BaltACD While using heat to cool may seem incongruous - remember RV refrigerators use a LPG flame to power the cooling cycle when electricity isn't available.
While using heat to cool may seem incongruous - remember RV refrigerators use a LPG flame to power the cooling cycle when electricity isn't available.
I researched this.
Both the A/C and the heat where I work are provided by steam generated at a central plant -- two of them, actually, the old one that used to be coal fired and was converted to natural gas fired, and the new one that is a gas turbine electric/steam cogeneration plant.
The steam heat works as you think it would -- my work building is heated just like a pre-1970's passenger car. The A/C is from chilled water derived from steam at the central plant.
The refrigeration system is an "absorption chiller" that works on the exact principle as your LPG-powered electricity-free RV fridge. The steam A/C in railroad cars, however, works on a completely different system. There, a "steam ejector" draws a vacuum, much like how steam was used to power vacuum brakes used outside North America. The vacuum evaporates water, this evaporation providing the cooling effect.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
John H. White's The American Rialroad Passenger Car had a section on the various A/C methods. The AT&SF and SAL were about the only ones using the steam ejector system, with SAL using them until the 1960's. Ice "powered" A/C's were used largely in New England along with a few carriers outside of the region. Engine driven compressors were developed by Waukesha and used by a number of RR's.
Pullman used straight mechanical drive from the axle to the compressor on their early installations, with some cars equipped with A/C's running off the axle generators.
The UP had HEP on some of their pre-war streamliners. The B.A.&P used 2400V for supply heat to the electrically hauled passenger trains, then went back to coal stoves for the mixed trains in later years.
Most electric passenger locomotives built in the US did not use Vapor Clarkson steam generators, rather more conventional boilers, though the PRR did have electrically heated boilers on the DD-1's (which were there more to keep the steam lines warm).
- Erik
P.S. The Sepember 1914 issue of General Electric Review had an article on the electrically powered flash boilers for the PRR DD-1's and the 2400V electric heaters for the B.A.&P. passenger coaches.
Never too old to have a happy childhood!
RME BaltACD Prior the HEP, steam was the heating and cooling power for passenger cars. i thought comparatively few passenger trains used steam-driven air-conditioning systems (Santa Fe being perhaps the biggest user). Fascinating how this stuff worked, but all that steam ... and still needs an extra axle generator too! Description of the comparative systems is pretty well covered in Kiefer's motive-power comparison study of 1947, including an assessment of how the power required to run the various systems affected locomotive performance over the range of acceleration (there is at least one highly enlightening graph there). Someone will have comparative statistics on what railroads used what air-conditioning approaches, but I suspect that non-steam methods (including ice-activated, which I don't really think fully 'counts') were more common. Steam heat -- that was far more ubiquitous, and for more sensible reasons.
BaltACD Prior the HEP, steam was the heating and cooling power for passenger cars.
i thought comparatively few passenger trains used steam-driven air-conditioning systems (Santa Fe being perhaps the biggest user). Fascinating how this stuff worked, but all that steam ... and still needs an extra axle generator too!
Description of the comparative systems is pretty well covered in Kiefer's motive-power comparison study of 1947, including an assessment of how the power required to run the various systems affected locomotive performance over the range of acceleration (there is at least one highly enlightening graph there).
Someone will have comparative statistics on what railroads used what air-conditioning approaches, but I suspect that non-steam methods (including ice-activated, which I don't really think fully 'counts') were more common.
Steam heat -- that was far more ubiquitous, and for more sensible reasons.
I believe CN/VIA Rail used steam cooling too, a friend recalls making a trip on VIA circa 1985 where the AC quit working, and the Conductor explained to him that it was because of a problem with the steam supply.
Greetings from Alberta
-an Articulate Malcontent
Santa Fe got steam AC even on postwar cars. Many were re-equipped with electro-mechanical AC during the late 1950s and early 1960s. Almost all other postwar cars were equipped with electro-mechanical AC as built. There were a few other types, notably Waukesha (UP, SP) and York (B&O).
RME BaltACD i thought comparatively few passenger trains used steam-driven air-conditioning systems (Santa Fe being perhaps the biggest user). Fascinating how this stuff worked, but all that steam ... and still needs an extra axle generator too! Description of the comparative systems is pretty well covered in Kiefer's motive-power comparison study of 1947, including an assessment of how the power required to run the various systems affected locomotive performance over the range of acceleration (there is at least one highly enlightening graph there). Someone will have comparative statistics on what railroads used what air-conditioning approaches, but I suspect that non-steam methods (including ice-activated, which I don't really think fully 'counts') were more common. Steam heat -- that was far more ubiquitous, and for more sensible reasons.
