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

[Jones1945]

(Original Thread Title: 3D NYCentral Dreyfuss Hudson and 3D PRR S1 #6100 2018)

In case you missed it! Some folks from K&L Trainz are making a 3D NYCentral Dreyfuss Hudson and the 20th Century trainset for the Trainz simulator. Classic Trains in computer simulator, stay tuned if you are interested.  

[Firelock76]

My, they have excellent taste in trains, don't they?

[Jones1945]

They do! My family love their works and have quite a lot of their product on my computer. Pennsy fans will love their collection. They are probably the most active 3D modeler who still making American steam locomotives for games. Their works are user-friendly which allows the user to reskin (repaint), exchange train trucks as well as editing of the config file. My first complete PRR Fleet of Modernism train set on my computer was modified from their works. My daughter contacted them for a PRR S1, but they told her that they are very busy and can't accept new project request until summer 2019. 

[Penny Trains]

Those are pretty darn gorgeous! 

[Jones1945]

Yes, they are very well detailed too. The game itself doesn't require a very powerful computer spec, a brand new computer from five years ago could handle it, but player better equips a graphics card for it. 

[BaltACD]

From several years ago

 

One nit to pick - No B&O CPL's for signals.

[Jones1945]

BaltACD

From several years ago

One nit to pick - No B&O CPL's for signals.

I have this one as well, It was Olive Dennis' iconic work. The cars didn't have the interior but I reskin all the windows with better texture; a trick used in the era of Microsoft Train Simulator. 

MILW's Class A:

[Firelock76]

Remarkable!  Olive Dennis lives!

[Penny Trains]

Holly cow!  Dreyfuss goes psychadelic! 

[Jones1945]

: )

It looks like Dreyfuss met Andy Warhol. I believe different colors represent different 3D parts of the engine in that pic. We can see the same feature in those professional construction engineering software. 

[Jones1945]

An update from K&L:

After 20 years of waiting ( My first PC was purchased in 1998), I finally have a chance to arrange a "train race" between the NYC J3a and PRR duplexes. I am gonna finalize the engine config file of my S1 for the "Battle of the Century" 

[Firelock76]

Oh boy, let us know who wins!

[Jones1945]

haha. I will try recording it using the Window 10 built-in function. But the video file will be quite big. Stay tuned, Firelock76! 

[Firelock76]

Thanks!  As cool as that S-1 is (was?) I have to admit I'm rooting for the Dreyfus Hudson, I've got a family connection with the Central.

[Overmod]

Firelock76

Oh boy, let us know who wins!

Why bother; it's the wrong comparison.  If you need to run a J3a for some unaccountable reason, at least give it a fair handicap by leaving all that tin off.

The interesting comparison is S1 to S1.

 (And please, for my sake if no one else's, the stylist is DREYFUSS.  The other spelling is a Frenchman unduly accused of treason in the 19th Century.  Or an investment brand...)

[Firelock76]

Dreyfuss.  I beg your pardon.  I probably dropped the second s due to excited anticipation of the turkey Lady Firestorm was cooking.

" L' Affaire Dreyfus?"  Hey, I know all about that, I've seen "The Life Of Emile Zola!"

Great film! 

[BaltACD]

Jones1945

haha. I will try recording it using the Window 10 built-in function. But the video file will be quite big. Stay tuned, Firelock76! 

That is why YouTube exists.

[Jones1945]

Overmod

The interesting comparison is S1 to S1.

That can be arranged. 

How about 25 T1s vs 25 T1s?

 

[Jones1945]

An "update" from K&L TrainZ, a nice presentation of the legendary history of The 20th Century Limited.

[BaltACD]

Jones1945

An "update" from K&L TrainZ, a nice presentation of the legendary history of The 20th Century Limited.

A couple of nits to pick.  The engine change at Harmon is depicted wrong if only 5 minutes is allowed for the change.  The electric engine would pull ahead far enough that the Hudson could come in behind it clearing the switch back to the train and then while the Hudson was going back to couple up the electric would clear the main.  As depicted the engine change would take upto 10 minutes.

Arriving LaSalle Street Station the James Whitcomb Riley is shown departing, the Riley operated in and out of the Illinois Central's station down closer to the Lake Michigan waterfront.

Beyond the nits, a great CGI video!

[Jones1945]

Welcome back, BaltACD. Thank you for providing the historically accurate details of how the engines were changed at Harmon! It would be interesting to see the Century and all of its sections changing engines at Harmon. IIRC, sections of The 20th Century Limited were 15 mins apart from each other. If there were three sections of the Century, the last section would arrive Harmon 45mins later than the first train wasn't it? 

Btw, you could drive the Century in the Trainz simulator.  But the route in the video is not available for purchases...

[BaltACD]

Jones1945

Welcome back, BaltACD. Thank you for providing the historically accurate details of how the engines were changed at Harmon! It would be interesting to see the Century and all of its sections changing engines at Harmon. IIRC, sections of The 20th Century Limited were 15 mins apart from each other. If there were three sections of the Century, the last section would arrive Harmon 45mins later than the first train wasn't it? 

Btw, you could drive the Century in the Trainz simulator.  But the route in the video is not available for purchases...

I can't say that the move I detailed was used - however, if the move displayed was used the car knockers would be standing there for five or more minutes without a engine attached to the train and the clock would be ticking.

One thing you learn working with T&E personnel - they KNOW HOW to get the job done with a minimum amount of work in a minimum amount of time.

[Jones1945]

Happy New Year to everyone!

After a long vacation, I finally reunion with my own PC again! I am glad to see our forum is alive and kicking during the long holiday. These are some pics captured in the computer game TrainZ Simulator by me and my family members who love trains. Some captured moments of the 3D NYCentral Dreyfuss Hudson and PRR's legendary duplexes racing for fun! Videos will be uploaded asap, please enjoy!

 

(The S1 on the left is freeware which has been released a few years. We re-skinned and improved the texture of it for better realism. )

(Player can customize the trains fleet number)

 

We converted and customized some cars from N&W The Powhatan Arrow into PRR's twins-unit dining car, therefore some details are not accurate due to technical difficulties (including the number of golden strips and the door on the Full-dinning car) It can't be fixed without creating a new 3D model of it.

[BaltACD]

Every Picture Tells a Story

[Overmod]

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...

[Jones1945]

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. . 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.  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! 

 

[timz]

Jones1945

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

Why would the engineer want to do that?

[Overmod]

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...

[Jones1945]

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 ) 

 

 

 

Next re-skin project: the PT tenders 

[timz]

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?