I'm reading Unfinished Business by Muary Klein. In one chapter about diesels replacing steam, he says that diesels are less sensitive to adverse weather than steam locomotives. How does adverse weather affect a steam locomotive?
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Does the outside boiler get super hot when on operation? If so, maby when it rains hard, it may cause stress on the outside boiler of the locomotive??? Just like when you get done mowing for a long time you don't spit, or pour ice cold water on the muffler. But a muffler, and a boiler are 2 very diffrent things...
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Justin, the boilers are covered with lagging and boiler jackets, so they are essentially covered and somewhat insulated on their surfaces exposed to rain and snow.
I am not an expert in this subject, but steamers have to spread their weight over several non-driven axles in many cases, so their adhesion on the rails where the tractive effort is being applied is less than it would be on a diesel where all wheels bearing weight are also driven. In wet conditions steamers will tend to slip more than diesels because the rails are wet and the drivers become wet in short order once the engine moves. So with the diesels, but they have more weight on the wheels doing the work.
Other than that, I can't think why either engine would be affected more than the other with varying weather.
-Crandell
Thermal losses in steam engines is quite large in cold weather. The loss of heat from the firebox to the cylinders can be extreme. IIRC, the ACE 3000 project used ex-C&O 614 to run tests and saw the measured thermal efficiency drop from 12-14% - down to 6%. A diesel-electric runs about about 25-35%, and usually does not lose too much in extreme cold weather.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
I have tonnage charts for Erie steam locomotives. Yes,when the temperature goes below freezing the tonnage it could haul dropped proportionatly. Also back then most car axle bearings were the friction type,not modern roller bearings. joe
My education continueth. Thanks, fellas.
Great data, Thank You!
selectorIn wet conditions steamers will tend to slip more than diesels because the rails are wet and the drivers become wet in short order once the engine moves. So with the diesels, but they have more weight on the wheels doing the work.
Have you thought about the fact that a steamer has all of its drivers connected ( articulateds excepted ) and adhesion will have to deteriorate enough to have all slip at once, whereas a diesels drivers are independent of each other and when just one driver slips the wheel slip system reduces power to all motors in order to recover from the slip.
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joseph2I have tonnage charts for Erie steam locomotives. Yes,when the temperature goes below freezing the tonnage it could haul dropped proportionatly. Also back then most car axle bearings were the friction type,not modern roller bearings. joe
The fact is, that after a certain speed is attained ( it may be as low as 7mph ) there is no difference in the rolling friction between roller & friction bearings.
jrbernier IIRC, the ACE 3000 project used ex-C&O 614 to run tests and saw the measured thermal efficiency drop from 12-14% - down to 6%.
selectorI am not an expert in this subject, but steamers have to spread their weight over several non-driven axles in many cases, so their adhesion on the rails where the tractive effort is being applied is less than it would be on a diesel where all wheels bearing weight are also driven. In wet conditions steamers will tend to slip more than diesels because the rails are wet and the drivers become wet in short order once the engine moves. So with the diesels, but they have more weight on the wheels doing the work.
Not always true. A GE AC60 weighs in at about 430,000 pounds when ballasted to the max. Compare that to a N&W A 2-6-6-4, which carried 432,350 pounds on its six driving axles. Granted, the lead and trailing trucks carried an additional 140,000 pounds, but the tractive weight equalled the biggest diesel. Sticking with N&W, look at the Y-6 2-8-8-2. Here you have 522,850 pounds on the drivers. Neither of these examples were the largest one could cite.
When you look at smaller two cylinder modern steam power (e.g.: NKP Berkshire) you find rough equivalence with four axle diesels, comparing weight on drivers. If the diesel is superior it is because of advanced traction control, which allows a more favorable factor of adhesion and thus, more pull per pound.
IIRC most steamers had an open cab, with no back wall. So the crew was exposed to the weather. No AC in the summer, some heat in the winter, have a coat handy to stay dry if raining,etc.The good news may have been frequent stops to drink lots of water & take care of needs.
By contrast, a diesel has facilities inside. Not sure how well the heater & AC units work. Older units may be as leaky & noisy as a steamer.
Setting aside the causes, some of which apply to the locomotive and some to the cars, the effect of cold on steam tonnage ratings was significant. From Great Northern Marcus Division ETT #5 of March 1911 the tonnage ratings on the 2.5% climb up Moslon Hill, which was in eastern Washington very near the Canadian border, for the various class G 4-8-0s, the heaviest locos rated on the territory were as follows:
Temperature Tons
over 25 deg F 425
25 to 5 400
5 to -10 375
below -10 350
Mac
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