Does anybody have any comparison data when these two classes of locomotives were pooled for coal trains on the PRR Sandusky line during 1956? Comparitive tonnage ratings? Fuel consumption? Running time? Hoggers' preferences? Firemen's preferences?
Eric Hirsimaki wrote such a comparison in the Autumn 1999 issue of The Keystone, PRRT&HS's magazine. This was a feature length article, pgs19-30. The ATSF locos would cover the line faster than the J1's, according to a table based on performance data from 6/15/56 to 6/25/56. I believe PRRT&HS offers single back issues.
The last edition produced by the folks at Classic Trains has a whole write-up on the Texas Type and its development. That would be the Fall 2010 edition released four months ago.
The Santa Fe 2-10-4's were more powerful than the J1 due mainly to the difference in boiler pressure. The J1 had 270 psi while the 5000's had 310...a substantial difference. However, the ATSF version had larger driver diameters, so the tractive effort was better on the J1. Respectively, the 5000's produced 93K lbs of tractive effort, while the J produced 110, but I believe that figure was achievable only with the booster on the later J1a. Without the booster, the difference between them, still in favour of the J1, was a mere 4000 lbs or so.
Crandell
selector The last edition produced by the folks at Classic Trains has a whole write-up on the Texas Type and its development. That would be the Fall 2010 edition released four months ago. The Santa Fe 2-10-4's were more powerful than the J1 due mainly to the difference in boiler pressure. The J1 had 270 psi while the 5000's had 310...a substantial difference. However, the ATSF version had larger driver diameters, so the tractive effort was better on the J1. Respectively, the 5000's produced 93K lbs of tractive effort, while the J produced 110, but I believe that figure was achievable only with the booster on the later J1a. Without the booster, the difference between them, still in favour of the J1, was a mere 4000 lbs or so. Crandell
I have read the PRR crews liked the 5011 class 2-10-4's better because they rode better at speed and since they were oil fired, they required less maintenance for the fireman. Having been on both type of locomotives, the cabs on the SF engines are larger and have more space for head end crews.
It is too bad none of the J1's were preserved since most other types of PRR early built power was set aside and given to the Pennsylvania museum for future generations to see.
CZ
Effingham Illinois coaling tower J1 being serviced
J1 westbound along US 40
SF 5020 at Railroad Fair in Chicago
I remember once reading that the Pennsy crews found that the AT&SF 5000's were somewhat slippery compared to their own J1s . When they wanted to start a train the Pennsy engineers were accustomed to simply yanking the throttle open and walking away with their train. The Santa Fe engines needed a more refined approach but once they got going they were more agile and smoother riding.
The power difference had little to do with the boiler pressure difference. Going from 270 lbs. to 310 lbs. is really not that much difference as a total percentage. In steam locomotive design, boiler pressure is often over rated as an indication of potential horsepower output. The biggest single factor of horsepower is a boilers ability to produce a high volume of steam. The more steam production, the more power. Also, remember that for a given size boiler, volume and pressure are inversely proportional. Increase the pressure, and the steam volume must go down. The Santa Fe locomotives were a more modern design, and could produce a higher volume of steam than the PRR version, which was based on the 1930's C&O T1 design.
Thanks guys, a very thorough discussion, and some good photos in addition.
Although I am sorry a J or the equivalent C&O engine has not been preserved, I am very happy one of the AT&SF 2-10-4 locos has been preserved and is care for.
GP40-2 The power difference had little to do with the boiler pressure difference. Going from 270 lbs. to 310 lbs. is really not that much difference as a total percentage. In steam locomotive design, boiler pressure is often over rated as an indication of potential horsepower output. The biggest single factor of horsepower is a boilers ability to produce a high volume of steam...
The power difference had little to do with the boiler pressure difference. Going from 270 lbs. to 310 lbs. is really not that much difference as a total percentage. In steam locomotive design, boiler pressure is often over rated as an indication of potential horsepower output. The biggest single factor of horsepower is a boilers ability to produce a high volume of steam...
