# 120
to finish the short feet Q2 matter
Edited version , some sentences revised , some words revised for better readability and understanding of points – please read again if you should have read original text
>> On a Q2 I think I'd reduce both bore and stroke on both engines, with the rough expectation of keeping the mass flow the 'same' at a given road speed <<
You may reduce cylinder volume by shortening stroke or diameter or by each some of both . From your remark >> keeping mass flow the same at a given road speed << I conclude you talk of cylinder volume to be reduced in proportion to reduction of drive wheel diameter ( resulting in same adhesion factor ) At *same road speed* this would demand same cut-off to be used for same volume ( not necessarily mass , mind it ) of steam to be passed through cylinders – for simplification in this theoretical consideration disregarding varying influence of throttling through given valve gear at different rpm speeds .
Reduced cylinder volume would thus largely nullify the effect aimed at with reduction of drive wheel diameter since again the same amount of steam , namely nominal boiler steaming capacity , will only be useable at *same* road speed not a lower one as intended .
Looking at *same rpm speed* , logically the engine with smaller cylinder volume cannot help being inferior in output compared with the original one since at same rpm speed as with the original engine , same volume of steam cannot be passed through the reduced cylinder volume whereby it doesn’t matter if cylinder diameter or stroke was reduced or both – except for using longer cut-off ! This however can only incompletely make up for lost cylinder volume since the original engine as built already had to use pretty long cut-off for full output – an attempt to increase mean steam pressure in cylinder to compensate for smaller cylinder volume by lengthening cut-off will thus soon meet a limit while truncated expansion will sensibly increase specific steam consumption . Consequently , maximum output at same boiler steaming capacity would really be reduced with reduced cylinder volume – which is simple logic if you come to think of the steam engine like any heat engine at a certain typical level of refinement can only produce so much power per unit of volume of work space .
A reduction of wheel diameter combined with concordant reduction in cylinder volume thus cannot lead to the desired shifting of ( unchanged ?) maximum output to lower speed range . It would however lead to a number of design headaches that were avoided with the larger wheels – you mention two of them : mass inertia and dimensioning of wheel centers and material thickness between axle and main pin fits , see second and third quotation .
Taking a look at the other one of principal theoretical choices : reducing drive wheel diameter with cylinder volume kept unchanged ( as previously assuming boiler pressure unchanged of course )
*This way* optimum point of power output *could* – theoretically – have been shifted to somewhat lower road speed range at same rpm speed , say from 50 mph with 69” wheels reduced back to the original Mika-typical 63” : 45.65 mph – a reduction of 4.35 mph or , as with wheels diameters , 91.3 % the former speed .
However , disregarding said problems of mass inertia and dimensioning of wheel centers and material thickness between axle and main pin fits , adhesion factor ( am definition ) will rise in proportion to reduction of wheel diameter and thus speed for same rpm running . While this may not look dramatic in my example as above , it sure will if wheel diameter reduction is to be carried further to make a more notable difference in speed ranges !
Thus , clearly , method of compressing optimum output speed range by reducing wheel diameter is severely being contained by limit of adhesion – which was already fully exploitable in most designs as they were ; smaller wheel diameter at unchanged cylinder volume only serves to produce a more slip-prone engine meeting virtually the same limits of adhesion and thus power output at any given speed in the lower range as the original engine .
Summing up : Reduction of drive wheel diameter is no practical way to shift steam’s optimum of performance towards lower speed range . Already adhesion , not cylinder power , has regularly defined limit of power output of any properly proportioned classic types of steam from standing start all over the lower speed range , even into medium speeds in cases of high performance locomotives . Further , optimum output is only reached when working at a decent degree of expansion , i e at tractive effort lower that adhesion limit and thus logically full boiler output was best used but in the upper speed range at *any* rate . There simply is no way optimum power output can be shifted towards lower speed by tampering with some major dimensions .
That’s why I had written a railroad supposed to use steam traction in a modern world by building upon and extending development of classic steam would effectively run trains in a way significantly differing from what diesel powered railways do – in a nutshell : in order to maximize ton-miles production , basically replace max tonnage by max speed as prime ruling factor .
Looks like I should add a word in general about my comments at times written in somewhat dry or laconic words : without further explanation or remarks they may appear like ad-hoc opinion , yet they are not . Usually they are but concise extracts from much wider contemplations backed by long and repeated pondering of related and inter-relating points in steam design and construction ; my comments are as terse as they are because I have long since spent much thought on concerning points ; the comments thus are but laconic glimpses to answer a specific question or point that has sprung up , without going into details or reasoning because I feel most users are not really into reading what thoughts I had spent on the larger range of tech topics influential in that specific matter .
>> and use full lightweight rods and valve gear <<
Because mass forces in drive gear increases by increase squared of rpm speed , essential reduction of reciprocating and revolving masses quickly becomes vital with smaller drive wheels , only to contain increase of mass forces at *same road speed* as of original engine without yet having gained any advantage in low speed performance .
>> Long-term strength of the wheel center, especially at the axle and pin fits, and adequate securement of the balance masses, would have a great deal to do with determination of the 'most effective' range of "lower" driver diameters.<<
Improving sturdiness and longevity of these in view of increasing stress in ever more powerful locomotives in fact was a major drive for using increasing drive wheel diameters in development of the high performance freight steam locomotive in America all through the early1930s to the end in 1949 . In relation to maximum power outputs about tripled during that period an increase from a Mike’s typical 63” wheels to 69” in 2-10-4 and 2-6-6-4 types , in cases even 70” to 74” must be considered moderate and sensibly measured .
