For example, if we are trying to estimate the mean of some variable, but the. The propelling force developed is generally referred to as tractive force or tractive effort. Locomotive tractive effort and power calculations tractive effort calculations. Tire traction force, or tractive force, is the force used to generate motion between a car or truck and the road or tangential surface. That kind of calculations are very important for motion planning and it should be done in order to avoid overloading. This is an easy redmine tool for comprehensive project price calculations and. 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. 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.
Tire traction can also refer to the maximum tractive force between a body and a surface, as limited by available friction. Tractive effort te and tractive resistance tr tractive effort te. Drive wheel motor torque calculations university of florida. What links here related changes upload file special pages permanent link page information wikidata item cite. You can set the state plane zone at the bottom of this dialog. Research shows that about 20% to 55% of the available tractor energy is wasted at the tractive devicesoil interface. The tractive force between a car wheel and the surface can be expressed as. Tractive effort values in tonnes at various speeds up to up to 5093 5400 table no. This tool enables software development effort estimation using 5 different methods. This is the ratio of the tractive effort force just necessary slip the wheels on the track to the adhesive weight.
Material provided by sachin buddhisagar, copyright 2011. Here week and month are dependent upon the company policy. In this calculator, the mechanical advantage can be calculated using load and effort and vice versa. Mckibben2 this publication treats specifically the application of tractor power to a towed machine or to a load pulled by a drawbar, but farm power is treated briefly in a broad way to establish relationships. Tractive effort determines how much a locomotive can haul. Tractive effort is the propelling force which a locomotive exerts at the rims of its driving wheels. Therefore, tractive effort was more important than horsepower for steam locomotives. So if they could handle the tractive effort of 80 000, then the engineer should not drive below 9. The tractive effort required to move a train consists of numerous factors, but for most applications only four need to be considered. To solve for latitude and longitude, fill in the northing and easting and press solve latlong. Power is the force needed to run a train at a certain speed. Equations behind the vehicle forces for driving up slope calculator. As this becomes a common way for plans to be distributed to contractors it become important to be able to accurately estimate from.
Dec 26, 20 effort is directly calculated from the size of the software. Tractive effort definition of tractive effort by merriam. Moreover, the paper presents calculation of the traction effort of tep70. In the main line train, tractive effort is caused by the locomotive, and in a suburban train, it is caused by motor coaches. Tire traction force equation and calculator engineers. 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. Influence of locomotive tractive effort on the forces between. First, a force of 2 to 5 pounds per ton of train weight is required to move on straight level track.
The speed at which both forces are equal is the maximum speed. The mcgrawhill companies, 2 what makes a successful project. Tractive force steam locomotives calculator fx solver. The aim of the project objectoriented modeling in railways, was to develop a catalyst for practical economic solutions to complex railway technology problems today, the railway simulation tool opentrack is a wellestablished railway planning software and it is used by railways. Vehicle forces for driving up slope equations and calculator. To solve for northing and easting, fill in the latitude and longitude and press solve ne.
The total tractive effort tte is the sum of the forces calculated in steps 1, 2, and 3. Project price calculations and quotations easy redmine. So the laboratory answer is that tractive effort is independent of power, but power is composed of force tractive effort, distance and time. Drawbar pull is the tractive effort minus the rolling resistance. Calculating tractive effort page 1 locomotives and. Dieselelectric traction has the following advantages. Use this calculation to find your crm roi technologyadvice. There is no method for the precise calculation of these resistances but the following formula has been evolved based on experience. To choose motors capable of producing enough torque to propel the example vehicle, it is necessary to determine the total tractive effort tte.
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. Steam locomotive tractive effort vs diesel electric. With the three cylinder locos the nsw d5758 class had that, the tractive effort was, d57 class. Tecorange orange effort estimation tool for software.