Hmm....well, if so, then it begs the question: why have boilers rated at such varying pressures if there is no expectation of improvement in at least one operation parameter? Why not de-rate boilers en masse and simply run them more safely at 150 psi? If you have the capacity to generate the steam (and I don't argue that it is a critical factor in keep a steamer doing hard work at speed), it seems superfluous to want to stress a pressure vessel with more pressure, and to impose all the weight and energy demands on the suspension and drive-train to withstand those pressures and all appliances that it takes to sustain it.
Heat and pressure are, and always have been, the prime indicators of work potential for a boiler. Those two, specifically, are the "ingredients" of useful enthalpy in steam. Yes, a small grate area will mean sharp and regressive drops in boiler pressure beyond a certain work requirement (throttle setting), but otherwise you must have hot mass occupying a smaller volume to get increased work capacity.
What am I missing?
selector Hmm....well, if so, then it begs the question: why have boilers rated at such varying pressures if there is no expectation of improvement in at least one operation parameter?
Hmm....well, if so, then it begs the question: why have boilers rated at such varying pressures if there is no expectation of improvement in at least one operation parameter?
With a fire-tube boiler, the increase in operating pressure was an attempt to improve thermal efficiency, which it did to a (very) small degree. It had a marginal effect on increased horsepower. It added additional issues however, including lower steam production, increased operating temps that the lubricants had a hard time dealing with, and a lower factor of adhesion. As far as using even lower operating pressures, there is a limit on how much volume of steam the cylinders can use, unless you can equip the locomotive with extremely large valves and cylinders to use such a large volume of steam. The "sweet spot" seemed to balance out between 225 to 300 psi with the cylinder/valve designs used for typical steam designs. Remember, the most powerful steamers, the Allegheny and Yellowstone Class, used steam pressure in the 240-260 psi range.
daveklepper Thanks guys, a very thorough discussion, and some good photos in addition. Although I am sorry a J or the equivalent C&O engine has not been preserved, I am very happy one of the AT&SF 2-10-4 locos has been preserved and is care for.
Actually, there are three or four of them preserved. There's one at the National Railroad Museum in Green Bay. IIRC, there's also one at the NMOT in St. Louis, plus a couple of others. The AT&SF had one preserved in the roundhouse at Belen, NM, but I believe that one's now in Sacramento at the CSRM along with the rest of their collection. Santa Fe did a pretty fair job of preserving steam power, the one notable exception being a 3800-class 2-10-2. Do a search on preserved steam and you'll likely come up with examples.
GP40-2 selector: Hmm....well, if so, then it begs the question: why have boilers rated at such varying pressures if there is no expectation of improvement in at least one operation parameter? With a fire-tube boiler, the increase in operating pressure was an attempt to improve thermal efficiency, which it did to a (very) small degree. It had a marginal effect on increased horsepower. It added additional issues however, including lower steam production, increased operating temps that the lubricants had a hard time dealing with, and a lower factor of adhesion. As far as using even lower operating pressures, there is a limit on how much volume of steam the cylinders can use, unless you can equip the locomotive with extremely large valves and cylinders to use such a large volume of steam. The "sweet spot" seemed to balance out between 225 to 300 psi with the cylinder/valve designs used for typical steam designs. Remember, the most powerful steamers, the Allegheny and Yellowstone Class, used steam pressure in the 240-260 psi range.
selector: Hmm....well, if so, then it begs the question: why have boilers rated at such varying pressures if there is no expectation of improvement in at least one operation parameter?
The one area that is fairly directly affected by the boiler pressure is the tractive effort, since the boiler pressure is related to the mean effective cylinder pressure. Good or bad design of the steam distribution system will either conserve or waste the boiler pressure. In any case the cylinder pressure times the surface area of the piston will determine the thrust and thence by leverage and angular vectors, the tractive effort.
beaulieu The one area that is fairly directly affected by the boiler pressure is the tractive effort, since the boiler pressure is related to the mean effective cylinder pressure. Good or bad design of the steam distribution system will either conserve or waste the boiler pressure. In any case the cylinder pressure times the surface area of the piston will determine the thrust and thence by leverage and angular vectors, the tractive effort.
