Tractive effort definition of tractive effort by merriam. Tractive effort is defined as the force at the rims or the outer edges of the driving wheels of moving trains. Pdf influence of locomotive tractive effort on the forces. Tractive effort and train resistance horsepower friction. The higher your speed, the lower your locomotives tractive effort. Whatever may be source or principle of working of traction motor, all provide tractive effort characteristics to encounter. F traction effort or force acting on the wheel from the surface n, lb f.
Pound force applied to the rear coupler to pull a train. Bachmann locos class 20, 37 and 66 vitrains class 37 pulling force one couplers all data are in metric grams. Wheel slip may lead to stalling, damage to rail and wheel. Im assuming power is how quickly the train will accelerate and tractive effort is ability to climb hills, but im not sure. We will be begin by discussing tractive effort or tractive force, which is the amount of force at the wheels available for moving a train. It is said that the tractive force between the wheel and the rail depends on the slip. In pairs the ei 15s offered the same tractive effort as a threesection sj class. First, a force of 2 to 5 pounds per ton of train weight is required to move on straight level track. 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. Pdf influence of locomotive tractive effort on the. As with power, there are different methods of measuring tractive effort. 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.
Catenaryfree operated electric trains, as one of the recent technologies in railway transportation, has opened a new field of research. Tractive effort, acceleration and braking 1tractive effort. 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. Starting tractive effort, found in the locomotive data sheet, is the rated tractive effort starting from a standstill in run8. Tractive effort hp curves for steam locomotives the first of these is the most obvious in its approach.
The tractive effort required to move a train consists of numerous factors, but for most applications only four need to be considered. Tractive power corporation innovative solutions for the. First we need enough power on the wheels and second enough weight to prevent the wheels from spinning. 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. An amount of torque distributed to the wheel from differential divided by wheel radius is the tractive effort an. Power is the force needed to run a train at a certain speed. Material provided by sachin buddhisagar, copyright 2011. Measurement of tractive force in the creep region and maximum.
Our lagrange, georgia based company created the railcar mover category in 1948 as a solution to specific customer needs in railcar switching. Total tractive effect required for accelerating the train on a level track. The tractive effort at the edge of the pinion is transferred to the driving wheel by means of a gear wheel. Four large rubber isolators minimize rail shock for a smoother ride. G6 rail king with tier4 final engine tractive effort nnrk 330. May 12, 20 tractive effort, when multiplied with speed at which the train is required to run, gives the horsepower. 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. A dieselelectric locomotive with very high nominal starting te will rapidly get to a speed where the effective tractive effort is governed by the maximal horsepower that its prime mover can develop, and where the effective te corresponding to this reaches the resistance of the train, you will be at the maximum speed that train can reach. Pdf influence of locomotive tractive effort on the forces between. This means that the locomotive must have at least 74. This defines the speed of the train and the needed power and tractivebraking effort of the locomotive. Vehicle dynamics calculation tractive effort of a car. Pdf calculation of the traction effort of switching locomotive.
Optimal control of an emu using dynamic programming and. Introduction to highway transportation engineering, module 02. Tractive effort versus horsepower trains magazine trains. Jun 22, 2017 tractive effort te is the force applied by a locomotive for moving itself and a train. 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. 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. Calculation of the traction effort of switching locomotive conference paper pdf available january 2012 with 2,624 reads how we measure reads. Innovative method for measuring the tractive effort of rail. Jun 20, 2018 tractive effort is the force available at the area of contact between the rear wheel tyres and the road for a rear wheel driven car. Locomotive tractive effort chart irwin car and equipment. For slopes, you will need an additional 100 newton per percent of steepness. W weight or vertical force between wheel and surface n, lb f m mass on.
Pdf calculation of the traction effort of switching. Pdf for the complex simulation of dynamic behaviour of a locomotive in connection with drive dynamics and traction control, large. Traction effort of switching locomotive chme3 with railroad slope 0. What is difference between tractive force and tractive effort.
The tractive effort of a locomotive should be enough for it to haul a train at the maximum permissible speed. The tractive effort required to overcome the force due to gravity. 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. Freefloating mounts allow rail axles to move up and down in the frame, enhancing stability. The train configuration used is a very common train load for a single 4axle locomotive. In railway engineering, the term tractive effort is often used synonymously. Nov 10, 2016 what is the difference in tractive effort and power in the locomotive stats. Influence of locomotive tractive effort on the forces between wheel and rail article pdf available in vehicle system dynamics 35supplement. 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. The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort.
