The tractive effort number is calculated, not measured, so the horsepower difference may account for the higher number despite the lower weight. I doubt that EMD made much better wheelslip control available in the 9 months that elapsed between the SD40 and SD45 deliveries.
From http://evilgeniustech.com/IdiotsGuideToRailRoadPhysics/HorsepowerAndTractiveEffort/
After converting units you get
T = 370 * (nP/V)
T is tractive effort in pounds
n is a 0-1 multiplier for unit efficiency (about .82 for SD40/SD45)
P= horsepower
V is velocity in MPH (calculated at 11.1 MPH)
The tractive effort calculation gets n =.82 for an SD40, .684 for an SD45. This is pretty consistent with what other railroads found, which is why SD45s tended to get moved away from drag service.
I intentionally phrased it as a trick question - in part to see how folks would react when they found out. As Bugs might say, Interestin', isn't it?
Hahn (where I got this tidbit) says it is because the SD40s were ballasted more, probably similar to the current generation of 'heavy' locomotive versions. Yes, I suspect improvements in wheelslip control (Hahn also went into detail on how bad synchronous slip on GP30s could be) might account for the absence of similar ballasting - as could a desire to lessen the perceived drawback of the SD45's higher specific fuel consumption by showing it is 'lighter' to move more train for its nominal tonnage rating.
Hahn lists the SD40 at 390,000 and not 391,000 which makes me wonder if some of them received equipment after construction that increased their weight 'enough' to make the Britherhoods or whoever interested enough to adjust the weight number.
Both classes had the same gear ratio, expressed by PRR as 62:15 ('permissible top speed' over 70mph).
How is that possible? Better wheel-slip control? Or different gear ratio?
PRR EF-36 SD45 (10-1966) is listed at 389,000 lbs. The EF-30a SD40 (1-1966) is listed in PRR diagrams at 391,000 lbs. I guess that makes the SD45 -1 ton "heavier". Source prr.railfan.net. The SD45 got an extra 100 lbs of tractive effort (82,100 vs 82,000), despite being lighter.
How much heavier were PRR's first SD45s than the previous 3000hp SD40s?
SD70M-2Dude Anyway, shouldn't Overmod ask a question?
He should, but he’s still trying to think of a good one.
Miningman The Intercolonial gets sold to the New York Central and Canadian Pacific much like the TH&B was set up. It becomes legendary for its passenger service. Today it is an important part of Norfolk Southern/Canadian Pacific.
The Intercolonial gets sold to the New York Central and Canadian Pacific much like the TH&B was set up. It becomes legendary for its passenger service. Today it is an important part of Norfolk Southern/Canadian Pacific.
The strength and close relationship of CP and NYC also means that the Penn Central merger never happens.
Anyway, shouldn't Overmod ask a question?
Greetings from Alberta
-an Articulate Malcontent
"Rich" like Switzerland, not like Switzerland, and the wealth was NOT ill begotten gains and with no questions asked.
Canadian Northern gets a few tips from Hays and does just fine They have a symbiotic relationship with the Grand Trunk. The Intercolonial gets sold to the New York Central and Canadian Pacific much like the TH&B was set up. It becomes legendary for its passenger service. Today it is an important part of Norfolk Southern/Canadian Pacific.
Somewhere in the quantum universes this happened.
Doesn't Switzerland have a state-owned Railway system?
And even if the GT system somehow managed to stay financially healthy, there are still the Canadian Northern bankruptcy and the Intercolonial's ongoing losses to deal with, those two would probably have been merged into a single state-owned system, no matter what happened with the Grand Trunk.
Wanswheel-- Yes, Edward Hungerford is a very good story writer, easy to read, flows nice and never makes you feel like it's work. Very enjoyable.
Pure speculation --The Grand Trunk Pacific never goes bankrupt, New England railroading is dynamic and dominated by the Grand Trunk. Canadian National never happens. As a result Canada is much less government dependent and has a strong free market philosophy. We are all rich, like Switzerland, only way bigger. Life is beautiful.
