IET trains does not have the correct acceleration rate and livery variants

[fam621]

Hello James, I have just finished playing Simutrans and I notice that the class 801 has better acceleration the the class 800 and for some reason they are not livery variant so what I mean is that the class 800 should be able to have the Virgin Trains livery and also to have the same acceleration rate as its no different in real life whether its on diesel or electric. So can that be a possible fix please?

[Rollmaterial]

As the livery issue is very easy to fix, I suggest you give it a go yourself. All you need to do is copy the livery definitions from one .dat file to the other.

[fam621]

And how do I do that?

[jamespetts]

Although in reality both class 800 and 801 are bi-mode, we do not yet have any simulation of bi-mode vehicles in Simutrans-Extended. This is planned eventually, but there is a very long queue of challenging higher priority features that must be dealt with first.

Until bi-mode vehicles are simulated, the Class 800 has been coded as diesel and the 801 as electric. This means that the Class 800 will have inferior acceleration compared with the Class 801. When bi-mode vehicles are simulated, the acceleration when running on electrical power will be superior to the acceleration when running on diesel power.

[Rollmaterial]

And how do I do that?

Copy/paste

[fam621]

Class 801s are not bi-mode its electric only and actually the class 800s are already bi-mode (ish) as they can be bought from a electric depot

[jamespetts]

Class 801s are not bi-mode its electric only and actually the class 800s are already bi-mode (ish) as they can be bought from a electric depot

But nevertheless, they are coded as diesel, and so have the performance that these units have when running on diesel power.

[fam621]

But nevertheless, they are coded as diesel, and so have the performance that these units have when running on diesel power.

They have near enough the same performance as when they are running on electric power and also a new bi-mode veriant of the IET fleet is coming as well in the form of the Class 802.

[jamespetts]

They have near enough the same performance as when they are running on electric power and also a new bi-mode veriant of the IET fleet is coming as well in the form of the Class 802.

I am not sure that I understand the intended significance of this comment. Do you mean to suggest that the power/tractive effort figures for the diesel version of these trains is incorrect? If so, I should be grateful if you could point me to a source for more accurate figures for these.

[fam621]

Yes. On wikipedia (the link given) is where you can find the correct power/tractive effort figures for the bi-mode class 800s. I have also given links to the class 802 power/tractive effort figures (for the Class 801, use the same power/tractive effort figures as on the Class 800's).

Class 800 power/tractive effort figures link (wikipedia page): https://en.wikipedia.org/wiki/British_Rail_Class_800

Class 802 power/tractive effort figures link (wikipedia page): https://en.wikipedia.org/wiki/British_Rail_Class_802

[jamespetts]

I do not understand which figures that you think are incorrect. The tractive effort figures are not provided on the Wilkipedia articles. The power figures are given as 560kW per powered vehicle - the power of the units in the game is 700kW, which is, according to a note, the original power of the engines before they were de-rated for these units (the reason for this is not given). Can you elaborate on which you think are the correct figures and how these diverge from the actual figures in the pakset?

[fam621]

What I mean is that the IET fleet should have the same acceration/power rate for operation on both 25KV AC overhead lines and on diesel and this should be the same for braking.

[ACarlotti]

That is not correct. There are a few different variations, but in every case the trains have more power running in electric mode than in diesel mode. Table 1 in this article has all the figures; read the section headed "Comparing power ratings" to see why the difference is even greater than is suggested by the raw figures in the table.
https://www.railengineer.uk/2017/10/24/bi-mode-trains-unlocking-opportunity/

I would however expect them to have the same tractive effort and braking force in either mode of operation, since the same electric motors and brakes are being used in either case.

[jamespetts]

Fam622 - the power of the units in the game is based on the published figures. If you think that those are wrong, you will need to find more reliable/accurate published figures than are on Wikipedia.

As to tractive effort, I cannot find any source that gives tractive effort. Does anyone know of any source giving the tractive effort of these units? I have found that it is generally very difficult to find tractive effort data for multiple units for some reason.

