beaulieu The weight of the inverters and other necessary equipment for a 3-phase AC drive system is not the issue it is the weight of the 16-cylinder diesel, the alternator, enough fuel to make it worthwhile and the cooling system to keep the emissions in check. A GP69ACe is more plausible. There are European electric locomotives with 8500hp on 4 axles operating in Europe with a weight of 97 tons.
The weight of the inverters and other necessary equipment for a 3-phase AC drive system is not the issue it is the weight of the 16-cylinder diesel, the alternator, enough fuel to make it worthwhile and the cooling system to keep the emissions in check. A GP69ACe is more plausible. There are European electric locomotives with 8500hp on 4 axles operating in Europe with a weight of 97 tons.
The lightweight high horsepower electrics served as the basis for Amtrak's AEM7's.
Doubt that they are hauling 15K ton or larger bulk commodity trains over undulating terrain.
Never too old to have a happy childhood!
Hey thanks, a bit complicated but understood. Now when I am out rail fanning I can get a bttr grasp on why CSX runs so many "beater" engines up here coupled to one good AC traction engine. Sort of like just last year I was recording a Intermodal CSX train out of the "rival" yard and she had a CSXSD40-2 single unit. It did not take long before we got a very cool show. The unit was in run 8 for a long long time (appeared that way) she finaly gave up the fight after about a mile or two up the main. The smoke show alone was worth it. We were close enough to hear the engineer or conductor come out of the engine and yell something very nasty (cant say here) about CSX engines. Guess it was to cold for him to stay out long though. As were leaving ( did not have a scanner at the time) another unit was running sort of quick time to the head end. Wonder what happened to that SD40-2 after they brought up another unit. Looked like a DASH 8? Im sure they hokked them together. We left so who knows. And thank you very much for the information you spent a lot of time typing here sir. God Bless you and may he keep you safe in all you do. Again thank you for your time
Locomotives have no real knowledge that they are coupled to other locomotives. They are connected through a 27 pin electrically based 'Jumper Cable' that transmits the electrical commands from the lead engine to all trailing engines. They are also coupled with several air hose connections to operate specific pneumatic functions at the direction of the lead unit. All engines are set up with switches that will permit the engine to be used in either lead or trail position, only the lead engine will have the switch set to the lead position and all the trailing engines will have the switch in the trail position. When the engineer moves the 'Reverser' to the forward position - that electrical command is transmitted to all the trailing engines. When the throttle is advanced from idle to a running position - that electrical command is transmitted to all the trailing engines. When the forward sanders are operated that command is sent to all the trailing engines. Each engine has its own operating parameters for each throttle position and will put out whatever power that individual locomotive is supposed to put out at that throttle position. Each locomotive performs it's own work as directed by the controls from the leader.
Where engineers have to be careful is when they have a lead locomotive that has 'Short Time' characteristics that exceed the characteristics of one of the trailing engines. If the train gets on a grade, the load meter will indicate more current (amps) is being fed to each of the traction motors in turning the current into motion the traction motors develop heat....the traction motor cooling ability of a engine is a known quantity for the sake of this argument we will specify that the 'weakest' trail engine has a continuous rating of 1000 amps ie. the traction motor can handle a current of 1000 amps for a unlimited amount of time without damaging the traction motor from overheating. If the load on that traction motor goes to 1100 amps, the cooling system for the motor can only permit the traction motor to operate for say 30 minutes at 1100 amps without heat damage to the traction motor, at 1200 amps load the cooling will only permit the traction motor to operate for say 10 minutes without damage. If the lead engine is able to operate at 1300 amps as it's continuous rating, the engineer must be mindful of the short time ratings of trailing engines that may not be up to that standard and operate his train within the abilities of his weakest engine. (note - all loading values I have specified are for example purposes only - individual classes of engines have their own specified operating parameters)
I hope this helps to explain how different locomotives can work with each other, despite their differing operating characteristics and manufacturer.
macsdace70 I even posted on how a AC runs with a DC or a older engine runs with a newer engine ect, but I got no real good answer to that one. GOD BLESS ALL
I even posted on how a AC runs with a DC or a older engine runs with a newer engine ect, but I got no real good answer to that one. GOD BLESS ALL
Well your right I should have posted this on some model forum I guess. The model is complete. Looks sort of cool. I just have not come up with a Class 1 road for it. "ghost". For me it is more "fun" since I live right next to a CSX main line and right down the road from 2 yards and the TORC facility and toledo docs. I spend so much time around locomotives I guess I never get into what makes them run. My dad retired from CSX engineer and two uncles from CSX (CONRAIL) I spent yrs on everything from GPs to SDs and anything in between I even used to run them when i was a kid. I weight lifted and hunted with so many RRs I cant even remmber all of there names! I even lost a friend or two in derailments but still I never got into the technical side of it or even wanted to work on the RR. Now I am starting to take notes on what makes them run thanks to you guys on this forum. I even posted on how a AC runs with a DC or a older engine runs with a newer engine ect, but I got no real good answer to that one. GOD BLESS ALL
Lyon_Wonder I suppose if EMD wanted too they can come out with a SD70ACe loco with A-1-A axles to compete with GE's ES44AC4, though EMD would have to modify it's AC traction since EMD's AC's are only one AC inverter per truck.
I suppose if EMD wanted too they can come out with a SD70ACe loco with A-1-A axles to compete with GE's ES44AC4, though EMD would have to modify it's AC traction since EMD's AC's are only one AC inverter per truck.
The EMD inverters probably could drive two axles instead of three like the present S70Ace models. It seems the GE version of one inverter per axle offers better control since each axle is independant and does not cause the unit to shake during hard pulls like all of the axles of the EMD slip and grab at the same time. This has been a reported complaint against the EMD method. The GE method controls the single axle as has been said in prior posts and each axle is corrected without reaction of the other axles.
