blue streak 1 BigJim: Wind does make a big difference and especially which direction it comes from. Maybe Mr. GP40 has a book written by a non-model railroader mathematician and can figure out the forces of nature. To use an event we can all understand... At car races the drafting of one car by another is well know and less well known is the effect of a strong wind on the race. Going round and round the racetrack you can notice the change in speeds. Jim do you notice a big difference in same tonnage trains when pulling mixed freight vs unit trains??
BigJim: Wind does make a big difference and especially which direction it comes from. Maybe Mr. GP40 has a book written by a non-model railroader mathematician and can figure out the forces of nature.
Wind does make a big difference and especially which direction it comes from.
Maybe Mr. GP40 has a book written by a non-model railroader mathematician and can figure out the forces of nature.
To use an event we can all understand... At car races the drafting of one car by another is well know and less well known is the effect of a strong wind on the race. Going round and round the racetrack you can notice the change in speeds.
Jim do you notice a big difference in same tonnage trains when pulling mixed freight vs unit trains??
Yes, there will be a difference.
Mixed consists, with many different car shapes, will have worse aerodynamics than a train with the same car shape. This is due to the turbulence between cars.
In fact, the total air resistance can either be increased or decreased by simply reordering the cars.
This stuff can get very complicated, very quickly.
But the important thing to remember is air is a type of fluid, and behaves as all fluids do. The bottom line is it takes an exponential increase in power to move through any fluid as speed increases. This is true for your personal car, a race car, a train or a plane.
BigJim Wind does make a big difference and especially which direction it comes from. Maybe Mr. GP40 has a book written by a non-model railroader mathematician and can figure out the forces of nature.
BigJim If the resistance was dominated by air drag, the figure for 70 MPH would have been more like 18 lbs per ton. The slopes for empty cars rise faster, which is consistent with air drag being more important for loaded cars than empty cars. Well, I honestly don't know about all that, but, I can share this with you about wind resistance; I once had a consist of three Dash-9's (all on line) and 95 empty hoppers (approx. 2900 tons). Across a long basically level stretch of track this day there was a strong quartering head wind. Those three big units couldn't get those hoppers over 40 mph. At the end of this stretch was a 30 mph curve. All I had to do to slow down was ease off of the throttle and the wind did the work of slowing the train. One week later, I had two Dash-9's and 105 empty hoppers (approx. 3150 tons). This day there was no wind to speak of. Across the same piece of track as above, I had no trouble getting the train up to the 50 mph speed limit. As usual, I had to use the dynamic brake to slow it down for the 30 mph curve. Wind does make a big difference and especially which direction it comes from. Maybe Mr. GP40 has a book written by a non-model railroader mathematician and can figure out the forces of nature.
If the resistance was dominated by air drag, the figure for 70 MPH would have been more like 18 lbs per ton. The slopes for empty cars rise faster, which is consistent with air drag being more important for loaded cars than empty cars.
The slopes for empty cars rise faster, which is consistent with air drag being more important for loaded cars than empty cars.
Well, I honestly don't know about all that, but, I can share this with you about wind resistance;
I once had a consist of three Dash-9's (all on line) and 95 empty hoppers (approx. 2900 tons). Across a long basically level stretch of track this day there was a strong quartering head wind. Those three big units couldn't get those hoppers over 40 mph. At the end of this stretch was a 30 mph curve. All I had to do to slow down was ease off of the throttle and the wind did the work of slowing the train.
One week later, I had two Dash-9's and 105 empty hoppers (approx. 3150 tons). This day there was no wind to speak of. Across the same piece of track as above, I had no trouble getting the train up to the 50 mph speed limit. As usual, I had to use the dynamic brake to slow it down for the 30 mph curve.
BigJim, you experienced exactly what I was referencing to. For trains, at speeds above 30 mph, increasing wind resistance becomes the single dominating factor in power consumption.
No need for me to write a book about this, it has been explained very well in hundreds of Physics text books published over the years.