I do note, however, that the acceleration figures in table 2 are different for diesel than they are for electric. Given that acceleration is determined by tractive effort in Simutrans-Extended, this suggests that it is correct to have these specified differently.

[fam621]

If you go onto that page which was linked by ACarlotti, table 1 is where the information for the Class 800/801/802s are reguarding power and power to weight ratios.

[jamespetts]

If you go onto that page which was linked by ACarlotti, table 1 is where the information for the Class 800/801/802s are reguarding power and power to weight ratios.

Yes, I have seen that table. That does not give tractive effort, nor does it have any information regarding the power which is in any way inconsistent with what is in the pakset, save that what is in the pakset has not been adjusted to take into account the down-rating of the diesel engines. Is what you wanted the down-rating of the diesel engines? That would create an even greater difference in the performance between the diesel and electric versions.

I am afraid that I am extremely unclear on precisely what you think is wrong with the actual figures for power and tractive effort, given that you have not cited any sources that give any different figures (aside from the downrating).

[fam621]

Yes, I have seen that table. That does not give tractive effort, nor does it have any information regarding the power which is in any way inconsistent with what is in the pakset, save that what is in the pakset has not been adjusted to take into account the down-rating of the diesel engines. Is what you wanted the down-rating of the diesel engines? That would create an even greater difference in the performance between the diesel and electric versions.

I am afraid that I am extremely unclear on precisely what you think is wrong with the actual figures for power and tractive effort, given that you have not cited any sources that give any different figures (aside from the downrating).

Can an up-rating of the engines increase acceration as a temp measure until I/we get the exact tractive effort?

[jamespetts]

Can an up-rating of the engines increase acceration as a temp measure until I/we get the exact tractive effort?

Have you tested and found that the acceleration rate in game is at variance with the published acceleration rate figures? If so, I would be interested in your detailed findings.

[fam621]

The power/tractive force in game is (for the Class 800s): 700 kV/55 kN. For the Class 801s its also 700 kV but its kN is: 62 kN.

[jamespetts]

The power/tractive force in game is (for the Class 800s): 700 kV/55 kN. For the Class 801s its also 700 kV but its kN is: 62 kN.

Which do you think is the correct value and why?

[fam621]

I am really unsure. But I've found this website which should have the correct acceration/braking rate. Site: http://www.railperf.org.uk/index/siteforum-list-action?post=3555&highlight=#siteforum-message-3555

[jamespetts]

The link that you gave did not give acceleration rates, but the Wikipedia article does give acceleration rates, suggesting that the Class 800 has a lower rate of acceleration than the Class 801. In light of that, what precisely do you think is incorrect about the tractive effort figures?

[fam621]

What I think is wrong is that the Class 800s tractive effort is far slower than the Class 801s tractive effort.

[jamespetts]

What I think is wrong is that the Class 800s tractive effort is far slower than the Class 801s tractive effort.

What are the data on which that view is based?

[fam621]

The data is on the acceration rate from 0mph-125/140mph from start to stop.

[jamespetts]

The data is on the acceration rate from 0mph-125/140mph from start to stop.

And how do those data show that it is incorrect for the tractive effort of the Class 800 to be lower than that of the Class 801?

[fam621]

If I'm honest. I dont think that I can find any information reguarding the IEP acceration rate but Ik from watching YouTube videos there acceration rate is much faster.

[jamespetts]

If I'm honest. I dont think that I can find any information reguarding the IEP acceration rate but Ik from watching YouTube videos there acceration rate is much faster.

I cannot really calibrate a specific figure as to tractive effort from that, I am afraid.

[fam621]

Kk

[fam621]

I cannot really calibrate a specific figure as to tractive effort from that, I am afraid.

