Going back to transition era technology, there was a widespread belief that 500HP/axle was the practical limit for a diesel. Thus, a truly high horsepower unit would end up with four trucks on span bolsters, like the UP 4500HP turbines.
One reason that EMD's products blew steam off the tracks was that EMD, with its GM automotive background, went out and aggressively sold their products while the big steam builders sat back and waited for the railroads to come to them. Then, too, the EMDs were standardized, while steam remained with railroad-specific custom designs right up to its last gasp.
Chuck
The original concept by Max Essl (see January 1963 TRAINS) involved a 2-D+D-2 running gear and eight 750 HP diesels mounted crosswise in the carbody. The carbody also involved modular construction. Due to wartime material restrictions, only four diesels were actually installed and a handful of test runs were actually run, none of them particularly successful. The only thing that got passed along to the Centipede was the running gear design, although I think that the running gear of the testbed was used under SAL 4500.
Except for the running gear, the Centipede was conceptually not that different from the E. Two 608SC engines rated at 1500 HP each were mounted in the carbody, not unlike two 567 engines in an E.
I had actually been on the railroad for quite sometime before i realized that the ice cream box wasn't the proper name. same with Michiana tank. their still referred to that this day.
In the 1940s Baldwin experimented with a 6,000hp diesel with a “centipede” wheel arrangement, though this used multiple prime movers. Production locos had two 1500hp prime movers. Only an handful of this less-than-successful-loco were built, mostly for Pennsy.
http://en.wikipedia.org/wiki/Baldwin_Centipede
creepycrankTo get back on topic, I see where Progress Rail is rebuilding some SD 50's for NS and installing CAT 3516 engines rated at 3005 HP at 1800 rpm. These engines are smaller and lighter than the 16F3's they replace but have a much higher piston speed, wear faster at that rate and the lube oil has to be changed out at 250 hrs of operation,. I noticed in the photos that they keep the same radiator so presumably they expect to operate at the higher power for a considerable period of time. The SD 50 was longer than the SD 40 in part so that there was enough room for the larger radiator. I know that the newer engines are so much more fuel efficient that now they have to stop the train to pump it off before it spills but the large radiator represents some of the energy from the fuel that's not convertible to shaft work. So what do we have,a smaller lighter engine in a locomotive that's pretending to be a SD 40 but' is larger and heavier that they are going to do what with- replace GP 38's in switching which is fine for the engine or to try it as a substitute for SD 50's as a line haul unit. Even with the smaller engine they don't seem to make any progress in reducing the size overall. I wonder if there will ever be any follow up on this experiment.
Are you certain about that? I've read online that the repowered units for NS are 4000 HP(including on one of the bigger NS fansites with lots of current roster info). That would mean that the units have either the 12-3600 engine or it's tier III successor (C280?). I have read that UP is having some SD40-2 repowered by Wabtec/MPI with 3000HP from 3500's...
http://www.nsdash9.com/rosters/4000.html
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carnej1 bubbajustin Well, you have to think. In the 1800's people didn't have microwaves. The tecnology just wasn't there. Still though some railroad's, not the N&W, were ready to get rid of the old steamers as soon as the right diesels were created. Remember that diesels were being built in the 30's, thay just wern't high enough horsepwoer for road freight service. Finally when EMD came out with the FT locomotive the railroads had never seen anything like it before. Kind of like what the Right Bro's. would do if thay saw an A380. Early diesels were big machines, compare this to a cell phone of the 70's to todays Razor phone, the prime movers were bigger but still didn't have as mutch horsepower. Today's GEVOS are smaller than the 657 prime movers, I think that's what thay are called, whatever's in a dash 9, but produce the same horsepower. The bottom line is that the tecnolagy just wasn't there. By "657" I think you mean FDL which is the older series of GE prime movers. The 567 and 645 diesel engines were EMD products...
bubbajustin Well, you have to think. In the 1800's people didn't have microwaves. The tecnology just wasn't there. Still though some railroad's, not the N&W, were ready to get rid of the old steamers as soon as the right diesels were created. Remember that diesels were being built in the 30's, thay just wern't high enough horsepwoer for road freight service. Finally when EMD came out with the FT locomotive the railroads had never seen anything like it before. Kind of like what the Right Bro's. would do if thay saw an A380. Early diesels were big machines, compare this to a cell phone of the 70's to todays Razor phone, the prime movers were bigger but still didn't have as mutch horsepower. Today's GEVOS are smaller than the 657 prime movers, I think that's what thay are called, whatever's in a dash 9, but produce the same horsepower. The bottom line is that the tecnolagy just wasn't there.