Now to be fair to Erik, when you look at actual freight car design, this area does get more complicated than what is stated in basic physics texts. That's why I told him he needs to look at specific air resistance for the type of car on the train (coal, box, covered hopper, well, etc) and consider whether that car is loaded or empty (which can change the specific air resistance greatly on open top cars). The interaction of air resistance (turbulence) between cars must also be accounted for. You need to also consider rolling resistance, which on a train has two components. One is speed independent, which means it is the same at all speeds. The other component is speed dependent, which means it will increase with speed. However, of the two, the speed dependent component of rolling resistance is minor player in the overall rolling resistance. That leaves the air resistance, which increases exponentially with speed, as the major influence in the need for drastically increased power to move a train fast. Which is why, in spite of what Dave keeps claiming, it makes no sense whatsoever to move a coal train at 70 mph.
First, air resistance does vary as a cube of the speed. In Ralph Johnson's "The Steam Locomotive" on page 189 the equation for horsepower absorbed by air resistance on each sqare foot of locomotive frontal area is (0.0024*V^3) / 375, where V is in mph. This doesn't account for wind, which of course affects total resistance especially if the wind is at an angle to train travel, ie increasing flange resistance.
Regarding which steam locomotive was the best freight locomotive, there has to be some type of defining parameters. Like most gross-ton miles, fuel cost per mile of operations, maintenance costs, return on investment, profitablility, etc. Don't forget railroads are businesses, the best locomoitve to the share holders are the ones that produce the greatest revenue.
"If a nation expects to be ignorant and free, it expects what never was and never will be." Thomas Jefferson
7j43k GP40-2: Ok, you read a book written by a model railroader..... it is obvious to me you don't understand this issue at all. Your comments have been mostly "cheap shots", correct though they are. You are, though, embarrassing yourself with your responses. I suggest you get a bit above the nyah-nyah-nyah level of discussion. I COMPLETELY agree with your point that steam locomotives were commonly designed/chosen for a particular task, and that until those tasks are "harmonized", choosing the "best" is stunningly difficult. Since your point has been made (but, apparently, easily ignored), it's time to move on. Do you have something else to add? And I think I'll mention the obvious: The best freight locomotive is the well maintained one on the ready track with a competent crew and a full load of fuel. And the absolute BEST steam freight locomotive was the Great Northern N-3. So there. Nyah-nyah-nyah! Ed Oh, yeah, I like your implied (by me) comments that it's a nice thing to actually think about what one is talking about rather than simply repeating it 'cause it sounds good.
GP40-2: Ok, you read a book written by a model railroader..... it is obvious to me you don't understand this issue at all.
Ok, you read a book written by a model railroader..... it is obvious to me you don't understand this issue at all.
Your comments have been mostly "cheap shots", correct though they are. You are, though, embarrassing yourself with your responses. I suggest you get a bit above the nyah-nyah-nyah level of discussion. I COMPLETELY agree with your point that steam locomotives were commonly designed/chosen for a particular task, and that until those tasks are "harmonized", choosing the "best" is stunningly difficult. Since your point has been made (but, apparently, easily ignored), it's time to move on.
Do you have something else to add?
And I think I'll mention the obvious: The best freight locomotive is the well maintained one on the ready track with a competent crew and a full load of fuel.
And the absolute BEST steam freight locomotive was the Great Northern N-3. So there. Nyah-nyah-nyah!
Ed
Oh, yeah, I like your implied (by me) comments that it's a nice thing to actually think about what one is talking about rather than simply repeating it 'cause it sounds good.
Thank you for your opinion.
Have a great day.
.
Didn't the N&W do at least as well if not better than the C&O and B&O in terms of return on investment to its stockholders? So possibly there is something to be said for a one-speed railroad?
Sure it took a lot more coal for the N&YW to move the coal at 70mph that it would have had at 35. But the N&W was a well run railroad, along with the AT&SF, on of the very best in the USA in the last days of steam. They would not have burned all that coal (which of course was less expensive for them to buy for equal qualitiy than most railroads, since the mines were on-line and were customers) if the savings in crew costs and equipment and reduction of delays for all trains did not cover these additional fuel expenses. They were doing this with 105-car coal trains and one locomotive on the point in the 70mph territory.
