Braking knowledge for trains.

How does a train crew know there if is a speed-reduction zone ahead and how far ahead it is? How does a train crew calculate braking distance and time for an upcoming speed reduction zone? How do they know exactly how much force to apply to the brakes, including dynamic braking?

A train operator might be approaching a speed zone of 45 mph from a 70-mph zone. If he starts to brake too late, he will be going too fast for the speed reduction zone he is about to enter. If he brakes too early, he will just waste valuable time. Ideally, you would want to time rate of deceleration just right, so you ease into the speed reduction zone safely and comfortably but without going too slow too soon. Braking distance might be attributed to many factors. Grades, weather, track condition, curves, visibility, human reaction time, train mass, train speed, train loads, train number of axles, mechanical condition of train, rail car and locomotive design and number of working engines in train. A train is not a car, a bus, a streetcar or even a big commercial truck. They are long and heavy often and don't stop on a dime.

There is emergency braking distance and normal service braking distance. A locomotive engineer must be a genius to gracefully brake a long and heavy train comfortably, efficiently and safely. I think proper and graceful train braking is an art much as properly landing an airplane is an art.

From what I was told, much of this comes from qualifying on the route. The crew and engineer are given trial runs and training by other experienced crew members. Once the crew knows the line inside and out, upside down, and sideways, they're then given the reigns to drive. There are also advance warning signs and signals to tell the crew when to slow down under normal circumstances.

A train crew running on a line 1,000 miles long or more are only human. It would hard to remember each and every speed zone on a massive line. I'm sure train crews have to be cognitive of their total train weight and overall length at all times. Perhaps radio communications from dispatchers can warn train crews to slow in advance as well. Often on motor highways, there will be signs indicating speed reduction ahead. I would think it would also be good for a train crew to know how far ahead there is a reduced speed zone. The train crew also has to know when their train has completely cleared a lower speed zone before they can accelerate to a higher speed in a higher speed zone. Not generally an issue with a short automobile or truck, but how does the conductor know his 1-mile-long train has cleared a lower speed zone?

JonMyrlennBailey said:

A train crew running on a line 1,000 miles long or more are only human. It would hard to remember each and every speed zone on a massive line. I'm sure train crews have to be cognitive of their total train weight and overall length at all times. Perhaps radio communications from dispatchers can warn train crews to slow in advance as well. Often on motor highways, there will be signs indicating speed reduction ahead. I would think it would also be good for a train crew to know how far ahead there is a reduced speed zone. The train crew also has to know when their train has completely cleared a lower speed zone before they can accelerate to a higher speed in a higher speed zone. Not generally an issue with a short automobile or truck, but how does the conductor know his 1-mile-long train has cleared a lower speed zone?

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A train crew wouldn't drive the full 1,000 miles. They have an hours-of-service limit of 10 hours maximum. After that 10 hours, they are required to have a rest period of so many hours.

A train crew knows the length of their train and they have a book that contains the signals, track section lengths, speed limits and grades for a given route rarely is there a speed limit sign like in Trainz. The train speed is governed by many things including the weight of the train, the kind of commodities being carried, the route itself, and the length of the train. Trains and their crews do not work even close to trucks or truck drivers. All of this information is spelled out in operation books, and notes from the train master and clerks who setup the train manifest. Yes, a dispatcher will have control over a section, block, or whatever you want to call it. The dispatcher stays in communication with the crew via radio and even GPS these days.

Locomotives built these days are equipped with what's called a 'trip optimizer'. It basically tells an engineer when to apply throttle or brake to be the most efficient in saving fuel, which saves the company money, and we all know how railroads want to save money.

jordon412 said:

Locomotives built these days are equipped with what's called a 'trip optimizer'. It basically tells an engineer when to apply throttle or brake to be the most efficient in saving fuel, which saves the company money, and we all know how railroads want to save money.

