"French Trains Set - freight rolling stock needs drawing

Snail · Post by **Snail** » 11 Apr 2007 13:57

Michael Blunck wrote: > Slow, not very powerful, [...]

It has a tractive effort of 266kN which is a lot for a European tank engine.

True, but its power is about 850HP...

BTW, we are missing the TE for some other tank engines... I found a value of around 280 for the 141TD, which appears to be a lot to me considering it wasn't a freight engine.
Another missing element is the Winterthur-built 141TA, maybe you could help us with that?

michael blunck · Post by **michael blunck** » 11 Apr 2007 14:50

> True, but its power is about 850HP...

Do you know about the dependency between tractive effort and power?

I found a value of around 280 for the 141TD, which appears to be a lot to me considering it wasn't a freight engine.

Well, according to http://www.trainvapeur.com/materiel/141TD.htm the 141TD has a "puissance" of 29t -> 29000kg -> 29000kg * 9,81 m/s² -> 285kN.

The only thing important for TE is "axle weight" (poids adhérent), regardless whether an engine is declared to be "passenger" or "freight".

regards
Michael

Snail · Post by **Snail** » 11 Apr 2007 15:48

michael blunck wrote:> True, but its power is about 850HP...

Do you know about the dependency between tractive effort and power?

Ok, but you said...

Michael Blunck wrote:The only thing important for TE is "axle weight" (poids adhérent)

so now I'm kind of confused... what did you mean exactly?

Basically, in the game the 151TQ should behave like a great hill climber (because of the high TE), but with a crippled max speed when pulling heavy trains (because of the low power).

Michael Blunck wrote:
I found a value of around 280 for the 141TD, which appears to be a lot to me considering it wasn't a freight engine.
Well, according to http://www.trainvapeur.com/materiel/141TD.htm the 141TD has a "puissance" of 29t -> 29000kg -> 29000kg * 9,81 m/s² -> 285kN.

Yes, 285, that's what I found... it seemed a surprisingly high value to me, but if you think it's correct, I'll put it in. Thanks!

michael blunck · Post by **michael blunck** » 11 Apr 2007 20:52

snail wrote:you said...

> The only thing important for TE is "axle weight" (poids adhérent)

so now I'm kind of confused... what did you mean exactly?

Ah, sorry, I meant "adhesive weight" (poids adhérent), o/c.

Well, for a steam engine,

- Power output is determined by the size of the fire, which, for a coal-fuelled locomotive, is determined by the grate area. Hence, high power needs a large grate area and a longer boiler, i.e. results into a larger (longer) and heavier locomotive.

- Tractive effort (TE) (or "tractive force") is in principal determined by boiler pressure, cylinder proportions, and size of driving wheels:

TE = D² * S * const * p / d

with D = cylinder diameter, S = piston stroke, p = boiler pressure, and d = driving wheel diameter. ("const" being a heuristic constant in the range 0.75 ... 0.85, depending on speed.)

- Because of the nature of the limited friction (µ) between wheel and rail, TE is limited by the weight on the driving wheels ("adhesive weight", Wadh), i.e. non-driven and slipping driving wheels cannot transmit force. In addition, friction depends heavily on the condition of the rails: clean, dry or sanded rails increase friction, but grease, ice, mud, leaves, etc. will all cause the locomotive to slip before nominal TE is reached. Thus, to transmit TE as best as possible, the quotient Wadh / Wtot should be as large as possible, which would be best achieved by a locomotive having only driving axles (0-x-0 scheme, Wadh / Wtot = 1).

- Max permissable axle load is determined by condition and type of track. In this way, the number of driving axles is limiting the adhesive weight and therefore the achievable TE.

- Power equals to TE * speed and is limited by the locomotives´ boiler steaming capacity. I.e., because the product TE * speed is constant, TE drops off proportionally as speed increases.

- Speed is determined mainly by driving wheel diameter. Higher speed requires larger driving wheels because piston speed increases with driving wheels RPM, and at high piston speeds, valves cannot deliver steam efficiently anymore. OTOH, large (and many) driving wheels result into a long driving wheel base, limiting the ability of the locomotive to take curves. This has been a main concern in steam locomotive design and resulted into a vast amount of technical solutions, featuring articulated designs, lateral motion devices, or the use of blind drivers.

Basically, in the game the 151TQ should behave like a great hill climber (because of the high TE), but with a crippled max speed when pulling heavy trains (because of the low power).

