I'm trying to build an HO scale model of a freelanced locomotive I have dreamed up, anyway I am trying to create a "prototype" explanation for the unit and I thought I'd stop in here to gets some other opinions...
Steve
If everything seems under control, you're not going fast enough!
NWP, it strikes me you'd be better off asking on the "Model Railroader" Forum, but let me say this. It's your model on your HO layout, so in the end you only have to please yourself. If you want to let your imagination run wild go for it!
If the locomotive looks strange or "cartooney" come up with any kind of blather you want to explain it. "Those aren't just dynamic braking grids, they're industrial strength toasters!" "Ever hear of Geeps with top mounted air reservoirs referred to as 'torpedo boats'? Guess what, those are real torpedoes!"
Get the picture?
True, but I'd still like to explain the types of Prime movers are in it and how many there are... I've started a thread on the MR forum already but I'm trying to get other opinions...
I don't know, you can't see the prime movers "under the hood" anyway, so I was thinking more in the line of external appearances.
Hey, how about an ALCO PA nose and cab on a Dash-9 body over a Baldwin "Centepede" frame and running gear? You can say it came out of "Rocco's Custom Locomotive and Chop Shop!"
Who knows? You might get people interested in what "Rocco" comes up with next!
A lot of the folks on the MR Forum tend to be "It's prototypical or it's nothing!" rivet counters, but there are some like "Broadway Lion" who have a good sense of the outlandish and ridiculous.
You may want to have a look at the "Classic Toy Trains" Forum and ask there. Now WE on the CTT Forum know how to play with trains! Prototypical operations come secondary to FUN!
I'm mostly concerned about the sound of the thing not so much the details under the hood... my idea is a B-D-B-B-D-B wheel arrangement with a NYC p motor style body made from old alco PBs oh and two Trainmaster style deck boxes that'll act as span bolsters for each B-D-B set of trucks...
Wrong Forum...go to Model Railroader
NWP SWP I'm mostly concerned about the sound of the thing not so much the details under the hood... my idea is a B-D-B-B-D-B wheel arrangement with a NYC p motor style body made from old alco PBs oh and two Trainmaster style deck boxes that'll act as span bolsters for each B-D-B set of trucks...
Sound? Uh, you're on your own there, but for what it's worth I added a Bachmann diesel sound package to my silent Williams O gauge FM Trainmaster. I used the EMD 567 engine sound unit. Hey, they didn't have an FM OP engine unit and I had to go with something. Hey I like it, it sounds diesel-ly enough.
Oh, and by the way, welcome aboard!
He started a thread in MR forum two weeks go: http://cs.trains.com/mrr/f/88/t/266905.aspx?page=1Regards, Volker
I'm here to get ideas for the "prototype" for my creation, why was it built, the PMs, ect... NOT to build a model...
Just make sure all your tunnels are reinforced before Big Bad John goes in.
You would not want to have a tunnel collapse on Big Bad John.
Oddly, I now have a craving for a Jimmy Dean breakfast sandwich.
I agree with Firelock about using EMD 567 recordings, one simply cannot beat the supercharged 2-stroke for sound. Your unit also sounds big enough for more than one prime mover.
Which gave me an idea for a Franken-locomotive of my own, a EMD-powered Centipede:
In my mind's eye I see it riding on four (4) Blomberg A1A trucks (2 connected by a span bolster at each end) and hear seven (7) V6 567 engines screaming away, one of which is for Head-End Power, giving the unit 3600 HP for traction.
The story behind this unit is that the railroad had already purchased Baldwin Centipedes, but quickly found them to be unreliable. They derailed on curves and switches due to their long, rigid wheelbase and the Baldwin diesels broke down frequently. Despite this, the railroad wanted high-horsepower multi-engined passenger locomotives, as they had long, remote runs and a union contract which required a Engineer and Fireman in each locomotive, even on diesels MU'd together.