>> whether derating the boiler pressure, ... would have benefited a Q2 as much as a Niagara <<
Let’s leave that standing as one of your more cryptic sentences and I will not wander into wondering how >> derating boiler pressure .. would have benefited .. a Niagara << in view of their cylinder volume already having been pretty clearly on the small side with a resulting adhesion factor of > 4 , cylinder volume only just adequate for NYC lines profile with water level or nearly having been given predominant consideration in design of this 4-8-4 and , consequently , having asked for > 50 % cut-off for full power output *at high speed* !
Regards
Juniatha
# 121
Hi Juniatha!
Pardon a question from a raw amateur at this, and someone who only knows what he's read in the history books, but aren't small drivers and speed mutually exclusive? That seems to be where this conversations going with folks talking about 63" drivers. I would think bigger is better for speed, say the 70" or larger range.
Also, wouldn't there be balancing problems with smaller diameter drivers? I've read of instances where main-line steam locomotives with balancing problems had them resolved by the simple addition of several inches to driver diameter.
Considering this is a mainline steam thread I'd assume we'd want to have new steam hustling down the line as fast as possible. Maybe even leaving a few diesels choking on coal dust?
Wayne
# 122
Yes, here is the very basic, simple rule that is normally true:
Larger Driver Diameter = More Speed, Lower Tractive Effort
Smaller Driver Diameter = Higher Tractive Effort, Lower Speed
Of course, tractive effort and speed are determined by more than just driver size. Cylinder size, stroke length, boiler pressure, and a number of other things. That equation above is just what you can infer about a locomotive by looking at the divers.
#123
Juniatha to finish the short feet Q2 matter
But it was finished already.
However, since you have brought it back up again, a short and concise answer turns out to be that the Q2 was already optimized for close to 50 mph anyway. According to the actual data from the test-plant runs, p.89, the peak of the DBHP curve at 130,000lb/hr (item 47) is reached at almost exactly that speed.
So the folks historically claiming the Q2 made its peak power at much higher speed appear to turn out to be about as right as those claiming the T1 was impossibly slippery.
"Improvements" on a Q2 would best be made in, say, reducing the ridiculous amount of dead space, or implementing better compression control, and adjusting the power developed by the front engine downward at least 4% -- by whatever method actually works to accomplish that. (And, arguably, keeping the engines dephased!)
And let that be the end of the Q2 discussion in this thread, where I thought we agreed it did not belong.
That’s why I had written a railroad supposed to use steam traction in a modern world in a way building upon and extending development of classic steam would ... best run trains in a way significantly differing from what diesel powered railways do – in a nutshell : basically replacing tonnage by speed as prime ruling factor .
Remains to be seen if you actually find an American railroad that would find a need to run that way. Plenty of cogent arguments have been made on this forum as to why there are significant problems with that operating model. How do you propose to overcome them? (Note: I do consider this an 'appropriate' subject for the current thread, as any 21st-Century operation of steam on main line freights would certainly seem to benefit from speed-optimized operation.)
>> whether derating the boiler pressure, ... would have benefited a Q2 as much as a Niagara << Let’s leave that standing as one of your more cryptic sentences and I will not wander into wondering how >> derating boiler pressure .. would have benefited .. a Niagara << in view of their cylinder volume already having been pretty clearly on the small side with a resulting adhesion factor > 4 , only just adequate for the NYC lines profile with water level or nearly having been given predominant consideration in design of this 4-8-4 and , consequently , having asked for > 50 % cut-off for full power output *at high speed* !
Let’s leave that standing as one of your more cryptic sentences and I will not wander into wondering how >> derating boiler pressure .. would have benefited .. a Niagara << in view of their cylinder volume already having been pretty clearly on the small side with a resulting adhesion factor > 4 , only just adequate for the NYC lines profile with water level or nearly having been given predominant consideration in design of this 4-8-4 and , consequently , having asked for > 50 % cut-off for full power output *at high speed* !
You can choose not to wonder as you wander, but Kiefer approved the idea of reducing boiler pressure from 285 to 265, for a variety of reasons (which, by your own logic, I do not feel I need to repeat in detail), and quite frankly I would trust his assessment over yours regarding what was needed for operation to meet contemporary NYC requirements. What's this about Niagara cylinder volume on the small side? Something important has been lost in the terseness...
Sorry I didn't have time to write a shorter reply
But any reply is good to see.
# 124
Hi Wayne
smaller drivers - lower speed . That's the basic trend if you leave mechanical level of perfection unchanged and thus rpm speel ceiling .
There have been balancing problems met with increasing mass and power of engines and that was another reason for increasing wheel diameter .
Mainline steam should go fast in a contemplation about contemporary revenue service , that's how I see it . Since steam's maximum tractive effort is much more limited than diesel-electric's multi-unit traction and steam performs best at decently elevated speeds , a hypothetical RR using modern steam ( yet classic concept - no nuke juke nor geared booster clustered type of ) would have to use high speed capacity of steam to produce ton-miles abounding . Btw , in Europe general mainline travelling speed of freight trains is 120 km/h ( 75 mph ) with electric traction , fast freight may be scheduled for 140 km/h ( 87 mph ) or above too . Sure you could do that with clusters of diesels per train - yet , you could do it with but one big steamer as they do it with but one modern electric . Just imagine ...
# 125
Prof Overmod
>> .. Q2 was already optimized for close to 50 mph anyways <<
Nowheres did I write that no did I intend to mean that . It was but a simple example to point out reduction of speed by reduction drive wheel diameter . I believe everyone could see that , so what are you after by wilfull misinterpretation ?
