7500+ HP is consistent with what I said for steam(which was 6000+HP), however Virginian's big electrics were north of 10,000HP. And while Steam does have a whole lot of torque at startup, it actually hits its torque max at low speed, not at a standing start. Electric traction motors hit their torque max at 0rpm (That said, DC traction motors have some issues at very low speeds which could lead to burned out motors in some situations, AC motors solved those issues, but that didsn't occur until the 70's and widespread adoption of AC designs happened in the 90's).
The reason that Diesel-Electrics didn't take over long drags right away despite the better starting torque per HP was that at low speed and heavy loads they could actually burn out traction motors quite easily on 4 axle units, which delayed D_E adoption for road drags. The introduction of 6 axle C-C units with 6 traction motors solved that problem (the early 6 axle units were A1A-A1A's with only 4 driven axles, for smoother rides in passenger service and lighter axle loadings for light rail) and adoption of them actually happened quicker than for road use, the SD7 showed up in 1952 and was the first really successful 6 axle unit, (The FM Trainmaster had superior power but was a maintenance hog), 8 years later they would be essentially dominant for heavy hauling. in comparison the FT (the first real road D-E) was introduced in 1940 but dieselization for road use didn't become dominant until 12-15 years later. Note the Big Boy is the UP's 4-8-8-4 road locomotives. The 2-8-8-2 never had a widely adopted name. The last mainlines to run steam were CN, CP and N&W all of which ran Steam into 1960. Steam Locomotives are a heck of a lot more impressive than diesels though, I will give them that. -Adam graywolf wrote: > That one you are wrong about, Adam. Norfork-Western ran steam longer > than anyone, even going as far as building their own locomotives. Their > main business was hauling coal from the mines to distribution points > around the US. One of their locomotives could haul a train that 5 D-E's > could not even start off with. Your HP figures are ridiculous many of > the largest steam locos had 7.5Khp+. They could spin all 12 to 16 > drivers on start up if the engineer was not careful. Steam engines have > almost infinite torque at startup. Also note that the HP goes up as the > train moves faster since they were direct drive. > > The claim has been made that N-W only gave up on steam after the last > supplier of control valves went out of business. Since they did not seem > to think it was any problem to build a whole locomotive that does not > sound likely. I would think it is more a case of they only had about 10% > or so of the revenue they used to have because coal was no longer a > mainstream fuel. > > > ***ADDED: If I can believe the stuff I found on the internet, N-W was > not building their own freight locos, but the passenger ones. Little > bitty things only capable of 100mph or so. Strangely I thought they > build 2-8-8-2's but I guess not. However the 2-8-8-2's are what I > remember their freight trains running. Also I was thinking that was the > Allegheny, but apparently it was the Big Boy, the Allegheny being an > 2-6-6-6 (8000hp) run by C&O. Anyway it looks like N-W ran steam up to > 1960 and was the last mainline RR to switch over, as I thought. In the > '80's they (by then merged with Southern as Norfolk-Southern) were > running steam specials until a couple of accidents ran the insurance up > too high and they stopped.*** > > > As an interesting aside, how many of us remember steam trains from back > when they were common. I was just a small kid, but the were about the > most impressive things I remember. Big, loud, smoke and steam spouting > everywhere, a whistle that made your ears heart (and soot on > everything). The drivers were more than twice as tall as I was. Yeah! I > remember. Standing between a couple of those engines ready to roll was > something I never will forget. > > An interesting website: http://www.steamlocomotive.com/ > > -graywolf > > > Adam Maas wrote: >> Brian Dunn wrote: >>>>> Write time to the X's drive is a bigger issue for me - it took a solid >>>>> 20 minutes to download each card to the X's Drive II. >>>> I have the same (Dane-Elec) card in 1Gb configuration. It takes about 3 >>>> minutes to write a full card (90+) to my PC, which is steam powered. You >>>> must have a really slow card reader. >>> >>> Possibly interesting trivia: >>> >>> Supposedly steam powered locomotives have massive torque and pulling power >>> and >>> can reach crazy speeds. They were phased out for other reasons, such as >>> maintenance and infrastructure support, but speed wasn't really a problem... >>> >>> >>> Brian >>> >> Speed wasn't an issue with steam. But low-end pulling power was. Electrics >> had replaced steam on several coal roads for that reason, and >> Diesel-Electrics were even better as they lacked the infrastructure support >> cost of electrics (Although electrics did offer 10,000HP single units). >> >> Steam's advantage wasn't torque (It was clearly outmatched by electric >> traction motors at low speeds) but horsepower. A single large steam >> locomotive has 6000+HP compared to 1350-1500HP per unit of an early >> diesel-electric unit (3000-4500HP on the average unit today). However >> Diesel-electrics can MU (Have multiple units under the control of one and >> operating in sequence) while multiple steam locomotives is an exercise in >> difficulty. In fact today you can MU with diesel-electric locomotives in the >> middle and rear of the train via radio link. >> >> Steam is maintenance intensive, short ranged and required a lot of >> infrastructure (Water and fuel, especially water). Diesel-Electrics have >> them beat on all fronts. And now they're even matching the HP, with 6000HP >> single units in service (GMD SD90MAC-H and GE AC6000). >> >> Steam is a whole lot nicer to look at though. >> >> -Adam >> Sometime railfan. >> >> >> >> > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