In this context, freight locomotives emphasised tractive effort, whereas passenger locomotives emphasised speed. In consequence, freight locomotives used multiplied axles, kept leading bogies to a single axle (if any), and grew a trailing bogie only as the firebox expanded. OTOH, passenger locomotives usually had two axle leading bogies for better guidance at higher speed, fewer driving axles but very large driving wheels in order to limit the speed at which the reciprocating parts had to move.

HTH
regards
Michael

Snail · Post by **Snail** » 11 Apr 2007 23:16

So you mean that from a table like this, you could get a reasonable TE for any steamer?

michael blunck · Post by **michael blunck** » 12 Apr 2007 08:53

So you mean that from a table like http://orion.math.iastate.edu/jdhsmith/ ... f.htm]this, you could get a reasonable TE for any steamer?

Yes, in principle, this should be doable. (BTW, J.D.H. Smith´s tables are one of the best things to be found on the Internet

)

"In principle" because "real" tractive effort can only be measured, rather than correctly calculated from the given stats, especially for finesses like compound steam, more than 2 cylinders, etc. pp., and o/c the limit set by friction ([*]).

But let´s try for that 141TD again.

I´ll use a slightly different formula which the DRG used for "plain steam" in contrast to "compound steam" in their steam locomotive manuals:

TE = 0,8 * p * D² * S * z / d * 2 (for plain steam)

("z" being the number of cylinders)

According to J.D.H. Smith´s table, numbers for the 141TD are as follows:

d = 1420 mm -> 1,42 m (driving wheel diameter)
D = 510 mm -> 0,51m, D² = 0,2601 m² (cylinder area)
S = 660 mm (3) -> 0,66 m (cylinder stroke)
p = 16 atm -> 1621200,384 N/m² (boiler pressure)

Then,

TE = 0,8 * 1621200,384 N/m² * 0,2601 m * 0,66 m * 3 / 1,42 m * 2 -> 235 kN

[*] for an adhesive weight of 75t and a friction coefficient µ between 0.25 (wet, slippery) and 0.33 (dry, clean) we get:

TEmax = 75 t * 9,81 * [0.25 ... 0.3 ... 0.33] -> 183 ... 220 ... 242 kN

I´ve tested the formula with some known german steamers (like the T18), where I have access to calculated and measured numbers for TE, and the results are pretty good:

T18 (measured): 112 kN
T18 (calculated myself): 116 kN

regards
Michael

Snail · Post by **Snail** » 12 Apr 2007 11:52

That's a very good suggestion! Could help us fill some numbers we don't have a clue about.

Would this work even for power (HP?)

michael blunck · Post by **michael blunck** » 12 Apr 2007 12:02

> Could help us fill some numbers we don't have a clue about.

Just give me the class numbers you need and I´ll post the tractive effort.

> Would this work even for power (HP?)

Well, it could be calculated from grate area, evaporation surface, etc. pp., but I don´t think results would be anything accurate as those TE numbers. This is just another cup of tea.

regards
Michael

Wile E. Coyote · Post by **Wile E. Coyote** » 12 Apr 2007 12:11

michael blunck wrote:> Would this work even for power (HP?)

Well, it could be calculated from grate area, evaporation surface, etc. pp., but I don´t think results would be anything accurate as those TE numbers. This is just another cup of tea.

AFAIK you can only measure steamers power, with appropriate equipment (wagons with dynamometers etc.), but if you can provide formula anyway, just to see is it my calculating aproximately correct...

Snail · Post by **Snail** » 12 Apr 2007 14:12

michael blunck wrote:
TE = 0,8 * 1621200,384 N/m² * 0,2601 m * 0,66 m * 3 / 1,42 m * 2 -> 235 kN

Hmm... actually, .8 * 1621200.384 * .2601 * .66 * 3 / 1.42 * 2 = 940749.2 ... so a whopping 940.7 kN... at least according to Excel... what did I miss?

-EDIT-

As for power, even an indicative number would be fine, especially to fill in some data when we know the exact figure of similar engines. For instance, I found out the power of the 230G (1400HP). Basing on that table, maybe we could get a sensible guesstimate of the power of a 230B PLM and a 230D Nord?

michael blunck · Post by **michael blunck** » 12 Apr 2007 14:24

> a whopping 940.7 kN... what did I miss?

Actually, the last "2" has to be in the denominator, i.e.

TE = 0,8 * 1621200,384 N/m² * 0,2601 m * 0,66 m * 3 / (1,42 m * 2) -> 235 kN

sorry for that.