However, increasing the boiler pressure without increasing the adhesive weight also lowered the locomotives adhesion. The additional tractive effort didn't do much good if the locomotive was spinning its wheels. Many of these locomotives were pushing axle loading to the max, so it was next to impossible to increase the adhesive weight. Increased boiler pressure was a double edged sword, and many railroads felt the costs outweighed the benefits. The "Super Power" concept had nothing to do with increasing steam pressure, it was about changing the boiler design to increase steam volume.
When the BP is increased, the cylinder bore can be reduced so that TE remains the same. That would take care of the adhesion issue. With increased BP there are benefits of higher steam temperature (more potential work) and lighter pistons (less recip weight, improved counterbalancing).
When N&W ran comparative tests on a J class 4-8-4 in Aug 1945, there was a reduction of about 8% in coal and water consumption at constant speed (approx 40 mph) and output (about 5,000 DBHP). All of the first 11 J's were raised to 300 psi by Oct 1945.
feltonhill ... at constant speed (approx 40 mph) and output (about 5,000 DBHP). .
... at constant speed (approx 40 mph) and output (about 5,000 DBHP). .
Was this 5000DBHP figure actually really achieved? Looks very high. Looking at
http://files.asme.org/ASMEORG/Communities/History/Landmarks/5609.pdf,
Figure 2 in this paper shows an increased DBHP of 10% at 40mph, to an incredible 50% at 100mph.
But here, the figure is calculated.
Without understanding too much about boiler design, i do not believe it you will got so much additional output, by just increasing it by 25 LBS.
feltonhill ...there was a reduction of about 8% in coal and water consumption
...there was a reduction of about 8% in coal and water consumption
This was the aim of many high pressure boiler designs, there were lots of German and other Europe experimental-machines here, but they all fated like the Baldwin 60000. Too much maintenance and costs.
The curve you refer to in the ASME booklet is not accurate for 300 psi. Where it came from, I'm not sure. N&W developed a pair of calculated curves for 275 and 300 psi as part of the August 1945 test report. The 275 psi curve in the ASME publication is a calculated curve using the Baldwin method which N&W favored. It was very conservative and N&W knew it. The N&W's 300 psi curve, also calculated using the Baldwin method, bears no resemblance to the curve in the ASME publication. N&W's curve looks very much like the 275 psi curve, but at a higher value and same configuration as speed increases. I've worked on this problem over several years, and I believe that the author of this curve was either grossly misled by someone, or misapplied the Baldwin method of estimating DBHP. I'll be in Roanoke over the next four days at the N&W Historical Society Archives so a response is going to be unlikely before early next week. Your observation that the 300 psi curve was a bit high was perceptive. The significant increase at 100 mph was a sure sign that something is wrong with the 300 psi curve. There is. Stay tuned.
BTW, this amounts to hijacking the thread, which started out comparing PRR and ATSF 2-10-4's.
feltonhill ... BTW, this amounts to hijacking the thread, which started out comparing PRR and ATSF 2-10-4's.
...
Well, I'll invoke some moderator's tolerance and allow it. Besides, between GP-40 and you, I would like to learn something. I hope very much to stop learning at precisely the moment buddy hammers the last nail on me.
uphogger daveklepper: Thanks guys, a very thorough discussion, and some good photos in addition. Although I am sorry a J or the equivalent C&O engine has not been preserved, I am very happy one of the AT&SF 2-10-4 locos has been preserved and is care for. Actually, there are three or four of them preserved. There's one at the National Railroad Museum in Green Bay. IIRC, there's also one at the NMOT in St. Louis, plus a couple of others. The AT&SF had one preserved in the roundhouse at Belen, NM, but I believe that one's now in Sacramento at the CSRM along with the rest of their collection. Santa Fe did a pretty fair job of preserving steam power, the one notable exception being a 3800-class 2-10-2. Do a search on preserved steam and you'll likely come up with examples.
daveklepper: Thanks guys, a very thorough discussion, and some good photos in addition. Although I am sorry a J or the equivalent C&O engine has not been preserved, I am very happy one of the AT&SF 2-10-4 locos has been preserved and is care for.
