Trains.com

Classic Trains in Computer Simulations (Trainz, Train Simulator 2020)

29824 views
81 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Friday, July 12, 2019 4:50 AM

The NYC J-3a Hudson and Dreyfuss Hudson (Boxpok drivers) for TS2019 (Train Simulator 2019), created by DSGDDR (Darlan Gomes) and RailWanderer (John R. Williams), is already available at Digital Railroading for FREE :

 

| Part One: Dreyfuss Hudson hauling 800+ tons | | Part Two (15:49): Dreyfuss Hudson hauling 1400+ tons | Part Three (30:21): NYC J-3a Hudson hauling 800+ tons| ====(Click "Read More" for the download link if you are watching on PC or laptop)====

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Tuesday, June 4, 2019 6:31 AM

I found four sets of rendering of the UP "Big Boy" front and rear engine bed from the gallery of Autodesk's community, a 3D model created by a retired aerospace engineer Mr. William Jones (his profile and other works: https://gallery.autodesk.com/fusion360/users/JWJ6PVFH7GTY ) for his live steam engine project. He was looking for someone who could cast the beds for him 2 years ago.

https://gallery.autodesk.com/fusion360/projects/81222/locomotive-bed-front-engine-union-pacific-big-boy 

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Wednesday, May 29, 2019 3:30 PM

I am glad to see that many youngsters keep expressing their passion for the steam engine by creating the 3D train models for computer simulator and model railroading. This 3D artist is creating a new model of the PRR S1 6-4-4-6 for the "Train Simulator 2019". If you like his work, please don't hesitate to show him some love! 

http://railworksamerica.com/forum/viewtopic.php?f=50&t=21210&p=243609&hilit=Pennsy#p243609

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Tuesday, May 28, 2019 12:22 PM

Overmod
Jones1945

The PRR Baldwin BP-20 "Passenger Shark" and the postwar Broadway Limited is available for train simulator now

Have they modeled the actual physics for these locomotives, particularly their rapid acceleration potential compared to contemporary competition (and even some modern designs?)

These things could accelerate radically better than, say, E units, both from a standing start and in the low-to-intermediate range above the low-speed motor limitations for hexapoles.  That is one substantial reason they found a home on the Long Branch commuter trains, and were happily kept running until PRR for "political" reasons decided to get rid of all the minority locomotives on a prioritized basis in 1963. 

Yes, Mr. Overmod. The physic engine in DTM's Train Simulator aka TS2019 is far better than Trainz in my opinion, the vehicle dynamic is calculated and rendered in a much more realistic way. *Base on my observation, the rail and the wheel are 3D solid objects so that friction between the rail and the driver of the locomotives was calculated and rendered. Unlike Trainz, where the rail and the driver are just a 3D mesh with surfaces. Therefore, if you create a driver with a shorter axle length than normal in DTM's 2019, the wheel will be swaying left and right on the track.

However, many users suspect that the script of the Broadway Limited is bugged, it seems that the train break is applied all the time and can't be released, causing brakes dragging on the whole train. We stated publicly on our YouTube channel that we inclined to not recommend this product until DTM fixed the problem, that's why I didn't provide the direct link of the DLC. I believe our forumer who interested in Train Simulation are smart enough to read the reviews before buying, although the DLC only worth about 15 USD and we still purchased it after reading the reviews. 

Regarding the realism of this DLC/Add-on, I would like to leave it to you to decide. I recorded a video which consists of 3 parts, part II starting from 10:00, the last one starting from 24:23, I will keep adding timestamp and description on the YouTube page and here as well. The Video is unlisted but it should be working for everyone who knows the link of it:

PRR BP-20 TESTING 

New Haven to New York Penn Station, 0-0.6% gradient, 545-1245 tons stock) 

Part I: BP-20 A unit + 545 tons passenger stock: 52mph reached (08:54), break Test (09:05) 

Part II ( 10:00 ) A-B-A unit + 545 tons passenger stock: 60mph reached (12:39), 65mph reached (13:50), hitting top speed 70mph (16:48), testing the speed of the A-B-A set (18:35), hitting 84.3mph (21:34), break Test (22:04) engine full stop (23:36)