Ik this is a dead topic but I wanted to bring it back to light because some stats were released in January by the rail news company 'RAIL magazine' regarding the Class 800s and I think it is worth wile the read. Link to the page: https://www.railmagazine.com/news/rail-features/does-great-western-railway-s-class-800-iet-pass-the-test

[jamespetts]

Sadly, while the article gives detailed seating dimensions, there are no tractive effort figures.

[fam621]

Ah lol k. Just seeing whether this would help. Would this help: https://www.railforums.co.uk/threads/iep-for-beginners.77790/page-18#post-1344308 Read the top post in this link

[jamespetts]

What is needed is a specific figure for the tractive effort. That is not the same as power (or power:weight ratio). If you can find a source for the tractive effort, that would be helpful. Anything else does not take things any further.

[fam621]

Well if this isnt enough, well I'm done for: https://www.railengineer.uk/wp-content/uploads/2017/10/Table-1-Hitachi-800-802-orders-V3-Avenir.pdf

[jamespetts]

Again, these do not have the tractive effort. There is no point in posting links to data that do not contain the tractive effort. As explained, tractive effort is not the same as power. Surely you can check before you post links to data whether they have the tractive effort rather than posting lots of things for me to check, taking up my time?

[fam621]

Unfortunately, there is no source which provides tractive effort. But the trains do have very good acceleration both on and off electric mode (as in they have just as good of acceleration on diesel mode)

[jamespetts]

Unfortunately, there is no source which provides tractive effort. But the trains do have very good acceleration both on and off electric mode (as in they have just as good of acceleration on diesel mode)

As already stated several times on this thread, without numerical data, it is not realistically possible to improve the calibration of the tractive effort.

[fam621]

Okay

[fam621]

In my opinion, I think that the Class 800/801 IETs might have near enough the same tractive effort as the Class 385s

[jamespetts]

In my opinion, I think that the Class 800/801 IETs might have near enough the same tractive effort as the Class 385s

What is the data source for that?

[fam621]

Me and someone else from the forum had a little discussion regarding this and also moving to liveries, will the class 800 be able to be liveried into LNER (London North Eastern Railway (VTEC (Virgin Trains East Coast when designed))?

[jamespetts]

I am not sure that I quite understand the question; it is possible in principle to produce graphics for the liveries of anything. I think that the .blend files for this are now available, so you should be able to modify the 3d models used to create the graphics for this rather than producing entirely new 3d models.

[fam621]

What I mean is that like can the class 800s ingame be able to be relievered into LNER livery

[jamespetts]

If someone makes the livery graphics and updates the .dat files, then certainly.

[fam621]

The graphics are already there (well the old VTEC graphics anyway). But do the acceleration rate have to be given in tractive effort?

[jamespetts]

The tractive effort and power (principally the tractive effort) are the only parameters in the physics engine that control the rate of acceleration.

If the graphics that you are interested in are already present, I do not understand your earlier question.

[fam621]

What I actually mean is that can the Class 800 also be able to be liveried into LNER (VTEC (East Coast franchise)) livery scheme and unfortunately, there is no available information regarding tractive effort. This is the best that I can do regarding that area regarding acceleration. The power output for the Class 800 is ‎560 kW (750 hp) per engine

[jamespetts]

The power has already been stated correctly, as this was set from data. I am aware that there is no available information for the tractive effort, as discussed quite some time ago on this thread, I believe.

I still do not understand the question about the livery: you are of course quite free to produce a new LNER (modern) livery for the class 800, and I believe that the .blend files exist and are available so that you can modify the existing 3d models to produce the new livery variants.

[fam621]

I think I've been wording it wrong all along. I mean this! The livery scheme thingy. Also, the info you might of got might of been or when it was still been tested and stuff. But if you go onto YouTube and search up 'class 800 acceleration to 110mph' you will note that it has very good acceleration

[jamespetts]

You mean the livery scheme? You can certainly add one of those: just add one to the end of the livery schemes section in the pakset specific simuconf.tab. You will see the correct format by looking at the others.

