Hi, Well the thread of multiple sound images from one sound decoder got me thinking. While I can only do one prime mover per decoder, that doesn't mean I can't place two decoders in the same car to handle a second prime mover. I have some visibility at the Roseville yard, and I see that most of the time EMD products and GE products are not intermixed. Is this typical behavior? Do the prototypes, as a rule, not mix locomotives manufacturers? Or is this just an impression form a not to great of a sample size? And if they do intermingle, are there specific lash-ups that are favored or avoided? I know there are prototype engineers on the site, can you guys weigh in? Thanks in advance!
For maintenance reasons RR's will try to group certain locomotive made by one manufacturer together. That cuts down on spare parts inventory and allows maintenance crews to specialize on one manufacturer's locomotives. In steam days some RR's designed their own locomotives or had locomotives designed to handle a specific task. But in the early days of diesels that was abandoned and RR's assigned locomotives based on the total tonnage. They developed tables which told them that for a given total train weight they needed X amount of horsepower. Not much thought was given to maintenance needs as the RR's generally experimented with diesels from different manufacturers and employed them all over their system. That changed as the RR's found that certain engines were better for some routes or tasks than others so they began to move locomotives to areas where they would give optimum performance.
Most of the rules for prototype consisting do not apply to model locomotives. There are rules concerning the number of powered axles allowed for motoring and dynamic braking. There are also rules concerning the number of locomotives in a consist that can be controlled with the independent brake handle. At one time if you were to mix AC traction motor locomotives with DC traction motor locomotives, the AC's could not lead. Now with the traction motor protection equipment, this is no longer the case. All locomotives setup for MU operation will have the 27 Pin Train Line MU cable, so mixing locomotives from GE and EMD is not a issue. At one time a locomotive manufacture you could not MU an ALCO, EMD or GE locomotive with, was the Fairbanks Morse road switchers, they used air operated throttles. One of my home town railroads used switchers and General Purpose units on road trains. all were setup for MU operations. Of course you run into another set of issues when it comes to locomotives equipped with dynamic brakes verses locomotives not equipped with dynamic brakes. In the above photo, P&LE 2060 is not equipped with dynamic brakes, so in turn it cannot control the dynamic brakes of the trailing locomotive. Whereas the 2036 in the first photo could control any trailing locomotive that would have been equipped with dynamic brakes. Of course on the P&LE this was a mute point, because the dynamic brakes on the ex-Conrail GP38's were disabled.
I once saw a NS train with eleven locomotives. Sometimes traffic patterns cause an imbalance in the distribution of motive power and therefore units are 'deadheaded' to where they are needed. In those cases they may under power or be treated as any other piece of rolling stock. I am sure the NS train I saw did not need eleven locomotives to haul the train so maybe eight or nine locomotives were deadheaded.
When i worked as a fireman on the NKP in the summers of the mid sixties while going to college it was not uncommon to have extra locomotives that were operating but were being shuttled to the end of a district to balance the locomotive needs. This was often the result of canceling a scheduled freight or because of extras being scheduled. Since the NKP prided itself on High Speed Service and there were speed limits through most of the towns the engineer wanted all of the power he could have to get back up to High speed coming out of a town. Most would open the throttle while the train brakes were on to overcome ethereally in the throttle getting up to horsepower. It was interesting to go back to the sixth engine to restart it at 50-60 MPH and change a huge fuse. Oh the fun!!
Hi Is there any big issue with coupling different power output/gearing units together? I see the switcher and road unit combo above and I wonder how the speeds and power outputs are matched? Thanks Donald Sent from my D5803 using Tapatalk
Hi Donald, Since they both used the same traction motors, they had the same gear ratios so there were not any issues. Now the railroad I work for had issues when we interchanged some units years ago with the Santa Fe. The units were run on a hot Santa Fe intermodal train and the Santa Fe super fleet was geared for 90 mph. Our units were only geared for 65 mph, the Santa Fe ended up bird caging some of the traction motors. They all had tripped the over speed fault and the event recorder sure enough indicated the units were operating at 90 mph.
