The May 2015 issue asks the question whether it’s SD9043MAC or SD90/43MAC.
Today I had an engine (SD70ACe) that’s equipped with EMD’s “Smart Consist” fuel saving system. (Most of us, including some managers, wouldn’t use the word “smart” to describe it, but that’s for another time.) In a nutshell, Smart Consist controls the lead engine plus up to 2 trailing engines. The system determines when the engineer throttles up or down, how to divide the load between the engines to get the most fuel efficiency.
Anyway, to enable the system you have to enter the trailing unit model designation. You do this by choosing from a list of models, both EMD and GE. (Being an EMD offering, there are a lot more specific EMD models. Going back to include the GP9.)
While enabling the system this morning I had to go through the list. I noticed it had the slash, SD90/43, in the listing. I don’t remember now if it had AC or MAC behind it. I’m thinking it didn’t.
While I’ve seen the slash in the designation before, I’ve seen it more often without the slash. Now those editors favoring the slash can reopen the discussion.
Jeff, if I hadn’t seen the question in the magazine, I would have envisioned a topic that involved somebody in a hockey goalie mask and some clueless college kids in a spooky house.[:D]
The use or not of a slash is one of those topics that could be the subject of great debates over something of little importance. Just one opinion, though.
The interesting thing is that any version of SD9043MAC really doesn’t need to exist. All of the 6000 HP units were classified by EMD as either SD90MAC-Hs or SD90MAC-H IIs as they had the 265H engine. Since all of them have been retired in North America, there really is no reason not to simply call the convertibles what they were originally designated by EMD: SD90MAC. It is interesting that UP apparently found differentiating the variants troublesome enough that they classified all of the 4300 HP units as SD9043MAC.
I don’t know about EMD’s practices, but I have seen times when even the manufacturer of a product cannot settle on what character to use to separate terms in a model number.
You will notice that the programmers of the system used here, solved the problem of deciding whether to use nothing between the sections of the “model number” terms, or to use a slash, (and whether a “Forward slash” like this, “/”, or a “Backslash”, like this "") or a dash, or an underscore, or a space, or a period, or a comma, or any other character that humans tend to use, at random and interchangeably, as a separator of terms, by giving the user a “list” of acceptable responses. It is MUCH easier to rely on the human to recognize the equivalences of the various forms than to anticipate what possible characters might be used by the human to type in the model number, and then write software code to recognize them all (so as to not get yelled at because someone’s favourite character for doing so was not recognized).
And don’t get me started on the people that don’t give a thought to using a string of characters that contain ambiguous shapes between numbers and alphabetics, such as “0” and “O”, or “l” and “1”. These ambiguities are maybe not important when a human is reading it, but to a computer they are as different as “0” and “1”, or “4” and “W”.
This reminds me of back in the 1980’s or so, when Trains Editor David P. Morgan changed the style of designating the wheel arrangement for articulated steam locomotives from the ‘pure’ Whyte style to one that was more logical to him, mainly by using a “+” symbol to designate the articulation point. For example, consider a N&W Y6b:
It started earlier than that, I believe around the time Kalmbach was reprinting with great hoopla Lionel Wiener’s book ‘Articulated Locomotives’ – in which Wiener gives great care to the syntactic conventions that express different methods of articulation. How influential Le Massena might have been in trying to get this + adopted for a hinged articulation is unknown to me; long before my time. But it makes enormous sense:
4-4-6-4 = rigid-frame duplex drive
4-6+6-4 = Mallet-style articulated chassis hinged between the engines
4-8-4+4-8-4 = simple way to express a Garratt chassis in extended Whyte coding.
Think of the fun you would have trying to illustrate a double- or "Super-"Garratt (which is a couple of Mallet-style chassis with the Garratt boiler arrangement between them) with nothing but the dashed notation:
2-6-6-2-2-6-6-2
vs. what Wiener might suggest with the parentheses:
(2-6+6-2)+(2-6+6-2)
that clearly shows you have three articulation connections.
Now, if I were doing a set of taxonomic conventions for this sort of articulated, I’d want more conventions than just + to show different kinds of articulation, for starters something that distinguishes Garratts with no pony wheels on the ‘inner ends’ from Mallets. (I am the sort of person who would like to have conventions distinguishing double-axis hinging of a Mallet forward engine from Alco-style hori
Paul, I think it was in the fifties that Dave Morgan commented on the matter. But, you know my memory. It was when I was quite new to the expanded world of knowledge that the magazine presents.
I don’t understand how the throttle decision is made. Assuming the engines are close to the same horsepower, does the system sometimes run one engine is notch 6 while the other(s) is at idle? Does the system have information regarding total train tonnage or route profile – presumably both of those are needed when PTC is implemented.
Today I had an engine (SD70ACe) that’s equipped with EMD’s “Smart Consist” fuel saving system. (Most of us, including some managers, wouldn’t use the word “smart” to describe it, but that’s for another time.) In a nutshell, Smart Consist controls the lead engine plus up to 2 trailing engines. The system determines when the engineer throttles up or down, how to divide the load between the engines to get the most fuel efficiency.
