The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort. First, a force of 2 to 5 pounds per ton of train weight is required to move on straight level track. Jun 22, 2017 tractive effort te is the force applied by a locomotive for moving itself and a train. Pdf influence of locomotive tractive effort on the. More tractive effort, lower emissions, greater fuel. Therefore, some efforts based on train traffic flow theory have been. The speed at which both forces are equal is the maximum speed the train can get to on a flat piece of track. These terms apply to different operating conditions, but are related by common mechanical factors. The maximum permissible traction force that can be applied to the wheels is governed by two things. The tractive effort of a locomotive should be enough for it to haul a train at the maximum permissible speed. Jan 07, 20 tractive force calculation for a vehicle tractive force or tractive effort or traction is the force applied between the tire and road surface to move a car or any vehicle for that matter. Calculating tractive effort page 1 locomotives and. Ive also suggested merging power at rail ie making power at rail redirect to a subsection of this article dealing with the relationship between power at rail, speed and tractive.
Tractive effort, curving and surface damage of rails. Acceleration is a measure of how quickly you are gaining or losing speed. Physically the tractive effort in the railwheel contact finno equals the the sum of all acting forces fw resistance on a train. Whatever may be source or principle of working of traction motor, all provide tractive effort characteristics to encounter train resistance and provide acceleration. Importance of tractive effort lies with its capability to start a train on the gradient and run it up to a speed of around 30 kmph whereas that of horse power is its ability to achieve and run at the maximum permissible speed. The tractive force between a car wheel and the surface can be expressed as. We have also found that combining this motor with bearing. For example the canadian set has coal wagons that limit the train s speed to 128 however, you also need a van in the back of the train or the train s speed is halved. For slopes, you will need an additional 100 newton per percent of steepness. Power is the force needed to run a train at a certain speed. Train movement simulation by element increment method xu. Traction and curving are the principal causes of high tangential forces between railway rails and wheels. In order to generate this tractive effort we need two things.
In other words, it is the sum of the tractive force and rolling effort on the road surface. In that case however, high discretization on the control variable is needed. When i have a passenger engine high speed, low te pulling cars of goods, i have to use tricks like not using sharp curves, keeping as many tiles as possible between elevation changes to give the train time to regain speed and keeping congestion down so there isnt a lot of start. It also says that for really heavy freight one can doublehead the train to provide more tractive effort. At very slow yard speeds only 2 to 3 pounds is needed while increasing to about 5 pounds at higher speeds. Innovative method for measuring the tractive effort of rail. As with power, there are different methods of measuring tractive effort. Traction can be defined as the friction between a drive wheel and the surface it moves upon.
In the powercentralized system, however, to obtain the tractive effort, the axle load of. Whilst tractive effort determines the ability of the locomotive to haul heavy loads, e. The adhesions factor depends on the translation speed of the vehicle and the gliding speed of wheel on rails, from empiric laws described on figures 3. Traction motor used for traction purpose is dc series motor, separately excited dc series motor, three phase induction motor, synchronous motor and permanent magnet synchronous motor. Speed profile for optimum train drive aauetd addis ababa. I suggest the merge of continuous tractive effort and maximum tractive effort into this article. A number that relates to a tractive effort on a dc motor locomotive that the traction motor can obtain indefinitely without overheating. I run a lot of time freight trains as i share tracks with passenger trains. See appendix b for a clipping from the teloc 1500 manual and formulas. Figure 31 tractive and braking effort vs speed curve for ingetem bilbao tramway.
The speed at which both forces are equal is the maximum speed the train. The tractive effort required to move a train consists of numerous factors, but for most applications only four need to be considered. It sets an upper limit on acceleration at least in real life, not in tf, effectively determining how much power a train can put down at low speed. If the rear wheels of the vehicle in the figure are driven with no slip taking place between the tires and the level road surface, the wheel force or the tractive effort te is equal to the torque at the driven wheels t w divided by the rolling radius or effective radius r w. Pdf calculation of the traction effort of switching. Figures 5 and 6 show optimum speed profile and tractive effort profile for a train with continuous tractive effort on a level track with no elevation. More tractive effort, lower emissions, greater fuel savings, and lower life cycle costs tractive power corporations newtp56 switcher is designed to meet the requirements for industrial applications. Tractive effort develops necessary linear and angular acceleration to the train mass, overcome the gravity component of the train weight, overcome the wind, frictional and curve resistance of the train. You might be right, ill bring that screen up next time and let you know. The boa ii not only improves locomotive tractive effort, but it provides operation protection and reliability for better train handling, adhesion and performance. Tractive effort te is the force applied by a locomotive for moving itself and a train. Tractive effort versus horsepower trains magazine trains. Tractive effort of steam locomotives locomotive ratiosii.