That is true sometimes, but there are also times when shops are over whelmed with power that needs serviced and/or repaired. In those cases the units are ferried to another shop. It all goes by shop count, you can't predict where something is going to have an issue. If the shop count is too high at the shop closest to the break down, the locomotive or locomotives will get sent to a shop with a lower shop count. It's just the nature of the beasts.
So my takes is that I can mix an EMD SD70ACe with a GE Gevo and a anything else and it would be prototypical.......
Yes, We do it all the time in 1:1 scale As an example, here is a ES44AC leading a SD70M, in other words a AC traction motor locomotive leading a DC traction motor locomotive. ES44AC is a GE product and the SD70M is a EMD product. https://www.flickr.com/photos/99819826@N08/14261592594
Thanks Rich, for the replies and info. If you end up running a 65 mph rated machine at 90, won't you lose any motive power benefit getting from it to the setup? Does it just kick back in again when it all slows down? Sent from my D5803 using Tapatalk
Gosh, Darn, Persnickety! I'm no engineer but I do come from a family of Rails. We had engineers, fireman, conductors, yard grunts, M.O.W., supervisors, REA agents and a yard master. Does that qualify me? #ell no! But allow me to share. It's always been the rule of road (railroads) to us whatever power is needed, Once a locomotive was serviced it was "Lashed Up" to whatever power was on the property at the time and dispatched as is. Even today, with no consideration for who made what..... they are lashed-up, mu'd and sent out to pull the next freight leaving town. The road foreman's, shop supervisors and locomotive crews and hostlers didn't have time to worry about what is aesthetic, looks aesthetically appealing or even have time to worry about GE's with EMD's. Rule of the day: Mix and match anyway they come out of the shop and keep the freights high-balling down the rails. Watch any video, any train video and you will see units old and new mixed together, GE and EMD, Alco and FM, PA's with E9's, FT's with F3's, F7 with GP7's. Are you beginning to see a pattern here? Anything goes and must go...period. There was absolutely no discretion, no segregation, no rules of consisting uhh...err "Lashing them up" used. "Consisting," where the #ell did that come from? We consist passenger trains but not freight trains. With one exception. Engines or motors geared for passenger service did not typically get mixed with engines geared for freight service....... for obvious reasons. So anything goes, I think I already said that. Yep, I did. First and foremost: It's your railroad you make the rules, you set the standards and you execute the train orders, to include how you want to run your stoves and motors. Now go have some fun. As far as DCC, I'm an official member of the DGAS Committe, having allowed most of my stuff to find the bottom side of the trash can. Who can afford it? Who can replace it? Happy with my Analog DC operations. Never mind all the inherent flaws built into DCC. Harrumph! However, I do like the performance I get with DCC and I will miss the multiple train operations, all off of one power source. So you guys and gals that still have it "Have Fun." The best to you. Besides my jalopy must have heard me talking about the plans for my layout and the monies I was going to spend and decided to sabotage the whole works by surprising me with a blown head casket uhh..err.. gasket. (To many years in the funeral business) I know! Grump, grump, grump. They shouldn't have woke grumpy, up so early in the morning It's Sunday and it should have been a sleep-in day. Harrumph! My feline friends were looking at me like I was breakfast. COL
There was an exception. Engines with pneumatic throttles. I'd guess the most well known were Baldwin diesels. I know that in later years, some were modified so they could MU with non-Baldwin units.
See there's always been an exception to most any rule. However, breaking the rule was always a whole lot more fun then ...well you know. Look...(as in pay attention I'm talking here)... as an official member of the DGAS committee... I don't care what you do. Just do it with all the gusto you can and enjoy the #ell out of this hobby. Let's get back to running trains anyway you want.
Too small a sample size. I drive by Roseville yard multiple times a week and while the DC SD70Ms are not regularly mixed with AC units, the GE and EMD AC units are mixed all the time. And even those mentioned DC units would occasionally run with them. Typical consists coming through Roseville could have ES44AC, AC4400s ET44ACs SD70ACe. Most of the 70Ms are laid up, but I have recently seen stack trains running with multiple 70Ms.
