PRR Duplexes and Experimental Engines ( S1, S2, T1, Q1, V1 etc.)

[thomas81z]

I have read & reread this thread since 2018 & it still blows my mind well from what i understand , wow just wow . thank you guys so much for deep diving for us that arent as knowledgeable  on this subject

[Overmod]

Look up 'Plancher System' for a different approach to four-cylinder compounding (e.g. the early Italian cab-forward 4-6-0 design)

The de Glehn-du Bousquet design, one of the more successful compounds, had the HP drive on the main with a conventional axle and the LP on a cranked leading driver axle.  Four sets of valve gear with the LP fully adjustable separate from the HP -- a reason the French called engine-drivers 'mecaniciens'.

Most of the balanced compounds (such as Cole and Vauclain type 2, the latter being the "Baldwin balance compounding' applied to the New Haven engines) had a cranked main-driver axle and all four mains bore on the same driver pair -- in other words, not divided-drive.

An interesting type that you'd think couldn't work all that well was the von Borries, which is a normal quartered 2-cylinder DA... run as a compound with HP on one side, LP on the other, and asymmetrical counterbalancing.  The original PRR T1, with the 84" drivers, was made this way and there is a photograph of it at high speed with a considerable train -- the trick was that the two sides had separate cutoff so it was relatively easy to adjust running balance at a given throttle opening and HP cutoff.

[timz]

BaltACD

On compound non-mallet engines.  Are the low pressure cylinders quartered on the same phase as the high pressure cylinders?

Guess a four-cylinder would always have the low-pressure 180 degrees from the high pressure on that side, wouldn't it? And the left and right sides the usual 90 degrees apart. Presumably that's why the main-driver counterweight is at the bottom on this 4-6-0

https://babel.hathitrust.org/cgi/pt?id=uva.x002211444&view=1up&seq=604&size=125

Next question: what was more common, four cylinders all driving one axle or low-pressure driving the lead axle and high-pressure the second?

[Overmod]

Thing is that it would require 180-degree opposition on each side to get the engine to balance, and that is manifestly not true of a Vauclain compound (I presume you mean type 1, with the high-pressure and low-pressure cylinders outside, driving on a common crosshead).  There are illustrations on the Web of the special piston valve and convoluted port and passage arrangement that is at the heart of this method of compounding, and although the porting and operation are complex to analyze, the system was certainly capable of developing near- if not actual world's-fastest speeds in the early 1890s.

I think the inside connections on a Cole balanced compound are quartered at something like 135 degrees relative  to the (quartered) outside.  Early compounds did not use the analogy to loop scavenging to lower effective HP backpressure going into the receiver, and I'd think dynamic balance would be a more important concern that equalizing MEP... especially with the actual condensation of LP steam in the receiver and then during expansion in the LP cylinders, which was often far more abysmal than manufacturers and designers seem to have realized.

The 'answer' of course can be seen first in effective steam-streamlined passages and superheating in modern compounds, and then in the 'booster valve' applied to some of the N&W Y-class engines (which of course were only circumstantially and accidentally 'in pnase' HP to LP).  I still have no hard information on whether the LP reheat 'superheater' on 160 A1 was actually useful or not.  In my opinion the 'best' approach is still that proposed by Chapelon, which is like a modulated version of the booster valve: high-pressure saturated or superheated steam is preferentially injected into the receiver at acceptable determined HP back-pressure excursion, so that not only the MEP but the instantaneous pressure on the LP pistons over the effective range of their stroke 'matches' what the HP cylinders are producing.  That does not require that the HP and LP be co-phased at all; in fact my RSR engine design phases the front and rear soft-conjugated engines (via a detent) at 135 relative (both engines being simple 2-cylinder DA in quarter) so that there are eight controlled power impulses per revolution for the engine as a whole, which also should help eliminate objectional high-speed surge effects.

[CSSHEGEWISCH]

BaltACD

Question - On compound non-mallet engines.  Are the low pressure cylinders quartered on the same phase as the high pressure cylinders?

 

It would have to be that way on Vauclain compounds and probably that way on cross compounds and D&H 1403.

[BaltACD]

Question - On compound non-mallet engines.  Are the low pressure cylinders quartered on the same phase as the high pressure cylinders?

[Flintlock76]

Backshop

You do know that was CGI?

 

I enjoyed the video!  Authentic footage where available (and the rendition was excellent) and CGI where needed.  A pretty good balance and a great end product.

I definately gave it a "Like!"

[Overmod]

Backshop

You do know that was CGI?

I was referring to the video clips at the beginning.  The MSTS was typical 2011 quality, no more, no less.