Miningman, thanks for reading two pages by Edward Hungerford, who was a pretty good story teller. He put together B&O's 1927 Fair of the Iron Horse, 1939 N.Y. World's Fair Railroads on Parade, and 1948 Chicago Railroad Fair.
Excerpt from http://www.sitnews.us/Kiffer/Titanic/040912_titanic.html - It’s impossible to know what might have happened had Hays lived. He was in his prime when he died, a month shy of his 56th birthday.
Thanks Wanswheel. Saskatchewans smallest "city" is Melville, an important and great Railroad place, named after Charles Melville Hays.
What if he had not perished on the Titanic? History would unfold quite dramatically different.
https://babel.hathitrust.org/cgi/pt?id=uc1.b3866496;view=1up;seq=5
All the ‘excitement’ for SNE construction had essentially ended by the time Federal control of railroads did, years before Grand Trunk was folded into CN.
I am still tickled by the heroic measures taken to keep the route out of Connecticut. Something I had not adequately realized was that CV already served an ice-free port on the Sound... but it was New London, in the NYNH&H’s home state.
Grand Trunk didn't become Canadian National until 1923.
Actully, I'm pretty sure the company that Controlled the Central Vermont Railroad was the Canadian National, because the track was originall owned by The Grand Trunk but when all Canadian Railroads where consolidated, and then GTW was made into a subsida for CN for U.S. Operations, there tracks in the East went to The Centeral Vermont. The Centeral Vermont was also made into a subsidary for running in the U.S., making the three companies very similar.
Overmod Grand Trunk, of course. If only the Titanic hadn’t sunk!
Grand Trunk, of course.
If only the Titanic hadn’t sunk!
Indeed, Hays was quite the visionary. Grand Trunk's eastern ports (Portland, New London, and of course the attempt at Providence) never really panned out and eventually faded away, and the GTP project bankrupted the company, but now 30,000 feet of double stacks head east from Prince Rupert every day, with only low grades to tackle across the continent. That place has finally come into its own. Only took 100 years.
The next question belongs to you Overmod.
Almost there, but who controlled CV, and was the real force behind the SNE scheme?
The New Haven is the other Class I, whose region they were trying to enter
You wouldn’t be talking about the SNE into Providence in pre-noodle CV days, competing with that infamous Canadian class I the New York, New Haven and Hartford, would you?
You wouldn’t be talking about the SNE into Providence, competing with that infamous Canadian class I the New York, New Haven and Hartford, would you?
The Class I was Canadian, and the line was also intended to give them greater access to a region dominated by another Class I.
I have been digging at this for a while but haven't found anything that quite matches. I have to assume this was in Canada since most US ports are ice-free.
Just before the First World War, a Class I railroad chartered and began constructing a new subsiduary in an attempt to gain access to another ice-free seaport. Construction progress was slow due to the war but although grading was mostly completed no track was ever laid, and the project was abandoned. Name the Class I, the subsiduary, and the port they were trying to enter.
SD70M-2 Dude:
Wow---you are correct and get to ask the next question.
Ed Burns
NP Eddie think farther north and in a large midwestern city.
think farther north and in a large midwestern city.
Ex-GN Stone Arch Bridge in Minneapolis.
Formerly known as "Hill's Folly", after the Empire Builder himself.
Dave:
Wrong bridge--think farther north and in a large midwestern city.
The bridge is still owned by the Union Pacific and officially is/was the Boone Valley Viaduct, near Boone, IA. It was and is popularly knoen as the Kate Shelley Brudge. Aaround 2009 UP built a new parallel bridge used for rail service with the old one used as you described.
Rob and All:
It took a bit of doing, but I figured out that the last road was the MILW.
My question: There is a famous former railroad bridge in this midwestern city that is now a pedestrian and bike bridge. Only emergency vehicles are allowed on said bridge. Name the town, former owner of the bridge, and who was it named after?
Happy hunting.
I knew it was the IT, but I did not know any details about the locomotives or had forgotten them.
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