The solution was to rebuild their Centipedes from the ground up, with new running gear, engines and electrical systems. The multi-engine design let them assign a single locomotive per train (sidestepping the crew issue) while still having redundancy in case of a engine failure. EMD trucks and engines were chosen due to their reliability.
Oh, and the units were also rebuilt with Sharknose cabs .
[Disclaimer: I have no idea if one could actually cram seven V6 567's into a Centipede, but the number sounded cool!]
EDIT: having gone over to the MR forum and read your thread there I see you are pretty far along in the design, but hope this helps. Crew-size regulations were a real-life reason for some outlandish and unconventional locomotive arrangements.
Greetings from Alberta
-an Articulate Malcontent
Here's a few pictures to help visualize...
1 the trucks I'd like to use... I'm using these because I cannot find both B and D trucks that are the same in design. (If you know of a 1940s/50s era trucks that are the same design just ones B trucks and the others D trucks please post it)
2 a drawing of the body styles I'm trying to pick.
3 a paper mock up of the unit not to scale.
A few more thoughts:
The first body style in your sketch will most likely limit you to one large prime mover due to the body's smaller size (looks like you have dual cabs?).
For sketches 2 and 3 it would be wise to articulate the carbody, or it will stick out excessively when going around curves, just like the boiler on a Challenger or Big Boy, and may hit things beside the track it is on (UP 3985 had a bad experience with some coal cars when it was first restored). For this point I am assuming that the span bolster attaches to the frame at its centre, between the middle two axles of the "D" truck.
Sketches 2 and 3 should easily accomodate more than one prime mover, you could probably fit 4 ALCO 6-251 or 539 engines in the third one, which would produce around 4000 HP.
As has been mentioned already in the other thread FM engines are quite tall, and would not be a good choice if you wish to have a PRR-style quill drive, with its relatively tall, spoked wheels.
If you want a single prime mover I would suggest a 18-cylinder ALCO 251, for its sheer power and outlandishness, but if you are going for mulitple diesel engines I would suggest smaller ALCOs, perhaps several 6-cylinder 539s which your railroad has salvaged from older switchers.
Could the quill drivers be smaller?
If not how bout the Bipolar drive?
What about two Alco V16s or four V8s?
Are there any trucks that are of the same design from the 50s in B and D types?
I would prefer not to articulate the car body...
There is no reason the quill drivers have to be larger than diesel wheelsets, but in most real-world applications they were. Probably a result of locomotive designers thinking with a steam mindset. Your railroad could have purchased smaller quill drive equipment but it would likely require some custom parts and engineering, and drive up the project cost for no real benefit.
I saw on the other thread that your locomotives are rebuilt Milwaukee Bi-Polars. Their traction motors were mounted directly on the axles, so there would be no pre-existing quill drive to re-use.
As was also noted in the other thread bipolar motors are inefficient, and a diesel locomotive with them would be inefficient and seem quite underpowered, especially compared to EMDs, ALCOs, FMs etc in the 1950s.
The most cost-effective real-world propulsion solution would be some off-the-shelf geared traction motors. EMD, GE and Westinghouse are the top 3 choices (ALCO used GE motors, FM and Baldwin used Westinghouse). GE would be the logical choice, as they originally built the MILW Bi-Polars and would most likely be able to produce equipment that would fit the running gear.
Two large prime movers or four smaller ones should fit nicely inside the full-length boxcab sketch, and if your railroad had previously operated large, articulated steam power clearances are not a concern, as long as the "new" diesels confrom to the same clearance limitations. With that there is no need to articulate the carbody.
I am also drawing a blank on "D" truck designs of the 1950s, but it would be wise (and cost-effective) to re-use the "1B" lead trucks from the Bi-Polars, and then obtain additional "B" trucks from another source.
Or reuse the D trucks from the Bipolar and modify the 1b trucks to just B trucks...
NWP SWP Or reuse the D trucks from the Bipolar and modify the 1b trucks to just B trucks...
That too.
And remember, nothing is set in stone here, after all it is your railroad and your locomotive. I am just raising some points that would most likely come up in a real-world setting. Dream away!
