What's so special about Big Boys?

[feltonhill]

The grade from Portsmouth to Williamson on the N&W is descending westbound at about -0.016% for the first 100 miles (range - level to -0.058%), upgrade 0.30% at Kenova over the Ohio River and -0.012% for the last 30 miles or so into Portsmouth.

Train weight varied depending on the mix of 50-ton and 70-ton cars. At a train length of 160 cars, trailing weight would be about 12,000 to 15,000 tons. Ultimately, a single A was expected to haul 180 cars over the division, a trailing weight of up to 17,000 tons.

According to GP40-2's figures, a CW44AC could develop 4,305 DBHP. To match the A's performance, it would need between 5,300 and 5,400 DBHP, so it would not match a single A's performance overall. The GE's operating economy would obviously be much better.

Again according to GP40-2's figures, a CW60AC would have about 5,895 DBHP. This is beyond the range of an A in daily service.

I've found no data for an FEF-3 above 75 mph, so I don't know what it would do with any certainty. Existing information indicates that they were very capable performers in regular service and could reach their design speed (100-110mph) easily. However, they were not record-breakers in the DBHP department according to the small amount of test info available. Don't know why.

GP40-2's figures for the P42 indicate that it would develop 3,850 DBHP at 100 mph. This would be pretty rarified atmosphere for steam and is likely well beyond the range of an FEF-3. My guess is that an FEF-3 would develop about 2,500 to maybe 2,700 DBHP at 100.

Since I don't have access to much diesel information, I find the relatively high percentage of rated HP making it to drawbar HP unusual. I didn't think they were that efficient from prime mover to rear coupler.

[GP40-2]

QUOTE: Originally posted by trainjunky29

How is a steamer's power curve related to a Gaussian Curve?
1.) A Gaussian curve returns to 0 as the x-component increases, a steamer's does not
2.) A steam locomotive has nothing to do with probability nor with quantum physics
3.) A steam locomotive's power curve has no points of inflection
4.) I plotted feltonhill's data, and it looks nothing like the curves shown in the above link or a "classic Gaussian distribution curve."

Sincerely,
Daniel Parks

Let's look at the data, and focus on speed vs. hp:

Speed - Calc TE (lbs) - Actual DB Pull (lbs) - Actual DBHP

0 - 135,300 - 131,000 - 0
10 - 132,500 - 124,000 - 3,307
20 - 109,000 - 98,000 - 5,227
30 - 83,000 - 75,000 - 6,000
40 - 67,000 - 57,000 - 6,080
50 - 56,100 - 43,000 - 5,733
60 - 48,700 - 32,000 - 5,120

SPEED=X HP=Y

X Y
0 0
10 3307
20 5527
30 6000
40 6080
50 5733
60 5120
70 4000 (extrapolated)
80 2800 (extrapolated)

Plot those, and you will get a bell shaped curve. Maybe not a "pure Guassian", but a bell shaped curve none the less.

I'm also curious why you think probability and statistics can not be used to describe how a steam locomotive works? After all, Monte Carlo routines are often used now in mechanical engineering design...

[Anonymous]

How is a steamer's power curve related to a Gaussian Curve?
1.) A Gaussian curve returns to 0 as the x-component increases, a steamer's does not
2.) A steam locomotive has nothing to do with probability nor with quantum physics
3.) A steam locomotive's power curve has no points of inflection
4.) I plotted feltonhill's data, and it looks nothing like the curves shown in the above link or a "classic Gaussian distribution curve."

Sincerely,
Daniel Parks

[GP40-2]

QUOTE: Originally posted by trainjunky29

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by trainjunky29

Dear GP40-2,
What exactly do you mean that a steamer's power curve is exponential in nature? I presume you don't mean b^x like in calculus class, nor do you mean x^p.

Sincerely,
Daniel Parks

I mean that a steam locomotive's power curve follows the classic Gaussian Distribution Curve (i.e "the Bell Shaped Curve"). If you plot Feltonhill's data, you will see what I mean. Of course, if you had recorded data at say every MPH from 0 to 80 mph, you would get a real nice Gaussian distribution.

Dear GP40-2,
I presume this is what you're talking about: http://en.wikipedia.org/wiki/Gaussian_function.
I have never seen a locomotive power curve that is a bell-shaped curve.