The method for calculation of tractive effort required for starting and hauling loads at particular speed, gradient and degree of curvature and also horse power, ohe current calculation is given in the following paragraphs. F traction effort or force acting on the wheel from the surface n, lbf. Theres also a side benefit to calculating the roi of your crm we cant ignore. This calculator can be used to calculate the resulting force in a toggle joint with arms with equal lengths. W weight or vertical force between wheel and surface n, lb f m mass on the wheel kg, slugs a g acceleration of. For the remainder of this article references to a steam locomotive shall be understood to be an ordinary two cylinder, reciprocating double acting, single expansion, non condensing, adhesion or friction traction, side rod driven steam. Ntractive was a privately held software development company based in grand forks, north. Opentrack began in the mid1990s as a research project at the swiss federal institute of technology. Pdf calculation of the traction effort of switching. The methodology and the various formula adopted are also given.
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. So our first guess at a tevsspeed curve is a hyperbola. For a given tractive effort, increased horsepower allows an increased speed with other things remaining the same. Managing customer relationships in the social media era. Traction effort of switching locomotive chme3 with railroad slope 5. F traction effort or force acting on the wheel from the surface n, lb f. 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 gradient. This is an effort estimation method based on expert judgment. Horsepower x 308 speed mph where 308 is 82% of 375 lbmiles per hour per hp. 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.
By the way, the term tractive effort is supposed to imply at the wheel rim, as opposed to at the locomotive coupler. Tireground adhesion and maximum tractive effort the slip, s, of a tire is usually defined as where v is the translatory speed of the tire center. Due to the relationship between power p, velocity v and force f, described as. W weight or vertical force between wheel and surface n, lbf m mass on the wheel kg, slugs ag acceleration of gravity 9. The last step is to calculate the axle torque required to generate this tractive effort. So if we look at an ac6000 compared to an ac4400, assuming the weight, traction motors and gear ratio are all the same, they are likely to haul the same load over a given. It was recommended that for indicated 1932, the author developed constants for a new m ethod of figuring horsepower and tractive effort of steam locom o. Tractive effort is the force needed to simply move the train. The calculator can be used for imperial and metric units as long as the use of units are consistent.
Rubbing speed for highspeed applications a further consideration is the linear speed at which the disc is passing between the pads when the brake operates. For steam locomotives, tractive effort was usually the limitting factor in the size of the train it could pull. This energy wears the tires and compacts the soil to a degree that may cause detrimental crop production burt et al. Apr 12, 2011 planswift construction takeoff and estimating software is a great way to do pdf estimate work. What links here related changes upload file special pages permanent link page. 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. For slopes, you will need an additional 100 newton per percent of steepness. May 12, 20 tractive effort, when multiplied with speed at which the train is required to run, gives the horsepower. The power transmission system is design to transmit the engine power to the track system with minimum power loss. Tractive effort is generally equal to or a little greater than the hauling capacity of the locomotive. Construction planning, equipment, sixth edition chapter.
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. Rolling resistance is vehicle weight times rolling resistance coefficient for example 0. Total tractive effort required by both front wheels, ftf n. There are various tractive effort curves available for different locomotives for different speeds, which enable the computation of the value of tractive effort. Braking calculations to optimise braking performance there are other considerations which must be taken into account. An approach for effort estimation of service oriented architecture soa projects article pdf available in journal of software 111. Pdf an approach for effort estimation of service oriented. The relationship between the client and the business. Effort can be calculated in staffmonth, staffweek or personhour. The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort. The continuous tractive effort would be determined by how much electricity traction motors could handle before burning up. Effort is time required for one person to complete the project. Effort percent person months conversion tables these conversion tables were designed to assist departments when converting effort in the form of a percentage to personmonths or converting personmonths to an effort percentage, based on the term of appointment.
