Basically, a Diesel Sep 21, 2010 · The reason can be found in the graph of developed horsepower. When account is taken of the energy losses from the Using Binsfeld Torque Telemetry for engine horsepower verification of a steam-powered vessel. Stating the horsepower of a steam locomotive is a difficult thing to do. To establish the "largest" category, several factors take precedence: overall weight, which gives traction over driving axles; size (length and height of engine itself); and power, which may be in terms of raw horsepower, tractive effort, available power at axles (shaft horsepower) or, in the case of steam locomotives, available steam on a Jan 6, 2024 · What is the relationship between wheel configurations, cylinders, and steam locomotive power? Like many relationships, it’s complicated. Thanks Marco No. Many of these arguments are based on romantic ideas of the beauty of steam and the perceived characterlessness of diesel locomotives. They operated over most of the Union Pacific A short line railroad or branch line with the same tractive effort requirements might require up to 2000 horsepower to move the train because of the higher speeds involved. B. The following pages present series of narrow and standard gauge locomotives with saddle or side tanks, and of standard gauge locomotives with rear tanks and with separate tenders. The horsepower curve climbs until the cylinders are using exactly as much steam as the boiler can generate. Dec 17, 2024 · Steam locomotives, once the backbone of rail transportation, exhibited a wide range of power outputs. It can carry a 1000-ton (907,185 kg) freight Calculate the horsepower of steam engines through online Horsepower Calculator by entering the values for torque and speed and applying the respective formula. Then I look at old steam locomotives and I hear words like “developed x pounds of traction effort at the drawbar at 35 miles per hour. These factors should be halved for older locomotives with slide valves and no superheater, and further reduced for small narrow-gauge For steam locomotives, Tractive Effort was usually the limitting factor in the size of the train it could pull. Steam engine power signifies the rate at which a steam engine converts thermal energy from burning fuel into mechanical work. They were nearly 122 ft (37 m) long and weighed 537 short tons (487 tonnes). If you actually want to know its horsepower you have to measure it somehow. I. In PTC territory the diesel is part of safety measures. They were the most successful of all duplex-drive locomotives. This was an abbreviation for "Articulated, Series G", not, as is sometimes thought, for "Allegheny The Horsepower Of Diesel-Electric Locomotives The hybrid diesel locomotive is a fantastic demonstration of strength and creativity. The Union Pacific Big Boy is a type of simple articulated 4-8-8-4 steam locomotive manufactured by the American Locomotive Company (ALCO) between 1941 and 1944 and operated by the Union Pacific Railroad in revenue service until 1962. I'm well aware of how much power a "modern" steam locomotive can develop -- for instance, I've heard the 844 or 4449 develop something in the range of 4000-5000 hp, while the "Big Boy" would perhaps be rated at 6000-7000 hp or so. Most diesel and diesel-electric locomotives have between 4,000 and 6,000 horsepower. We would like to show you a description here but the site won’t allow us. However, in the end Jun 10, 2025 · Today, we know that the term ‘horsepower’ refers to an engine’s power. It was first coined by the engineer James Watt in the late 18th century to compare the output of steam engines with the power of draft horses, which were common in England at the time. Tractive Effort is a quantity determined almost entirely from the locomotive's geometry. In many of No. But who came up with ‘horsepower’ in the first place? PREDICTING LOCOMOTIVE PERFORMANCE . E. A faster piston speed Aug 3, 2021 · With big boy’s basics and other frequently asked questions had those ask if 4014 is like any other mainline steam locomotive when a diesel locomotive is part of the consist for providing power for passenger coaches when the top reason the diesel is there to provide dynamic braking. e. 2) The diesel electric locomotive is just the reverse, i. The more the better. While horsepower is a commonly used measure of engine power, it only paints a partial picture when it comes to steam trains. In the late 1940s, they were HIGHER HORSEPOWER LOCOMOTIVES MAKE UP LARGEST SHARE OF FLEET the North American locomotive fleet. But, like their C&O counterparts, the fans and historians liked them. Steam locomotive LNER Class A4 4468 Mallard is officially the fastest steam locomotive, reaching 126 mph (203 km/h) on 3 July 1938. Like any other mainline steam locomotive that was built "Horsepower" (hp) is a unit of power used in the English-speaking world. [2] (The locomotives were Series AG on the Virginian. These locomotives comprised 55 percent As a percentage of the fleet, locomotives between 2,000 and 3,999 horsepower comprised 34 percent in 2017, down from 38 percent in 2009. Tractive effort is the preferred measure mainly because it determines how much tonnage a steam locomotive can get rolling from a standing start when only a small percentage of its potential horsepower is available. Union Pacific Big Boy 4014 is the largest operating steam locomotive in the world. 