So if they could handle the tractive effort of 80 000, then the engineer should not drive below 9. I work for eversholt rail a train leasing company that owns about a. Track information a train running diagram, without any stop and normal track conditions was the base for the calculation. When moving up in the slope the drive has to produce tractive effort to overcome the force due to gravity. The maximum permissible traction force that can be applied to the wheels is governed by two things. Sep 09, 2015 introduction to highway transportation engineering, module 02.
Speed profile optimization of catenaryfree electric. The backbone of train simulation physics is the simple equation, fma force mass x acceleration. As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion. A number that relates to a tractive effort on a dc motor locomotive that the traction motor can obtain indefinitely without overheating. Tractive effort te is the force applied by a locomotive for moving itself and a train. With this in mind, there are two places we can get tractive effort. 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.
These terms apply to different operating conditions, but are related by common mechanical factors. At very slow yard speeds only 2 to 3 pounds is needed while increasing to about 5 pounds at higher speeds. Dieselelectric traction has the following advantages. Tractive effort and resistance to motion tractive effort resistance to motion i have extended the speed range on the graph to show the point where the resistance to motion gets larger than the tractive effort. As with power there are different methods of measuring tractive effort.
What is the difference in tractive effort and power in the locomotive stats. Dec 26, 2011 bachmann locos class 20, 37 and 66 vitrains class 37 pulling force one couplers all data are in metric grams. Evaluation of advantages of highspeed emus in the case of. Im assuming power is how quickly the train will accelerate and tractive effort is. Innovative method for measuring the tractive effort of. 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.
Cte is non applicable for an ac traction motor, which use te only. 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. 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. To move any object, a force must be applied to overcome the resistance or inertia of the resting object.
Influence of locomotive tractive effort on the forces. Irwin corporate headquarters 9953 broadway route 993 po box 409 irwin, pa 15642. Whatever may be source or principle of working of traction motor, all provide tractive effort characteristics to encounter train resistance and provide acceleration. The continuous tractive effort would be determined by how much electricity traction motors could handle before burning up. I run a lot of time freight trains as i share tracks with passenger trains. W weight or vertical force between wheel and surface n, lb f m mass on the wheel kg, slugs a g acceleration of. Train movement and energy consumption electrical engineering. When the wheels of the train slip on the rails, the torque is decreased to avoid the continuous.
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. The necessary tractive effort f t 220000 mass in kg x 0,23148 acceleration 50926 newtons, or. Steam locomotive mechanical resistance until recently turned up the web site of a man in austrailia who offered detail mathematical formulas for determining what needs to be subtracted from indicated tractive effort the calculated value of the direct effect of steam acting on the cylinders to obtain tractive effort at. Tractive effort is the force needed to simply move the train. Essential driving mechanism of an electric locomotive is shown in fig. Crest speed, average speed and schedule speed of train 4. 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. Pdf on jan 1, 2012, anton rassolkin and others published calculation of the traction effort of switching. Emus, the traction system equipment can be distributed over a train set, and tractive axles throughout the train set can obtain the required tractive effort without executing a heavy axle load. Starting tractive effort required to haul ferrmed trains. Physically the tractive effort in the railwheel contact finno equals the the sum of all acting forces fw resistance on a train. In the main line train, tractive effort is caused by the locomotive, and in a suburban train, it is caused by motor coaches.
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. We are the leading manufacturer of bimodal railcar movers, with more than 11,000 sold globally. 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. The armature of the driving motor has a pinion diameter d. The tractive force between a car wheel and the surface can be expressed as. A wellformulated solution for this problem should consider the characteristics of the energy storage device using validated models and. Tractive power the tractive power of a locomotive should be adequate enough to overcome these resistances and haul the train at a specified speed. Tractive effort of steam locomotives locomotive ratiosii. The speed at which both forces are equal is the maximum speed the train can get to on a flat piece of track.
In other words, it is the sum of the tractive force and rolling effort on the road surface. However, in some trains tractive effort is discrete, meaning that driver has. Calculating tractive effort page 1 locomotives and. Introduction to train movement and energy consumption 2. There are various tractive effort curves available for different locomotives for different speeds, which enable the computation of the value of tractive effort. Resistance due to friction resistance due to friction is the resistance offered by. In order to generate this tractive effort we need two things. Acceleration is a measure of how quickly you are gaining or losing speed. Horsepower and tractive effort the idiots guide to. With the three cylinder locos the nsw d5758 class had that, the tractive effort was, d57 class. 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.
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