To me the A was the very best steam freight lomotive built . And the J the best steam dual-service locomotives built and one of the very best passenger steam locomotives built. But that does not mean in any way that I deny anyone else the right to a different opinion. Was it the most succesfful steam freight lomotive build? I didn't say or write that . Possibliy the most succesfull steam freight locomoitve built was either the light or heavy USRA Mikado, of which more were built than any other frieght locomotive and that might be a measure of success. (Of course on could say the the 4-4-0 American was the most successful beacause for much of the 19th Century more than 90% of the North American locomotives operating were 4-4-0's. But I don't think I would get very far in saying it was the very best freight locomotive. Or passenger for that matter. But then there is the Hiawatha 4-4-2, a real revival of what was thought an obsolete wheel arrangement. Successful? Best passenger locomotive? Some may think so, but I would look elsewhere, possibly to the AT&SF Hudson for a pure passenger locomotive.)
When it somes down to it, certainly the AT&SF Texas type is worthy of consideration, I think it is the best non-articulated freight locomotive. Heavy on the track? Question is, does the railroad want to spend more on track maintenance or locomotive maintenance? Articulateds are more complex and obviously require more maintencance (which was alway superb on the N&W).
As far the J, in comparison, I may be considering esthetics in judging passenger locomotives, and I've stated before that I consider the J and New Haven I-5 as the most succesful streamlining of steam . Of course I also like the Daylights and CP Royal Hudsons and the one Southern streamlined 4-6-2. Obviously I don't like inverted bathtubs like the Hiawathas, the Commodore Vanderbilt, the Rexall, etc. The smokebox fins on the Century J3a's bother me a lot. Somehow Lowey's K4 and S-1 seem just too slick. The PRR T-1's are interesting, but not a match of the I-5 or J, esthetically. But esthetics are matters of opinon, and anybody's opinion has equal weight with mine. Some like Beethoven, some like Elvis Presley.
Are any of the locomotives that I consider as candidates for best truly my favorite locomotive? My favorites have to be the GG-1 electric and the K4 Pacific because of the many fine times I had riding behind them. One cannot call the K4 best in anything except longevity, and it is not beautiful, but beauty is in the eye of the beholder, and it has charm for me, and I hope I will have the chance to ride behind one again. As a locomotive, the GG-1 was bettered by the New Haven EF-3, just as the GG-1 was a development of the New Haven EP-3. There were vastly more GG-1's than all the New Haven\s 4-6-6-4's put together, thought (EP-3, E-4 and EF-3, the latter two the streamlined ones). But the GG-1 is the one I would most wish to ride behind again. Or in the cab, which luck would have it occured once. And it is a beautiful locomotive, to me anyway.
And don't get me started on the state of modern light-railcar esthetics! Streetcars looking like a cross between a rocket ship and high speed passenger train. Others just boxes.
GP40-2 Ok, you read a book written by a model railroader..... it is obvious to me you don't understand this issue at all.
erikem GP40-2: What? The increasing need for power at speed (assuming everything else is the same e.g. grade resistance , curvature) is always due to increasing air resistance. Using your example of a coal train on straight level track, if the grade is the same (level), the curve resistance is the same (none), and the rolling resistance is the same (steel wheels on rolling on steel track) , and the mass is the same (x amount of tons) what else could increase the demand for power? This is high school physics people. From the second edition of The Railroad - What It Is, What It Does, figure 2-8 on page 21 shows the train resistance for generic empty and loaded freight cars. At 35 MPH, the loaded car produces about 4.5 lbs per ton of resistance, at 70 MPH, the loaded car produces about 10.2 lbs per ton for roughly a factor of 2.3 increase, which translates into a factor of 4.6 increase in power (note those numbers were based on eyeballing a graph, so could easily be off by 10%). If the resistance was dominated by air drag, the figure for 70 MPH would have been more like 18 lbs per ton. The slopes for empty cars rise faster, which is consistent with air drag being more important for loaded cars than empty cars. - Erik
GP40-2: What? The increasing need for power at speed (assuming everything else is the same e.g. grade resistance , curvature) is always due to increasing air resistance. Using your example of a coal train on straight level track, if the grade is the same (level), the curve resistance is the same (none), and the rolling resistance is the same (steel wheels on rolling on steel track) , and the mass is the same (x amount of tons) what else could increase the demand for power? This is high school physics people.