Well, you have to think. In the 1800's people didn't have microwaves. The tecnology just wasn't there. Still though some railroad's, not the N&W, were ready to get rid of the old steamers as soon as the right diesels were created. Remember that diesels were being built in the 30's, thay just wern't high enough horsepwoer for road freight service. Finally when EMD came out with the FT locomotive the railroads had never seen anything like it before. Kind of like what the Right Bro's. would do if thay saw an A380. Early diesels were big machines, compare this to a cell phone of the 70's to todays Razor phone, the prime movers were bigger but still didn't have as mutch horsepower. Today's GEVOS are smaller than the 657 prime movers, I think that's what thay are called, whatever's in a dash 9, but produce the same horsepower. The bottom line is that the tecnolagy just wasn't there.
By "657" I think you mean FDL which is the older series of GE prime movers. The 567 and 645 diesel engines were EMD products...
YAh that's what I meant. I admire you guys who can tell what kind of prime mover a loco' has just by listning to it. I wish I could do that.
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Railway ManInterestingly, when I worked in a locomotive shop, it was always "main generator" whether it was A.C. or D.C. You looked in the EMD 190 parts catalog, the AR10 alternator was a "main generator." But now I see that some in the industry are starting to call it a main alternator -- VMV and EMD both use that on their websites now. Ugh. RWM
Interestingly, when I worked in a locomotive shop, it was always "main generator" whether it was A.C. or D.C. You looked in the EMD 190 parts catalog, the AR10 alternator was a "main generator." But now I see that some in the industry are starting to call it a main alternator -- VMV and EMD both use that on their websites now. Ugh.
RWM
It is more appropriate now to call them Alternators, or at least AC generators. On SD70M-2s and SD70ACe locomotives EMD has removed the Rectifier Assy, not just from inside the case of the generator, but even from the same compartment of the locomotive. It is now in with the switch gear.
oltmanndwas there a company called Michiana who was a supplier to EMD once upon a time?
I believe so. In the back of most of the engines at work, the tank says "Michiana" on it. The newest engine is from 1980.
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oltmanndRailway ManInterestingly, when I worked in a locomotive shop, it was always "main generator" whether it was A.C. or D.C. You looked in the EMD 190 parts catalog, the AR10 alternator was a "main generator." But now I see that some in the industry are starting to call it a main alternator -- VMV and EMD both use that on their websites now. Ugh. It was that way when I was in Mechanical, too. Sometimes, EMD would refer to it as the "Traction Alternator" - which I liked. Sometimes we just referred to it by it's model. You'd just call it the "AR10" or "D32". There was no confusion. I have forgotten some of the EMD colloquialisms over the years, but just happened on a VRE engine (not locomotive) rebuild spec. They actually used the term "ice cream box" for the lube oil strainer housing and "Michiana tank" for the lube oil filter housing. (was there a company called Michiana who was a supplier to EMD once upon a time?) Actually, VRE is just looking for a "PACO"
Railway ManInterestingly, when I worked in a locomotive shop, it was always "main generator" whether it was A.C. or D.C. You looked in the EMD 190 parts catalog, the AR10 alternator was a "main generator." But now I see that some in the industry are starting to call it a main alternator -- VMV and EMD both use that on their websites now. Ugh.
It was that way when I was in Mechanical, too. Sometimes, EMD would refer to it as the "Traction Alternator" - which I liked. Sometimes we just referred to it by it's model. You'd just call it the "AR10" or "D32". There was no confusion.
I have forgotten some of the EMD colloquialisms over the years, but just happened on a VRE engine (not locomotive) rebuild spec. They actually used the term "ice cream box" for the lube oil strainer housing and "Michiana tank" for the lube oil filter housing. (was there a company called Michiana who was a supplier to EMD once upon a time?) Actually, VRE is just looking for a "PACO"
The Ice Cream Box! Yeah!
You are bringing back not so fond memories of black grease that never washed off, skinned knuckles, a scar I have in my head from creasing it on the bottom of an F7 electrical cabinet door when I sat up to reach for a megger, and a 4th finger that 20 years later is still not quite right after an SD40 door slammed shut on it.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
CSSHEGEWISCHAlco actually beat EMD to the punch with the C630, "The Joneses already have one". When the 645 engine was introduced, the GP40, SD40, SDP40 and SD45 were equipped with main alternators and rectifiers. The GP38, SD38 and the two switcher models used main generators. Main generators had reached their size limit with the GP/SD35 and the C628 so the use of main alternators had become a necessity. EMD equipped F9A 462 with a main alternator as a testbed about two or three years prior to the introduction of the 645 line.
Alco actually beat EMD to the punch with the C630, "The Joneses already have one". When the 645 engine was introduced, the GP40, SD40, SDP40 and SD45 were equipped with main alternators and rectifiers. The GP38, SD38 and the two switcher models used main generators. Main generators had reached their size limit with the GP/SD35 and the C628 so the use of main alternators had become a necessity.
EMD equipped F9A 462 with a main alternator as a testbed about two or three years prior to the introduction of the 645 line.
Thanks for confirming the C630 date. I wasn't sure.