Part III (24:23 ) A-B-A unit + 1245 tons passenger stock: 33.1mph reached (29:33), 39.7mph reached (32.40), waiting for Overmod in the observation car (35:56), passenger car truck close up and loco brake test (36:50), emergency brake testing (37:29),train full stop (37:51), testing the speed of the A-B-A set (38:54), 82.5mph reached (42:42), emergency brake testing (43:16), full stop (44:02)

 https://www.youtube.com/watch?v=jPf8b9IKVVY

Overmod

The potentially sad part of this is that PRR famously rebuilt a set of Sharks with Alco running gear, but little of the Westinghouse electrical gear was compatible so what you wound up with was essentially an Alco locomotive 'above the deck'.  Meanwhile of course PRR had rather famously tested a six-motor 2400hp Alco as a commuter locomotive and found it really capable ... but had no money to spend on acquiring a fleet for what was by then a money-losing set of operations.  Might have been interesting to see what a government-sponsored rebuild after the mid-Sixties might have involved, with a 2400hp 251 powering hexapole motors (or, grudgingly, heavy-frame 752s or even 751s if you needed to keep it 'all in the family' with Alco motor-parts support).  Project might even have kept Alco in the locomotive market longer...

Ah, "the saddest words of tongue or pen ..."*

*(I could quote the original, but both the scansion and the meter suck... I use Euclid's famous phrase to fill it out in my version) 

I am really not familiar with PRR's diesels, I assume that the Alco diesel you mentioned was RSD-12 isn't it? I think the front end design of the Alco RS11 was quite good looking, if the RSD-12 which had a similar front end design had a chance to became the prime power of PRR's commuter trains (or even became the prime power for crack trains), that would be very cool. (I don't like diesel for freight service or ATSF's EMD F7s just because they were using a 4-wheel truck and had a rather short body length)

The scenario of Maud Muller and the Judge could be applied to the train simulation world. It might have been the best educational software if Microsoft didn't cancel their "Train Simulator 2" in 2002 (?), it would have been a perfect combination of DTM's Train Simulator and Trainz offering up to date graphic, best physic engine and diverse (Free) content.

Now, folks who love America's classic locomotive have no choice but to use Trainz, which allow user to create their own content (but with less impressive graphic) while DTM's Train Simulator mainly focus on EU market and seldom creating any classic train content of North America.

But we probably will never understand the Eternal's will...... only God knows what would have happened if Maud Muller married the Judge! Though, in real life,  I am quite sure that Blanche Monnier's mother was as vicious as the devil!

What might have been if Monnier eloped with her boyfriend that night they hesitated? 

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Monday, May 27, 2019 9:55 AM

Jones1945

The PRR Baldwin BP-20 "Passenger Shark" and the postwar Broadway Limited is available for train simulator now

Have they modeled the actual physics for these locomotives, particularly their rapid acceleration potential compared to contemporary competition (and even some modern designs?)

These things could accelerate radically better than, say, E units, both from a standing start and in the low-to-intermediate range above the low-speed motor limitations for hexapoles.  That is one substantial reason they found a home on the Long Branch commuter trains, and were happily kept running until PRR for "political" reasons decided to get rid of all the minority locomotives on a prioritized basis in 1963. 

The potentially sad part of this is that PRR famously rebuilt a set of Sharks with Alco running gear, but little of the Westinghouse electrical gear was compatible so what you wound up with was essentially an Alco locomotive 'above the deck'.  Meanwhile of course PRR had rather famously tested a six-motor 2400hp Alco as a commuter locomotive and found it really capable ... but had no money to spend on acquiring a fleet for what was by then a money-losing set of operations.  Might have been interesting to see what a government-sponsored rebuild after the mid-Sixties might have involved, with a 2400hp 251 powering hexapole motors (or, grudgingly, heavy-frame 752s or even 751s if you needed to keep it 'all in the family' with Alco motor-parts support).  Project might even have kept Alco in the locomotive market longer...

Ah, "the saddest words of tongue or pen ..."*

*(I could quote the original, but both the scansion and the meter suck... I use Euclid's famous phrase to fill it out in my version)

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, May 26, 2019 7:35 AM

The PRR Baldwin BP-20 "Passenger Shark" and the postwar Broadway Limited is available for train simulator now.