>> What's this about Niagara cylinder volume on the small side? Something important has been lost in the terseness .. <<
No , it's all in there , just read . As I wrote :I will not wander into that , wondering . ( your switching words turned my little joke into something meaningless , thank you )
As concerns Kiefer's would be aproving to lower boiler pressure , it was of course *not* for improving performance . Instead , it was to be one of the typical end-of-era steam maintenance easing measures since full power output had by then proven to rarely asked of the Niagaras . There were materials problems encountered by boiler maintenance , it was anticipated reducing b p would make things easier in the final years of service . Same with a couple of other classes , often on an individual basis , thus destroying uniformity of power capacity of members of a class with all its questionable effects on service efficiency and reliability . Mind under Pearlman the NYC dropped steam as fast as possible or impossible , no regards to devastation of capital just formerly invested and not yet having returned due profits , nor to amount or good profitability of even more capital to be invested all over again . Revolution instead of evolution usually comes with chaos and destruction and that's just what it all ended up with Penn Central - a merger clashed together by Pearlman , too - if only it blew up after he had wisely left in time , for sure .
>> why there are significant problems with that operating model. <<
Well , I can see a bad moon rising if you try this model of operation with tracks run down as were occasionally shown in posts linking to a video where trains are supposed to be nursed over incredible spots at walking pace and with lots of praying .
Union Pacific could do it , there are some other RRs that could . As I just wrote before in Europe general mainline speed of freight is 120 km/h , fast freight are scheduled 140 km/h or over . No problems encountered .
= J =
#126 (something stripped the tag# out of the original post)
Juniatha ... As I wrote :I will not wander into that , wondering . ( your switching words turned my little joke into something meaningless , thank you )
For those who might not have gotten the 'little joke' (or my turn on it), for poor orn'ry people like you and like I, here is what I consider a good version.
I think the concerns with the operating model are much more with areas other than pure train speed, particularly issues with yarding consists. We might well remember that one of the last successful uses of American mainline steam, on Nickel Plate, involved just the idea of high-speed bridge-line operation, and locomotives optimized for that service. The question I'd raise, specifically in reference to this thread, would be which contemporary American services are best suited for speed-optimized operations, or perhaps for an American version of plandampf that could be speed-optimized on an otherwise QoS-optimized railroad system.
In my opinion there is very little commonalty between approaches that work in Europe and those that will be practical here regarding increasing freight road speed. I think those high freight speeds are almost entirely the result of a need to coexist with frequent and fast passenger service, and would no more be observed in the absence of that requirement than, say, a modern version of the Super C would be observed on the current Transcon. I dearly wish there were more of a market for high-speed scheduled freight service here -- hopefully someone like Don Oltmann will weigh in with where services like the accelerated Z trains, in particular lanes that would suit the practical requirements of reciprocating steam, might be practicable.
# 127
I should point out that although the NKP and similar Birksheres were optimum for NKP's fast bridge service, they were (and are) versitile steam locomotives, more versatile than most steam locomotives, have enough power for RELATIVELY low-speed drag service when required, and can be passenger power when required.
# 128
OvermodIn my opinion there is very little commonalty between approaches that work in Europe and those that will be practical here regarding increasing freight road speed. I think those high freight speeds are almost entirely the result of a need to coexist with frequent and fast passenger service
I agree that passenger services running at decent top speeds of 110 mph are difficult on tracks owned by freight lines because the differential is too high. However, I think the reason you give is incorrect. From my observations, European freight trains, at least in Germany, run at much higher speeds than here because of demand for freight cargoes to be, in effect, a conveyor belt for "just in time" manufacturers and industries, even for bulk commodities.
C&NW, CA&E, MILW, CGW and IC fan
#129
schlimm (#128)From my observations, European freight trains, at least in Germany, run at much higher speeds than here because of demand for freight cargoes to be, in effect, a conveyor belt for "just in time" manufacturers and industries, even for bulk commodities.
Without in any way disagreeing with the observation:
Implementation of kanban in the United States generally values precision in arrival time FAR above in-transit time or speed. So there is usually considerable value in providing slack time in a rail schedule in order to assure that delivery, by whatever mode it is made, can be truly 'just-in-time'.
I developed several systems in the '70s and '80s to provide accelerated service to minimize the in-transit lag, in part assuming that just-in-time supplier systems were going to catch on, and the inherently higher costs of very fast intermodal service would be justifiable given the potential production economies. That has not been the case in North America at any time I have observed; and the business case for faster ground transportation of express and freight as a common-carrier service (a la Blue Streak Merchandise and later Super-C, the Apollos, Z trains, etc.) has never provided a compelling 'enough' economic case for running enough of a whole railroad to accelerated timings to make the trick work. (And no one, perhaps, is more bitter about this than I am.)
I am reasonably convinced that there are systems of top-down slab-track construction that will support even HAL traffic at high speeds while reasonably maintaining 110mph geometry. (There are also some that won't, but I think testing has established 'which is which' definitively enough...) It remains to be seen whether there will be incentives for freight traffic -- perhaps specialized freight traffic supporting just-in-time-at-both-ends models -- to run at faster speeds in corridors built with the right track systems and support.
#130
daveklepper (#127) I should point out that although the NKP and similar Berkshires were optimum for NKP's fast bridge service, they were (and are) versatile steam locomotives, more versatile than most steam locomotives, have enough power for RELATIVELY low-speed drag service when required, and can be passenger power when required.
I should point out that although the NKP and similar Berkshires were optimum for NKP's fast bridge service, they were (and are) versatile steam locomotives, more versatile than most steam locomotives, have enough power for RELATIVELY low-speed drag service when required, and can be passenger power when required.
That is part of the reason I have such respect for the AMC.