For one thing, a bell-shaped curve is used in probablilty, quantum and atomic physics, and mathematic theory (as stated on the above website). Locomotive horsepower is not at all related to probability, and the Big Boy is a long way from the quantum.

To use some big words:
The "Bell Shaped Curve" is concave up at the beginning, but has a point of inflection on the way up. It then returns to y where the limit of y as x aproaches infinity is 0 (sorry about having to write that out--it's hard to type in mathematic notation).

The locomotive horsepower vs. velocity curve on the other hand is usually always concave-down without a point of inflection, and as speed increases after peak horsepower, the horsepower tends to approach a limit somewhere toward the middle of the horsepower range, rather than returning to 0. In theory, because of friction, air resistance and such, this "post-max" horsepower limit would tend to dictate a maximum speed for the locomotive. In practice, other factors, such as counterbalancing, prescribe a lower maximum speed limit usually.

The locomotive horsepower curve might in part be exponential, but were we to work out an exact equation, would almost certainly have trigonometric and probably power components as well. Add to that a ton of constants for friction and steam flow, and you'd get a graph resembling a measured locomotive horsepower curve.

Sincerely,
Daniel Parks

What I was trying to impress was that steam locomotives and diesel-electrics have much different shaped power curves.

There is a difference in the pure mathematical definition of a Gaussian Curve and a workplace definition when decribing a process that has a Gaussian shape to it.

I was trying to explain a complex power curve in simple terms. Let's just say a steam locomotive power curve has a strong Gaussian component to it, but other factors modify the curve at various points.

Clear as mud, right?

[Anonymous]

Terribly sorry--I must have read about the piston strokes and diameters somewhere else.

Sincerely,
Daniel Parks

[GP40-2]

QUOTE: Originally posted by trainjunky29

Dear GP40-2,
Please clarify on what it is that I don't understand. If you would be so good as to point to a specific statement with which you have an issue, I'd appreciate it.

As for the locomotive horsepower vs. boiler pressure:
You yourself stated that the Big Boys had smaller piston strokes and diameters than other locomotives. In part, the larger force on the piston from the greater cylinder bore on the Yellowstone, and the greater Mechanical Advantage from the larger stroke on the Allegheny, made up for the decreased boiler pressure. Also, if you give an engine large (wide) steam ports and large valves, it will increase horsepower, as long as you have a boiler to match. Do bear in mind that the lower boiler pressure allowed the boiler to create more steam at a lower pressure with the same heat. The boiler would therefore be able to create more steam for the cylinders to use, whereas the Big Boys would need a slightly shorter cutoff.

Sincerely,
Daniel Parks

I don't recall making any statements about the Big Boy's piston diameter or stroke in this thread....as for the rest of your statement that's old news. I really don't see that you are making a new point. In fact, the rest of your statement seems to be pretty much what I said in the first place.

[jchnhtfd]

Pressure is important. So is piston diameter and stroke. But as far as power goes (as distinct from tractive effort), the bottom line is how much power (in terms of pounds of fuel per hour) can the boiler use and what are the losses on the way to the cylinders. Other characteristics of locomotive design are dependent on these. If you want so and so much power, you need such and such a fire box and firing arrangement, which will produce so and so many pounds of steam per hour. Then you look at pressure, and higher pressure makes for smaller pipes and valves and pistons, which are easier to work with. But you might want bigger drivers (if you are looking for speed) to allow more time for each piston event and for better balancing. And so on.

It all has to work together...

[Anonymous]

Also, I've seen different HP numbers for Big Boys and DM&IR Yellowstones which could put either one in the lead depending on what numbers you used (or even a tie).

[Anonymous]

Dear GP40-2,
Please clarify on what it is that I don't understand. If you would be so good as to point to a specific statement with which you have an issue, I'd appreciate it.

As for the locomotive horsepower vs. boiler pressure:
You yourself stated that the Big Boys had smaller piston strokes and diameters than other locomotives. In part, the larger force on the piston from the greater cylinder bore on the Yellowstone, and the greater Mechanical Advantage from the larger stroke on the Allegheny, made up for the decreased boiler pressure. Also, if you give an engine large (wide) steam ports and large valves, it will increase horsepower, as long as you have a boiler to match. Do bear in mind that the lower boiler pressure allowed the boiler to create more steam at a lower pressure with the same heat. The boiler would therefore be able to create more steam for the cylinders to use, whereas the Big Boys would need a slightly shorter cutoff.

