Glad to khow the I-5's problems were correcte. They must have been when I rode behind one on the Yankee Clipper, Boston - GCT late August 1948. The lightweight parlors had not been delivered, and our camp group rode in the old six-wheel heavyweight variety, while the 8600 lightweigths were the coaches. A fast on-time ride, with only six minutes for the engine-change at New Haven.
The N&W J's and the New Haven I-5"s were the best-looking streamlined steam in my opinion.
JuniathaOh btw coming back on your asking what reference to balancing : I checked through the Johnson pages you linked - interesting but you can clearly tell how far back it all dates , I wouldn't recommend to use it for any engineering purpose today , there are much better present day methods that can be applied since the engine unit of a steam locomotive is but another - somewhat special - form of a piston engine.
Ever so correct. (Of course, we also have to remember that Johnson was from that certain suburban-Philadelphia locomotive works that is Not To Be Mentioned by Alco people...) What he's describing is the procedure done most cost-effectively by contemporary railroad outfits (and at least one build-to-a-price builder!) that accomplished results tolerable in American practice.
As Johnson somewhat cryptically notes, many Europeans were waaaaay in front of general American practice when it came to care in balancing -- which for steam locomotives more than almost any other type of locomotive ought to involve dynamic balancing. Many shops had balancing machines of reasonable sophistication -- even in the old days of mechanical indication of runout. Even before we get into adapting IC-engine balancing theory to the special case of reciprocating steam, we can consider the use of modeling software, FEA, and the like to plan and design as precisely as needed.
I'd be delighted to look at the dynamics of a high-speed Mallet chassis (see how cleverly this gets around the whole issue of expansion!) both running 'forward' and 'backward'. If there is ever a reciprocating-steam renaissance at the scale of two 4400-hp diesels coupled cabs-out, it would most probably involve a Mallet chassis -- so yes, this is far from a completely-dead topic. (imho at least)
RME
Hi Overmod
Thanks for exhaustive reply - however , it was just a joke ! Nobody - including me - would have suggested an articulated version of but an eight drivered power !
Oh btw coming back on your asking what reference to balancing : I checked through the Johnson pages you linked - interesting but you can clearly tell how far back it all dates , I wouldn't recommend to use it for any engineering purpose today , there are much better present day methods that can be applied since the engine unit of a steam locomotive is but another - somewhat special - form of a piston engine .
We would maybe have to get into discussing that topic of how a Mallet - disregarding steam expansion mode for this - behaves as a vehicle and what the flange forces are in curves in fwd / bwd running . You must forgive my sometimes letting go topics that tend to become controversial because I'm not here to have issues with other users but to have some fun discussing steam and so I prefer to let everyone believe what they treasure to believe - wrong or right - as long as they don't become insulting . After all , nothing is gained by proving something to someone that he (she) doesn't want to see , and it's of no purpose since the engines discussed are long since gone - never to come back .
Regards
Juniatha
Juniatha ... uhm , what about making it a 2-4-4-4 SE Mallet ( not Duplex - o-m-g what do you think !? )
... uhm , what about making it a 2-4-4-4 SE Mallet ( not Duplex - o-m-g what do you think !? )
It's an interesting idea, but I think the gains from the flexible wheelbase and lighter running gear would have been substantially outweighed by the higher costs, including those for all the flexible piping (e.g., same number of joints as a large 2-6-6-x or 2-8-8-x). You'd also have to make the drivers high enough that the main rod angularity would remain tolerable (note that most Berks, 6-coupled articulateds, and so forth drive on the third coupled axle) and you would have to do some VERY careful management of swing of the forward engine. The specific Alco method (of using carefully-ground contact plates to eliminate any vertical motion of the forward engine's chassis relative to the rear) would be needed. I presume you are familiar with the history of the Santa Fe Mallets with a four-coupled leading engine (and 4-wheel lead truck and 73" drivers). That was a suspension and guiding disaster, but not all the 'fault' could be attributed solely to the large pistons and low steam pressure.
On the other hand, the equalization would be similar in kinetics to one of the early 8-coupled locomotives which 'broke' the continuous chain of levers at the middle of the rigid wheelbase (as all the revised T1 suspension layouts did). I honestly do not know whether that experimentation (you can see a number of examples in the MR Steam Locomotive Cyclopedia or that "100 years of steam" commemorative book) was a success -- it appears to have become a design 'fad' in the early years of the 20th Century, and then almost completely died out. Personally, I think it is a VERY good idea for implementing equalization on anything that is divided-drive with short driven wheelbase -- meaning that it does deserve some consideration as an alternative to conventional duplexes of comparable size and capacity.