While we are on the strict subject of Berkshire design, I would like to see a revisiting of the A2a Berkshire design, in order to see whether something like that design could in fact be given reasonably flexible versatility over the lower range of practical speeds we were discussing. (Note: not in any way as a 'historic reconstruction' - that can of worms is tight shut.) In light of what the 1938 rebuilding of T&P 610 achieved practically, I remain unconvinced that it is not possible to design a 63"-drivered engine with acceptable augment and inertia forces for those speeds, particularly if modern materials and techniques can be applied.
# 131
( I'd appreciate if the boys could add their post # by themselves without mom's nursing just as Prof Overmod can , thanx )
Overmod I am reasonably convinced that there are systems of top-down slab-track construction that will support even HAL traffic at high speeds while reasonably maintaining 110mph geometry. to run at faster speeds in corridors built with the right track systems and support.
I am reasonably convinced that there are systems of top-down slab-track construction that will support even HAL traffic at high speeds while reasonably maintaining 110mph geometry. to run at faster speeds in corridors built with the right track systems and support.
# 132
( DR Co-Co diesel class )
Hello guys
Ok , I will not offer a word on this subject of diesel – mind it : ! d-i-e-s-e-l ! – powered traction of freight trains in the US :
a – there are different railroad systems in the US , interacting ;
b – they are often more into focusing on bulk traffic not so much handling diverse traffic as RRs in Europe ;
c – they run trains of maximum tonnage by accumulating vast numbers of power units – a direct consequence of specific surrounding conditions in the US , as for instance labor costs , layout of lines , signaling , tracks and train per hour traffic density and other , however generally regarded inefficient by railroad outside the US .
As concerns focus on train speed on European mainlines , I mention just one major point :
Traffic density is generally *much* higher on #1 mainlines in Europe , often so high trains are following each other in block signal distance for hours on end , which asks for precise timing of *all* trains involved *at any point* over the line . Simply to arrive at destination on time just wouldn’t do and a – theoretical – thing like a slow tugging super long freight with a slew of slow diesels up front and spread within the train would cause nothing short of disaster in traffic congestion , in no time holding up trains by the numbers , affecting other trains following held up trains and spreading late running to adjacent lines , so that even days after such an event the effects will be felt and several hundreds of trains will have been affected – the consequential claims for the damage would be beyond any private rail enterprise to pay for . No , there just is *no* line capacity left for any such dilly-dally poke-along trains !
Aspect of very fast passenger train traffic as mentioned by one user has an influence in cases , yet does not explain all of it . ( in fact it has an adverse effect on freight train handling and traffic density in that it implies longer signal block sections and thus tends to expand density of freight traffic ! on fully equipped lines this has been dealt with by means of electronic individual train control )
Besides said traffic density , customers do not want to – or *cannot!* in case of sensible merchandise – wait for their cargo to linger out on the line for days while truck traffic would offer delivery within a day . Modern railways have to compete and since the Fall of the Iron Curtain distances in the EU are increasing with more and more international traffic – in the event to become probably no less than in the US – freight trains have to go fast .
Another aspect is length of freight yard tracks , just not suited to accept US size five digit tonnage trains . Besides , however , especially in mountainous regions , it is considered technically less effective to run vastly long trains which would reach all around half circle turns or extend over several adjacent curves at a time , flange wear – and in the end rail inner edge wear – would become inacceptably high due to the enormous tractive effort needed , causing excessive sideways thrust especially on the leading part of the train as compared to cutting such a load into , say , four or more trains with less flange running resistance , wear and also better handling by the leading engine : there is less surge through the train with brake application / release with less longitudinal thrust accumulation , all of which US freight cars are built especially sturdily and heavily (!) to take up while by watching videos of freight trains up Horse Shoe Curve or other winding mountain lines it appears US RR don’t seem to bother about flange wear nor about resulting train running resistance . Mind , in that context , up-grade freight train speed is like 40 mph on Swiss or Austrian railways for example - this way and only this way it was possible to pass all that cargo over existing old mountain pass lines such as Benner pass , St Gotthard , Simplon as is presently being handled by railways .
However ..! ( and now we’re back to the roots à) .. the one aspect for giving speed a higher status or preference all of you have forgotten about is the very one I had mentioned in the beginning and was the underlying reason for my sketching of preferable train handling with a theoretical modern steam traction :
steam’s typical output curve
with limited starting tractive effort yet hp rate heftily rising with speed increasing and
a clear indication ( as by extrapolating historical development and combining it with improvements partly realized by A Chapelon and others , further improvements possible ) modern steam’s power output curve would be *even more extremely* emphasizing higher speeds with starting tractive effort but showing but mince improvements – all for identical wheel arrangements of course .
All I was saying is : if you would use that type of power you would have basically two ways to choose from : first , do as the diesel powered RRs do and ignore your power’s differing characteristics ; second , accept your power’s output characteristics and adapt traction to make the best of it – and *that!* , mind you , was what I had described in the beginning .
This does not say anything about problems that might be encountered by having to accept other RR’s freight cars maintained and equipped in such ‘economic’ ways as to make them clearly inapt for any speed above some 30 or 40 mph . Logically , fast running implements – and again I did believe this was sine qua non and still mentioning it would be almost insulting to a knowledgeable readership – appropriate track upgrading and maintenance as well as according cars technical upgrading and maintenance for smooth tracking at such speeds .
What commercial water level line speed would I think of with a theoretical modern yet classic type steam traction :
~ 60 mph heavy bulk trains ,
~ 70 mph mixed freight ,
~ 80 mph fast freight
... to offer but a *rough rule of thumb* idea of an appropriate speed range .