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, May 19, 2019 5:30 AM

New NYC Husdons for "Train Simulator 2019" work in progress.

Railworks "Train Simulator 2019" offers a much higher level of details, lighting, sound and texture rendering. At 18:10 in this video, the 3D artist demonstrates a feature that can't be found on "Trainz" (another train simulator) or even on my HO scale brass train collection in real life. Though Trainz offers a much higher degrees of freedom in the game and much easier content creation, sharing and editing. (If you want me to add your face on the front end of a train, just send me the pic)

The NYC Hudsons, a PRR T1 (Phototrype) and PRR Class G5 will be part of the content of a new route which simulates the NYCRR Water Level Route. I heard a PRR S1 6100 is also work in progress by another artist. 

It will be released as freeware and I don't know the 3D artist in person, but I think he or his team deserve some support and exposure! Coffee

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, February 24, 2019 3:15 AM

 2D, 3D Art and Animation for Classic Trains:

~ 18-car 20th Century Limited Speed Test ~ 

https://www.youtube.com/watch?v=AyEj4Imvm2A

 

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Saturday, February 9, 2019 1:18 PM

BaltACD

President class engines were 4-6-2 Pacifics.  Engine 5304 was streamlined for a brief time in the 1938ish era for it's use on the Royal Blue between New York and Washington.  Then in 1947 engines 5301-5304 were streamlined for their use on The Cincinnatian, first between Mt. Royal Station in Baltimore and Cincinnati; then in 1950 account low patronage The Cincinnatian was changed to run between Detroit and Cincinnati.  The Cincinnatian engines retained their streamlining until they went to the scrappers in 1956 or 1957.  The B&O Museum the class original, Engine 5300, remains as a static display.

K&L Trainz has produced a video of the Cincinnatian's run between Mt. Royal and Cincinnati.  My only 'nit' to pick with it was they did not use B&O's legendary CPL signals in their rendering.  A second 'nit nit' was The Cincinnatian changed engines in Grafton and their rendering shows the original engine continuing through to Cincinnati

B&O P7 #5304 was the only P7 to be streamlined twice in its life, I think the design of Otto Kuhler was nice, and he said that Raymond Loewy's office asked him and B&O for permission to use the bullet nose design. The second streamlined shrouding of 5304 was designed by miss Olive Dennis.

K&L Trainz is a 3-man team so they have their limitation, but of course, there is still rooms for improvement! I wish they can make a route of America set in the 1940s so that I can drive my trains without squeeze down under the UK's overpass. Smile

 

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Saturday, February 9, 2019 7:45 AM

Jones1945
 
BaltACD

Still find it amazing that the trains 'squeeze down' to fit through some of the overpasses.

Stories passed down from my Father and Grandfather about the B&O and PRR 'racing' from Washington Union Station for about 2 miles to a point just railroad East of the B&O's F Tower.  In the early 20's the PRR trains with K-4's would beat the B&O consistantly.  When the B&O obtained their P-7 President Class Pacifics in 1927 the tide went to the B&O trains with P-7 consistantly beating the K-4 led Pennsy train.  When the PRR electrified in the middle 30's with the GG-1's, the juice jacks were by far faster accelerating with the horsepower and low speed torque advantages of the electrics. 

 

Love your sharing, Balt! I will try to find a B&O 4-6-0 3D trains to render the race mentioned by your father and Grandfather! If there was a steam engine hauling considerable passenger load had an even better accelerating rate than the GG1, that would have been the real "Train of Tomorrow". :P 

Trainz - "Fight of the Century" 1939 (Part I)

 

President class engines were 4-6-2 Pacifics.  Engine 5304 was streamlined for a brief time in the 1938ish era for it's use on the Royal Blue between New York and Washington.  Then in 1947 engines 5301-5304 were streamlined for their use on The Cincinnatian, first between Mt. Royal Station in Baltimore and Cincinnati; then in 1950 account low patronage The Cincinnatian was changed to run between Detroit and Cincinnati.  The Cincinnatian engines retained their streamlining until they went to the scrappers in 1956 or 1957.  The B&O Museum the class original, Engine 5300, remains as a static display.