I would have to run some calculations and perhaps even simulations to see whether that arrangement could be run with minimal overbalance. (BTW: I find I only have a partial reference to the JILE (Journal of the Institution of Locomotive Engineers) report on the class 36 and 38 balancing, but here is the page:
It can be enlarged if necessary to read it, and anyone with ATHENS access can read the whole report.)
Lateral control of yaw in the forward engine is the principal issue, I think (the rear engine having so high an effective polar moment of inertia). It would be pinned relative to the rear engine, at the appropriate "Bissel" pin location, so some form of lateral guidance relative to the rigid chassis would need to be provided, and it would need very good restoring force close to center, but also very wide lateral travel on slower curves. I'm thinking that some sort of clutchable arrangement, perhaps activated on demand by air, would allow the lateral device to be switched effectively between modes. The lead truck also helps steer the front of the articulated engine, and of course easily handles any cross-level issues that might otherwise require careful attention to the leading-driver gauging and flange profiles.
I'd think it would at least solve some of the stiff-rigid-wheelbase issues the J encountered, although it would still likely be at least as sensitive to cross-level or 'dip/sag or hump' concerns as a J due to the longer effective 'rigid wheelbase' in pitch.
Hmmmmmm...
Thanks for the response Leo! I had no idea the I-5's were so "buggy", but I guess even someone like Baldwin could have something not quite up-to-snuff slip through the cracks. Obviously nothing that couldn't be fixed, but I'm sure it was embarassing.
Hi Juniatha! The 4-8-4 on Saluda Grade was N&W's 611 during its excursion career. It was NEVER intended for use on 4%-plus grades. As a matter of fact, Saluda's on the old Southern Railway, not the N&W. Why'd they do it? I don't know. Showing off how good 611 was, maybe? Because "why the hell not?" Who knows?
Firelock76I hadn't heard there were problems with New Haven's I-5's. Do you know what they were?
They were well liked and capable machines.
But they had severe frame issues due to some design and manufacturing problems that were expensively cured when it was later discovered. And the streamlined nose cone trapped in excessive heat causing trouble with the insulation of the wiring to the headlight melting and shorting out. But that too was cured by installing wiring suited to the heat. And their turbo injector that was installed in place of a feedwater heat was inadequate when steam demand was high. And five of them had a different type of roller bearing for their driving wheels that was causing wheel centers to work off their axles but that was cured when it was discovered by changes to their axles.
I suspect though that he was referencing their inadequate counterbalancing that caused serious vertical pounding. It was especially bad when they would slip at high speed. And besides the ride quality, it would cause serious track kinks when the drivers would be lifted off the rails and crash back down. It got so bad that they installed valve pilots to help engineers and in order to analyse the tapes so they knew when and where they had to replace rail.
Ultimately the problem was resolved by rethinking their counterbalancing. Standard Steel, Baldwin, and New Haven cooperated to cure their problems and they settled down in high speed service like other Hudsons afterwards (Or "Shore Line" if you want to use the New Haven's official name for them). That the problems were successfully addressed is often forgotten these days when this class is mentioned. Some are under the impression that they had speed restrictions and such right until the end but they in fact handled the fastest assignment on the road due to their rapid acceleration until the very end of New Haven steam.
A 4-8-4 on a 5 % grade ???
Well , dunno what that experiment was to prove , yet for crawling up the mountain sides at right angle *any* additional driven axle should be of help - however , wouldn't a 2-12-0 have been better suited - or rather a 2-12-4 tank engine or 2-12-2 rack tank as the Austrian 297 series that once roamed the Erzberg line ? In a 4-8-4 with twelve wheel tender 4 axles of 14 all together are powered , a relation of 0.286 ; maximum reliable adhesion on dry rails was 0.25 for steam , makes 0.0714 or 7.14 %
Btw what was the incline of the Erzberg line ? see http://de.wikipedia.org/wiki/Erzbergbahn
--> 7,1 % - no further comment needed .