As for the acceleration being "very good", as I believe has been discussed on this thread now quite a number of times, such vague information is unusable. I need numerical data for calibration. Please do not keep asking me to adjust the tractive effort based on unusable vague information.

If you have numerical data on actual acceleration rates on the flat with a specific configuration/formation, you can run your own tests in-game to deduce the correct tractive effort by testing to see whether it accelerates to the given speed within the correct number of tiles at 125m/tile based on the source data, and, if it does not, adjust the tractive effort multiplier in the advanced settings dialogue (press the "i" key to access) until it is correct. This multiplier can then be reset in the advanced settings dialogue but multiplied by the tractive effort figures given in the class 800's .dat files. If you do this, you will need to give me full information on the numerical source so that I can verify its accuracy, and also upload the saved game that you used for testing.

[fam621]

You mean the livery scheme? You can certainly add one of those: just add one to the end of the livery schemes section in the pakset specific simuconf.tab. You will see the correct format by looking at the others.

As for the acceleration being "very good", as I believe has been discussed on this thread now quite a number of times, such vague information is unusable. I need numerical data for calibration. Please do not keep asking me to adjust the tractive effort based on unusable vague information.

If you have numerical data on actual acceleration rates on the flat with a specific configuration/formation, you can run your own tests in-game to deduce the correct tractive effort by testing to see whether it accelerates to the given speed within the correct number of tiles at 125m/tile based on the source data, and, if it does not, adjust the tractive effort multiplier in the advanced settings dialogue (press the "i" key to access) until it is correct. This multiplier can then be reset in the advanced settings dialogue but multiplied by the tractive effort figures given in the class 800's .dat files. If you do this, you will need to give me full information on the numerical source so that I can verify its accuracy, and also upload the saved game that you used for testing.

Maybe we should leave the tractive effort thing for now because I have looked for it and no website gives the figures for tractive effort unfortunately. Also how to do mod the simuconf.tab?

[jamespetts]

It is a text file, so you can edit it in the same way as any other text file.

[fam621]

Okay, I'm in it now. So exactly, what do I do to get the VTEC livery from the class 801 to be applied onto the class 800?

[jamespetts]

This is not the question that you were asking before: previously, you were just asking about adding a livery scheme for the new LNER livery, which is not at all the same thing as applying the livery of one sort of vehicle to the livery of another sort of vehicle.

I cannot remember now whether the class 801's vehicles all look identical to the class 800's vehicles. If they do, you can just use the graphics for those class 801 vehicles in a new livery of the class 800. If not, then you will need to create new graphics.

However, are there class 800s (as opposed to class 801s) in the VTEC livery?

[fam621]

One class 800 was liveried into VTEC livery in real life and the class 801s look exactly like the class 800s. Just that the 801s are Electric only and the 800s are bi-mode. So yes, the graphics for the class 800/801s are the same (just that they are in different liveries)

[jamespetts]

Splendid, thank you for confirming. Do let me know when you have modified the .dat files so that I can update the pakset with them.

[fam621]

Where can I find these .dat files?

[Rollmaterial]

Where can I find these .dat files?

In the sources!

[fam621]

Where are these sources, because I cant just guess what sources there in because their are alot of sources of Simutrans stuff. Please be more specific next time!

[jamespetts]

All the details are on this stickied thread, to which you have responded in the past.

[fam621]

I've worded it wrong again, havent I? Sorry for the run around but I mean the .dat file sources.

[jamespetts]

This is a quote from the thread to which I provided a link above:

When you clone the Github repositories in the relevant part of the tutorial, use this link for the .png and .dat files (i.e. the pakset repository):

https://github.com/jamespetts/simutrans-pak128.britain.git

and this link for the 3D models:

https://github.com/jamespetts/Pak128.Britain-blends.git

[fam621]

This is the modded .dat file for the Class 800 which should include livery options for it to be ran in either GWR or LNER (Virgin when this livery was made) livery. Check over it because it may have some errors in it

https://simutrans-germany.com/files/upload/br-800.dat

[jamespetts]

You will need to compile this yourself to check for errors: you should at least check yourself that your code works before uploading it.