An actual render in modern CGI would be much closer to 'photorealism', both in ray-tracing lighting effects and resolution.  See the 3D derived-pointcloud models that were produced for the T1 Trust about a half-decade ago, but in color...

[CSSHEGEWISCH]

BaltACD

 

Backshop

You do know that was CGI?

 

 

CGI can illustrate things that no longer exist as well as things that only exist in the mind of the creator.

 

It would be interesting to see some of the more outlandish proposals that were never built but turned up in Wiener's "Articulated Locomotives".

[BaltACD]

Backshop

You do know that was CGI?

CGI can illustrate things that no longer exist as well as things that only exist in the mind of the creator.

[Backshop]

You do know that was CGI?

[Overmod]

That video has some of the most splendid video quality I've ever seen in a YouTube video -- even before we consider the subject matter.  It's well worth watching, and I think we should encourage his 'channel' with likes and subscribes.

[BaltACD]

https://www.youtube.com/watch?v=2RusRdlE-gg

[M636C]

Overmod

See if this makes the link clickable:

https://www.mosafilm.de/CF/heftbesprechung/hobby/5706/superzug.html

Note the reference to 200km/h stability here, too.

Is it just me or does that Russian nuclear locomotive have styling cues based on the PRR T1? Quite apart from the "duplex" arrangement of driving wheels, look at the front casing and the shape of the casing over the wheels...

Peter

[Overmod]

See if this makes the link clickable:

https://www.mosafilm.de/CF/heftbesprechung/hobby/5706/superzug.html

Note the reference to 200km/h stability here, too.

 

[djlivus]

https://www.mosafilm.de/CF/heftbesprechung/hobby/5706/superzug.html

[djlivus]

https://www.mosafilm.de/CF/heftbesprechung/hobby/5706/superzug.html

[djlivus]

"Will it be so far in a few decades that railway giants, super trains of dimensions still unimaginable today, 'ships on rails', pulled by nuclear locomotives, speed through the Russian steppes? Many technicians in the Soviet Union think it is possible, yes they have already worked out the plans for it. Because the solution of the traffic problem, especially the transport of huge amounts of goods through the endless expanse of the Russian, but above all the Siberian area, has become one of the most urgent tasks in the Soviet Union. The railway network of the Soviet Union currently has a route length of about 160,000 kilometers (USA 380480). Since the railroad is still the most important means of transport in the Soviet Union, work is ongoing to expand it. However, while in most other countries in the world one only deals with increasing the speed of travel (by strengthening the substructure and using stronger locomotives), increasing the comfort of passengers and improving the loading and unloading systems, new types are to be found in the Soviet Union Railways are built that would be able to cope with all traffic requirements in the foreseeable future. These plans - as fantastic as they may sound to traffic experts - undoubtedly have a real basis in the Soviet Union, in fact they are becoming a necessity there, considering that this country has only a relatively weak network of well-developed roads and motorization despite all efforts, will not have reached the level of the western world by a long way.

The planned super railway - it definitely deserves this name - should have a track width of 4500 mm. That is about three times the width of today's standard gauge, which is 1435 mm and is used on 74 percent of all railway lines in the world. (This dimension can probably only be traced back to the fact that at the time of the first railways the axis length of the stagecoach was precisely that dimension (see also 'From readers to readers', p. 9). All other important railways use a larger track width. In in the Soviet Union, Finland, Turkey and Panama it is 1524 mm each. In Ireland, Brazil and parts of Australia the 1,600 mm gauge is found, while the largest to date of 1,676 mm is found in Spain, Portugal, India, Ceylon, Argentina and Chile is in use. Narrow-gauge railways are available down to a track width of 600 mm. The oversized gauge of the Russian project would of course require the construction of wagons with a capacity that is still unimaginable today. Large goods wagons - apart from individual special wagons - nowadays have an average load weight of 50 to 60 tons on standard-gauge railways. Freight wagons with a loading capacity of 100 tons were used on the long, flat stretches of the USA and the Soviet Union. But this in turn comes at the expense of the train length, since a freight locomotive is only able to move a certain weight. A wagon for the planned Russian super broad-gauge railway would hold around 27 times as much as a conventional freight wagon, i.e. around 1,600 tonnes of payload instead of 60 tonnes.