= J =
Overmod >> I can't help but wonder whether N&W would have developed (for its new acquisitions) "2/3 of a Class A" as a Berkshire design. THAT would be an interesting locomotive. <<
.. that would then have been the 'a' class , presumably ?
erikem Overmod Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2... Minor correction, the 2-6-6-2 was the last steam locomotive built by Baldwin for an American railroad, IIRC Baldwin built some steam locomotives for India in 1955....
Overmod Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2...
Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2...
Minor correction, the 2-6-6-2 was the last steam locomotive built by Baldwin for an American railroad, IIRC Baldwin built some steam locomotives for India in 1955....
You are right, and I stand corrected. In fact, an even better thing would be to say 'very last reciprocating steam locomotive for the United States', as BLH was responsible for the 'locomotive' aspects of the N&W TE-1 turbine...
Overmod Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2, to a very old fundamental design but with some modern 'conveniences'. Would a similar locomotive based on the Z class be an ongoing solution? Would it be given the full roller bearing treatment for ease of maintenance, or would longer-life versions of plain bearings be chosen instead? What sorts of servicing arrangements would be made for them?
Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2, to a very old fundamental design but with some modern 'conveniences'. Would a similar locomotive based on the Z class be an ongoing solution? Would it be given the full roller bearing treatment for ease of maintenance, or would longer-life versions of plain bearings be chosen instead? What sorts of servicing arrangements would be made for them?
Minor correction, the 2-6-6-2 was the last steam locomotive built by Baldwin for an American railroad, IIRC Baldwin built some steam locomotives for India in 1955. It does bring back memories of an ad in a summer 1964 issue in RMC about a model of the C&O 2-6-6-2, that the order for the H-6's "marked and meant the end of steam".
A scaled down Y6b would have been an interesting engine.
B-b-b-boosters on a T1? ('Scuse me, I just got back from my favorite Italian restaurant and have a half-carafe of the house red in me. I feel GOOOOOD!) Anyway, it's been said before and there's no harm in saying it again, but a lot of the problems with slipperyness on the PRR's T1's was caused by improper throttle handling due to poor crew preparation. Throttle handling on a K4 for example was "Pull it like you MEAN it!" Yank it open and get things goin'! You couldn't do that with a T1. Easy does it was the way, in much the same way you'd handle an articulated. A booster was more of a "nice to have" item than a necessity.
Once enginemen knew what to expect it wasn't so bad.
Shameless plug here. The restaurant is Franks West in the Tuckahoe Village shopping center on Patterson Avenue in Henrico Va. Yummy!
I should probably have been more clear.
What I was referring to was a very specific use of the booster: assisting the starting and low-speed acceleration of an engine with a FA so low as to make it 'dangerously slippery' at those times.
This could certainly be 'abused' by an operating department, if they were dumb enough to think that the booster added to perfect adhesion on the main engine under all train-starting conditions. I'd like to think they were smarter than that!
As a potentially-interesting note: One of the prototype T1s was equipped with a booster. But boosters were not supplied on the 'production' engines, despite the established "slippitiness" of the locomotive at starting, and perhaps more significantly, boosters were never proposed as a 'cure' for the engine's problems with slips in service, even as some very wild changes in equalization and lateral motion were being tinkered with. To me, this strengthens the idea that boosters did not provide enough 'bang for the buck' to justify their cost and maintenance... at least, on PRR in passenger service, where I would think a booster was not only warranted, but flat out needed as far as practical operation was concerned.
Overmod
>> I agree that the Franklin booster was a complex and expensive device to provide and maintain, but it would make a locomotive with lower FA more tractable at starting and low in the acceleration range. <<
No question , or basically : total t.e. *could* be increased with a booster and if you are at the throttle climbing the mountain side in a rainy black night with a freight slowly , all too slowly winding through the curves and threatening to bear you down to a stall with just one more wild slippage , for sure you'd *wish* the railroad had not informed the builder "Uhm , on the production engines we won't need those booster .."
Only , I fear - with the booster the railroads daily traffic thinking would be "Oh-awright , just hang it on , those mammoth's do have a booster !" and then climbing that mountain in that night would find you in just the same borderline situation - only you'd pray the booster , too , won't let you down after having been engaged for so many miles on end !
