Tractive effort values in tonnes at various speeds up to up to 5093 5400 table no. Material provided by sachin buddhisagar, copyright 2011. The relationship between the client and the business. 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. Tractive effort is defined as the force at the rims or the outer edges of the driving wheels of moving trains. So the laboratory answer is that tractive effort is independent of power, but power is composed of force tractive effort, distance and time. Tractive efficiency of the farm tractor iowa state university. The total tractive effort tte is the sum of the forces calculated in steps 1, 2, and 3. Opentrack began in the mid1990s as a research project at the swiss federal institute of technology. Pdf influence of locomotive tractive effort on the. 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 and acceleration ce 322 transportation engineering dr. 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. Coefficient of traction for various surfaces surface rubber tires crawler tracks dry, rough concrete 0.
So if they could handle the tractive effort of 80 000, then the engineer should not drive below 9. Tire traction can also refer to the maximum tractive force between a body and a surface, as limited by available friction. The speed at which both forces are equal is the maximum speed the train can get to on a flat piece of track. 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. Locomotive power calculations greenville, south carolina. Locomotive tractive effort and power calculations tractive effort calculations. The last step is to calculate the axle torque required to generate this tractive effort. Influence of locomotive tractive effort on the forces between. This is an effort estimation method based on expert judgment. 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. To solve for northing and easting, fill in the latitude and longitude and press solve ne. 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. This conversion from software size to total project effort can only be done if you have a defined software development. 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.
First, a force of 2 to 5 pounds per ton of train weight is required to move on straight level track. 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. Tire traction force, or tractive force, is the force used to generate motion between a car or truck and the road or tangential surface. Vehicle forces for driving up slope equations and calculator. We now have the speed rpm and the required tractive effort. Tractive effort is generally equal to or a little greater than the hauling capacity of the locomotive. Vehicle dynamics calculation tractive effort of a car. Therefore, tractive effort was more important than horsepower for steam locomotives. Tractive effort is the force needed to simply move the train. Estimating effort once you have an estimate of the size of your product, you can derive the effort estimate. 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. Elements crm ios is a mac customer relationship management mac crm solution built by ntractive for apple business using apple devices.
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. For example, if we are trying to estimate the mean of some variable, but the. Conceptual design of a rubber tracked mini vehicle for small. For steam locomotives, tractive effort was usually the limitting factor in the size of the train it could pull. To do this we will use the maximum tractive effort calculated in equation 9 which was 100 lbs. Drive wheel motor torque calculations university of florida. Braking calculations to optimise braking performance there are other considerations which must be taken into account. 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. An approach for effort estimation of service oriented architecture soa projects article pdf available in journal of software 111. 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. Dieselelectric traction has the following advantages.
There is no method for the precise calculation of these resistances but the following formula has been evolved based on experience. The tractive force between a car wheel and the surface can be expressed as. 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. Rolling resistance is vehicle weight times rolling resistance coefficient for example 0. 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. Jul 07, 2005 ok boys and girls i have a math quiz for you all. Ntractive was a privately held software development company based in grand forks, north. 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. The maximum permissible traction force that can be applied to the wheels is governed by two things. F traction effort or force acting on the wheel from the surface n, lb f. In other words, it is the sum of the tractive force and rolling effort on the road surface. The calculator can be used for imperial and metric units as long as the use of units are consistent.
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. Use this calculation to find your crm roi technologyadvice. Drawbar pull is the tractive effort minus the rolling resistance. Application examples illustrate the influence of locomotive tractive effort on the forces between wheel and rail. The mcgrawhill companies, 2 what makes a successful project. Moreover, the paper presents calculation of the traction effort of tep70. The continuous tractive effort would be determined by how much electricity traction motors could handle before burning up. 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. What links here related changes upload file special pages permanent link page information wikidata item cite. If the tractive effort is much greater than what is required to haul the train. Tractive effort is the propelling force which a locomotive exerts at the rims of its driving wheels. Total tractive effort required by both front wheels, ftf n.
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. Otherwise, the calculation is based on your job settings gps zone. Managing customer relationships in the social media era. Traction effort of switching locomotive chme3 with railroad slope 5. Project price calculations and quotations easy redmine. As this becomes a common way for plans to be distributed to contractors it become important to be able to accurately estimate from. In railway engineering, the term tractive effort is often used synonymously with tractive force to describe the pulling or pushing capability of a locomotive. For slopes, you will need an additional 100 newton per percent of steepness. In the main line train, tractive effort is caused by the locomotive, and in a suburban train, it is caused by motor coaches. The mcgrawhill companies, 1 software project management 4th edition software effort estimation chapter 5 2.
