That seems counterintuitive to me. I would appreciate your help in understanding this. And thanks for your patience with a physics newbie. When the train pulls the carriages their wheels are rolling not sliding. That means the coefficient of friction of the carriage wheels with the rails is not relevant. The engine just has to be able to produce enough force to overcome whatever drag exists in the carriage axles and wheel bearings.
The locomotive connects the bogies well above the center line of the loco wheel. When the loco pulls the frictional force rolling times the bogies total weight makes the rear wheels of loco to exert more vertical force due to moment arm and this adds up to the loco dead weight. The pulling frictional force of loco becomes thus more than the total bogies weight times rolling friction. This makes loco to pull the bogies without slip. Also when the loco starts it gives a jerk while pulling, this contributes to rolling contact friction.
Sign up to join this community. They also have footrests. Although taking the train might be slower than flying, it's definitely a lot more comfortable. There is plenty of room to walk around, and you can eat in a dining car or look at the view from the the top of the lounge car. Some trains even have private rooms for first-class passengers -- not a bad way to get from here to there.
For more information on diesel locomotives and related topics, check out the links on the next page. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. How Diesel Locomotives Work.
By: Karim Nice. Contents Why Hybrid? Why Diesel? Why Hybrid? Steel Wheels " ". Traction " ". The Layout: Cab and Trucks " ". The Layout: Power, Fuel and Batteries " ".
The Engine and Generator " ". Number of cylinders : 12 Compression ratio : Displacement per cylinder : The Trucks: Braking " ". The brakes are similar to drum brakes on a car.
Driving a Locomotive " ". This computerized display can show the status of systems all over the locomotive. Riding the Train " ". The seats on this car can be turned around to face each other so four people can sit together. The train also has a kitchen that serves mostly sandwiches and light snacks. For first-class passengers on this train, there is an observation car that has a sunroom upstairs and a bar.
When diesel is ignited, it gives power to the pistons connected to an electric generator. The generator then produces energy to supply power to the motors that turn the wheels to run the locomotive. How many horsepower is a diesel locomotive?
A locomotive's diesel engine is connected to an electric generator that is either DC or AC. In either case, the power produced is around 3, horsepower. The generator uses this power to convert it into a massive amount of current, approximately 4, amperes. What is the difference between a hybrid diesel locomotive and a traditional locomotive?
A traditional locomotive simply relies on mechanical energy to drive the locomotive. On the other hand, a modern hybrid diesel locomotive combines both electrical and mechanical energies to give better power output. It consists of massive 12 cylinders connected to a two-stroke diesel engine and some heavy-duty generators and electric motors to increase the power output. Why are locomotives diesel powered? In terms of efficiency, diesel engines are more powerful and energy-efficient than gasoline engines.
This is because diesel engines work on higher compression ratios. This gives about 20 percent more efficiency than gasoline engines at the same compression ratio. Why do trains have steel wheel? Trains have steel wheels to decrease the rolling friction. So, metal or steel wheels give low rolling resistance, consume less energy and save operating costs.
Auto Fuel Economy Does a diesel engine equal fuel cost savings? Cite This! Try Our Sudoku Puzzles! Modern locomotives are equipped with various traction control systems that allow them to reduce or eliminate wheel slip. These types of technology are oftentimes used to govern how much power is sent to the wheels in order to avoid wheel slip and retain traction.
Although too much wheel slip could cause inevitable damage to both the locomotive and the railroad infrastructure, some wheel slip is actually advantageous. Many modern locomotives are equipped with a system called CREEP, which regulates how much wheel slip the locomotive experiences. This system is controlled by computers and other facets of technology that needs to work in unison in order for this feature to operate correctly.
Although this technology is effective, it must be maintained regularly in order to work properly. Although these various systems are effective in controlling wheel slip, engineer skill is paramount in maintaining traction. Engineers must know how to control the slack in the couplers in order to maintain control of the train, which prevents breaking coupler knuckles and draft gear.
One of the most prominent offenders hindering operations are leaves on the track, predominantly in the fall. When leaves fall from the trees and land on railroad tracks, they are crushed by passing trains, causing the leaves to exert various oils, which are slippery, and often cause delays. Snow and ice greatly hinder railroad operations as well, as it causes the rails to be incredibly slick, and in some instances, impassible. Various railroads combat these conditions with snow jets, which is a jet engine powered blower.
This blower operates as a powerful snow blower and de-icer, clearing tracks and switches of ice and other debris. Amtrak sleeper cars are a great way to see everything this country has to offer.
After releasing the caboose, the train still could not start. The problem was that when the train attempted to start with the caboose brake on, it stretched all the inter-car couplings so that the whole train was just like one big car. At this point, the friction from the engine train wheels was not enough to get the whole thing going. Instead, you need to just get one car moving at a time - this is why there is space between the couplings. I think there is some interesting physics here.
In particular, there is something curious about the difference between static and kinetic friction. First, let me make some observations and assumptions. The train has a big engine in it. This engine makes the wheels turn to pull the rest of the cars.
If we consider the train and wheels as the system, the force that changes its momentum is the static friction force between the wheels and the rail. Yes, right. What about the cars? They also have wheels. However, these are not driving wheels, they just roll but they also have friction. I will assume that the frictional force is in the axle of the wheels. For these rolling cars, the friction is kinetic friction and not static. What is the difference between kinetic and static friction?
Static friction is the model for the frictional force between two surfaces that are at rest relative to each other. This would be the case of the engine car's wheels.
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