Sincerely,
Daniel Parks

[GP40-2]

QUOTE: Originally posted by trainjunky29

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by trainjunky29

True, but it's the pressure that causes the force on the piston, not the volume. The volume comes into play when trying to conserve steam--take away to much steam and the boiler pressure goes down.

Sincerely,
Daniel Parks

No, the cylinder has a difinite volume that needs to be filled. If you limit the volume of steam entering the piston, regardless of the pressure, you limit the power. As the high pressue steam enters the cylinder, it expands and transfers its energy to the cylinder. Once a volume of steam is done expanding, no more power transfer. That's why the Allegheny was so powerful with just 260 lbs pressure. It was not the pressure producing the HP, it was the boilers ability to pruduce high volumes of steam to keep the cylinders filled at high speed.

Dear GP40-2,
The volume won't do you any good unless it's under pressure. The steam if it is under any decent amount of pressure whatsoever will expand to fill the full volume of the cylinder. The is then is what pressure it's under, and consequently, how much force it's exerting. Increasing pressure is probably the single most effective way to increase tractive effort and horsepower.

Also, the steam does not expand in the admission phase, only cutoff and a little bit in compression (though by the time compression comes, it's pretty much done usefully expanding). In admission, the volume is being fully filled by steam straight fromt the boiler. Just clarifying.

Sincerely,
Daniel Parks

Ok, if you think pressure is so important, use you logic to explain the far higher horsepower from the Allegheny @ 260lbs pressure, and the greater HP and tractive effort from the M3/M4 Yellowstone at only 240 lbs pressure.

[GP40-2]

QUOTE: Originally posted by trainjunky29

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by trainjunky29

True, but it's the pressure that causes the force on the piston, not the volume. The volume comes into play when trying to conserve steam--take away to much steam and the boiler pressure goes down.

Sincerely,
Daniel Parks

No, the cylinder has a difinite volume that needs to be filled. If you limit the volume of steam entering the piston, regardless of the pressure, you limit the power. As the high pressue steam enters the cylinder, it expands and transfers its energy to the cylinder. Once a volume of steam is done expanding, no more power transfer. That's why the Allegheny was so powerful with just 260 lbs pressure. It was not the pressure producing the HP, it was the boilers ability to pruduce high volumes of steam to keep the cylinders filled at high speed.

Dear GP40-2,
The volume won't do you any good unless it's under pressure. The steam if it is under any decent amount of pressure whatsoever will expand to fill the full volume of the cylinder. The is then is what pressure it's under, and consequently, how much force it's exerting. Increasing pressure is probably the single most effective way to increase tractive effort and horsepower.

Also, the steam does not expand in the admission phase, only cutoff and a little bit in compression (though by the time compression comes, it's pretty much done usefully expanding). In admission, the volume is being fully filled by steam straight fromt the boiler. Just clarifying.

Sincerely,
Daniel Parks

Wow! All I can say is you really don't understand this stuff. I can see way you have so many misconceptions about the reality of steam locomotives.

[Anonymous]

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by trainjunky29

Dear GP40-2,
What exactly do you mean that a steamer's power curve is exponential in nature? I presume you don't mean b^x like in calculus class, nor do you mean x^p.

Sincerely,
Daniel Parks

I mean that a steam locomotive's power curve follows the classic Gaussian Distribution Curve (i.e "the Bell Shaped Curve"). If you plot Feltonhill's data, you will see what I mean. Of course, if you had recorded data at say every MPH from 0 to 80 mph, you would get a real nice Gaussian distribution.

Dear GP40-2,
I presume this is what you're talking about: http://en.wikipedia.org/wiki/Gaussian_function.
I have never seen a locomotive power curve that is a bell-shaped curve.

For one thing, a bell-shaped curve is used in probablilty, quantum and atomic physics, and mathematic theory (as stated on the above website). Locomotive horsepower is not at all related to probability, and the Big Boy is a long way from the quantum.

To use some big words:
The "Bell Shaped Curve" is concave up at the beginning, but has a point of inflection on the way up. It then returns to y where the limit of y as x aproaches infinity is 0 (sorry about having to write that out--it's hard to type in mathematic notation).

The locomotive horsepower vs. velocity curve on the other hand is usually always concave-down without a point of inflection, and as speed increases after peak horsepower, the horsepower tends to approach a limit somewhere toward the middle of the horsepower range, rather than returning to 0. In theory, because of friction, air resistance and such, this "post-max" horsepower limit would tend to dictate a maximum speed for the locomotive. In practice, other factors, such as counterbalancing, prescribe a lower maximum speed limit usually.