JuniathaBasically , steam did *not* improve in versatility by being cluttered with auxiliaries or if you prefer ancillary engines by the numbers . All these extra machinery often enough of quite special design and inevitably adding mass which drew on possible boiler size , too , by default was to be inactive for most of a trip and therefore gave a low return of value for capital spent - it just was not cost efficient
It's interesting that in Britain, boosters were carefully tried, and showed the same advantages they did here, but were not adopted. For exactly the stated reason Juniatha gives.
On the other hand, I think there is a case for some kind of booster that gives added working TE (or allows lower propensity to slip the drivers) -- on some railroads. I agree that the Franklin booster was a complex and expensive device to provide and maintain, but it would make a locomotive with lower FA more tractable at starting and low in the acceleration range.
I concur that many of the auxiliaries that were coming into use were overcomplicated devices with minimal return. One reason I like the idea of the Snyder preheater and Cunningham circulator is that they were explicitly designed to do their job in a real railroad environment, with minimal tinkering or breakable parts involved. It's interesting to consider whether a reliable feedwater heater or exhaust-steam injector that did not involve many little moving parts supplied by the lowest bidder could be built.
eagle1030 friend611In my opinion, the N&W would have kept the Berkshires in operation on the NKP. Now with the Wabash, that is more open to question, though it is possible Berkshires may have been used there as well.Lois I know at least one portion of the Wabash line (Moberly-KC) was hilly enough to warrant 4500hp diesel consists. That's around what a normal 4-8-4 could produce, and a superb 2-8-4 would be more equal to the task. And I do not think Wabash had any Berks, but it's not my preferred road and I may be wrong. I do know they had some Northerns.
friend611In my opinion, the N&W would have kept the Berkshires in operation on the NKP. Now with the Wabash, that is more open to question, though it is possible Berkshires may have been used there as well.Lois
I know at least one portion of the Wabash line (Moberly-KC) was hilly enough to warrant 4500hp diesel consists. That's around what a normal 4-8-4 could produce, and a superb 2-8-4 would be more equal to the task.
And I do not think Wabash had any Berks, but it's not my preferred road and I may be wrong. I do know they had some Northerns.
If I remember correctly, the Wabash 4-8-4s were ancient (built 1930) and would have been fertile ground for rebuilding to better specs in the late '40s. Interesting to me is that the Wabash also had some Mountains of very similar dimensions built for them at about the same time -- and it might be interesting to see whether there were key differences in the approach taken to modernize the two classes.
Just what WOULD an O-1 get to modernize it?
I can't help but wonder whether N&W would have developed (for its new acquisitions) "2/3 of a Class A" as a Berkshire design. THAT would be an interesting locomotive.
eagle1030 Something also to be considered is N&W's merger with the Wabash and NKP, two fast freight lines. Would N&W have kept Berkshires, or would it be more Class A's?
Something also to be considered is N&W's merger with the Wabash and NKP, two fast freight lines. Would N&W have kept Berkshires, or would it be more Class A's?
Considering the geographical layout of the both the Wabash and NKP, Berkshires I feel would be a more logical choice. Rolling and flat lands, area's where the Berk performance was just fine.
Also, think about the maintenance requirements of the two, again, some advantage to the Berk. Add on some modern type thinking and improvements the Berk could be an even more awsome piece of machinery. The NKP, assuming steam had another decade, would have pushed the technology of the Berk even further. Seem's they liked those suckers.
Berk or A - that's like asking more Chevys or more Cadillacs
Paul,
in a nutshell :
my bet for a light Mike
axle load for go-everywhere , I guess some 55 lb10³ - you may tell me a more accurate value
ihp in the 3000 range
speed in the 70 mph range ( or 100 if you'd use J class rpm )
Again , certainly no chain driven Bulleid power trucks or the like fancy plumber's nightmares .
Basically , steam did *not* improve in versatility by being cluttered with auxiliaries or if you prefer ancillary engines by the numbers . All these extra machinery often enough of quite special design and inevitably adding mass which drew on possible boiler size , too , by default was to be inactive for most of a trip and therefore gave a low return of value for capital spent - it just was not cost efficient .
carnej1 Do you think that the design of the "power trucks" in the patent would have been better than say, the Bulleid Leader's bogey design? I realise that that may be an "Apples-and-Oranges" type of question in the sense that the two designs are aimed at different applications....