What power output @ speed can be expected from modern versions of classic wheel arrangements when designed to service mass per axle rather somewhat reduced relative to the heavy classes of 1940s Super Power :
For example some classic types in a typical modern version all without any fancy onboard stuff
( please do *not* start to argue about plus/minus some inch , ton or hp @ mph , these are but rule of thumb examples , Prof O you know )
Type of wheel arrangement – drive wheel diameter [ins] / engine adhesion mass / engine service mass [t metric] – power output [ihp metric] @ speed [mph]
Mika – 67 / 100 / 140 – 5000 @ ~ 70
Berkshire – 70 / 120 / 190 – 6400 @ ~ 75
Santa Fé – 67 / 125 / 170 – 5700 @ ~ 65
Texas – 70 / 150 / 220 – 7200 @ ~ 70
Allegheny – 70 / 198 / 314 – 9500 @ ~ 65
If that would be enough to compete with diesel traction must be left to each one's consideration or conjecture .
edited a couple of times for corroding typing erroded in posting through the Big Gates of Bill's
#133
blue streak 1 (from post #131) Overmod I am reasonably convinced that there are systems of top-down slab-track construction that will support even HAL traffic at high speeds while reasonably maintaining 110mph geometry. to run at faster speeds in corridors built with the right track systems and support. Way out thought. If 110 MPH HAL track could be built. 1. Install ECP on any freight trains probably only using intermodals cars. 2. Run HrSR passenger trains on these routes that would blend in with the freights. 3. Limit all axel loadings to passenger standards making it easier to maintain class 6 track. 4. Tightly monitor all cars with WILD and other detectors to prevent premature rail wear. 5. have some trains for roll on roll off tractor trailers that will allow truck drivers to meet HOS rules.
None of this is particularly 'way out' -- I think it shows good thinking on your part. If you have not read about the FRA slab-track testing on the HAL loop, I encourage you to do so now (e-mail me if you need references). There are good (or at least good-sounding) reasons why high-performance slab track, even of a class above 6, may not require the adoption of 'passenger axle-loadings' to hold up well in service -- perhaps even up to 125 mph, not just 110. I suspect that the adoption of magic-wear-rate maintenance, good TOR and flange lubrication, and a few other details may suffice to keep the rail steel and head geometry concerns under control.
Quite a bit of benefit can be derived from PTC implementation in these scenarios -- among other things, it inherently provides flexible-length 'block' following for differently-braked consists.
I consider 110-mph corridors to be a logical place to start transitioning to a practical system of ECP braking. Both 'unit' and intermodal consists will be relatively easy to convert, imho. (I have an intermediate system providing some of the benefits of ECP quick action for single-pipe consists, which may be 'enough' for the required safety aspects when PTC is implemented.)
Even with CTC and judicious fleeting at flexible headway, there's going to be some limitation on scheduling the regional-HSR trains (and I generally dislike the idea of facing moves at potentially over 200 mph closing velocity!) Part of this is helped if there's a reasonably large number of stops in the passenger service, as you can operate a slower 'one-speed' freight service around the 'window' actually occupied by a given passenger consist even though its peak or average running speed be higher.
I'm a fan of putting small detectors on each truck to enable distributed remote monitoring of wheel and bearing condition. You'd backstop this with wayside sound/vibration and temperature detectors, and with out-of-loading-gage detection for slipped loads or suspension distortion, etc. I would also strongly advise the provision of some forms of realtime wheel-turning facility so that any consist operating over a high-speed line essentially have true profiling and no flat spotting on all its wheels, all the time.
Your point 5 is intriguing -- are you suggesting, as I think you are, that you'd run an 'iron highway' that operates as I remember some European tunnel 'crossings' doing -- the trucks are loaded and unloaded circus-style as quickly as the drivers can manage, and the tractors stay coupled up for the duration of the run?
The economics I have seen for this kind of operation (most recently for 'train ferry' service from New Jersey to the Northeast and Long Island bypassing NYC) are not quite good enough, but I'd like to see that change (probably via judicious and heavy peak-hour tolls per truck axle both on crossings and toll roads, and perhaps via more generous interpretation of driver compensation and HOS for the time spent 'riding'.).
I like systems that can load and unload in parallel, like the CargoSpeed trailer system (not the intermodal-railcar CargoSpeed) and the parallel sideloading system I worked out in the mid-'70s. These cut train dwell time down to a few minutes even when large numbers of trailers/containers are being exchanged, and allow multiple tractors/chassis to load and unload simultaneously, and have the potential advantage that low-tare-weight cars can be used, the dead weight of all the tractors need not be carried, and there is no potential fire/explosion hazard from the truck fuel, batteries, etc. At least theoretically it gives drivers at the 'endpoints' more of a chance to work close to home, and I'd think it would allow drivers working out of a particular facility to have more familiarity with the local driving environment, conditions, etc.
And yes, all this should have the potential effect of optimizing operation behind steam.
This is all very interesting and you're now jumping from slowing down Q2 engines to speeding up super fast passenger trains on new generation high speed track - which however still makes reduction of mass carried on axle highly recommendable if not mandatory for a number of reasons outside considerations of sturdiness of track or flange wear ( Jesus , if you talk about running with flange contact to rails and want to improve by flange lubrication , this is what is being used to bring down wear on severely curved mountain lines - at 150 to180 or 200 mph as now run by these high energy electric trains you have to do *without* actual flange / rail contact )
However you are again hijacking this thread - seems like your own tracking not only bounces with rail-to-rail flange contact but regularly climbs rails too .