For example, a 3000 hp locomotive will have approximately 74,000 lbs. Continuous tractive effort is the tractive force that can be maintained indefinitely, as distinct from the higher tractive effort that can be maintained for a limited period of time before the power transmission system overheats. Planswift can do estimates from just about any plan type but does exceptionally well with pdf files. Influence of locomotive tractive effort on the forces between wheel and rail article pdf available in vehicle system dynamics 35supplement. Whatever may be source or principle of working of traction motor, all provide tractive effort characteristics to encounter train resistance and provide acceleration. On higher speed vehicles friction in drive components may warrant the addition of 10%15% to the total tractive effort to ensure acceptable vehicle performance. Car vehicle driving up a slope equation and calculator. The speed at which both forces are equal is the maximum speed the train can get to on a flat piece of track. The mcgrawhill companies, 1 software project management 4th edition software effort estimation chapter 5 2. G5t 2 up to 5400 up to 5400 haulage capacity for wag5tao locomotive 3 step weak field gr 15. Analysis of empirical software effort estimation models.
Otherwise, the calculation is based on your job settings gps zone. Application examples illustrate the influence of locomotive tractive effort on the forces between wheel and rail. Elements crm ios is a mac customer relationship management mac crm solution built by ntractive for apple business using apple devices. Available tractive effort road vehicle performance. Jul 07, 2005 ok boys and girls i have a math quiz for you all. Software effort estimation is one of the oldest and most important problems in software project management, and thus today there are a large number of models, each with its own unique strengths and weaknesses in general, and even more importantly, in relation to the environment and context in which it is to be applied. Calculation of the traction effort of switching locomotive. The total axle torque is tractive effort times the. Tractive effort to haul a passenger train at 75 mph on level track. Tractive effort and acceleration ce 322 transportation engineering dr. Pdf influence of locomotive tractive effort on the. This conversion from software size to total project effort can only be done if you have a defined software development. In other words, it is the sum of the tractive force and rolling effort on the road surface.
I have just had a power run done on my r32 gtr and have a reading for tractive effort, and i want to convert that to an approximate torque figure nm. 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. Tractive effort is a measure of the force that a locomotive can apply to the train it is pulling. Tractive effort is defined as the force at the rims or the outer edges of the driving wheels of moving trains.
Coefficient of traction for various surfaces surface rubber tires crawler tracks dry, rough concrete 0. Tractive efficiency of the farm tractor iowa state university. Midyear economic analysis 201220 department of economic. Locomotive power calculations greenville, south carolina.
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. Vehicle dynamics calculation tractive effort of a car. These terms apply to different operating conditions, but are related by common mechanical factors. Theres another usage for these terms in the railroad business. The force required for the motion of a load can be reduced using simple machines, the result of usage of such simple machines is the mechanical advantage which is the ratio of load and effort. Conceptual design of a rubber tracked mini vehicle for small. Acceleration is a measure of how quickly you are gaining or losing speed. I do this to see which is the best solution for romanian forest. It is usually expressed in pounds the relation between tractive effort, rail horsepower, and speed in miles per hour is tractive effort 270 rail horsepower kg speed note. The use of the model enables effort estimation from nonexperts e. Tractive effort of steam locomotives locomotive ratiosii by a. Force of vehicles engine maximum value transferable maximum tractive effort define the point at which additional enginegenerated tractive effort is not productive. These tables can be especially useful during the proposal process to determine effort. Estimating effort once you have an estimate of the size of your product, you can derive the effort estimate.
If the tractive effort is much greater than what is required to haul the train. To do this we will use the maximum tractive effort calculated in equation 9 which was 100 lbs. Horsepower and tractive effort the idiots guide to. The total axle torque is tractive effort times the wheel radius. Effort estimation models based on the number of code lines have one considerable shortcoming. Ahmed abdelrahim available tractive effort tractive effort determined by. 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. We now have the speed rpm and the required tractive effort. The maximum permissible traction force that can be applied to the wheels is governed by two things. Abstract reliable effort estimation remains an ongoing challenge to software engineers. Accurate effort estimation is the state of art of software engineering, effort estimation of software is the preliminary phase between the client and the business enterprise.
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