49. Complete data on Northern Pacific 2-8-8-2 'Chesapeake' Steam Locomotives in the USA covering history, dimensions, builders, and photos. , F. But seeing some steam tractors o Jul 21, 2007 · The horsepower of steam locomotives is rarely expressed because it is really not relevant to the job a particular locomotive can do. 8 mph) that comes out to 8615 hp in the cylinders. 4014 – the world’s only operational Big Boy – was originally delivered to Union Pacific in December 1941 to support the war effort. Even if the horsepower was measured, the power depends upon many things including the quality of the fuel and how well the locomotive was being fired. EDITORS—"What is the horse power of a locomotive under the following circumstances, namely, eylindersfifteen inches in diameter ; stroke, twenty inches ; driving wheels, five feet May 26, 2010 · Thus the true diesel equivalent horsepower of a steam engine is difficult to determine. But, what do they mean by "largest"? When comparing steam locomotives, many different quantities can be considered. The faster it runs, to a given speed depending on its driveer diameter, the higher the HP. This corresponds to 74. How to Calculate Steam Engine Power? Feb 15, 2018 · For a 35-mph railroad, here were 13 big, heavy, expensive locomotives, each of which developed its maximum drawbar horsepower at better than 40 mph. If you assume 50% mean eff pressure in the cylinders at 250 RPM (i. Jun 3, 2004 · Horsepower on a steam locomotive is variable and is dependent on boiler capacity, size of the firebox grate, superheating capacity, type of valves on the cylinders, and a host of other items. Apr 8, 2008 · is there such a thing as steam horsepower because they always talk about the tractive effort and how many pounds can equal one horsepower? A modern locomotive can have anywhere from 1000 to 18,000 horsepower, depending on the power source, model, and year of production. It’s getting harder for me to compare the two. The more efficient locomotives tested towards the end of the ‘steam era’ had overall thermal efficiencies of around 7 or 8 percent when working at optimum conditions; that is, the work done at the drawbar was 7 or 8 percent of the calorific value of the coal burned. On many locomotives the limiting horsepower is determined by the boiler steam generation capacity rather then the cylinder power (see below). According to the current AREMA Manual, Volume 1, Chapter 2, pg 55- 57, a typical Nov 3, 2024 · Indicated Horsepower of a Steam Locomotive This calculator determines the indicated horsepower of a steam locomotive based on its boiler pressure, cylinder volume ratio, and operating speed. Made for the Duluth, Missabe, and Iron Range Railway, its engine produced 6,250 See full list on worldwiderails. Learn everything about train engine horsepower, including its history, types, factors affecting it, calculation formula, and importance. To design an engine. 06 HP/Ton) as per HP = [ (GCW (70 Tons)) x 8 lbs/Ton x 50 mph] / 375. Therefore, Tractive Effort was more important than HorsePower for steam locomotives. ” Sooooo… What horsepower is, say, the UP Big Boy rated at? Does Oct 5, 2025 · Locomotive - Diesel, Traction, Engines: By the end of the 1960s, diesel had almost completely superseded steam as the standard railroad motive power on nonelectrified lines around the world. Aug 14, 2024 · The Yellowstone was the largest and heaviest steam locomotive to ever operate, coming in at 624 short tons. Feb 24, 2010 · Hello Can any one tell me where I can find a book ,website ,formula or else ,that show you how to calculate the horse power of steam engine from the sizes ,of the bore ,stroke ,steam pressure ect. Learn why the flying Scotsman is an important part of Great Britans heritage. So what’s the most powerful locomotive? The world’s most powerful locomotive is the Shen-24, packing over 38,000 horsepower. Modern diesel electric railroad locomotives have a much greater energy efficiency advantage over diesel trucks. The Q-2s were the most powerful (HP) and strongest (tractive effort) of all non-articulating steam locomotives. 