EMD would not have to modify the inverter, as the inverters that are now supplying 3 traction motors can easily supply 2. All of which begs the question, why EMD hasn't gone the individual inverter route that GE chose, thus keeping more of the pulling power of the unit when it develops a traction motor problem.
Today's railroads load their trains to the maximum rated tonnage for the the engines supplied for the train...losing 1/2 a unit with a train that is at max tonnage for the route has effectively killed the trains ability to make the run without securing additional power.
carnej1 macsdace70: Gonna have some fun this week as time permits. I have two extra Athearn Blue box models of GP60s and a KATO SD90 sitting around. I have already taken the models apart and I am gonna make a GP70ACe. Just got inspired today when we were out rail fanning. We were in the process of catching HUGE CN train pulling into Stanley (former Conrail) yard today and right as the end pass'd a brand new set of SD70ms CN pass'd us by. I have always liked the GP59s 60s ect and was like hmmm mabey I can make something interesting. It does not matter that it is not prototype for any "rivet" counters becuse I model my own HO scale RR. I enjoy as time permits "messing" with models. As I said it will be just some fun. Figure I have already begun cutting up the new Kato model so I should see how far I can take this. U gotta love CN and there massive trains. We get to talk to some of the CN crews where we rail fan and they are very friendly and very proud of there train size. God Bless All Seems like a post better suited for the "MODEL RAILROADER" forum but if your wondering why EMD hasn't offered such a locomotive it is because the GP70Ms were right at the practical weight limit for a 4 motored roadswitcher (the various 4 axled AC drive units being built for transit operators use a Monocoque type structure making them lighter than a freight unit would have to be) and the added weight of AC equipment would make the unit too heavy for BB trucks. Another issue is the current and future emissions standards mean a larger cooling system would be required, again adding lots of weight.. That's why the BNSF bought A-1-a trucked ES44ACs rather than "ES40BACs"...
macsdace70: Gonna have some fun this week as time permits. I have two extra Athearn Blue box models of GP60s and a KATO SD90 sitting around. I have already taken the models apart and I am gonna make a GP70ACe. Just got inspired today when we were out rail fanning. We were in the process of catching HUGE CN train pulling into Stanley (former Conrail) yard today and right as the end pass'd a brand new set of SD70ms CN pass'd us by. I have always liked the GP59s 60s ect and was like hmmm mabey I can make something interesting. It does not matter that it is not prototype for any "rivet" counters becuse I model my own HO scale RR. I enjoy as time permits "messing" with models. As I said it will be just some fun. Figure I have already begun cutting up the new Kato model so I should see how far I can take this. U gotta love CN and there massive trains. We get to talk to some of the CN crews where we rail fan and they are very friendly and very proud of there train size. God Bless All
Gonna have some fun this week as time permits. I have two extra Athearn Blue box models of GP60s and a KATO SD90 sitting around. I have already taken the models apart and I am gonna make a GP70ACe. Just got inspired today when we were out rail fanning. We were in the process of catching HUGE CN train pulling into Stanley (former Conrail) yard today and right as the end pass'd a brand new set of SD70ms CN pass'd us by. I have always liked the GP59s 60s ect and was like hmmm mabey I can make something interesting. It does not matter that it is not prototype for any "rivet" counters becuse I model my own HO scale RR. I enjoy as time permits "messing" with models. As I said it will be just some fun. Figure I have already begun cutting up the new Kato model so I should see how far I can take this. U gotta love CN and there massive trains. We get to talk to some of the CN crews where we rail fan and they are very friendly and very proud of there train size. God Bless All
Seems like a post better suited for the "MODEL RAILROADER" forum but if your wondering why EMD hasn't offered such a locomotive it is because the GP70Ms were right at the practical weight limit for a 4 motored roadswitcher (the various 4 axled AC drive units being built for transit operators use a Monocoque type structure making them lighter than a freight unit would have to be) and the added weight of AC equipment would make the unit too heavy for BB trucks. Another issue is the current and future emissions standards mean a larger cooling system would be required, again adding lots of weight..
That's why the BNSF bought A-1-a trucked ES44ACs rather than "ES40BACs"...
carnej1
Good solid concepts with the problems of a GP70Ace, however this is HO and a GP70Ace does not have to meet the Tier whatever in HO scale. I was actually suprised when the GP60 and GP60M was built since they were overpowered at the time and SP probably should have purchased the SD60's instead of the 195 GP60's. I don't think he will have to worry about his design being wrong since they probably have no chance of being built in the one to one scale.
The 8-40BW was a high powered unit and that design worked out fairly well but as you have said, the new GE units have the C truck with the A1A motor design. They also lift weight off of the center axle of each truck at speeds below 12mph on start up to add weight on the powered axles. This gives them 1100 HP per powered axle and they were said to be used for high speed transcon service.
CZ
macsdace70 Gonna have some fun this week as time permits. I have two extra Athearn Blue box models of GP60s and a KATO SD90 sitting around. I have already taken the models apart and I am gonna make a GP70ACe. Just got inspired today when we were out rail fanning. We were in the process of catching HUGE CN train pulling into Stanley (former Conrail) yard today and right as the end pass'd a brand new set of SD70ms CN pass'd us by. I have always liked the GP59s 60s ect and was like hmmm mabey I can make something interesting. It does not matter that it is not prototype for any "rivet" counters becuse I model my own HO scale RR. I enjoy as time permits "messing" with models. As I said it will be just some fun. Figure I have already begun cutting up the new Kato model so I should see how far I can take this. U gotta love CN and there massive trains. We get to talk to some of the CN crews where we rail fan and they are very friendly and very proud of there train size. God Bless All
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
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