[fam621]

k

[fam621]

Coming back to this (after some while), will it be possible to make the class 800/801 have the same livery variants.

[jamespetts]

Coming back to this (after some while), will it be possible to make the class 800/801 have the same livery variants.

If you would care to modify the files accordingly and test them, I should be happy to include such a change.

[fam621]

If you would care to modify the files accordingly and test them, I should be happy to include such a change.

The only thing is now is that the IET fleet will not carry Virgin livery and now carry the LNER livery and also that I am no good at doing such stuff.

[jamespetts]

The only thing is now is that the IET fleet will not carry Virgin livery and now carry the LNER livery and also that I am no good at doing such stuff.

If you can find somebody who has the time to do this and is willing and able to do so, I should be happy to incorporate this into the pakset.

[fam621]

About the acceleration rate thing, did you say that you wanted the acceleration rate in horsepower, because I found the horsepower for the class 800s on wiki. and the horsepower is 750 (560 kW) per engine (for I assume diesel).

[jamespetts]

About the acceleration rate thing, did you say that you wanted the acceleration rate in horsepower, because I found the horsepower for the class 800s on wiki. and the horsepower is 750 (560 kW) per engine (for I assume diesel).

The power is easy to find - it is the tractive effort that governs acceleration and that is hard to find (as discussed extensively above).

[fam621]

The power is easy to find - it is the tractive effort that governs acceleration and that is hard to find (as discussed extensively above).

James, how did you find the tractive effort for the other trains in Simutrans?

[jamespetts]

James, how did you find the tractive effort for the other trains in Simutrans?

If they were not available on Wikipedia or another source, I had to guess based on extrapolating from other locomotives or multiple units whose tractive effort is known.

Generally, it is easy to find the tractive effort of locomotives, but difficult to find the tractive effort of multiple units. I believe that I did manage to find somewhere the tractive effort for some of the "Desiro" series of multiple units (the class 450, etc.), but I could not find it for many other units, and had to extrapolate many of the other modern units from this.

[fam621]

If they were not available on Wikipedia or another source, I had to guess based on extrapolating from other locomotives or multiple units whose tractive effort is known.

Generally, it is easy to find the tractive effort of locomotives, but difficult to find the tractive effort of multiple units. I believe that I did manage to find somewhere the tractive effort for some of the "Desiro" series of multiple units (the class 450, etc.), but I could not find it for many other units, and had to extrapolate many of the other modern units from this.

How should the tractive effort look like in terms of a figure and units?

[Rollmaterial]

Tractive effort is a force, so the unit is Newtons (N). You will typically find it given in kN.

[Sirius]

Wiki states that it has an acceleration of  0.7m/s² and a weight of 243t (5 cars set) or 438t (9 cars set)

As 1N:=1kg*m/s², this results in a tractive effort of

243000kg*0.7m/s²=170kN (5 cars set)
438000kg*0.7m/s²=307kN (9 cars set)

Could not find acceleration data nor weight for class 801


Please let me know for which trains you need tractive effort, maybe I can assist in this.


Edit: forgot to mention about brake force.
As Wiki states class 800 has a deceleration of 1m/s² in service, or 1.2m/s² in ermergency, this would result in
243kN or 292kN (5 cars set)
438kN or 526 kN (9 cars set)

Only thing you have to do now is calculate it down to single cars as I don't know how the engines are spread over the train.

[fam621]

Wiki states that it has an acceleration of  0.7m/s² and a weight of 243t (5 cars set) or 438t (9 cars set)

As 1N:=1kg*m/s², this results in a tractive effort of

243000kg*0.7m/s²=170kN (5 cars set)
438000kg*0.7m/s²=307kN (9 cars set)

Could not find acceleration data nor weight for class 801


Please let me know for which trains you need tractive effort, maybe I can assist in this.