The other SF 2-10-4 ( 5030) is at Santa Fe New Mexico. The 5011 is at St. Louis, the 5021 ended up at Sacramento and the 5017 is at Green Bay. The orginal 5000, a smaller but very nice 69 " drivered 2-10-4 called the Madam Queen is at Amarilo TX. The Santa Fe did a great job of giving locomotives to parks and musuems.
feltonhill When the BP is increased, the cylinder bore can be reduced so that TE remains the same. That would take care of the adhesion issue. With increased BP there are benefits of higher steam temperature (more potential work) and lighter pistons (less recip weight, improved counterbalancing).
True, but...
By making the piston diameter smaller, the steam has less area to work on to produce power. The higher steam pressure would have more potential energy, but the smaller piston would limit how much of that potential energy is converted into kinetic energy. For a given boiler, pressure and volume are always inversely proportional. If pressure goes up, volume must go down. The higher PSI steam has more potential energy, but there is less volume of it per unit of time.
feltonhill When N&W ran comparative tests on a J class 4-8-4 in Aug 1945, there was a reduction of about 8% in coal and water consumption at constant speed (approx 40 mph) and output (about 5,000 DBHP). All of the first 11 J's were raised to 300 psi by Oct 1945.
The the raise in thermodynamic efficiency was by far the the most pronounce effect of raising boiler pressure. The N&W thought the 8% increase was worth the increased wear and tear on the locomotive by using a higher operating pressure. Many railroads felt is was not worth it. In the big picture, a J running at 275 PSI had dismal thermodynamic efficiency. A J running at 300 PSI still had dismal thermodynamic efficiency. That's why coal roads such as the N&W and B&O, no matter how long they tried to hang on to steam, eventually went the all diesel-electric route.
selector feltonhill: ... BTW, this amounts to hijacking the thread, which started out comparing PRR and ATSF 2-10-4's. Well, I'll invoke some moderator's tolerance and allow it. Besides, between GP-40 and you, I would like to learn something. I hope very much to stop learning at precisely the moment buddy hammers the last nail on me. Crandell
feltonhill: ... BTW, this amounts to hijacking the thread, which started out comparing PRR and ATSF 2-10-4's.
Thank you o lot for keeping this forum open-minded. Following Crandells comments, those first hands data from feltonhill and GP40-2 "hijacks" me, as well.
Maybe we should start to a boiler thread? Pooling interesting sub-topics of specific designs, like those of a C&O J3, for ex.
-lars
I will be honest with you Seeing a Late Santa Fe TExas in Steam again would be a treat Seeing a 5011 Class Peroid under power again would be the Cats Meow for me. I will be Honest I ever will a Lottery I would pay for Restoration of one of the 5011 class units that is still out there.
GP40-2 For a given boiler, pressure and volume are always inversely proportional. If pressure goes up, volume must go down. The higher PSI steam has more potential energy, but there is less volume of it per unit of time.
For a given boiler, pressure and volume are always inversely proportional. If pressure goes up, volume must go down. The higher PSI steam has more potential energy, but there is less volume of it per unit of time.
I don't understand why the volume has to change. The water volume in the boiler won't change unless you don't replace it, and if you want more pressure out of the sublimated water, you simply add more heat. That will cause more activity in the molecules, but you don't necessarily have to reduce the number of those molecules. Their motions are just more energetic. And if they are more energetic, their kinetic moment against the piston surface area increases per stroke...piston surface area being fixed.