I don’t understand how the throttle decision is made. Assuming the engines are close to the same horsepower, does the system sometimes run one engine is notch 6 while the other(s) is at idle? Does the system have information regarding total train tonnage or route profile – presumably both of those are needed when PTC is implemented.
Progress Rail has a PDF touting the benefits of the Smart Consist system, but cagily avoid disclosing any details of the algorithm used except to provide a cryptic graph showing specific fuel consumption ‘gains’ overlaid on throttle position. The system provides fuel gain of “1 to 3%” – which may not look like much but is substantial over time, and probably represents much more significant fuel economy during certain relatively short periods like acceleration into sags. (I would also expect that the ‘fuel optimization’ algorithm would be tied into pollution-reduction algorithms, such as slow changes in fueling for engine acceleration, and perhaps traction-alternator field modification.)
It is not too difficult to develop an algorithm to ‘optimize’ engine throttle position if the sfc o
Yes, you can have one engine loading while the other engine isn’t. (I’ve so far only used it when I was only allowed two engines on line due to fuel conservation rules.)
I don’t think the system knows anything about tonnage or grade profiles. There is nothing programmed by the engineer, unlike the NYAB’s LEADER system. (Another winner[:-^].) Usually it seems to drop the load on the lead engine. Generally, it has the lead engine stop loading about notch 4 and it won’t start again until notch 6. Many of the newer engines have a consist monitor. You can see not only how the lead engine is loading, but also how the entire consist is doing. Without that feature, you’re just hoping the other engine(s) are still working when it decides to drop the load on the lead unit. (Note, the other engines also have to have that feature to work on the lead engine.)
I didn’t know that Smart Consist only promises 1 to 3%. At least that’s more honest than the LEADER. When it was rolled out, LEADER was supposed to deliver 11% fuel use reduction. I read somewhere that it was actually in the “high single digits.” They wouldn’t come right out and say the actual percentage, but it was still described as a huge success.
The other day I heard another engineer tell Loco Mtce his LEADER system wasn’t working. He said the system wanted to go slow (5 to 10 mph under authorized speed) where it should go fast (authorized speed) and wanted to go fast where it should be starting to slow down.
It was all I could do to not break in over the radio and say that’s how it always works.
Still a bit short on ‘hard’ technical information, particularly about the rather interesting use of lines in the 27-pin MU cable to carry relatively high-speed data, but still very useful. Note that one of the specific ‘optimizations’ is to reduce noise in the cab (perhaps the result of ‘focus group’ analysis from road-slug users?[}:)]) which is almost surely the principal reason why the lead unit is observed to load less than the others in a consist.
There are few things more annoying than automatic ‘assist’ systems that can’t be relied upon to do the right, or the safe, thing at critical times. This is what I look at as the chief problem with things like NAJPTC, and with the upcoming mandated versions of PTC so far: if they can’t be trusted to do the ‘right’ or the safe thing consistently, they’ll cause more ‘unsafety’ than they help (as crewmembers burn out having to constantly worry and second-guess what the system is telling them). I understand that older versions of Microsoft Windows were infamous for doing this.
There are EMD advertisements from the late 40’s and early 50’s, that include a dash in model designations like the GP7. So nothing new for EMD to not stick strictly with their own standard.
Probably made a tiny bit of sense in this case, at the time this software was in development. It wasn’t the impossibility that it is today that they’d have an H engined SD90MAC in the consist. This logically differentiates between two types of locomotives with greatly different capabilities, where the common factory model designation doesn’t.
Le Massena was behind this switch at Trains from 1982-1987.
“American either did no read Allen or Wiener or was not impressed until a non-tradesman, Robert A. Le Massena, dropped anchor (Or should we say hyphen?) in his Articulated Steam Locomotives of Amerca and urged TRAINS to follow suit.” - May 1982 Trains
Happily, they soon tired of the confusion and complaints, and of course eventually killed this nonsense off. Nobody likes reinventing the wheel when it’s unnecessary. There was no confusion that something like 4-6-6-4 referred to an articulated wheel arrangement (Granted, there are duplexes and other isolated examples, where it could legitimately be of use to a novice steam fan).
If you are wondering, this is the historical reference:
Were you capitalizing for emphasis, or as an illustration of how to denote groups of powered axles?
It could have been worse. For those familiar with Alfred Bruce’s book ‘The Steam Locomotive in America’, either the author or his copyeditor decided to leave ALL punctuation out of the Whyte code references, perhaps referencing a French system but with wheels instead of axles. A Berk, for example, is “284”, and a Texas type ‘2104’. A Super-Garratt in this system would be 26622662. Pass the Anacin.
[Note to Kalmbach IT department: Smileys do not render correctly in quoted text, and now I see that text attributes like size and weight don’t, either. I’d be surprised at this, so many years into the 21st Century, except that I see places like Yahoo Groups suffering with even sillier and more egregiously slipshod problems. Is this an endemic problem with some Web-site ‘design environment’ packages?]
This is where a modified Whyte-Wiener system would shine: A Mallet-Garratt would be classified as a 2-6-6-2+2-6-6-2. I’ll stick to the vagaries of diesel wheel arrangements, much easier to understand.