K&L Trainz has produced a video of the Cincinnatian's run between Mt. Royal and Cincinnati.  My only 'nit' to pick with it was they did not use B&O's legendary CPL signals in their rendering.  A second 'nit nit' was The Cincinnatian changed engines in Grafton and their rendering shows the original engine continuing through to Cincinnati

Never too old to have a happy childhood!

              

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Saturday, February 9, 2019 2:14 AM

BaltACD

Still find it amazing that the trains 'squeeze down' to fit through some of the overpasses.

Stories passed down from my Father and Grandfather about the B&O and PRR 'racing' from Washington Union Station for about 2 miles to a point just railroad East of the B&O's F Tower.  In the early 20's the PRR trains with K-4's would beat the B&O consistantly.  When the B&O obtained their P-7 President Class Pacifics in 1927 the tide went to the B&O trains with P-7 consistantly beating the K-4 led Pennsy train.  When the PRR electrified in the middle 30's with the GG-1's, the juice jacks were by far faster accelerating with the horsepower and low speed torque advantages of the electrics.

Love your sharing, Balt! I will try to find a B&O 4-6-0 3D trains to render the race mentioned by your father and Grandfather! If there was a steam engine hauling considerable passenger load had an even better accelerating rate than the GG1, that would have been the real "Train of Tomorrow". :P 

Trainz - "Fight of the Century" 1939 (Part I)

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Friday, February 8, 2019 8:24 PM

Jones1945
Can I call this 3D Art and Animation of Classic trains?

NYCentral Dreyfuss Hudson and the PT tender is done: 

Thank you for watching. 

Still find it amazing that the trains 'squeeze down' to fit through some of the overpasses.

Stories passed down from my Father and Grandfather about the B&O and PRR 'racing' from Washington Union Station for about 2 miles to a point just railroad East of the B&O's F Tower.  In the early 20's the PRR trains with K-4's would beat the B&O consistantly.  When the B&O obtained their P-7 President Class Pacifics in 1927 the tide went to the B&O trains with P-7 consistantly beating the K-4 led Pennsy train.  When the PRR electrified in the middle 30's with the GG-1's, the juice jacks were by far faster accelerating with the horsepower and low speed torque advantages of the electrics.

Never too old to have a happy childhood!

              

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Friday, February 8, 2019 2:12 PM

Can I call this 3D Art and Animation of Classic trains?
NYCentral Dreyfuss Hudson and the PT tender is done: 

Thank you for watching. 

Tags: 3D Art , Animation
  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Tuesday, January 29, 2019 9:43 AM

Working on it:

I am not going to re-skin the 20th Century Limited train set to 1940s scheme. Thank you K&L TrainZ for letting user reskin their 3D model! 

In case you feel extremely bored:

CoffeeSmile, Wink & Grin

Tags: PT tender
  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Monday, January 21, 2019 5:11 AM

Flintlock76

Well. That Pennsy engineer must have been asleep at the switch to have let the Century get that far ahead of him!

No matter, he more than made up for it!

Of course, we have to remember that both NYC and PRR officials always insisted there was never  any race between the Century and the Broadway!  Whistling  Smile, Wink & Grin  Laugh 

Or maybe the S1 engineer was just messing around with the Century? Smile I know it was not a fair "race" since S1 was too powerful, but it is all for fun. I think a NYCentral J3a vs PRR K4s would be a nicer match. 

  • Member since
    January 2019
  • From: Henrico, VA
  • 9,728 posts
Posted by Flintlock76 on Sunday, January 20, 2019 7:13 PM

Well. That Pennsy engineer must have been asleep at the switch to have let the Century get that far ahead of him!

No matter, he more than made up for it!

Of course, we have to remember that both NYC and PRR officials always insisted there was never  any race between the Century and the Broadway!  Whistling  Smile, Wink & Grin  Laugh

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, January 20, 2019 12:09 PM

5 PM departure of the 20th Century Limited (Unstreamlined J3a + PT tender): 




PRR S1 #6100 chasing NYC Dreyfuss Hudson at 100mph:

Thank you for watching. Drinks

 

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, January 13, 2019 10:20 AM

I want to share one more video before I start re-skin the PT tender for the Dreyfuss Hudson. This is a video I made earlier and never think I would share it on YouTube. In this video, you could see the Dreyfuss Hudson have better acceleration rate with much lighter load behind her while the PRR T1 could reach higher top speed.