But it would be wise to use a "B" truck with a wider space between axles for greater stability, as opposed to simply chopping off the lead axle from the Bi-Polar "1B" truck. Note the difference between axle spacings on this Great Northern W-1 (B-D-D-B), for precisely that reason:
NWP, in case you haven't gathered it yet, with the SD-70 Dude you're working with a real railroader. I don't know if the 'Dude models but I sure like the way this thing's going!
I just had a thought. If "Big Bad John" doesn't work out it could make a great centerpiece for a gag scene on the layout, say the interior of the erecting shop where "John" has been put together, but he's too big to get through the doors! Kind of like a guy who builds a boat in the backyard but can't get it out past the house!
From here I think I'll just sit back and watch! Have fun boys!
Firelock76 I don't know if the 'Dude models but I sure like the way this thing's going!
I don't know if the 'Dude models but I sure like the way this thing's going!
I have a decent collection of HO-scale equipment and track, but have never gotten around to building a proper layout. On occasion I will set the stuff up on the floor, but for some reason model trains attract Catzilla, so I can't leave it.
I do enjoy the 1:1 scale equipment we work on at the Alberta Railway Museum, my volunteering now takes up most of the time I could otherwise spend modelling.
One of our Basset Hounds, Tillie, used to play Dogzilla with the floor layout under the Christmas tree, but only to the extent of slinging her 80 pound butt on the main lines and going to sleep!
Ballad of Big Bad John:
https://www.youtube.com/watch?v=KnnHprUGKF0
I am familiar with the Ballad Of Big John...
SD70Dude NWP SWP Or reuse the D trucks from the Bipolar and modify the 1b trucks to just B trucks... That too. And remember, nothing is set in stone here, after all it is your railroad and your locomotive. I am just raising some points that would most likely come up in a real-world setting. Dream away! But it would be wise to use a "B" truck with a wider space between axles for greater stability, as opposed to simply chopping off the lead axle from the Bi-Polar "1B" truck. Note the difference between axle spacings on this Great Northern W-1 (B-D-D-B), for precisely that reason:
One of those two GN electrics pictured above was bought by UP for a coal-fired gas-turbine experiment in the early 60s. It was scrapped after a few road tests. It is pictured in thw Second Diesel Spotters Guide, on page MISC-431.
I have an idea for fuel bunkerage how bout just giving it a tender... Also I'm kinda sold on the boxcab body style just not the configuration yet...
What I actually was hoping y'all would give Steven was a prototype explanation for the kinds of service that would justify a locomotive of his design.
As an example: Batchelder drive was optimal for certain kinds of passenger service, as it is essentially silent and requires very little ongoing maintenance. There's a reason MILW rebuilt theirs in the '50s with roller bearings, but no change in the drive. I do not think the relative inefficiency of the motors (due in part to the larger air gap, straight pole faces, etc.) is that much of an issue when you get into the hyperbolic constant-horsepower part of the curve; starting torque and low-speed operation would be compromised by the lack of practical forced cooling, so you have an engine that might be good for transition-era 'intermodal' trains.
I wonder if the 6-567s would 'fit' in the general clearance diagram of the Essl Baldwin locomotive, and if so, whether they could be mounted on 'sleds' complete with radiators and other cooling shaped to carbody profile -- interesting use of the small crankcases as the need for switch engines decreases, which gets around at least some of the cost issues that sank the marketability of the Essl design. I have to admit that I chuckled at the idea this could give rationality to a turbocharged version of the 6-567...
You don't want a quill drive with low drivers, even if wheels with the necessary structure to accommodate the spiders were still legal for new locomotive service. Use something like the Brown-Boveri disc drive which is correct for the era, or if you are a glutton for punishment one of the French systems like floating-ring with Fabreeka/composite 'silentblocs' instead of straight rubber. For better or worse the drivers on the PRR V1 turbine, which was mechanical shaft final drive, were 40" -- it would probably have been wise for PRR to invest in Hegenscheidt had they actually built any number of those.