The locomotive horsepower curve might in part be exponential, but were we to work out an exact equation, would almost certainly have trigonometric and probably power components as well. Add to that a ton of constants for friction and steam flow, and you'd get a graph resembling a measured locomotive horsepower curve.

Sincerely,
Daniel Parks

[Anonymous]

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by trainjunky29

True, but it's the pressure that causes the force on the piston, not the volume. The volume comes into play when trying to conserve steam--take away to much steam and the boiler pressure goes down.

Sincerely,
Daniel Parks

No, the cylinder has a difinite volume that needs to be filled. If you limit the volume of steam entering the piston, regardless of the pressure, you limit the power. As the high pressue steam enters the cylinder, it expands and transfers its energy to the cylinder. Once a volume of steam is done expanding, no more power transfer. That's why the Allegheny was so powerful with just 260 lbs pressure. It was not the pressure producing the HP, it was the boilers ability to pruduce high volumes of steam to keep the cylinders filled at high speed.

Dear GP40-2,
The volume won't do you any good unless it's under pressure. The steam if it is under any decent amount of pressure whatsoever will expand to fill the full volume of the cylinder. The is then is what pressure it's under, and consequently, how much force it's exerting. Increasing pressure is probably the single most effective way to increase tractive effort and horsepower.

Also, the steam does not expand in the admission phase, only cutoff and a little bit in compression (though by the time compression comes, it's pretty much done usefully expanding). In admission, the volume is being fully filled by steam straight fromt the boiler. Just clarifying.

Sincerely,
Daniel Parks

[GP40-2]

QUOTE: Originally posted by trainjunky29

True, but it's the pressure that causes the force on the piston, not the volume. The volume comes into play when trying to conserve steam--take away to much steam and the boiler pressure goes down.

Sincerely,
Daniel Parks

No, the cylinder has a difinite volume that needs to be filled. If you limit the volume of steam entering the piston, regardless of the pressure, you limit the power. As the high pressue steam enters the cylinder, it expands and transfers its energy to the cylinder. Once a volume of steam is done expanding, no more power transfer. That's why the Allegheny was so powerful with just 260 lbs pressure. It was not the pressure producing the HP, it was the boilers ability to pruduce high volumes of steam to keep the cylinders filled at high speed.

[GP40-2]

QUOTE: Originally posted by trainjunky29

Dear GP40-2,
What exactly do you mean that a steamer's power curve is exponential in nature? I presume you don't mean b^x like in calculus class, nor do you mean x^p.

Sincerely,
Daniel Parks

I mean that a steam locomotive's power curve follows the classic Gaussian Distribution Curve (i.e "the Bell Shaped Curve"). If you plot Feltonhill's data, you will see what I mean. Of course, if you had recorded data at say every MPH from 0 to 80 mph, you would get a real nice Gaussian distribution.

Diesel Electrics do not have a Guassian power curve bacause the diesel is not directly connected to the traction motors. The diesel engine can produce full HP at any speed, with locomotve DBHP really only limited by continious traction motor ratings (DC motors) OR low speed adhesion (AC motors)

[GP40-2]

Here another example:

CSX CW60AC #602 recorded 36,719 lbs continious pull @ 60 mph.

Big Boy recorded 32,000 lbs continious pull @ 60 mph

At this point the CW60AC is starting to run away and hide from the Big Boy...

[Anonymous]

Dear GP40-2,
What exactly do you mean that a steamer's power curve is exponential in nature? I presume you don't mean b^x like in calculus class, nor do you mean x^p.

Sincerely,
Daniel Parks

[Anonymous]

True, but it's the pressure that causes the force on the piston, not the volume. The volume comes into play when trying to conserve steam--take away to much steam and the boiler pressure goes down.

Sincerely,
Daniel Parks

[GP40-2]

QUOTE: Originally posted by tree68

I recall reading some time ago that steam engines came into their own at higher speeds, and that if it weren't for the physical problems of wheel balance and steam production, they would have no practical top end. It frankly surprises me that an FEF would take 10 miles to get to 110mph - I'd expect it sooner, but that's just my impression.

As timz said, whishful thinking.