Starting vs continuous tractive effort trains magazine. The continuous tractive effort would be determined by how much electricity traction motors could handle before burning up. When the locomotive is in perfect condition and is tested under constant conditions of workcutoff, speed, loadthe test will show higher figures than when the regular road locomotive is tested with a commercial train on an. The magnitude and direction of these forces are calculated for equilibrium curving of a conventional twoaxle bogie in curves of 6001800 m radius, both without traction and for a level of tractive effort of 0. This means that the locomotive must have at least 74. Tractive effort definition of tractive effort by merriam. Nov 10, 2016 what is the difference in tractive effort and power in the locomotive stats. Things like this make the game really difficult to play intuitively, because this information is not readily available and immediately clear to the player. W weight or vertical force between wheel and surface n, lb f m mass on. When the locomotive is in perfect condition and is tested under constant conditions of workcutoff, speed, loadthe test will show higher figures than when the regular road locomotive is tested with a commercial train on an undulated profile and at variable conditions of work.
Bachmann locos class 20, 37 and 66 vitrains class 37 pulling force one couplers all data are in metric grams. Tractive force calculation for a vehicle tractive force or tractive effort or traction is the force applied between the tire and road surface to move a car or any vehicle for that matter. But it gives no indication of the relationship between the tractive effort and the amount of cargo it can haul effectively. Optimal control of an emu using dynamic programming and. Pdf calculation of the traction effort of switching locomotive. Subsequent comments should be made in a new section.
Tractive effort definition is the force in pounds exerted by powered equipment as a locomotive as measured for statistical purposes at the rim of the driving wheels. Pdf on jan 1, 2012, anton rassolkin and others published calculation of the traction effort of switching locomotive. Tractive effort or tractive force is measured in kilonewtons kn or pounds force lbf where 1 kn 228. More tractive effort, lower emissions, greater fuel savings. Dec 27, 2017 whilst tractive effort determines the ability of the locomotive to haul heavy loads, e. Traction effort of switching locomotive chme3 with railroad slope 0. May 12, 20 tractive effort, when multiplied with speed at which the train is required to run, gives the horsepower. Locomotive tractive effort chart irwin car and equipment. F traction effort or force acting on the wheel from the surface n, lb f.
Tractive effort hp curves for steam locomotives the first of these is the most obvious in its approach. For steam locomotives, tractive effort was usually the limitting factor in the size of the train it could pull. Our markets with over 300 new movers coming into the north american annually, there is a good market for industrial locomotives. Pdf influence of locomotive tractive effort on the forces. It is the amount of force a wheel can apply to a surface before it slips. A wheel will have different traction on different surfaces, as, the coefficient. As with power there are different methods of measuring tractive effort. Particularly, recent power electronics technology has realized a lightweight and compact traction system. Influence of locomotive tractive effort on the forces. Factor of adhesion for a dc locomotive is usually taken as 2225% on dry jointed rail. First, tractive effort is a function of weight on drivers and the factor of adhesion. So if they could handle the tractive effort of 80 000, then the engineer should not drive below 9. In the main line train, tractive effort is caused by the locomotive, and in a suburban train, it is caused by motor coaches. W weight or vertical force between wheel and surface n, lb f m mass on the wheel kg, slugs a g acceleration of.