What? The increasing need for power at speed (assuming everything else is the same e.g. grade resistance , curvature) is always due to increasing air resistance. Using your example of a coal train on straight level track, if the grade is the same (level), the curve resistance is the same (none), and the rolling resistance is the same (steel wheels on rolling on steel track) , and the mass is the same (x amount of tons) what else could increase the demand for power? This is high school physics people.
From the second edition of The Railroad - What It Is, What It Does, figure 2-8 on page 21 shows the train resistance for generic empty and loaded freight cars. At 35 MPH, the loaded car produces about 4.5 lbs per ton of resistance, at 70 MPH, the loaded car produces about 10.2 lbs per ton for roughly a factor of 2.3 increase, which translates into a factor of 4.6 increase in power (note those numbers were based on eyeballing a graph, so could easily be off by 10%). If the resistance was dominated by air drag, the figure for 70 MPH would have been more like 18 lbs per ton.
- Erik
Ok, you read a book written by a model railroader.
Let's see. Everything stays the same (grade resistance, curve resistance, rolling resistance, train mass) except the air resistance as speed increases. So, if as you claim, the increasing air resistance is not the dominating factor, what is?
Please explain the physics behind your answer.
Edit: I'll give you a few hints since it is obvious to me you don't understand this issue at all.
When calculating total resistance of empty trains vs full trains you must differentiate the specific air resistance between full and empty cars as rolling resistance is proportional to load.
Happy calculating!
GP40-2 What? The increasing need for power at speed (assuming everything else is the same e.g. grade resistance , curvature) is always due to increasing air resistance. Using your example of a coal train on straight level track, if the grade is the same (level), the curve resistance is the same (none), and the rolling resistance is the same (steel wheels on rolling on steel track) , and the mass is the same (x amount of tons) what else could increase the demand for power? This is high school physics people.
Bruce's book! Now there's a good read! Ed
I have that one too and didn't think much of it.
BigJim If I am not very much mistaken, the late Dr. Eugene Huddleston did some "engineering data" comparisions between the UP Challenger, the C&O Allegheny and the N&W Class A in his book "The Worlds Greatest Steam Locomotives". It's a good read.
If I am not very much mistaken, the late Dr. Eugene Huddleston did some "engineering data" comparisions between the UP Challenger, the C&O Allegheny and the N&W Class A in his book "The Worlds Greatest Steam Locomotives". It's a good read.
I bought and read the book and it didn't do much for me. I was expecting a well reasoned engineering treatise (hopefully well written!) and got mostly emotional proclamation.
Bruce's book! Now there's a good read!
erikem GP40-2: . The problem with your idea is that speed takes horsepower. Lots and lots of horsepower that burns lots and lots of fuel. On the order of an increase as the cube of velocity. The power being proportional to the cube of velocity is true when the drag is dominated by air resistance. For a fully loaded coal train on level track, that doesn't happen until train speeds go north of 70 MPH. If the train has enough power to maintain 20 MPH on a ruling grade, it probably has enough power to hit 70 MPH on level track - especially if the train is being hauled by a steam locomotive . The idea of a "one-speed" railroad goes back a long time, the New York, Pittsburgh and Chicago RR that was being championed by L.F. Loree in the early 1920's was intended as a one speed railroad, with trains averaging close to 50 MPH. See the article written by William Moedinger in the June 1943 issue of Trains. - Erik
GP40-2: . The problem with your idea is that speed takes horsepower. Lots and lots of horsepower that burns lots and lots of fuel. On the order of an increase as the cube of velocity.