Nothing unpredictable, just for fun! Stick out tongue

 

This post is dedicated to NYCentral's Dreyfuss Hudson and the 20th Century Limited, therefore I can promise you that the next video is all about NYC's renowned trains, including the Niagara and special guests.  Coffee

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Sunday, January 13, 2019 12:06 AM

BaltACD
 

Great effort!

Minor complaints - NYC and most US roads operate on the right hand track in double track territory.  The 20th Century, I belive had a 5 PM departure and was rarely on the track in the early afternoon as your lighting would indicate. 

Thanks a lot, BaltACD! haha, I knew people will mention about the "driving on the wrong side" thing, but no worries, I am gonna make another video for another Dreyfuss Hudson which using Boxpok drivers.

The time was set in the early morning in this video for better lighting so the next video will show the Century depart at 5 PM, but since the route I used run north to south in the UK so the shadow on the train probably won't be historically accurate. I am still searching for a proper route set in America for testing these high-speed engines. 

On the other hand, I am gonna add more cars to the 20th Century. IIRC the maximum length of the Century was 18 cars wasn't it? Smile

Flintlock76

Well you drove that Dreyfuss pretty well Mr. Jones!

A lot better than this kid drives his streamliner.

https://www.youtube.com/watch?v=4Ox3IAwYL2w  

By the way, how'd you get the locomotive to pass through the bridge without wrecking it?

Oh, I know, it's a "Ghost Train!"  BOOOOOOO!!!   A dream of things past!

Thank you for the kind words, Wayne. Those streamliners in that cartoon were actually quite beautiful! Note the beautiful streamliner only exist in the kid's dream while in "reality", we can see an unstreamlined engine before his dog saved him.

As you might have noticed that in the 3D world, not all object is solid but just a rendering. From my understanding, both train simulators available on the market don't want to encourage people to use them as a "trainwreck simulator" so if the user creates his own route and place a house in the middle of the track, the program won't simulate a train accident like Microsoft Train Simulator of 2001. 

But I know there are some games which can show you how a car or object will be damaged when hitting obsoletes, like this one:  

CoffeeLaugh

  • Member since
    January 2019
  • From: Henrico, VA
  • 9,728 posts
Posted by Flintlock76 on Saturday, January 12, 2019 7:05 PM

Well you drove that Dreyfuss pretty well Mr. Jones!

A lot better than this kid drives his streamliner.

https://www.youtube.com/watch?v=4Ox3IAwYL2w  

By the way, how'd you get the locomotive to pass through the bridge without wrecking it?

Oh, I know, it's a "Ghost Train!"  BOOOOOOO!!!   A dream of things past!

 

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Saturday, January 12, 2019 4:44 PM

Jones1945
This is the first video of me "driving" the 3D NYCentral Dreyfuss Hudson and the 20th Century Limited in the Trainz Simulator, more video will be uploaded for fun! 

 

Great effort!

Minor complaints - NYC and most US roads operate on the right hand track in double track territory.  The 20th Century, I belive had a 5 PM departure and was rarely on the track in the early afternoon as your lighting would indicate.

Never too old to have a happy childhood!

              

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Friday, January 11, 2019 10:29 PM

This is the first video of me "driving" the 3D NYCentral Dreyfuss Hudson and the 20th Century Limited in the Trainz Simulator, more video will be uploaded for fun! 

 

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Friday, January 4, 2019 6:55 PM

I am not the developer of any train simulation product but a user of them. I am afraid that only forum member who knows how different 3D physics engines work and the formula they are using could give you a satisfactory and satisfying answer.

Rendering of wheel slip of a locomotive is not something new, the Microsoft Train Simulator from 2001 can render a locomotive wheel slipping if the engineer(user) applies too much power to the drivers. 

At least it is historically correct that PRR S1 #6100 was prone to wheel slip and "starting problem". If a simulator using 3d physics engines could not simulate such a situation, it is not a realistic simulator in my book. 

What a 3D physics engines in 2009 can do:

This is another train simulator  "Railworks Train Simulator", the rival of Trainz Simulator. The game using a better graphics engine but focus on the UK and the EU market. Editing the configuration files in this simulator or creating your own trains is for "PC Guru" only. This video shows how it simulate wheel slip of an engine.