The Soviet Union seems to be well aware of the difficulties that stand in the way of creating such a super-railroad. Today there is no railway line that has the width required for this gauge. When they were built, completely new dams would have to be built and bridges with a corresponding load-bearing capacity would have to be built. The stability of the substructure and the rails would have to be considerably greater than with today's routes. But none of this should present any insurmountable difficulties when building this super-railway through the endless expanses of the Russian area, through the plains of the Ukraine and the steppes. According to the plans, unevenness in the terrain should be compensated for by extensive excavations or embankments. Incidentally, the costs of building the route are hardly likely to be higher than the cost of a motorway that can cope with all weather conditions. As far as has been reported, the first sections of this super-railway are to connect the cities of Moscow-Leningrad-Kiev with each other, while the further expansion would primarily extend to a ring connection between the new industrial centers in Siberia.

Nuclear power is supposed to solve the fuel problem of these giant trains. Nuclear locomotives, the construction of which is being considered in all technically advanced countries, could not be realized to this day because the dimensions and weight of the nuclear reactor, but especially the inevitable radiation protection, take up too much space and make the machines too heavy for the substructure of current railways would. The nuclear locomotive the size of the Russian super broad-gauge railroad certainly does not have these space concerns. These giants of the rail line are supposed to be three times the width of a standard-gauge locomotive and at least as great a height and, since the routes are to be kept extremely curvy, also have an almost arbitrary length dictated only by the weight.

The achievable speed at which there is no longer any 'fluttering' or swinging of the trains is assumed to be 200 km / h. A higher speed would lead to excessive wear on the rails. The trains should consist of around ten cars. The amount of payload carried by a single train would correspond to that of ten normal current freight trains. Since the block spacing of the trains running one after the other did not need to be greater than today, but the speed is considerably higher, a fifteen to twenty-fold increase in performance in transport was calculated.

The super railways, which are primarily intended for freight transport, are also intended to be used for passenger transport. Given the spaciousness of the wagons, it would be possible to completely deviate from the type of railway wagon with its narrow seats, which was customary up to now, and to give the wagons an arrangement that is only possible on ships today: that is, numerous individual compartments, spacious, housed in a multi-storey structure Lounges, cinemas, baths, etc. Fresh air should only be supplied through an air conditioning system in order to keep dust levels to a minimum and to always create a pleasant temperature - in summer and winter.

Apart from the Soviet Union with its endless plains, there is hardly a country - the routes in the USA and Canada are too short and lead through frequently changing terrain - that has the conditions that make the construction and operation of such a super-railway appear profitable to let."

[Overmod]

djlivus

Soon, negotiations began with the creators of the X-12 on the development of a similar locomotive for an ultra-wide gauge."

Not content with deploying liquidized weapons-grade uranium across the general system of transportation, they want to send it through a variety of Central and South American nation-states, including one then largely influenced by Juan and Evita...

[djlivus]

https://e-news.su/history/256660-zheleznodorozhnyy-futurizm-sverhshirokaya-koleya-i-bezumnye-proekty-voennyh.html

"At the same time, there was an active discussion of the construction of the Pan American Intercontinental Highway to connect the Americas, and with it the idea of ​​an intercontinental broad-gauge railway was considered. It was supposed to go from Alaska to Argentina and turn both continents into a single economic zone. Nuclear locomotives were the best fit for this project. Soon, negotiations began with the creators of the X-12 on the development of a similar locomotive for an ultra-wide gauge."

 

[djlivus]

https://mi3ch.livejournal.com/2637409.html?page=2 :

"After the materials on the Hitler super train were declassified, similar projects appeared in the USSR.

Deputy Director of the Institute of Complex Transport Problems of the Academy of Sciences of the USSR, Soviet scientist Vasily Zvonkov, in particular, wrote: “The existing generally accepted railroad gauge in our country - 1524 millimeters - was proposed by one of the builders of the St. Petersburg-Moscow road, engineer Melnikov. Already today it cannot satisfy us. A track gauge of 3 - 5 meters will allow us to build significantly more lifting wagons and use locomotives with a capacity of 40 - 50 thousand horsepower to ensure a speed of 250 - 350 kilometers per hour. The question of using nuclear reactors on such locomotives will be greatly facilitated. After all, as you know, only a significant weight of biological protection prevents nuclear locomotives from entering our roads today,

The throughput capacity of BAM has been exhausted for today. The main problem of the inhabitants of the Far East is isolation from the center of Russia.

Nuclear reactors on trains are too dangerous. Today the train from Moscow to Vladivostok takes 7 days. At a speed of 250 km / h, this time will be reduced to one and a half days"

[djlivus]

Thank you for this very comprehensive answer!