The problem with your idea is that speed takes horsepower. Lots and lots of horsepower that burns lots and lots of fuel. On the order of an increase as the cube of velocity.
The power being proportional to the cube of velocity is true when the drag is dominated by air resistance. For a fully loaded coal train on level track, that doesn't happen until train speeds go north of 70 MPH. If the train has enough power to maintain 20 MPH on a ruling grade, it probably has enough power to hit 70 MPH on level track - especially if the train is being hauled by a steam locomotive .
The idea of a "one-speed" railroad goes back a long time, the New York, Pittsburgh and Chicago RR that was being championed by L.F. Loree in the early 1920's was intended as a one speed railroad, with trains averaging close to 50 MPH. See the article written by William Moedinger in the June 1943 issue of Trains.
In your example, the locomotive is producing maximum power to move the coal train up a grade at 20 mph. Maximum power means maximum fuel consumption. Now, the train crests the grade and can run on level track, buy why would you still want to run the locomotive at maximum power and fuel use just to hit 70 mph? Wouldn't it make more economic sense to throttle back and run the coal train at 40 or 45 mph, use less fuel and decrease your costs of running this train? Coal doesn't need to get to its final destination as an express train.
CSX loads coal trains with massive amounts of power coming off the old B&O West End in WVa just so they can get up the mountain grades. Usually only 2 ACs take the trains to Baltimore. Why not leave all 6 AC units on an move a 20,000 ton coal train easily at 70 mph. Because it makes no economic sense whatsoever. Just because you have the power available to run at 70 mph doesn't mean it makes any sense to do it.
GP40-2. The problem with your idea is that speed takes horsepower. Lots and lots of horsepower that burns lots and lots of fuel. On the order of an increase as the cube of velocity.
The book I mentioned isn't exactly a "gee whiz" railfan book, but a pretty scholarly attempt to tell a story and the "whys and wherefores" of the same. If you ever find one you'll see what I mean. However, you DO seem to know what you're talking about so I won't argue your points. Like I've said, I look at this forum as a place to have some fun and learn something, not to get heartburn arguing arcane points that really don't matter anymore.
Firelock76 Interesting discussion we've got going on here, and we sure can learn from one another, can't we? Of course, since steam's gone and it's not coming back the topic's got the same importance as discussing how many angels can dance on the head of a pin! That being said, I dug into the archives here at the "Festung Firelock" and pulled out my copy of Alfred W. Bruce's "The Steam Locomotive in America", published in 1952 as the steam era was drawing to a close, which the author recognized and accepted. I was looking for facts, figures and numbers and made some interesting discoveries. Horsepower figures for locomotives of all types aren't listed AT ALL except in a very general sense. Tractive efforts most definately are! As a matter of fact, horsepower doesn't seem to enter into the equation unless the author is discussing locomotives with traction motors, i.e. diesels and electrics, or the attempts at steam-turbo-electric locomotives. Interesting. Possibly there was no really reliable way to measure steam locomotive horsepower, or it just wasn't as important to the old-timers as sheer pulling power. Mr. Bruce doesn't say, and since he's been dead "lo, these many years" we can't ask him. At any rate, the book is an entertaining gold mine of information just the same, so if you haunt used book shops, book fairs, or train shows as I do keep your eyes out for it and grab it if you see it. You won't be disappointed!
Interesting discussion we've got going on here, and we sure can learn from one another, can't we? Of course, since steam's gone and it's not coming back the topic's got the same importance as discussing how many angels can dance on the head of a pin!