From an eariler Feltonhill post:

Speed - Calc TE (lbs) - Actual DB Pull (lbs) - Actual DBHP

0 - 135,300 - 131,000 - 0
10 - 132,500 - 124,000 - 3,307
20 - 109,000 - 98,000 - 5,227
30 - 83,000 - 75,000 - 6,000
40 - 67,000 - 57,000 - 6,080
50 - 56,100 - 43,000 - 5,733
60 - 48,700 - 32,000 - 5,120

You can see power is decreasing as speed increases, largely as a result of the greater cutoff needed to accelerate the locomotive. A steam locomotive's power curve is exponential in nature, and you would see even more dramatic power loss from 60 to 70 mph and from 70 to 80 mph.

[GP40-2]

QUOTE: Originally posted by trainjunky29

QUOTE: Originally posted by timz

QUOTE: Originally posted by tree68

I recall reading some time ago that steam engines came into their own at higher speeds, and that if it weren't for the physical problems of wheel balance and steam production, they would have no practical top end. It frankly surprises me that an FEF would take 10 miles to get to 110mph - I'd expect it sooner, but that's just my impression.

When an 80-inch-driver engine is running 110 mph, each piston stroke takes 0.065 seconds, and the valve is open for maybe a third of that time. So the steam has maybe 1/40 of a second to get into the cylinder. It's a mystery that a steam locomotive can pull at all at that speed. The notion that steam has some sort of high-speed advantage is mostly wishful thinking; remember R. P. Johnson gave us an example of it in his book, in the chapter on high speed trains?

Yes, but the steam's under a lot of pressure.

Let's not get into a steam vs. diesel debate--we'll never get out of it.[:)][:D][8D]

Yes, but pressure and volume are inversely proportional, so with the limited time available for steam to enter the cylinder at high speed, along with the high pressure, not much volume of steam gets into the cylinder, does it? Darn, another one of you fantasies shot down by physics....

[GP40-2]

QUOTE: Originally posted by feltonhill

GP40-2,

I'm sure you know (and most everyone else here as well), that an N&W Class A could pull 160 cars between Williamson and Portsmouth, but on a very slight downgrade with many curves. They also could make at least 40-45 mph with this load. After the addition of a-tanks, they did the route non-stop with as many as 180 cars in about 3.5 to 4 hours. Every day, nothing special.

OK, a single AC4400 could start considerably more than 160 cars, maybe as many as 320 as you claim. However, it couldn't make 40 mph with that load. I doubt that a single AC4400 could make 40-45 mph with 160 cars over that line.

Trainjunky29's estimate of an FEF3 being able to make 100 mph in 10 miles is possible, but I doubt it would be more than an 800-900 ton train (about 12-13 cars). The AAR tests in 1938 set a goal of getting a 1000-ton 15-car train to 100 mph and an FEF-1 managed 102 mph on a slight downgrade (about -0.15% IIRC), not on level track. But how many cars could a single P42 get to 110 mph in 2 minutes? 12-13 sounds unlikely.

It would further everyone's knowledge of trains if you would provide some additional context with your examples.

Feltonhill,

First, some questions for you questions, then some test data for you to play with:

What exactly do you mean about "a very slight downgrade" How much in grade percent are we talking about for the gravity assistance for the Class A?

What was the tonnage of the N&W trains? 160 cars is somewhat meaningless if we are compairing WW2 era coal cars vs 130 ton modern coal cars.

Some test data for context:

CSX CW44AC #523 recorded 180,000 lbs continious pull @ 8.5 MPH and 32,288 lbs. continious pull at 50 MPH when tested in 2002

CSX CW60AC #602 recorded 44,212 lbs continious pull @ 50 MPH when tested in 2000

GE tests of P42's (no locomotive # specified in my copy of the tests) showed 14,438 lbs pull at 100 MPH. What was the pull of the FEF's at 100 MPH?

I am not familar with the routes in your examples, so you can plug the above numbers in and report the results.

[Anonymous]

QUOTE: Originally posted by timz

QUOTE: Originally posted by tree68

I recall reading some time ago that steam engines came into their own at higher speeds, and that if it weren't for the physical problems of wheel balance and steam production, they would have no practical top end. It frankly surprises me that an FEF would take 10 miles to get to 110mph - I'd expect it sooner, but that's just my impression.