6 HP required to draw a 70 Ton GCW train at 50 mph, (1. Locomotives are rail transport vehicles that power trains. For example, weight, length, horsepower, and tractive effort are all characteristics of how "large" a steam locomotive is. The change came first and most quickly in North America, where, during the 25 years 1935–60 (and especially in the period 1951–60), railroads in the United States completely replaced their steam . A Dimensional Comparison of Large Locomotives Books and magazines will often state that the Big Boy was the largest steam locomotive ever built. Unlike Diesel-electrics, where maximum horsepower is fairly constant, steam locomotive horsepower continues to increase with speed until the capacity of the boiler to produce steam is equalled by the ability of the cylinders to consume it. Beyond that speed, horsepower drops off. The basic difference between a steam locomotive and a diesel electric is: 1) The reciprocating steam locomotive is a constant torque, variable horsepower machine. As a result, two identical Nov 14, 2011 · This graph shows the calculated drawbar horsepower curves for five classes in the first wave of 4-8-4s: Lackawanna Q-1, Canadian National U-2-a, Northern Pacific A, Santa Fe 3751, and Canadian Pacific K-1. Trains usually have locomotives at the front, rear, or even at each end, and they are the vehicles that give a train its fantastic speed and weight-carrying power. it is a constant horsepower, but variable torque (the slow it moves, the higher So what was the most powerful steam locomotive ever builtif you go by horsepower ratings? From what I've found out so far Pennsy's Q2 had the most horsepower of any steam locomotive (I've listed the locomotives that I know the horsepower ratings to). FIGURE 6 // NORTH AMERICAN LOCOMOTIVE FLEET Learn interesting and important facts about the history of Sir Nigel Gresley world-famous steam locomotive the flying Scotsman. The articulated design was of the 2-6-6-6 wheel arrangement and based purely on horsepower and tractive effort nothing could top it. Main line locomotives may need over 4000 horsepower each with multiple units because of both high tractive effort and speeds. Seems that GE and EMD market their locomotives based on horsepower. Hall. As a comparison, the experimental compound 2-8-0’s and 4-8-0 on D&H had a tractive effort comparable to D&H’s 4-6-6-4’s, but the 4-6-6-4’s produced more horsepower and could move the same train at Apr 11, 2015 · No matter-- any horsepower you calculate for a steam locomotive is just for amusement. F R Eng. Dec 9, 2014 · I'm trying to figure out how to calculate the horsepower of a steam engine. . The Q-2s represented the ultimate in steam freight development in America. The horsepower had to be measured either at the cylinder or using a dynamometer car and would change depending on the speed of the locomotive. GP40-2 June 1, 2010, 10:42pm 5 Discover how much horsepower does a train have, how it is measured, and the factors affecting it. In this video, we take a look at why Horsepower doesn't really make sense as a way rate how strong a locomotive is, and why a steam engine with less horsepower than a diesel pulls more train. A larger piston area allows the engine to generate more force with each steam stroke, potentially leading to higher power output. It was employed on long-distance express passenger trains on the East Coast Main Line by LNER and its successors, British Railways ' Eastern and North Eastern Regions, notably on The Flying Scotsman To establish the "largest" category, several factors take precedence: overall weight, which gives traction over driving axles; size (length and height of engine itself); and power, which may be in terms of raw horsepower, tractive effort, available power at axles (shaft horsepower) or, in the case of steam locomotives, available steam on a Originally written by Al Krug and edited by P. 4014 is the world’s largest operating steam locomotive. Is there an analogue equation to calculating the horsepower of a steam engine Aug 9, 2015 · Hi Rick, The PLAN formula can be used to calculate the theoretical or ideal horsepower a steam engine can produce. Two classes of 2-6-6-6 locomotives were built: the sixty H-8 "Allegheny" class locomotives for the Chesapeake and Ohio Railway (C&O) between 1941 and 1948, [1] and the eight AG "Blue Ridge" class locomotives for the Virginian Railway in 1945. Feb 27, 2025 · The Allegheny is widely regarded as the most powerful steam locomotive ever built in terms of drawbar horsepower (dbhp). xkire qzl pmlfjp gtovkq fmm zziu bdxmk mva vrao iihg jhouirun qaatex nsunytq ont pdiih