BaltACD
My understanding is that steam AC was the first step beyond circulating ice cooled air for AC and it was the first system that was adopted by Pullman and most of the carriers. Electric powered refrigeration systems came on the scene later and were used for most new construction after the bugs were worked out. I believe updating steam AC to electric was a somehat involved process and wasn't done except for major rebuilds.
BaltACDPrior the HEP, steam was the heating and cooling power for passenger cars.
Main line electrics during the period prior to Amtrak all had steam boilers for passenger service. Prior the HEP, steam was the heating and cooling power for passenger cars.
New Haven railroad electric passenger locomotives had
steam generators, too.
MILW's EP-4's (Little Joes E-20 and E-21) were not designed with space for a steam generator so the S/G had to be installed in one of the cabs.
The two Swiss 0-6-0 switchers that were fitted with electric heaters (E 3/3 8521 and 8522, redesignated as E(e) 3/3 after refitting) could produce 240KW (about 320 HP) from the two separate heating elements. Pantographs were standard "Traktor" pantographs, with the roof-mounted transformers set to produce 20 volts at very high amperage which was carried by bus bars to the electric heaters. The heaters operated at 20V and 6000 Amps (two per lok). The locomotives retained their fireboxes and usually had a banked fire, though they could be fired normally when used on non-electrified trackage. They were operated by the normal steam throttle. The electric heating tube had a circulating pump to circulate the boiler water past the heating elements to cool them (!). Because the electric heaters were capable of popping the safeties the engine crew had to cut the heating elements in and out when the engine was idle or steam demand was low, since there was no other way to control the "fire". The electric elements remained in the engines until 1952, when they were rebuilt into normal E 3/3 switchers.
Installation cost was CHF (swiss Francs) 100,000, coal savings 700-1200KG/day ~ CHF 36,000 per year, so a three year payback. Electricity came from hydro-electric plants, so no direct fuel costs.
http://www.lokifahrer.ch/images/Lokbilder/SBB-E-3-3_elektro.jpg
http://bahnbilder-von-max.ch/pictures-small/max00225.jpg
CandOforprogress2 they are so huge?
they are so huge?
Actually, a GG1 isn't all that large, as far as locomotives go. If you compare a G to a second generation diesel, such as a GP38, the G isn't that much bigger. The diesel is noticeably higher. The GG1 had to fit through the tight clearances of the tunnels into New York's Penn Station.
I actually own some GG-1 boiler inspection reports. They had to be flushed and hydrotested just like a locomotive boiler. The last thing one thinks about involving a GG-1 is in fact it had a boiler for steam and a tank for fuel oil. There are some photos around that show GG-1s blowing down their boilers to remove excess steam after a run. They blew off steam as well as any PRR steam locomotive ever did!
Very informative post RME, thanks!
I THINK that GG-1 cutaway diagram you mentioned was in a past issue of "Classic Trains," the big GG-1 issue. It's one I should have kept. I just checked and unfortunately it's not available as a back-issue.
The actual steam generator is not very large, not much bigger than a big potbelly stove. Bunkerage of fuel and water more substantial, but not a large item ... see how the device was packaged in an early Geep:
(Someone can find the fancy phantom-view drawings of the GG1 that were in the special Kalmbach 'anniversary' issue, which show the generator and bunkerage position and size in that locomotive very well...)
The cost of using electricity to make steam at appropriate volume and pressure for trainline use would be considerably higher than the cost of the fuel oil; the time required to build up pressure would also be considerably longer than that required for a good monotube like a Vapor-Clarkson. Here is a PDF download of a manual for your reference.
The only other thing you need to compare is the economics of the converted steam switcher design the Swiss cobbled up during WWII -- look at the amount of input power required to get the trick to work. Now imagine how much power you would need to get the necessary rapid heat transfer both for starting and required mass flow... and how much cost and space would be required for the elements, controls, pressure vessel, etc. (Leaving aside how you safely boil water with 11kV catenary voltage - better have still more good large transformers or fancy tap arrangements...)
Well, that's part of the reason. A lot of what was under the hood were transformers and other power conversion equipment to turn that 11,000 volts of AC from the overhead catenary into something the traction motors could handle.
What suprised me when I found out about it was the steam generator used fuel oil and not an electric element to make the steam.
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