  • Member since
    February 2005
  • 2,366 posts
Posted by timz on Friday, January 4, 2019 12:15 PM

Jones1945
Shutting off the throttle, adjust the reverse gear to a shorter cutoff (around 20%) is the only way to successfully starting the train on the level track in the simulator.

Which suggests your simulator assumptions are wrong. How does your simulator decide the engine is supposed to slip?

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Thursday, January 3, 2019 5:56 PM

Overmod

 

...In spite of this, I believe what Jones1945 is actually saying is not that the train 'starts better' with 20% cutoff, but that it just slips wildly and produces no effective TE until cutoff is reduced to that point (which might indicate that the throttle steps or control are too crude).  I hope he will provide a bit more detail (or some video clips!) showing what is going on.  In actual practice 'driving on the throttle' with the valve gear kept down in the corner usually reduces slipping, for a variety of reasons...

...Something Porta proposed to get around the starting consequences of 'limited cutoff' in the ACE3000 was the use of what he called "Weiss ports" (which were also used in some PRR locomotives under a different name) - these are very narrow ports near the end of the cylinder which are fed steam early even when cutoff is limited by port placement or design otherwise, or is advanced somewhat.  This has the effect of eventually increasing cylinder pressure at low cyclic rpm for better starting without compromising design or tuning of the main ports and valve gear for more efficient operation at higher speed.  But these are not going to help the effect of short stroke and low relative rod angularity in starting a heavy train at low speed...

...I have to think the reported effect is a programming artifact, especially since Jones1945 notes the program does not take into account any of the special characteristics of valve gear.  If 'horsepower' is calculated in the program with something like modified PLAN, it might suffice to use a common piston-rod thrust at nearly full boiler pressure over the portion of the stroke up to peak rod angularity, and then calculate the change in torque in, say, 15-degree increments (as Wardale did) for the resultant of the two cylinders and get this translated into wheelrim "pull" (and thence drawbar TE).  For the timespan mentioned to get a 'start' this should be a reasonable first approximation of reality...

 

 
I will post the video on youtube after I found a way to improve the quality of it (the testing video I uploaded was an "antique" 360P clip).
 
Overmod explained what I was trying to say and summarized the limitation of the simulator and what probably happened when I using it(thanks).
 
If I starting the PRR S1 with the reverse gear in the maximum cut-off position (full gear) and maximum throttle, all drivers will be sprinting nonstop without moving the engine forward. Shutting off the throttle, adjust the reverse gear to a shorter cutoff (around 20%) is the only way to successfully starting the train on the level track in the simulator. (Adjust the throttle at full gear won't do anything.( I am not that dumb :-P ) Coffee
 
 
 
Next re-skin project: the PT tenders 
  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Thursday, January 3, 2019 12:51 PM

Jones1945
Was starting a steam locomotive at very low cutoff a normal thing in the past?

Can we please arrive at a common term in this discussion for 'cutoff'?  I would suggest for example 'short' and 'long' with the understanding that short is the same as early: the valve gear cutting off admission relatively quickly so that only expansion finishes the stroke.  Using "low" and "high" leaves it critically ambiguous whether the mechanical effect of the gear or the results in steam admission are meant.

It makes no sense to me that early cutoff, particularly in a radically short-stroke design like the PRR S1 (the effect of 26" stroke being even more pronounced with the 84" drivers than it would be on the T1s) would produce better starting in any respect.  We might remember that in the C&O testing of the T1, the actual "problem" reported in starting was not slipping, but a stall even with longest possible cutoff.

In spite of this, I believe what Jones1945 is actually saying is not that the train 'starts better' with 20% cutoff, but that it just slips wildly and produces no effective TE until cutoff is reduced to that point (which might indicate that the throttle steps or control are too crude).  I hope he will provide a bit more detail (or some video clips!) showing what is going on.  In actual practice 'driving on the throttle' with the valve gear kept down in the corner usually reduces slipping, for a variety of reasons.