That being said, I dug into the archives here at the "Festung Firelock" and pulled out my copy of Alfred W. Bruce's "The Steam Locomotive in America", published in 1952 as the steam era was drawing to a close, which the author recognized and accepted. I was looking for facts, figures and numbers and made some interesting discoveries. Horsepower figures for locomotives of all types aren't listed AT ALL except in a very general sense. Tractive efforts most definately are! As a matter of fact, horsepower doesn't seem to enter into the equation unless the author is discussing locomotives with traction motors, i.e. diesels and electrics, or the attempts at steam-turbo-electric locomotives. Interesting. Possibly there was no really reliable way to measure steam locomotive horsepower, or it just wasn't as important to the old-timers as sheer pulling power. Mr. Bruce doesn't say, and since he's been dead "lo, these many years" we can't ask him.
At any rate, the book is an entertaining gold mine of information just the same, so if you haunt used book shops, book fairs, or train shows as I do keep your eyes out for it and grab it if you see it. You won't be disappointed!
Unless you have access to locomotive tractive effort curves (tractive effort produced at all speeds), the tractive efforts listed in railfan books are usually the maximum theoretical starting tractive effort.
Horsepower is directly related to the amount of tractive effort produced at a given speed. For example, if you know how much pull a locomotive is producing at 40mph, then you can calculate exactly how much horsepower it is producing.
daveklepper Waste of money? Crew costs are the main expense of railroads. Getting crews over the road efficiently saves lots of money. Also cars and locomotives cost money. Having fewer cars and locomotives to do the same job saves lots of money. Also, a one-speed railroad that runs coal trains, merchandize trains, general freight , piggy back, and passenger all at the same speed means more reliability and better service for everyone.
Waste of money? Crew costs are the main expense of railroads. Getting crews over the road efficiently saves lots of money. Also cars and locomotives cost money. Having fewer cars and locomotives to do the same job saves lots of money. Also, a one-speed railroad that runs coal trains, merchandize trains, general freight , piggy back, and passenger all at the same speed means more reliability and better service for everyone.
Let's take a look at this quote from Dave who proposed that running the Class A with coal trains at 70 mph would have somehow saved the N&W money.
Historically, crew costs and benefits were the largest single expense for a railroad. However, fuel costs are a very close second.
Whatever power it took for the Class A to pull a particular tonnage of coal at 35mph, it would take eight times the power to pull that coal at 70 mph.
So Dave, how does expending 8 times the power to move the same tonnage not waste money?
Are you suggesting that if NS would start pulling all their coal trains at 70 mph, they would be even more profitable?
JimValle [said-in part]: "...AT&SF 2-10-4s could pull a long freight of 4000+ tons up the Abo Canyon grade without a helper.."
Many people are not aware that the genesis of at least 20 of the ATSF 2-10-4's were the 10 of the 2-10-10-2's from the ATSF Shops at Topeka,Ks..Tried by ATSFRR, but did not work as well as expected so they went back and were cut up to make 20 2-10-4's. The Virginian Rwy had their AE Class of 2-10-10-2's and they served them well for something like 30-35 years.
http://upload.wikimedia.org/wikipedia/en/8/8d/ATSF_3000.jpg
I think the A is certainly a worthy contender for overall best freight locomotive in North America . That does not mean that anyone else does not have a right to another opinion. But I have right to mine and I give substantial reasons for my opinion.
As far as the J, not only was it a great 4-8-4 mechanically, but streamlining was comparable with the Daylights, and yes the SP Daylights were also great 4-8-4's, but I happen to like the J a bit better. For streamlining, the J and the New Haven I-5 are my overall favorites, and the J was of course a better locomotive than the New Haven I-5 Hudson, which for some reason had counterblancing problems that should have been corrected but were not. Also, the welded boilers had problems.
Unofrtunately, my experience in riding behind a J was only one trip in the NY - Norfolk sleeper on the N&W from Petersburg to Norfolk, but I did see them in action more frequently. Did ride behind a New Haven I-5 in 1049 from Boston to New Haven (riding through to NY) on the Yankee Clipper. At the time, the coaches were all the post-WWII fluted side 8600's but the parlors, which I was privileged ot ride, were still heavyweight 12-wheelers. Normal power for the train was Alco diesels at that time, so drawing an I-5 was a treat, appreciated by a 17-year-old..