EMD was often not the first out the factory door with an innovation, because they had the market share, thus could test more thoroughly, whereas the competitor had to be first out because they desperately needed market share. In other words, he without the market share has to take bigger gambles. This is consistently the case throughout the heavy capital goods industries.
And let's not forget the boost of power the diesel engine got when equipped with a turbo instead of the Roots blower.
trainfan1221I believe some locomotives had AC alternators (or Dynamo, if you prefer), and had it converted to DC for the motors. I know as early as the GP38s there was an experimental AC model. Its not a brand new technology to railroads, but one thats been perfected for use in modern engines.
I believe some locomotives had AC alternators (or Dynamo, if you prefer), and had it converted to DC for the motors. I know as early as the GP38s there was an experimental AC model. Its not a brand new technology to railroads, but one thats been perfected for use in modern engines.
EMD began offering AC main generators in 1965 along with the introduction of its 645-series prime mover. The AC is rectified to DC by diodes immediately after generation, and the control and power circuits are DC. This method continues as the standard today for EMD and GE for DC-drive locomotives. Alco offered it also, beginning with (I think) the C630.
The GP38AC was not experimental, but offered as an option to the GP38DC. The AC main generator cost more to purchase but was less expensive to maintain.
EMD had an over forty year run replacing four units with three as power improvements were possible. What are the limits? A number of factors such as weight, length, cost, operating practice (are two smaller units more versatile), track restrictions, and a variety of other factors.
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Ulrich When diesels first began to replace steam back in the 40s and 50s railroads had to get used to locomotives of much lower horsepower than the steam engines they were replacing...the early diesels had 1200 to 1500 hp...and they had to be run in consists of three or four to replace one large steam locomotive. Why was it not possible to build larger more powerful diesels from the outset? Was a 3000 hp diesel not possible in the 40s and 50s...and it took 30 years...until the late 60s to finally build one that is reliable?
When diesels first began to replace steam back in the 40s and 50s railroads had to get used to locomotives of much lower horsepower than the steam engines they were replacing...the early diesels had 1200 to 1500 hp...and they had to be run in consists of three or four to replace one large steam locomotive.
Why was it not possible to build larger more powerful diesels from the outset? Was a 3000 hp diesel not possible in the 40s and 50s...and it took 30 years...until the late 60s to finally build one that is reliable?
Another thing to consider is that EMD(and Alco, etc.) marketed their early units as "modular" locomotives (although they didn't use that term back then). When an EMD rep. called on a RR's chief mechanical officer he wasn't trying to sell single unit FT's to replace a 4-8-4s or mallets, he was offering A-B-A or A-B-B-A sets which many RR's thought of as a single locomotive (the numbering scheme on may RR's F's and other cab units reflected this where a three unit set of F's would have been numbered 101A,101B,101C rather than 101-103). So it was not a case of replacing 4000HP with 1350HP.
Traction generators were/are pretty much limited to 2500HP, the 8500HP UP Big Blow used four traction alternators geared to the output of the turbine. Traction alternators, which allowed for greater than 2500HP, were not practical until the development of the high current silicon rectifier in the early 1960's.
DC traction motor technology has advanced since the time of the first diesel locomotives. One of the most important improvements was the use of kapton for electrical insulation allowing for higher maximum winding temperatures. As an example, 8 GE-750 motors were required to produce 5500 HP in the Little Joes of the late 1940's, where only 6 GE-750 motors were needed to produce 5400 HP in a design from 1969.
AC traction motors are a relatively recent development for US locomotive use (first work in the US for transit sized motors was in the late 1960's). These mainly became practical after the development of the Gate Turn-Off Thyristor (GTO), and became even more practical with the development of the IGBT. The GTO is slightly more efficient than the IGBT, but the IGBT is much simpler to drive.
The early diesel engines were not anywhere near being up for the task of producing 6000 HP from a single locomotive. The Alco PA was one of the first locomotives to produce 2000 HP from a single engine and it had a lot of reliability problems. Fairbanks-Morse had engines capable of putting out 2400 HP in the early 1950's but reliability wasn't there until later in the decade (i.e. Trainmaster).
- Erik
The limitiations can be many. technology back then wouldn't have supported a lot of what we have now. For example, maybe they might have developed a 4000hp engine back then, but would there be a generator or traction motors that could handle it? Even when the fairly modern units such as GP40s came to be, the horsepower was a lot for only four motors. A locomotive is a machine that has to have everything matched up to work properly. Even today, 6000hp in one unit has been a problem and generally not favored. The idea behind diesels from the FT onward was that you could put several together and get the job done efficiently, in the case of steam the diesel was more efficient even with four units as opposed to one.
Ulrich...and they had to be run in consists of three or four to replace one large steam locomotive.
I assume it's true a 3000-hp diesel would have been a challenge in 1950-- but as long as nobody needed much more than 6000 hp total in one diesel consist, why would the RRs care that they couldn't buy 3000 hp in one unit?
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