Something Porta proposed to get around the starting consequences of 'limited cutoff' in the ACE3000 was the use of what he called "Weiss ports" (which were also used in some PRR locomotives under a different name) - these are very narrow ports near the end of the cylinder which are fed steam early even when cutoff is limited by port placement or design otherwise, or is advanced somewhat.  This has the effect of eventually increasing cylinder pressure at low cyclic rpm for better starting without compromising design or tuning of the main ports and valve gear for more efficient operation at higher speed.  But these are not going to help the effect of short stroke and low relative rod angularity in starting a heavy train at low speed.

I have to think the reported effect is a programming artifact, especially since Jones1945 notes the program does not take into account any of the special characteristics of valve gear.  If 'horsepower' is calculated in the program with something like modified PLAN, it might suffice to use a common piston-rod thrust at nearly full boiler pressure over the portion of the stroke up to peak rod angularity, and then calculate the change in torque in, say, 15-degree increments (as Wardale did) for the resultant of the two cylinders and get this translated into wheelrim "pull" (and thence drawbar TE).  For the timespan mentioned to get a 'start' this should be a reasonable first approximation of reality...

  • Member since
    February 2005
  • 2,366 posts
Posted by timz on Thursday, January 3, 2019 12:21 PM

Jones1945
Was starting a steam locomotive at very low cutoff a normal thing in the past?

Why would the engineer want to do that?

  • Member since
    April 2018
  • 1,618 posts
Posted by Jones1945 on Thursday, January 3, 2019 2:08 AM

Overmod

Perhaps I should have said "S1 to S1b" to make it a bit clearer.  Big Engine vs. Niagara.  A few nominal DBHP down but better working adhesion at most speeds for the 4-8-4.  Also the advantages of Timken would be seen over the older style of lightweight motion.

Additional fun if you modified a RailDriver or similar platform to have proportional controls and effort for each of these locomotives, and simulated 'typical' or exemplary PRR and NYC enginemen handling the acceleration to speed.  (Do the passenger cars have prototypical engagement of the undercar Spicer generators? if not, that's a good thing to implement...)

Pity the comparison of T1 to S2a wouldn't tell us much about Franklin type A...

I also hope that there was an official testing report focus on the differences of performance between PRR S1 and NYCentral S1b!

RailDriver is an interesting device and good for the elderly since a user doesn't need to adjust the throttle with a little mouse and arrow! But you are right that some modification will have to be done for steam locomotive's simulation. Smile, Wink & Grin. These train simulators available on the market "probably" can't simulate the differences of performance between an engine using poppet valve gear or conventional gear, a user can only adjust the parameter manually base on estimation or assumption.

 

A mix and match :-P

In the game, I didn't edit the engine config file of the Niagara, but their overall performance is as durable as N&W Class J but I might give it a try to see if the data in the config file of Niagara in the game can be further improved for better realism! There is no undercar Spicer generator in this game and details like valve travel in the cylinder: the lap, the lead, the exhaust clearance, valve diameter seems to be not applicable to improve the realisticity...But I can make a car with your avatar on it within 5 mins. :P

In the forthcoming video, I will try to demonstrate S1's wheel slip problem if the engineer starting up the train at maximum cutoff (70.6? %), apply full throttle. Using updated data, PRR S1 will only start moving if the cutoff was set at 20% or less plus full throttle. Within 12 mins, it will reach 100mph+ with 1360 tons behind her, depends on the gradient of the track (I am not using a level track). I don't know if this is realistic or a bug or glitch of it but I can't even start the train on level track at 30% cutoff due to wheel slipping. Once the engine started accelerating, she will run like a wild horse (with 1360 tons behind her!!) Was starting a steam locomotive at very short cutoff a normal thing in the past? Thanks a lot!

 

 


 

-Further reading-

In this thread on Trains Forum: 

"An assessment of the benefits of the application of Franklin valves on the

PRR K4 and T1 classes"

 Link:  http://cs.trains.com/trn/f/740/t/272776.aspx 

 

Forum member Dreyfusshudson (He has very rich experience in railroading, including developing and using computer software to simulate different steam trains performance, but he said he prefer to stay anonymous in the forum) showed us a table in one of his post:

Dreyfusshudson

Thanks, Jones 1945.

As tim z points out below, it’s not quite as you think- the resistance of the locomotive would not change, only the coach resistance would fall in proportion to the weight, and the figures themselves are not directly useful.

I have two answers to your question about how long it would take 6100 to accelerate 1065 tons to 100mph on level track.