GP40-2Why just stop with those three? What about all the others?
Good point, but, I didn't say some others weren't included. Get the book. It's a good read.
For all we know, the PRR could have just as easily ordered the N&W to stop building its own locomotives and use Altoona built J 2-10-4s for freight operations, and the N&W may have had similar financial results.
BTW, one thing I can say about the Pennsy, they were smart enough not to tell the N&W what to do.
Why just stop with those three? What about all the others? Maybe because it is impossible due to lack of data? So again, how can any one of those three be called "The Greatest" when they can't be compared to all the rest. Just as silly as the NFL calling the Superbowl winner "World Champs" when the rest of the world doesn't play American football...
daveklepper J: lighweight rods and excellent counterbalancing allowed a locomotive with smaller dirver (72"?) to still be a 100 mph locomotive but with the TE of smaller drivers.
J: lighweight rods and excellent counterbalancing allowed a locomotive with smaller dirver (72"?) to still be a 100 mph locomotive but with the TE of smaller drivers.
So did a number of other 4-8-4s. Still doesn't prove the J was "better" than any of them.
daveklepper A: Hauled coal trains at timetable authorized 70mph. Name any iother frieght locomotive that did that.
A: Hauled coal trains at timetable authorized 70mph. Name any iother frieght locomotive that did that.
Why would anybody want to haul coal at 70 mph? Seems like a huge waste of money from a railroad known for being financially smart.
As far as simple articulated locomotives that hauled freight at 70 mph +, quickly off the top of my head I can think of the Allegheny, EM1, Big Boy, UP Challenger, WM Challenger, D&H Challenger, SP ACs, probably many more if I bothered to look them up.
So your point is exactly what?
BigJim Well, if not from "engineering data" per se, but, from performance and fiscal data. The fact that the N&W locos racked up some impressive gross ton miles and utilization statistics along with paid dividends high enough to keep the Pennsy afloat should confirm that what the N&W had was the best for the N&W.
Well, if not from "engineering data" per se, but, from performance and fiscal data. The fact that the N&W locos racked up some impressive gross ton miles and utilization statistics along with paid dividends high enough to keep the Pennsy afloat should confirm that what the N&W had was the best for the N&W.
Well, thank you for your opinion. You know, you could be very right. You also could be very wrong.
GP40-2 BaltACD: This is a very easy argument when equipped with 60 years of 20/20 hindsight. The decisions the carriers were making 'in the day' were clouded by the fog of unknowable foresight. They 'thought' they knew what they wanted and they 'thought' they knew what it would take to achieve that end, but the era of true data collection and processing had yet to occur...they made the best educated guesses that the underlying knowledge of the time would permit. Very astute point. I'll take my challenger 1 step higher: Not only can it not be proven from an engineering viewpoint that the N&W J was the "best" 4-8-4 or the N&W Class A was the "best" simple articulated design, it can't even be said that the Class J or the Class A were the "best" designs for the N&W itself. Again, if anyone can disprove my statement with accurate, comprehensive engineering data (opinions don't count!) I'd be more than willing to change my stance.
BaltACD: This is a very easy argument when equipped with 60 years of 20/20 hindsight. The decisions the carriers were making 'in the day' were clouded by the fog of unknowable foresight. They 'thought' they knew what they wanted and they 'thought' they knew what it would take to achieve that end, but the era of true data collection and processing had yet to occur...they made the best educated guesses that the underlying knowledge of the time would permit.
This is a very easy argument when equipped with 60 years of 20/20 hindsight. The decisions the carriers were making 'in the day' were clouded by the fog of unknowable foresight. They 'thought' they knew what they wanted and they 'thought' they knew what it would take to achieve that end, but the era of true data collection and processing had yet to occur...they made the best educated guesses that the underlying knowledge of the time would permit.
Very astute point.