I suggest the merge of continuous tractive effort and maximum tractive effort into this article ive also suggested merging power at rail ie making power at rail redirect to a subsection of this article dealing with the relationship between power at rail, speed and tractive effort. Cte is non applicable for an ac traction motor, which use te only. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Based on the capacity of a boiler to produce steam, a tractive effort curve is drawn by calculating what percentage of the steam needed to produce the maximum tractive effort at each speed is available, then multiplying this percentage by. Then, combining the rolling and aerodynamic resistance we can have the running resistance. Calculating tractive effort for steam locomotives when modeling a set of train vehicles, an important information needed for the dynamics of a locomotive is max tractive effort te, resp max te, which is determining the ability of a locomotive to pull up a train. Innovative method for measuring the tractive effort of. For design purposes, usable locomotive tractive effort should not exceed w4, where w is. I work for eversholt rail a train leasing company that owns about a. The higher your speed, the lower your locomotives tractive effort.
Constant tractive effort maximum tractive effort zone 2. Horsepower and tractive effort the idiots guide to. What is the difference in tractive effort and power in the locomotive stats. The tractive power models are competitively priced and tractive power corporation can offer a longterm leasing and service plan for qualified customers. If the rear wheels have such a torque applied to them that they are on the. Wet rail will knock adhesion down to about 18%, but sand will get you back to 2225%. Im assuming power is how quickly the train will accelerate and tractive effort is ability to climb hills, but im not sure. Pound force applied to the rear coupler to pull a train. No reduction of tractive effort except to the one that slipped.
Vehicle dynamics calculation tractive effort of a car. Tractive effort te and tractive resistance tr tractive effort te. Help with tractive efforthorsepower page 2 railroad. Other engines available based on individual requirements. Tractive effort is defined as the force at the rims or the outer edges of the driving wheels of moving trains. In detail the resistant force fw can be devided in an acceleration force fwa, an inclination force fwn, a curve force fwb and a running force fwl. Train traction systems for passenger comfort and easier. Starting tractive effort, found in the locomotive data sheet, is the rated tractive effort starting from a standstill in run8. With the three cylinder locos the nsw d5758 class had that, the tractive effort was, d57 class.
Tractive effort is a measure of the force that a locomotive can apply to the train it is pulling. For obtaining train motion without slipping tractive effort f should be less than or t athe most equal to w where the coefficient of adhesion between the wheel is and the track and w is the weight of the train on the driving axles called the adhesive weight. In pairs the ei 15s offered the same tractive effort as a threesection sj class dm3. First we need enough power on the wheels and second enough weight to prevent the wheels from spinning. For all cases where only the total force of a vehicle is of importance, an innovative tractive effort method patent pending has been invented at the research and technology centre munich of the deutsche bahn. With this in mind, there are two places we can get tractive effort. If a cross over the tractive effort curve would appear for the next gear by remaining in gear until maximum rpm, then a small, roughly triangular shaped section would be cut out of the available area every time when gear is changed. Tractive effort is the force needed to simply move the train.
This manual describes the opentrack program and summarizes the. Evaluation of advantages of highspeed emus in the case of. Influence of locomotive tractive effort on the forces between wheel and rail article pdf available in vehicle system dynamics 35supplement. Since simply removing a vertex will merge the edges on either side of. But it sure doesnt feel like it, and the tractive effort barmeter on the main menu screen says other wise to what you claim. Irwin corporate headquarters 9953 broadway route 993 po box 409 irwin, pa 15642. Railways tractive effort, acceleration, and braking tractive effort, acceleration and braking context for a railway to operate efficiently and safely, its locomotives should be powerful enough to accelerate their trains rapidly to the maximum allowed line speed, and the braking systems must be able to bring a train reliably to a standstill at a station or signal, even on an adverse. Resistance bound to the slope of 2% will oppose a force of fp 220 tons x 9,806 knewton x 2 100 64,7 kn. Regardless of locomotive power, usable tractive effort is always limited by wheel rail adhesion. A locomotives tractive effort at all speeds is limited by its adhesive weight and the available coefficient of adhesion between wheel and rail, as illustrated in the above diagram and as discussed in more detail on the adhesion page of this website the maximum speed that a locomotive can attain with any given train occurs when the locomotives drawbar tractive effort exactly equals. Te is the tractive effort n r w is the rolling radius or effective radius m. There are various tractive effort curves available for different locomotives for different speeds, which enable the computation of the value of tractive effort.
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