I wouldn't mind at all if you'd open up a thread of your own on FRA slab track and related topics of very high speed running - which definitely does not relate to *any* kind of steam since it is exclusively in the range of electric traction . Again , I wouldn't mind a thread on modern electric traction neither but *this* is *not* topical *here* .
May I courteously ask you to respect this now - thank you .
#135 (in response to #134... which had no posting number on it when I replied... ;-} )
There is nothing I've mentioned that doesn't have a potential impact on running steam on 21st Century main lines in North America, whether or not you happen to agree with the points in question.
However, as a favor to you, and since this is your thread, I will comply with your expressed request going forward.
#136
Hey, I remembered to number my post! Maybe I'm not getting early-onset Alzheimers after all!
All the tech-talk is very interesting, even if my eyes start to cross a bit, but we may be loosing sight of the forest for the trees.
To return to Juniatha's original postulation running steam in the 21st Century:
OK, I'm a realist, a broken hearted realist, so I know there's no way steam is going to return to daily service. So, steam running in the 21st Century is going to be at the indulgence of the Class One 'roads. If they're going to let a steam engine out for a romp on the mainline certain conditions are going to have to be realized:
1) The locomotive is going to have to be reliable. No embarassing breakdowns that will hold up the freight traffic are going to be tolerated, not even the possibility of same.
2) The steam crews and organizations running said locomtives are going to have to be as hard-core professionally as the real railroaders. If they can't impress the pros with how good they are, they're not getting on the mainline.
Now quite possibly this may mean new steam and not rebuilt old steam. If new, put all the improvements in 'em you can. Whatever it is, it has to work. Build a new Hudson, a Niagara, a T1, whatever, as long as it looks the way it's supposed to it doesn't matter what's under the skin. Modern metals, roller bearings, hell even a nuclear furnace as a heat source, it has to be reliable and it has to WORK.
That's all.
Oh, and thanks everyone for your responses to my driver diameter question.
# 137
J -
Some interesting thoughts, but I think you have mischaracterized US freight railroad operation to some extent.
There are really four distinct markets the US railroads serve. They are intermodal, bulk commodity unit train service, finished automotive vehicles (and auto parts) and "loose carloads".
From last week's stats:
Intermodal = 46%
Coal = 20%
Grain = 4%
Finished vehicle and parts = 3%
everything else = 27%
This somewhat overstates intermodal loading because they are counted by trailer/container, not by rail car. (a common conversion factor is 1.7 boxes = one car load)
The level of service provide tends to be dictated by the value of the commodity. Bulk stuff isn't often worth very much, so slow and steady wins the race. Intermodal boxes are usually loaded with consumer goodies, so it pays to move them pretty quickly.
Intermodal trains tend to get powered by HP/ton standard, which directly correlates with running times. Schedules are set to fit the markets served. For example, NY to Chicago is typicall second morning delivery - which is the same a single driver with a trailer can do - and it fits well with the daily and weekly logistics cycles of the industries involved.. It would not benefit getting the average trains speed on these train up from 35 to 45 (max authorized speed of 60 mph). In fact, as intermodal traffic grew, RRs found that they could lower the HP/ton and lower the max authorized speed from 70 to 60 mph and still compete as well for truckload traffic in the lanes served.
Intermodal is the area where highway truckloads are being converted to rail intermodal at a great rate. The challenge isn't generally to figure out how to run trains faster as it is finding money to build or enlarge intermodal terminals.
Bulk commodity stuff moves in unit trains. These trains are powered to a) get over the ruling grade w/o stalling - primarily and b) move along well enough to not get in the way of the other trains.
The"loose carload" traffic velocity is primarily a function of dwell between trains at classification yards. The speed of the trains is not as important as the design of the train service network to minimize the number of times the trains have to be classified and switched. As this has become better understood, more and more, merchandise trains are being powered more like unit trains and less like intermodal trains.
Fuel is a large cost for the railroads and "speed kills". It's just regular old physics at work. Aero drag goes up with speed squared. Reducing HP/ton has been the primary "lever" that RR management pulls to improve fuel economy - either directly or indirectly.
So, what are the locomotive performance parameters that fit these classes of service? As it turns out, a 4500 HP locomotive with about 150,000# of tractive effort works pretty well in most cases. If you power a unit train with these, and put just enough on to get the train up the hill, it has just enough HP to make decent speed on the flat. If you put them on an intermodal train or, in some cases, merchandise trains to make schedule (HP/ton) you might not come close to needing all 150,000# TE, but the penalty is rather small - a little bit of wasted capital and a little bit of fuel lugging around a couple extra traction motors. There may be substantial gain in utilization having a "universal" locomotive.
If you are willing to have a segregated fleet, then you might field two types of locomotives - as BNSF does.
An example from history: N&W replaced three very different kinds of steam, Y6B for loaded coal, A class for merchandise service, and J class for passenger with one class of diesel locomotive, the GP9.
The ratio of HP/max TE for a GP9 is nearly identical to an SD40 and an SD80MAC (Conrail was right! Everyone else was wrong!), and only a bit higher than that for current production AC locomotives.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
# 138
Good response Don, but I don't think I've mischaracterized the current railroad scene at all, and if any of the pros want to correct me on this I stand ready to be corrected.
See, what I think of is the Union Pacific allowing only their own steam on their lines, Why do they do this? Well, Steve Lee explained it several years ago. Big Steve said it was the UP's responsibilities to their shippers that made them adopt the policy. If there were going to be any breakdowns that affected shipments, and the speed of that shipment is irrevelant by the way, the UP was going to have to take responsibility for it since it's THEIR road, and it wouldn't do any good to blame it on any steam preservation group they let out on the line. A UP problem with a UP engine is a lot easier to explain to a customer than saying "Well, those PEOPLE told us they could be trusted!"