I'll take my challenger 1 step higher:
Not only can it not be proven from an engineering viewpoint that the N&W J was the "best" 4-8-4 or the N&W Class A was the "best" simple articulated design, it can't even be said that the Class J or the Class A were the "best" designs for the N&W itself.
Again, if anyone can disprove my statement with accurate, comprehensive engineering data (opinions don't count!) I'd be more than willing to change my stance.
Your reply could lead to a new thread on a subject that has interested me for years:
"Someone," I've thought, "should write a book on how locomotive engineers (designers of locomotives, that is) and master mechanics and locomotive superintendents tried to measure performance." That someone, so far, hasn't been me.
Google Books has opened up hundreds of volumes of journals, books, textbooks on this topic.
From the earliest days, engineers were trying to evaluate locomotive performance and it seems pretty clear to me that such efforts pushed locomotive design throughout most of the steam era. When I've read a report by a leading locomotive engineer on this or that latest view of the best way to measure performance, the comments section in which master mechanics of various railroads discuss the relevance are often the most useful (and most colorful).
locobasede Have you ever attempted the exercise?
Have you ever attempted the exercise?
I wouldn't waste my time trying.
However, it appears that a lot of people without Engineering backgrounds have wasted a lot of time on this.
locobasede So, lacking this kind of 1:1 mapping of opinion on reality, we can only go with a) what the operators did and b) some gross comparative measures. a) could include repeat orders at later times; long operating careers; even railroad performance over time. b) includes measures I've played with but won't claim any universal applicability for. You can see some of them on Wes Barris's steamlocomotive.com site, where he hosts the Locobase entries I've created over a couple of decades.
So, lacking this kind of 1:1 mapping of opinion on reality, we can only go with a) what the operators did and b) some gross comparative measures. a) could include repeat orders at later times; long operating careers; even railroad performance over time. b) includes measures I've played with but won't claim any universal applicability for. You can see some of them on Wes Barris's steamlocomotive.com site, where he hosts the Locobase entries I've created over a couple of decades.
Those parameters are fine if one likes to crunch numbers for fun that may or may not have any relationship to the actual performance/economy of use for a steam locomotive. But from an engineering viewpoint it really doesn't tell us much about the real power / performance / economy of a particular locomotive. It especially doesn't allow us to compare different locomotives and declare one "better" than another.
To quote BaltACD "Each carrier thought they had the best for their particular circumstance."
I highlighted "thought" because the railroads didn't even know for themselves if they had the best steam locomotive for their particular operations.
Again, my intention is not to flame anybody. It seems to me, however, that over the years a lot of people have spent a lot of time writing books, articles, etc declaring one locomotive "better" than others based on incomplete, inaccurate, or non-existant information.
Leaving aside the obvious intent of the word "possibly" in my Niagara comment, which was to offer a nomination based on testimony from the operators of that and other large passenger locomotives, let me challenge your reply by asking you how in the world one can use the "accurate, comprehensive data from every single 4-8-4 design produced" to prove anything? What magic formula will pull together all of the different data points into an integrated number or even group of numbers that "proves" the "bestness" of any design?
Have you ever attempted the exercise? It's a little like saying "I'll believe gravity works on every earthbound object when I've catalogued the movements of every molecule and electron and photon and ...." .
Now back to the earlier comment. The period I chose in my post begins in 1941 precisely because it was the beginning of true freight diesel competition and the simultaneous limitation in the numbers of any new locomotives during the war years.
in any case, there really was very little that was new in the use of syphons or circulators, roller bearings, feedwater heaters after 1935 (or even in most cases 1930). The materials certainly improved, but the basic operating North American steam locomotive's last big upgrades were the adoption of the superheater in the late 19zeroes, the substantial increase in firebox volume in the 1920s, and the demonstration and adoption of the roller bearing in the late 1920s. You can toss in the integrally cast steel frame from around the same period.
The Great Depression and the War Years suspended many promising new avenues of research. The improvements that are clearly seen in the later locomotives are improvements in degree (and valuable in their own right) but not in kind.
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