There were some aspects of Bulleid's trucks that were better: the primary springing and damping arrangements, the centerless design with multiple 'side bearing' pads, the use of welding and rotating jigs for fabrication. I have grave doubts that the triple-throw crank could be made to work properly in the long run. The thermodynamic and performance advantages of the sleeve valves turned out to be minor overall, with greatly increased maintenance problems -- I admit I am still in awe of the Napier Sabre, and Bulleid's valve arrangement is not far behind, but even the joys of Meehanite are not going to keep those sleeves and rings both free-moving and steam-tight at the same time...
The detail design of the chain final drive was recognized as a kludge at the time; it could probably have been made to work with American clearances (where there would have been room for fore-and-aft chains on both sides, relieving the awful reversing stresses on the crank and the distorting effects of the one-sided drive on the flexible suspension. (As a note: Bulleid was impressed with chain drive because he saw it on industrial machinery... driven at reasonably constant torque, and not reversed. Had he recognized more about the behavior of Morse chain, things might have been different both on the Pacifics and on the Leader class. Note that the Turf Burner had conventional little piston-valve-equipped cylinders not unlike what Steins calls for).
When Riddles was criticizing the design, he noted it would benefit from 'smaller wheels'. There is little doubt that this would improve most aspects of a 'general purpose' locomotive.
The principal 'catch' here is that Steins has those trucks the way he does for a reason; they have extremely short wheelbase, to facilitate working very sharp curves, with... I think... the polar moment of inertia made purposely large to damp yaw oscillation from that short wheelbase. If that is a design criterion, Bulleid's long wheelbase trucks with minimal lateral excursion (limited by the chain side play) is NOT a particularly good answer. There are some ways to get around this (one being to use curved rather than cylindrical rollers in the chain, with similar radius to what was used in spherical rod bearings) but unless you go to a radial truck -- which would require something like Klien-Lindner axles to work with the chain drive -- you will still have substantial restriction on where the locomotive can work.
Similar issue with adapting Besler's New Haven railcar trucks -- the wheelbase is so long that the flanges would start to bind...
Overmod carnej1That would be this patent: https://www.google.com/patents/US2586109?dq=ininventor:%22C.+K.+STEINS%22 It seems that it would use trucks somewhat akin to the then current Steam Locomotive booster engine designs, although my understanding is that booster engines were uni-directional and the power trucks on the proposed locomotive would have to be able to supply the same tractive effort in forward or reverse so ther must be some mechanical innovations, correct? That is indeed the correct patent! Looking at the date on this patent, and on Kirchhof's patent that became Franklin type D (which is this one), leads me to think that the general type D idea, of a RC poppet gear with 'automatic cutoff control', is what would have been used. The system would involve control air strictly as digital control (the air moves the cam to full engagement of either forward or reverse from the 'neutral' cam profile, and the arrangement centers automatically), so there would be no synchronization problem between trucks; the operation would be just like USATC 2728/611: forward, reverse, and neutral, with the throttle then being used for speed control. The stated effect of the 'wiredrawing' would be enhanced with the small wheels. In my opinion, as with the T1 (and, apparently, according to Tuplin, the Niagara) there would be benefits from sliding-pressure firing at starting and perhaps at other times; among other things, it relieves the problems inherent in throttling the inlet steam flow before it gets to the valves... From the way he describes the drive, I think that it consists of simple cranks, probably in trunk pistons (as in a conventional automobile engine). These could be synchronized with external side rods as indicated, but note that he only puts them in as an option. Note that the Kirchhof patent indicates that the "type D" system would inherently act to control slips from propagating, which would be a big concern on a locomotive with individual axle motor drive!
carnej1That would be this patent: https://www.google.com/patents/US2586109?dq=ininventor:%22C.+K.+STEINS%22 It seems that it would use trucks somewhat akin to the then current Steam Locomotive booster engine designs, although my understanding is that booster engines were uni-directional and the power trucks on the proposed locomotive would have to be able to supply the same tractive effort in forward or reverse so ther must be some mechanical innovations, correct?
https://www.google.com/patents/US2586109?dq=ininventor:%22C.+K.+STEINS%22
It seems that it would use trucks somewhat akin to the then current Steam Locomotive booster engine designs, although my understanding is that booster engines were uni-directional and the power trucks on the proposed locomotive would have to be able to supply the same tractive effort in forward or reverse so ther must be some mechanical innovations, correct?