The situation with FM OP power is interesting, and adaptive reuse of the Milwaukee chassis components 'intact' may make better sense here (as taking the buff and draft through the chassis leaves no longitudinal 'stressing' in the cab and engine framing. which might allow relatively low deck height or even a dropped section for the lower crank clearance). There is relatively little reason a turbocharged adaptation of that engine is more difficult than other contemporaries; in fact, the engine as built today regularly produces over 8400shp ... just not for locomotives; the group that builds them, apparently, specifically forbids use of 'their' engines in locomotive projects. I don't know whether the Elliott approach tried by UP (multiple smaller units) would have worked cost-effectively in the transition era ... or whether there would have been alternative markets, e.g. in OTR trucking, that would bring the per-unit cost of appropriately-sized turbos into feasibility. Of stuff like this is imagineering made!
I don't think there is any point in having a nonarticulated carbody on something using a bipolar underframe: the structure itself required articulation in three parts, and a considerable amount of new fabrication might be needed to relocate the pivot and sliding points to work with a longer central 'boxcab' or carbody. I would not lose the single-axle engine trucks on the outer chassis; these would NOT benefit from Batchelder drive and there is little point in even considering putting a geared traction motor, cooling ducts, etc. on them.
Any fuel tender on a diesel locomotive will be treated either as a MATE or as a road slug would be; it would have motors under it, with appropriate derating as the 'contents' were used. These would likely be geared traction motors with appropriate low-speed derating characteristic, and would have all the limitations of contemporary traction motors of that design (such as the need to cut armature current going over crossovers or rough grade crossings due to carbon-dust shakeout or brush bounce).
It might be remembered that the Essl/Centipede chassis was designed to be inherently capable of extremely high speed with a minimum of chassis length (see the Kiefer 1947 report on motive power) - if you don't need those advantages, the heavy but precise cast underframes aren't helping you much compared with the light fabricated Batchelder equivalent. By 1948 Westinghouse had essentially standardized its 'game' all the way up to 7500hp continuous with nothing but one common "B" truck, and modeling this with existing locomotive chassis is drop-dead simple even if he needs some custom sideframe modifications. (Of course it's not as cool looking as a bipolar chassis, or as effective as a bunch of EMD cab units and boosters ... but it's there and was only modified in practice by the use of effective trimount C trucks instead of Bs...
Overmod What I actually was hoping y'all would give Steven was a prototype explanation for the kinds of service that would justify a locomotive of his design.
I was hoping you would show up here.
He seemed to be pretty far along in his thread over on the MR forum, his railroad wanted a locomotive that could run through from one end of the system to the other (which explains the fuel tender), drawing power from the wires when in electrified territory and using the diesels when elsewhere. It also seems they got a good deal buying the MILW Bi-Polars, hence the running gear. I assumed that his railroad has the long, heavy through trains that would require such a powerful locomotive.
The union/crewing issue I raised earlier could account for the desire to build a very large single-unit locomotive, as opposed to simply MU-ing many smaller diesels together.
SD70DudeI assumed that his railroad has the long, heavy through trains that would require such a powerful locomotive.
But long, heavy trains per se are not the right use of the Batchelder drive (dramatic demonstrations pushing three steam locomotives backward not being that difficult to accomplish when you think about it a bit). The armatures are not force-cooled and cannot be; as noted, the pole gaps have to be large enough to permit suspension action and the pole faces must accordingly be straight and not curved around the armature. There are also only two active poles at any given point in armature rotation, although there can be relatively many armature sectors in reaction, so also as noted the peak power developed by each of the motors is restricted. There is also a fairly large lateral shock moment due to the unsprung mass of the armature being very low, so his civil people have to be 'up on' extremely good spiraling, no abrupt lateral changes at frogs or in higher-speed crossovers, very quick fixing of kinks, etc., and I suspect his railroad will be an early adopter of Pandrol fixation or similar means of elastic rail control when it becomes marketed in the transition era.