When an 80-inch-driver engine is running 110 mph, each piston stroke takes 0.065 seconds, and the valve is open for maybe a third of that time. So the steam has maybe 1/40 of a second to get into the cylinder. It's a mystery that a steam locomotive can pull at all at that speed. The notion that steam has some sort of high-speed advantage is mostly wishful thinking; remember R. P. Johnson gave us an example of it in his book, in the chapter on high speed trains?

Yes, but the steam's under a lot of pressure.

Let's not get into a steam vs. diesel debate--we'll never get out of it.[:)][:D][8D]

[Anonymous]

Just to clarify, I was talking about an FEF-3 with a respectable passenger train in tow.

[timz]

QUOTE: Originally posted by tree68

I recall reading some time ago that steam engines came into their own at higher speeds, and that if it weren't for the physical problems of wheel balance and steam production, they would have no practical top end. It frankly surprises me that an FEF would take 10 miles to get to 110mph - I'd expect it sooner, but that's just my impression.

When an 80-inch-driver engine is running 110 mph, each piston stroke takes 0.065 seconds, and the valve is open for maybe a third of that time. So the steam has maybe 1/40 of a second to get into the cylinder. It's a mystery that a steam locomotive can pull at all at that speed. The notion that steam has some sort of high-speed advantage is mostly wishful thinking; remember R. P. Johnson gave us an example of it in his book, in the chapter on high speed trains?

[Modelcar]

....The fact the name "Big Boy"...introduced by an employee may have contributed too.

[tree68]

I recall reading some time ago that steam engines came into their own at higher speeds, and that if it weren't for the physical problems of wheel balance and steam production, they would have no practical top end. It frankly surprises me that an FEF would take 10 miles to get to 110mph - I'd expect it sooner, but that's just my impression.

It doesn't take much to humble a locomotive, though. The brief time I ran an old ALCo C424 included a period in notch 8, with just 4 passenger cars on the drawbar, on a 2% upgrade. I was just holding track speed at 25 mph with the throttle full open...

There are a number of steam locomotives that were purpose-built. My favorite, the Berkshire, was designed to haul freight at high speeds, which is exactly what it did, especially for the NKP. Other locomotives may have been bigger and/or faster, but a little marketing made the Big Boy the giant that many perceive it to have been...

[timz]

QUOTE: Originally posted by GP40-2

A GE P42 can be crusing at 110mph in 2 minutes from a station stop not alone 10 miles.

Sounds crazy, but read it again-- he said a P42, not a P42 pulling a train. So he might be right.

[Anonymous]

QUOTE: Originally posted by GP40-2


Of course, I fully expect you to "respectfully disagree" with the above statement.

Wow, you're good! [:)][:D][8D]

[feltonhill]

GP40-2,

I'm sure you know (and most everyone else here as well), that an N&W Class A could pull 160 cars between Williamson and Portsmouth, but on a very slight downgrade with many curves. They also could make at least 40-45 mph with this load. After the addition of a-tanks, they did the route non-stop with as many as 180 cars in about 3.5 to 4 hours. Every day, nothing special.

OK, a single AC4400 could start considerably more than 160 cars, maybe as many as 320 as you claim. However, it couldn't make 40 mph with that load. I doubt that a single AC4400 could make 40-45 mph with 160 cars over that line.

Trainjunky29's estimate of an FEF3 being able to make 100 mph in 10 miles is possible, but I doubt it would be more than an 800-900 ton train (about 12-13 cars). The AAR tests in 1938 set a goal of getting a 1000-ton 15-car train to 100 mph and an FEF-1 managed 102 mph on a slight downgrade (about -0.15% IIRC), not on level track. But how many cars could a single P42 get to 110 mph in 2 minutes? 12-13 sounds unlikely.

It would further everyone's knowledge of trains if you would provide some additional context with your examples.

[GP40-2]

The Trainjunky said:

"The other thing is that steam locomotives could in reality do some incredible things--a class A hauling 160 cars on the level, an FEF-3 cruising at 100 just 10 miles out of a station stop, etc."

Really, you think that is incredible?

The Class A was a fine locomotive, but a single AC4400 would have no trouble pulling twice that amount of cars on level track.

A GE P42 can be crusing at 110mph in 2 minutes from a station stop not alone 10 miles.

The REALITY is that even really good steam locomotives such as the Class A and FEF-3 couldn't compete with first generation diesel-electrics in the 1950's, not alone with what we have today.

Of course, I fully expect you to "respectfully disagree" with the above statement.