[daveklepper]

Informative and accurate reply/

[Overmod]

djlivus

My question would be if a freight locomotive can be regeared for passenger traffic or, conversely a passenger one for freight use. If so, what such an operation would imply? I ask that questioon having in mind some examples like New Haven EF3(adapted for pasenger use) or Baldwin Centipedes "rebuilt" for freight

The answer for diesel-electrics is simplified because some of the most ubiquitous types were inherently designed suitable for dual service, with relatively small changes.  Up to the inherent limits of nose-suspended motors the 'change' is one of gearing, with the numerical ratios chosen for an integer number of teeth on pinion and bull gears that fit into the gearcase.  (PRR typically lists this the other way round from most everybody else; EMD liked expressing it in mph (presumably representing the highest safe speed to spin the motors).

As you might suspect, suspension and guiding are key characteristics of true dual-service locomotives.  The Centipede chassis was good for over 120mph by Baldwin's perhaps over enthusiastic figuring (they had touted the ATSF 3460 class as "120 mph locomotives" and Seaboard happily bought them for 85mph freight service (replacing rather good 2-6-6-4s).  Most of the 1930s articulated-underframe high speed design -- originally serving a somewhat different purpose on the maid-of-all-work Essl locomotive) was not "as good" as evolved truck designs, like those attributed to Blomberg at EMD.  Indeed, Westinghouse seemed to be proposing nothing but AAR type B trucks on all their locomotives -- advantages as you'd expect for B instead of C trucks in high-speed work, and plenty of easily-cooled span-bolstered motor power if you want to pull freight...

The poster child for dual-service electrics is the GG1, which evolved from the New Haven design.  This was easily changed from high-speed passenger engine to capable freight locomotive with little more than a simple gearing change, as all the rest of the suspension and underframe remained substantially 100mph capable.

The Rc-4, on which the AEM-7 'toasters' were patterned, is a successful freight locomotive in Europe, albeit one that may require additional time in starting heavy trains.  If I'm not mistaken, many features of the ACS-64 'Sprinters' are shared with Vectron electrics, although I do not know how detail-design differences for high-speed service might impair its suitability.

[djlivus]

German breitspurbahn project considered more than 40 locomotives - some designed for high speed passenger trains,some for freight. My question would be if a freight locomotive can be regeared for passenger trafic or, conversely a passenger one for freight use. If so, what such an operation would imply? I ask that questioon having in mind some examples like New Heaven Ef3 (adapted for pasenger use) or Baldwin Centipedes "rebuilt" for freight

[Overmod]

The Lyle Borst tale is amusing.  He assigned the design problem as a hypothetical exercise.  Afterwards there was enough interest that he patented some of the design features... the AEC apparently being willing at the time to find alternative markets for uranium enrichment other than as constituents of explosives.  It does not appear that security of what is basically weapons-grade U235 for use on the general system of railroad transportation was a cost concern.

There was a brief frenzy of transportation applications when submarine reactors became known. If FM engines worked in subs and were more or less successfully ported to locomotives... why not PWRs?

The Alco A-100, which I only know from a single drawing, may use a comparable cycle, although it is tough to dispense with ocean cooling (as some Erie-Built customers reputedly recognized!).  While some improvements over the PRR S2 were needed, they were not critically incapable of solution.  And there was the promised long running time between (subsidized) reprocessings...

[djlivus]

Very interesting considerations!

 

[Overmod]

There was no insurmountable issue with the 'double-track train' going around curves or cross-equalizing... and the test was done with HO snap track...  Note that the 'four rails in 18' gauge -- I'd suspect 5m -- would give an interesting centerline distance if considered as double track, say of 5' gauge.

Did the Russian system note that the two 'subsidiary tracks' were each lined and surfaced separately for use?  Or that the spacing of the four rails was not 'equal' spanwise?

An issue that came up with the 'double-track train' was the way superelevation and crossovers were to be handled.  Note that the Breitspurbahn freight and these Russian systems do not emphasize high speeds (and presumably would be built with limited superelevation as with contemporary "PSR" optimization (?) to 40-45mph with minimized wear and deflection to the rails.  That would simplify how crossovers,  etc. are provided for the individual tracks.

I continue to presume that carbody-mounted motors remain a good solution for these enormous things, although I see very little mention of the idea explicitly either in the German planning or these Russian versions.  You could easily have whatever final drive you wanted with transverse balance on either the upper or lower 'deck', with final drive to the individual span-bolstered 'bogies' running on their pairs of gauged rails.

I have learned more about this stuff in three months than in a whole lifetime of pottering research on some of this stuff.

[djlivus]

https://pbs.twimg.com/media/D8oDSKgUYAA_tJz?format=jpg&name=large

 

Another soviet proposal  rendering  here