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On my Trainz layout, I have added these trackside signs to warn "rookie" train crews of reduced speed zones ahead. I want no speed traps or nasty surprises on my idyllic American railroad. This sign should prompt the train to start to slow down. I figure 1/2 mile warning for each and every 10 miles per hour to be reduced. If there is a reduction by 25 mph ahead, the train would get a 1 1/4 miles warning. This should be sufficient comfortable service braking distance for the heaviest American standard gauge trains under the worst possible braking conditions. On my idyllic railroad, I don't cheap out on power for the train. I, out of safety consciousness, strive to operate my railroad and its vehicular equipment in nothing less than ship shape. My long freight trains have at least 1 d/e locomotive for each and every 1/4 mile of freight train, about 15 cars. My 15-car passenger trains always have at least two engine units. Most of if not all my freight trains have d/e locos with dynamic braking. A number of locomotives is as important for braking and speed control especially in graded track areas as it is for pulling power and acceleration. A train or any other vehicle should never travel any faster than it can safety come to a stop in an emergency.






Of course, AI will decelerate trains at a much quicker rate than physical trains normally do in the real world. Instead of reducing train speed by 10 mph for each and every half mile to the reduced speed zone, AI will brake the train more like only 1/4 to 1/8 mile ahead approaching a 10-mph-reduced speed limit sign ahead. The MOW Amtrak road-railer truck will practically stop from 50 MPH on a dime.

Speaking of Amtrak MOW road-railer trucks, how many axles does this vehicle have anyway? Three axles have tires on them and there are also the front and rear single-axle rail adapter bogies. The male voice on my defects detector calls out that there are four axles whenever this road-railer truck passes. Does this man even know how to count? Does this truck have three or five axles? Do the flanged adapter wheels count as "axles" even?

Tip: Use the session rule Display Custom HUD. This will show how close the next speed limit, and what the speed limit is; what the next signal is and how far away it is; has an odometer, trip meter, and shows the current grade. Very handy.

One locomotive engineer, Al Krug, used to write various comments about running BNSF trains between Sheridan Wyoming and Laurel Montana (just south of Billings). His Tales from the Krug online pages were interesting to read. He retired back in 2005, so isn't writing online anymore as far as I know. Reportedly, he wrote much more in a Yahoo group, but I never saw that material.

I wish that I could find postings from other engineers.

Thanks for that link, OddRails! Some great photo essays there!

jordon412 said:

Tip: Use the session rule Display Custom HUD. This will show how close the next speed limit, and what the speed limit is; what the next signal is and how far away it is; has an odometer, trip meter, and shows the current grade. Very handy.

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It's handy in TRAINZ driving but I am designing my route as if it were my own real-world physical railroad. Like fantasy baseball, my Trainz sim is fantasy railroading. As a real-world railroad owner, I would make such trackside signs a rule for my pike. It's kind of like yellow road signs warning even experienced truck drivers of steep downgrades ahead and to downshift in advance. There might also be techy electronic stuff in the engine cabs as audible vocal warnings to assist in the safe navigation of trains as well.

JonMyrlennBailey said:

Speaking of Amtrak MOW road-railer trucks, how many axles does this vehicle have anyway? Three axles have tires on them and there are also the front and rear single-axle rail adapter bogies. The male voice on my defects detector calls out that there are four axles whenever this road-railer truck passes. Does this man even know how to count? Does this truck have three or five axles? Do the flanged adapter wheels count as "axles" even?

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As far as Trainz is concerned it has 4. The enginespec used for the MOW is the "<kuid:104722:51150> SW1500 Engine" espec (maybe a bit overpowered) and it includes this tag in the motor container: "axle-count 4".

Bob Pearson

JCitron said:

A train crew wouldn't drive the full 1,000 miles. They have an hours-of-service limit of 10 hours maximum. After that 10 hours, they are required to have a rest period of so many hours.

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Actually it's 12 hours max on duty and a minimum of 10 hours of rest.

jordon412 said:

Locomotives built these days are equipped with what's called a 'trip optimizer'. It basically tells an engineer when to apply throttle or brake to be the most efficient in saving fuel, which saves the company money, and we all know how railroads want to save money.

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Trip Optimizer is sort of a cruise control so little to no input is required by the Engineer.

OddRails said:

One locomotive engineer, Al Krug, used to write various comments about running BNSF trains between Sheridan Wyoming and Laurel Montana (just south of Billings). His Tales from the Krug online pages were interesting to read. He retired back in 2005, so isn't writing online anymore as far as I know. Reportedly, he wrote much more in a Yahoo group, but I never saw that material.

I wish that I could find postings from other engineers.

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Most of us are too busy working versus writing blogs in our limited off time as Al Krug did. (See my reply to JCitron above - 12/10 hours)