On the other hand, the '50s rebuilds gave him full and fairly new roller bearings throughout, and I suspect most of the wiring problems with the rebuilds apply more to the HVDC and not to the motors. So he has a clean, low-maintenance articulated chassis that runs silently at what can be high sustained speed, one that with a little care installing auxiliary resistive brushes might have substantial brush life compared to even enclosed motors. That, to me, indicates he has NYC&StL-like bridge trains, that can be 'fleeted' even over single track to permit high end-to-end speed without slacks or checks, and perhaps that he has the correct arrangements approaching and within yards and junction points to keep dwell low even with the size of consist that matches the locomotive developed power -- hence the emphasis on intermodal service, used wisely and well. It occurred to me that this locomotive does what a consist of Alcos with Hi-Ad trucks could do, without the harmonic rock and other issues, and even in late transition era it's reasonably competitive with what, say, the equivalent hp in something like GP-40s might produce.
The alternative, which I proposed he think about, is to use the chevron-sprung welded-frame trucks seen on some of the GP40X locomotives, or more effectively on the GM10B electric. While these are a bit later than his transition era, a couple of GM10Bs' worth of those B trucks (as noted, the general equivalent of a freight-geared Rc-4/AEM-7 truck, with DC motors as built) are going to give you all the high-speed horsepower to the rail you could use, are inherently suited to operation under catenary with high instantaneous power, and share many components with follow-on passenger power for him. It struck me as perhaps significant that the truck structure is relatively easy to model, and of course eBay often has truck parts or electric-locomotive models to give him a starting point on the hard part of his actual construction.
The issue with fireman crewing is a reasonable piece of 'verisimilitude' and is precisely the sort of thing I wanted to see people raise for Steven to think about. Note that the absolute weight of the consist was never the issue there, but lying about the consist weight (think Alleghenies!) definitely was. I was concerned at the outset that even though he has a pretty large locomotive, it isn't a massively powerful one; with your suggested powerplants it's about on a par with a good set of F units -- and he needs it to be capable of more than that set of F units, helpfully financed by GM with equipment-trust bank access relatively easy because of the demonstrated fungibility of the Fs in other service, would provide him.
Now, I suggested to him that he follow up the Hamilton, then Lima-Hamilton, then Baldwin-Lima-Hamilton idea of using free-piston gas generators to provide much more peak horsepower (with better fine control over incremental fuel consumption at part load) in a locomotive with plenty of TM capability. If he can solve his way around detuned intake noise he could easily get a match between TM rating and developed 'engine' horsepower at any speed or load; I leave as a solution for the alert reader how you'd make it MU-compatible with a 'digital' Woodward-governor relay control setup...
The nice thing about Imagineering is that you can change reality if necessary, in this case one can re-size the railroad to better suit "Big Bad John".
If the Bi-Polar electric drive is better suited to fast priority trains, then I guess that's what the NWP-SWP runs. And though the engines I mentioned may not be any more powerful than a set of F-units, how many railroads regularly used more power than that on even their priority trains?
When did ALCO first start producing V18 251's? Two of those would fit in his long boxcab sketch, and provide well over 6000 HP.
If even more power is desired then the turbocharged FM's or some sort of turbine setup would be best, UP's largest contemporary gas turbine was rated at around 8500 HP. Relatively constant high speed (high load) operation would likely mean better reliability from the FM's, and less fuel waste (while idling) from the turbines.
A desire to use a fuel other than diesel would also be a good, real-world reason to go for a turbine powerplant.
Also fuel tenders would be readily available from recently retired steam locomotives, and I believe this how UP got the tenders for their turbines.
Well the NWP-SWP System runs from New Orleans to the west coast all the way to the top then on to Chicago...
Could theoretically jet turbines be used in the locomotive? Being fueled by aviation fuel?
Overmod, I really appreciate your help, but some of the stuff your saying is going over my head could you try to explain your ideas in layman's terms?
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