Good policy, bad policy, I leave it up to you to judge. Hence my statement that whatever new steam is built is going to have to WORK, and work reliably, or it's never going to get the chance to do anything but chug up and down museum trackage or some lightly trafficked short line.
See where I'm coming from? It's great that there's some Class Ones with some classy ones running them that will allow steam on their 'roads, but always keep in mind that for those folks it's a business, not a playground. Steam ops have got to be as professional as possible, maybe even more professional than the pros themselves.
# 139
This looks like a rate-maker's or traffic manager's view of life.
Revenue in transportation is generated on a unit per distance travelled: ton/mile, pax/mile, etc. Capacity is ability to generate revenue per unit of time. Up the average speed and the capacity increases. That is why the NYC and the Pennsy generated about the same revenue but the Pennsy needed twice the physical plant because it had half the average speed of the NYC.
The slower the speed, the higher the operating cost for all items except fuel. The capital cost for the physical plant remains the same.
Another way of looking at it: when The Great Wall Express was instituted between Beijing and Tianjin as a train set, the service went from 4 trains each way each day to 10 trains each way each day. Same number of seats on the single train set, simply faster speed enabling it to make more trips per unit time.
Same reason that ships now are predominantly container or bulkers. Breakbulk simply spends too much time in port being loaded and offloaded and not enough time in revenue service moving cargo.
Point being: when diesels arrived, speed took a hit because the diesels were underpowered relative to their tractive effort. And have been all this time, relatively speaking. Being simply electric locomotives with self-contained generators, they excelled in the hills and on grades relative to steam but in flat territory they were notably outperformed by steam in the 30mph to 90mph zone. True electrics are another story since they are not self limited in hp. Witness the FS in Milano with 16-20 cars on a passenger train and a single 6000hp electric (back in 1960's). A single diesel would have been 1/3 the hp for the same tractive effort.
# 140
puffyThe slower the speed, the higher the operating cost for all items except fuel. The capital cost for the physical plant remains the same.
Correct. But, by and large,in the world of North American rail freight service, maximum authorized speed has little correlation with asset velocity - which is the thing driving cost. For example, loaded freight shipments only spend about 20% of their time on trains. Also, NS NY to Chicago intermodal schedules do not differ in end to end speed from the original PRR TrucTrain or NYC SuperVan schedules significantly, despite running at much lower HP/ton on a fixed plant with far fewer tracks with a lower MAS.
# 141
puffyPoint being: when diesels arrived, speed took a hit because the diesels were underpowered relative to their tractive effort. And have been all this time, relatively speaking.
Correct. Another way of putting it would be that steam was overpowered relative to it's starting tractive effort. Maximum train speeds may have taken a hit, but asset velocity did not.
Diesel locomotives are a good fit for North American freight service on the rail network.
# 142
Hi Oltmannd
quote : >> Diesel locomotives are a good fit for North American freight service on the rail network.<<
I don't know - it sounds a bit like one always having had nothing but sandwiches with just butter on and believing it’s best , never having tasted apple pie with fresh cream on and declining it .
( I used to have lots of cream and cakes in my teen times when it used to be all 'burned' in no time leaving nothing gained by inches nor lbs and turn it down nowadays *in spite* of knowing how delicious it can be if well prepared with good biological ingredients - but that's another story !)
Sure , there are problems with long distance wiring and powering , sure adhesion and raw low speed tractive effort are higher ranking in American railroading ...
In Europe , trains on intensely used mainlines do not run fast just because of the customers asking ( that is a factor , although not with all the shipments , as rightly pointed out ) but because higher speed means higher amount of traffic passed through per hour ! As again has been mentioned in fact it also is a means of harmonizing train succession in view of fast moving passenger service on the same tracks ( time and again it is part of contemplation on future development of rail traffic to physically separate freight trains from passenger trains by using special tracks each ; it has been realized with some new built TGV lines in France and no doubt is technically successful , yet regarded as excessively expensive by other railway's managements ) Last not least , yards are no large enough to accommodate freight trains of lengths as common in the US . Mind , practically pure freight hauler railways are virtually non-existent in Europe ( except for some recently sprung up private rail business in a barn as headquarters , their rolling stock consisting of but a handful of locomotives hauling other companies' cars relying on slots allowed on national railways networks )
JuniathaMind , practically pure freight hauler railways are virtually non-existent in Europe ( except for some recently sprung up private rail business in a barn as headquarters , their rolling stock consisting of but a handful of locomotives hauling other companies' cars relying on slots allowed on national railways networks )
Well, except for DB Schenker....they are not so small.
I had a nice tour of Machen Yard outside Hamburg a couple years ago. They invest in a lot of "jewelry" order to get their single block, single locomotive, single crewman trains out of the yard and accross the network in a big hurry. Since train productivity is so low, asset turns is the only way to get into the game.
Oltmannd
O-M-G DB Schenker is a sub-division of DBAG ; DBAG is successor of both DB and DR ; both were national systems Germany West / East . DB-S was formed simply by DBAG having bought up Schenker .
And as I said there are some private enterprises - again I have to point out the obvious :
This is *NOT* the place to make references to *ALL* those enterprises there are in Europe dealing with rail transport .
What I wrote was *the GENERAL picture*
Inevitably , it is the nature of a general picture that some lesser details get lost and thus it is always possible to point to one of those and remark : you dropped this or that detail !
Do you really want to read a list of some several hundered enterprises and what they deal with ?
Would you go through the list scrutinizingly and compare it with what *you* know of these enterprises and if you see a deviation from what you think is right , sit down get your keyboard and hammer out a correction ?
and if I may ask you : what for ?