I get that the evaporative surface area may need to change, and that the grate area may need to change, even fuel consumption, but I'm still not seeing how an increase in pressure, which must necessarily be brought to bear on the cylinder's surfaces, one sliding, won't translate to increased motive power.
In the Classic Trains article, it seems that there is not much difference between the ATSF version and the J1, and if anything the J1 has more generative capacity....I think. Yet the article says the highest cylinder thrust recorded was on an ATSF Texas type @ 219K lbs. Was this unrelated to operating pressure?
Derailing this thread (slightly) are there any good DVD's showing the J1's and the 5011's running on the Sandusky Line? I've seen some videos on YouTube, but I'd rather have a proper 'program' rather than pirated off the internet.
Also, this is a very interesting line of discussion. And also very polite!
Stuart
selectorYet the article says the highest cylinder thrust recorded was on an ATSF Texas type @ 219K lbs. Was this unrelated to operating pressure?
Here is a link for your pleasure, lots of info’s + nice shots:
http://www.columbusrailroads.com/prr%20santa%20fe.htm
Some interesting passages:
" We expected to see a PRR J1 slogging up the hill at its normal 15-25 mph. Instead a Santa Fe class 5011 locomotive, which always seemed to be going 10 mph faster then a J1 powered train, was in the lead. "
" According to Eric Hirsimaki, in his excellent article on the Santa Fe 5011's in Columbus, published in the Autumn 1999, Keystone magazine, the Santa Fe's made the Columbus - Sandusky trip on average 2 1/2 hours faster then a train headed with a J1. A typical train would contain 110 cars weighing 9,430 tons. "
On another threadl where I claimed (and still claim) that the AT&SF 2-10-4 was the very best NONARTICULATES North American freight steamer, criticism was that lines hosting 2-10-4's required too much track maintenance. Does the Sandusky Line history support this claim?
On another thread, it was claimed that lines hosting 2-10-4's required too much track maintenance. Does this line's history support this claim?
Crandell,
This is very interesting information and I thank you for providing it in a very sensible manner. I had always thought that the J's were the Pinnacle of development of steam. You have really put it into perspective for me.
Best,
Bob
Bob to put it in perspective the ATSF 5011's and the 2925 war Baby Northerns had some of the Longest runs they routine ly went Between Lu Juntia CO and Kansas City Mo with out Replacement. The 3460 class 4-6-4 and 3751 class would normally take trains 1500 Miles on the ATSF. In fact the 3461 has the record for the Longest run by a Steamer in Revenue Service she took the Pacific Fast amil from LA to Chicago without being Replaced at anypoint on the line. The ATSF was not afarid to push their engines hard with longer runs. When they Traded in their FT's to EMD for GP 20-30-35's some of them had over 3 million miles on them.
Another perspective is that, a road that lasted in its territory, or that expanded and generated more revenue than when it first started, and continued to do that for more than a couple of decades, must have had good management. Those people knew how to talk to each other, what was important in revenue generation, and how to run a reasonably happy and motivated work-force. Included in those machinations must have been a deep understanding of their customer base, their line profiles and problems, and what motive power would be needed to keep to the timetables. In other words, they knew their business, and knew what motive power, of what description, would be required to meet demands. Since there was marked variance between corporations, it stands to reason that there was marked variance in the motive power between them.
When the referee blew the final whistle on steam, there were some players in mid swing. Some had completed their kicks and had motive power that represented about the best that affordable and modern technology and metallurgy could provide. Some were just realizing that they were getting behind the 8 ball.
Personally, I really like the J1, but it was based on a 12 year-old C&O design. The credit should be shared with the people who ran the C&O and who stipulated the performance parameters for their T-1.
And the people who regulated the erection of locomotives during the second world war...they would not allow new designs, so the Pennsy had to go shopping. Literally and figuratively.
Bob, you are welcome for any small bit I contribute. I am laughably far from being truly conversant about steam locomotives, but if I can facilitate exchanges such as these, I'll happily do so. I get something out of it, too, after all.
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