That is indeed the correct patent! Looking at the date on this patent, and on Kirchhof's patent that became Franklin type D (which is this one), leads me to think that the general type D idea, of a RC poppet gear with 'automatic cutoff control', is what would have been used. The system would involve control air strictly as digital control (the air moves the cam to full engagement of either forward or reverse from the 'neutral' cam profile, and the arrangement centers automatically), so there would be no synchronization problem between trucks; the operation would be just like USATC 2728/611: forward, reverse, and neutral, with the throttle then being used for speed control. The stated effect of the 'wiredrawing' would be enhanced with the small wheels. In my opinion, as with the T1 (and, apparently, according to Tuplin, the Niagara) there would be benefits from sliding-pressure firing at starting and perhaps at other times; among other things, it relieves the problems inherent in throttling the inlet steam flow before it gets to the valves...
From the way he describes the drive, I think that it consists of simple cranks, probably in trunk pistons (as in a conventional automobile engine). These could be synchronized with external side rods as indicated, but note that he only puts them in as an option. Note that the Kirchhof patent indicates that the "type D" system would inherently act to control slips from propagating, which would be a big concern on a locomotive with individual axle motor drive!
Do you think that the design of the "power trucks" in the patent would have been better than say, the Bulleid Leader's bogey design? I realise that that may be an "Apples-and-Oranges" type of question in the sense that the two designs are aimed at different applications....
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Overmod Another interesting question is what would have been used on the heavier branches, the ones served by the 2-6-6-2s. The very last new steam locomotive built by Baldwin was a 2-6-6-2, to a very old fundamental design but with some modern 'conveniences'. Would a similar locomotive based on the Z class be an ongoing solution? Would it be given the full roller bearing treatment for ease of maintenance, or would longer-life versions of plain bearings be chosen instead? What sorts of servicing arrangements would be made for them? I had thought the 'standard' light branchline engines were the 4-8-0s. I would think an eight-coupled engine would be about the 'lightest' that would be used for any branch service on N&W; modern truck design ought to allow a 2-8-0, perhaps with lead-truck parts in common with the larger classes. I had the impression N&W did not have (substantial) trouble with reverse moves by the 4-8-0s, so it might not be necessary to go to a formal 2-8-2 to get adequate reverse guiding -- the principal reason would be if a deep wide firebox were to be used, rather than a narrow box or a wide one over the rear drivers -- the latter probably being the most likely. It might be fun to speculate on the further development of the M2 Automatic modification of 4-8-0s and its application to branch as well as switching service... but I would doubt the expense of the conversions would produce any meaningful return on the investment in road service. I don't see any likelihood of turbines, even if the TE-1 were to prove the technologies workable in service, although it might be interesting to compare the Swedish 2-8-0 Ljungstrom turbines with the work requirements... PRR (when it was N&W's majority owner) was working on some interesting all-wheels-driven ideas that might have been useful for this service. (See the Steins patent # 2586109.)
I had thought the 'standard' light branchline engines were the 4-8-0s. I would think an eight-coupled engine would be about the 'lightest' that would be used for any branch service on N&W; modern truck design ought to allow a 2-8-0, perhaps with lead-truck parts in common with the larger classes. I had the impression N&W did not have (substantial) trouble with reverse moves by the 4-8-0s, so it might not be necessary to go to a formal 2-8-2 to get adequate reverse guiding -- the principal reason would be if a deep wide firebox were to be used, rather than a narrow box or a wide one over the rear drivers -- the latter probably being the most likely. It might be fun to speculate on the further development of the M2 Automatic modification of 4-8-0s and its application to branch as well as switching service... but I would doubt the expense of the conversions would produce any meaningful return on the investment in road service. I don't see any likelihood of turbines, even if the TE-1 were to prove the technologies workable in service, although it might be interesting to compare the Swedish 2-8-0 Ljungstrom turbines with the work requirements...
PRR (when it was N&W's majority owner) was working on some interesting all-wheels-driven ideas that might have been useful for this service. (See the Steins patent # 2586109.)
That would be this patent:
Appreciate your input Big Jim. Maybe we should narrow or specify our definitions of "branch lines." When I think N&W branch lines I think of things like the Abingdon branch. I completely forgot about all those lines from all those coal mines that would have needed big power like a Y6. Those strike me more as "semi-main" lines, for lack of a better term, especially if they needed the muscle of a Y6.
I had thought the 'standard' light branch line engines were the 4-8-0s.
.
Our community is FREE to join. To participate you must either login or register for an account.