> As for power [...]

I´ll do some calculations today evening, based on my DRG material. Let´s see where this leads to.

regards
Michael

Snail · Post by **Snail** » 12 Apr 2007 14:44

Thank you very much!

Now it matches. We will probably refer to that table to have another estimate of the TE for engines we cannot find measured data for.

And thanks in advance for your help with power

MagicBuzz · Post by **MagicBuzz** » 11 Jul 2007 19:25

Hello,

I see no update since a... long time

How is the project ?
Can we hope find a teaser soon ? May be it was moved to another topic ?

jvassie · Post by **jvassie** » 11 Jul 2007 19:30

MagicBuzz wrote:Hello,

I see no update since a... long time

How is the project ?
Can we hope find a teaser soon ? May be it was moved to another topic ?

Hmm, im sorry to not have seen any progress too, but the team is busy with other things atm, so progress is painfully slow unfortuantely.

This is the topic though, so check back for updates

Snail · Post by **Snail** » 12 Jul 2007 15:10

Well, due to the Patch's new possibilities in terms of callbacks and the possibility to switch to OTTD (which would allow for a much more complex set), some of the features of the set itself are being redesigned. There will be few additions in terms of engines and features.

In terms of stuff to be drawn, real life is heavily interfering at this time. GF has come to see me and I doubt I'll have much time to draw trains until the end of the summer

Still, we can assure that, at least as far as I'm concerned, this project will NOT die. Death was given the steamers to code, and he might end up packing a teaser sooner or later.

Look_fr · Post by **Look_fr** » 13 Jul 2007 08:29

Hello !

I present me, I am a french student who want to work in the railway industry. Indeed I am Found of trains and OpenTTD too !!!!

I have no time to read all your post today but I read the three first pages and I have three word to say : go, Go, GO !!!

If I can help i would

.

First, I want to show you that there is already a frset.
-> http://rail.free.fr/deluxe/

But i do not know who did this set

.

Otherwise, there is a website where you can have technical information about french trains :
-> http://perso.orange.fr/florent.brisou/

So I have a little knowledge about french trains. If you want some information I will be happy to participate to the cration of this set.

I hope my englich is'nt too bad and you can understand me.

Thank you !

Look

Snail · Post by **Snail** » 13 Jul 2007 15:01

Welcome Look!

Thanks for your kind words. It's always great to feel so much enthusiasm around our project.

The website you pointed out is interesting and we could use it to make some realistic train consists. As for the other stuff, we already have everything we need in terms of engines specs and pictures. A new tracking table will be available in the next future (bot don't hold your breath) and hopefully my drawing process will start after the end of the summer.

I would like to keep drawing most of the trains, at least to give the entire set a similar, homogeneous look. We already had a look at the GRF file you pointed to and, although it has lots of engines, it's a very early work and doesn't use many of the most recent Patch (or OTTD) features. This is why the FRSet is being done from scratch.

So far, only the steamers are drawn (and a bunch of early electrics) so they will be the first items to be released in a future teaser.

N'hesite pas à m'écrire un PM (même en français

) si tu veux plus d'infos!

Nasher · Post by **Nasher** » 18 Jul 2007 15:01

I'm french too and like look i'm interested by the set you're developing.

Will it contain actual regional Alsthom and Bombardier trains (diesel, electric, hybrid) ?

I dunno much about trains technical info but i'd gladly help...

(dunno if can help but i found a huge list of technical data about french trains through ages from 1937 to nowadays, surprisingly the oldest train is electric...)

Snail · Post by **Snail** » 02 Oct 2007 03:59

A long, long time and no updates

Well, hopefully things will change in the next future. I'm back from my break and I'm planning to take this set forward with some new stuff.
After we decided to make the FRSet playable since 1900, a slight change to the train list has been made to accommodate some early rolling stock. The main result is the following:

- a 030TB "Boër", of the État company, designed in the late XIX century, for very early operation (it will become extinct very soon after 1920); you can find some pictures at the bottom of this page (my model was the 35xx series);
- a 240A of the PLM company, a freight engine designed in 1907 that will be a good heavy-duty hauler before the cheaper 140's or the massive 151's will be available; due to IDs restrictions, this locomotive will only be available in the Alpine climate.

I'm currently working on some early variants of a couple of already drawn engines to lengthen their lifespan. After this is done, the steamers for Alpine and Temperate will be finished.

Comments and critics are welcome!