The first is, if we assume that flat out working is 7200HP (I don’t know how this  reported figure was arrived at), and that when starting you can put down about 70% of the rated TE without slipping (Pure guess, about the maximum normally applied ion the UK), then you reach 100mph in 11 miles, about 9¾ minutes. After that, you can maintain 100mph with about 5400HP. During the acceleration, steam rate is in excess of 100000lbs/hr, and you are burning about 17000lb/hr top quality coal. This kind of time is what you might claim for PR purposes.

However, my sense of the way locomotives were actually expected to perform is somewhat different. Starting is about TE, sustained performance is about how hard you are prepared to steam the boiler. As far as I can tell, it was unusual for US boilers to be steamed much above about 600lbs steam/sqft/ grate/hr, sometimes less. (This figure refers to top quality Coal of about 13500BtU/lb; it would be less for lower calorific values). Above this specific evaporation rate, unburned coal losses rise sharply, and it may be that this was a prudent level to avoid high boiler maintenance costs, e.g. due to cinder cutting, by not asking too much of them- the draughting usually allowed up to at least 900lbs/sqft/hr- a whopping 120000lbs/hr for the S1.

Looked at this way,  the Table below shows how a number of different locomotives might be expected to perform with a 1065 ton train on a level track, again working at 70% maximum TE up to 20mph, maximum steam rate about 600lbs/sqft/hr beyond that. All numbers are just indicative of relative potential, not precise.

Speed after 20 miles and elapsed time

 
 

final speed, mph

elapsed time, mins

sustained HP

PRR S1

96.8

16.50

5500

NYC J3a

84.6

18.75

3750

Niagara

90.4

17.25

4500

T1 Franklin

86.9

18.00

4100

T1Walschaerts

86.2

18.00

4100

K4

71.2

24.50

2400

 

 

Not even the S1 can reach 100mph, though all are still accelerating slowly, and the S1 would eventually get there. The Niagara comes out better than the T1 versions, because the PRR banked the supposed engine efficiency advantages of the Franklin valve and reduced their grate size from 100 to 92 sqft, thus, according to my criteria, reducing the maximum sensible steam rate.

Of course, on any real line there will be gradient fluctuations, which might enhance acceleration. On the Water Level Route and PRR Crestline to Chicago the gradients are gentle, but the eight coupled designs would all get up to 100mph after a while, and cruise in the low 90s. And, if a train is overloaded or running late, there is likely plenty of upward power reserve to knock a hole in these figures...

If our forum members interested in this topic, please read the original post for complete messages! I believe there is no doubt that the PRR S1, a train designed for speed can surpass the design top speed of Niagara, N&W Class J etc.

Anyway, all these simulations can be seen as a reference since there are way too many things that general computer cannot simulate. Coffee But the result about PRR S1 probably explained why she was assigned to the Trail Blazer, a money tree of PRR before the decline started in 1946. Note that there were a few stops before the train arrives Chicago or Crestline, Ohio, which required an engine had a reasonable acceleration rate and ability to reach higher speed to stay on the schedule. 

 "Why can't we be  friends?"

The color of the Keystone plate will be updated.

By the way, BaltACD, Thanks for the song! Yes

 

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, January 2, 2019 11:02 AM

Jones1945

Overmod
The interesting comparison is S1 to S1.

That can be arranged.

Perhaps I should have said "S1 to S1b" to make it a bit clearer.  Big Engine vs. Niagara.  A few nominal DBHP down but better working adhesion at most speeds for the 4-8-4.  Also the advantages of Timken would be seen over the older style of lightweight motion.

Additional fun if you modified a RailDriver or similar platform to have proportional controls and effort for each of these locomotives, and simulated 'typical' or exemplary PRR and NYC enginemen handling the acceleration to speed.  (Do the passenger cars have prototypical engagement of the undercar Spicer generators? if not, that's a good thing to implement...)

Pity the comparison of T1 to S2a wouldn't tell us much about Franklin type A...

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Wednesday, January 2, 2019 8:34 AM

Every Picture Tells a Story

Never too old to have a happy childhood!

              

SUBSCRIBER & MEMBER LOGIN

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

FREE NEWSLETTER SIGNUP

Get the Classic Trains twice-monthly newsletter