Be sure I didn't forget about DB Schenker , I didn't mention for a reason , see above - just lean back and relax , the world goes on turning .
DB Schenker is kinda the proverbial 900 lb gorilla of rail freight service in Europe. If you're looking of an example of the "general case", they'd be it. Yes, they are "owned" by the state, but they behave very much like a private enterprise.
So, if you want to compare and contrast European rail freight operation in the general case with that of North America, and understand motive power application, using DB Schenker ain't a bad place to start.
Schenker has to buy "slots" on the national network, same as those small companies operating out of a barn....
>> Yes, they are "owned" by the state <<
and *THAT'S* the point .
Full stop .
Hi Juniatha.
great post by the way. what are the perspectives of steam? well..... i think that we want to run and restore something from a by gone era. I think that we are trying to give show what it was like to run a steam locomotive from back in the day. but to also preserve the history and to enjoy what steam is all about. i don,t think we should them to the ground sot of speak. but to keep them in prime condition. if you put all the money and time and effort to make it look like what it did when it first rolled out of the shop. it makes no sense to go and do the oppsite. you want to keep the engine in tip top shape. take the nickle plate road 2-8-4 765 for example. they restored her to brand new status. they have made shure that they keep her that way. in you question why run main line steam?
well.... why not? we used to do it every day of every moonth of every year. but it is also to show what it was like back then. i think it ,s to have a engine ( streetch their legs ) sort of speak. we wanna relive what it was like to run a big or small steam locomotive on the mail line. we also want to pass on the tridition to the next generation. cause we need to keep steam going. plus running a big steamer on a little distant back and forth.... and back again gets old. we wanna let them free on the tracks they they used to run. plus it was what it supposed to be. no what new steam will we see? gee. yuo put me in a spot.
i think we are in a age where we are seing steamers that used to run back in the 80's and 90's then put on display and then taken off and restored to steam return. i also think that we are seeing the return of the (classic,s). now what i mean by that. I may be 21. but to me the classic,s was the 1980's to the 1990's. where you had the pennsylvania 4-4-0 1223 and 4-4-2 7002. the southern pacific 4-8-4 4449. union pacific 4-8-4 8444. cottten belt 4-8-4 819. milwaukee road 4-8-4 261. reading 4-8-4 2101, 2102. 2101. norfolk and western 4-8-4 611. santa fe 4-8-4 3751. we had others.too. like frisco 4-8-2 1522. norfolk and western 4-8-0 475. great western of colorado 2-10-0 90. frisco 2-10-0 1630. articulated 4-6-6-4 3985 from union pacific and norfolk and westrn 2-8-8-4 1218. and much much more... we have seen and continue to see more of them return. we are now seeing the 611 return. the cotten belt 819 being restored to running order. we are seeing the return of santa fe 4-8-4 2926. we have now two 2-6-6-2t's running in america. the first to run in america was black hills central 2-6-6-2t 110 in hill city. witch i live in rapid city in south dakota. and have been to multiple times. and now clover vally 2-6-6-2t 4. we are seeing a bigger articulateds return as well. cheeapeake and ohio 2-6-6-2 1309. another logging 2-6-6-2 but with a tender return in washington state. we are seing a big boy return as well. we are seeing the return of little engines as well.
Now... what keeps them going and needs to keep them going is us. SO many steamers that should have returned fell short. what the problem with that is the fact is the person give up on it. if you work so hard to only give up is a problem. you need to stay commited in it. because if you give up then that is one engine lost and the heritaige is loseing more people to help. the generation today is more involved ith games and etc. yes a few have taken the reins and keep it going but we need to keep it going.
NOW........ what steam will we want to see in the next comming years? well good question. may i point out tha we have seen new engines built by groups that were scrapped. david klokehas built the jupiters sister. 4-4-0 the Leviathan. and the york for a tourist railroad. now i bet you mean BIGGER engines right?.
well. we got a long way to go. what i mean by that is that we need to catch up with our friends in the u.k. they have been building engines and rebuilding engines for years. they have made brand new boilers for engines. and have even built a brand new 4-6-2 peppercorn class locomotive in the last few years. and have even states that the construction of a prince williams 2-8-2 class. leaves us in the dust. but we can catch up. i think with the T-1trust that is going to build the pennsylvania class 4-4-4-4 class but with a number that wasn,t on the roster. is a good start.
i hope to see ore engines like that. what i think we should make brand new that we haven't seen is this. i think we should rebuild a new york central hudson. i think we should make a brad new stam locomotive that is efficient. now.... that said. there was a programe that was called A.C.E. it involved the cheasapeck and ohio 4-8-4 614. witch was the last coal burning super power steam locomotive made. she was capable of puling a 19 car train at 70mph+ with little or no smoke consistenty. she was proven to be better then the modern diesel. and is still considered. but the point was can a Modern day coal burning steam locomotive be more powerful and efficient than the modern day diesel? the answer with the 614 was yes. but just when she was makeing progress the funding was cut at the worst time. people was just too far shure that a steam engine was done and would not accept the fact that it could. but we now have a second chance. with a group wanting to use a santa fe 4-6-4 and make it run on a renewable fuel. made up of pellets made by chewed up railroad ties. it cannbe done.
well i have enjoyed writting this. thank you for letting me to take the time to write this. sincerally: Joseph Newstead. AKA: Joseph the steam buff.
Joseph ,
herewith I declare :
You *ARE* one steam buff .
no doubt
today
no question about -
Jippy-Yay !
With a "choo-choo"
( O-M-G these colors are auhwful , miss option to compose my own )
awe.... thanks Juniatha.
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