May 12, 20 tractive effort, when multiplied with speed at which the train is required to run, gives the horsepower. 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. W weight or vertical force between wheel and surface n, lbf m mass on the wheel kg, slugs ag acceleration of gravity 9. What links here related changes upload file special pages permanent link page. Steam locomotive tractive effort vs diesel electric. Tractive force steam locomotives calculator fx solver. Effort estimation models based on the number of code lines have one considerable shortcoming. Car vehicle driving up a slope equation and calculator. I do this to see which is the best solution for romanian forest. Horsepower x 308 speed mph where 308 is 82% of 375 lbmiles per hour per hp. 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. Midyear economic analysis 201220 department of economic.
The total axle torque is tractive effort times the. Pdf an approach for effort estimation of service oriented. There are various tractive effort curves available for different locomotives for different speeds, which enable the computation of the value of tractive effort. Construction planning, equipment, sixth edition chapter. That kind of calculations are very important for motion planning and it should be done in order to avoid overloading. Theres also a side benefit to calculating the roi of your crm we cant ignore.
First, a force of 2 to 5 pounds per ton of train weight is. Tractive effort of steam locomotives locomotive ratiosii by a. Tractive effort determines how much a locomotive can haul. Tractive effort is a measure of the force that a locomotive can apply to the train it is pulling. To choose motors capable of producing enough torque to propel the example vehicle, it is necessary to determine the total tractive effort tte. To solve for latitude and longitude, fill in the northing and easting and press solve latlong. 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. 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. Tecorange orange effort estimation tool for software.
Analysis of empirical software effort estimation models. Whatever may be source or principle of working of traction motor, all provide tractive effort characteristics to encounter train resistance and provide acceleration. You can set the state plane zone at the bottom of this dialog. G5t 2 up to 5400 up to 5400 haulage capacity for wag5tao locomotive 3 step weak field gr 15. The power transmission system is design to transmit the engine power to the track system with minimum power loss.
Force of vehicles engine maximum value transferable maximum tractive effort define the point at which additional enginegenerated tractive effort is not productive. W weight or vertical force between wheel and surface n, lb f m mass on the wheel kg, slugs a g acceleration of. So our first guess at a tevsspeed curve is a hyperbola. Planswift can do estimates from just about any plan type but does exceptionally well with pdf files. This tool enables software development effort estimation using 5 different methods.
Tractive effort to haul a passenger train at 75 mph on level track. Calculating tractive effort page 1 locomotives and. 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. 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. Equations behind the vehicle forces for driving up slope calculator. For a given tractive effort, increased horsepower allows an increased speed with other things remaining the same.
Effort is time required for one person to complete the project. Power is the force needed to run a train at a certain speed. Tractive effort te and tractive resistance tr tractive effort te. The methodology and the various formula adopted are also given.
Effort can be calculated in staffmonth, staffweek or personhour. Pdf calculation of the traction effort of switching. The propelling force developed is generally referred to as tractive force or tractive effort. This is the ratio of the tractive effort force just necessary slip the wheels on the track to the adhesive weight. For example, a 3000 hp locomotive will have approximately 74,000 lbs. The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort.
Tire traction force equation and calculator engineers. F traction effort or force acting on the wheel from the surface n, lbf. Available tractive effort road vehicle performance. These terms apply to different operating conditions, but are related by common mechanical factors.
The tractive effort required to move a train consists of numerous factors, but for most applications only four need to be considered. 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. Influence of locomotive tractive effort on the forces between wheel and rail article pdf available in vehicle system dynamics 35supplement. With the three cylinder locos the nsw d5758 class had that, the tractive effort was, d57 class. 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. This energy wears the tires and compacts the soil to a degree that may cause detrimental crop production burt et al.
Tractive effort definition of tractive effort by merriam. The total axle torque is tractive effort times the wheel radius. Apr 12, 2011 planswift construction takeoff and estimating software is a great way to do pdf estimate work. Horsepower and tractive effort the idiots guide to. The speed at which both forces are equal is the maximum speed.
By the way, the term tractive effort is supposed to imply at the wheel rim, as opposed to at the locomotive coupler. 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. Ahmed abdelrahim available tractive effort tractive effort determined by. Due to the relationship between power p, velocity v and force f, described as. 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. These tables can be especially useful during the proposal process to determine effort.1468 738 1149 876 1528 753 298 505 88 966 738 1021 41 270 18 317 596 1243 1095 562 925 1144 685 1403 924 1202 507 1257 46 1207 896 763 598 1232 987 1280 935 560 938 516 730 664 533