Edit: forgot to mention about brake force.
As Wiki states class 800 has a deceleration of 1m/s² in service, or 1.2m/s² in ermergency, this would result in
243kN or 292kN (5 cars set)
438kN or 526 kN (9 cars set)

Only thing you have to do now is calculate it down to single cars as I don't know how the engines are spread over the train.

Nice work.

[jamespetts]

Freahk - thank you for this: this is most useful.

As you may be aware, we do not have any means of simulating bi-mode traction in the game at present, so the class 800 represents this as a diesel train and the class 801 represents this as an electric train. In reality, these are almost identical save that the class 801 has fewer diesel motor cars. The Wikipedia article does not specify whether the acceleration rate given is for diesel or electric power, and I suspect the latter. I have thus adjusted the class 801's tractive effort accordingly, and used a guessed figure for the 800 (being the previous figure for the 801). I have also updated the brake force based on your calculations and corrected the weight.

If you are able to extrapolate the correct tractive effort for any other multiple unit aside from the Desiro series, that would be very helpful, as that is the only unit for which I have actual tractive effort figures, I believe (I have a vague recollection that I might have a tractive effort figure somewhere for a much older electric multiple unit, but I cannot be sure now and I cannot remember which).

Likewise, if you are able to calculate the brake force for any modern multiple units, that would be most helpful. For reference, we use the maximum service braking rate in the game, not the emergency rate.

[Sirius]

Good to know.
As I don't have my computer with my C++ dev environment in range currently, I will recalculate some tractive efforts and brake forces for MUs in the next few days.

[Matthew]

James, there appears to be a typo in line 11 of br-800.dat:

Code Select Expand

speed=225simutrans-pak128.britain

[fam621]

Freahk - thank you for this: this is most useful.

As you may be aware, we do not have any means of simulating bi-mode traction in the game at present, so the class 800 represents this as a diesel train and the class 801 represents this as an electric train. In reality, these are almost identical save that the class 801 has fewer diesel motor cars. The Wikipedia article does not specify whether the acceleration rate given is for diesel or electric power, and I suspect the latter. I have thus adjusted the class 801's tractive effort accordingly, and used a guessed figure for the 800 (being the previous figure for the 801). I have also updated the brake force based on your calculations and corrected the weight.

If you are able to extrapolate the correct tractive effort for any other multiple unit aside from the Desiro series, that would be very helpful, as that is the only unit for which I have actual tractive effort figures, I believe (I have a vague recollection that I might have a tractive effort figure somewhere for a much older electric multiple unit, but I cannot be sure now and I cannot remember which).

Likewise, if you are able to calculate the brake force for any modern multiple units, that would be most helpful. For reference, we use the maximum service braking rate in the game, not the emergency rate.

The class 801s are electric only trains.

[Sirius]

Sorry but you are wrong.
Class 801 is only in service at electrified tracks but in fact, the 5 car trains and the 9 car trains, both do have one (instead of 3 or 5 in case of class 800) diesel motors installed, allowing them to continue their journey at very limited speed and providing electrical energy e.g. for light using the installed 580 kW diesel generator, which is installed under the second last car, in case tracks electrification fails.

[fam621]

Sorry but you are wrong.
Class 801 is only in service at electrified tracks but in fact, the 5 car trains and the 9 car trains, both do have one (instead of 3 or 5 in case of class 800) diesel motors installed, allowing them to continue their journey at very limited speed and providing electrical energy e.g. for light using the installed 580 kW diesel generator, which is installed under the second last car, in case tracks electrification fails.

Ik that but in terms of general operation the class 801 is broadly electric only

[Sirius]

Where in technical terms it remains a bi-mode.

[fam621]

Hello James, I have just finished playing Simutrans and I notice that the class 801 has better acceleration the the class 800 and for some reason they are not livery variant so what I mean is that the class 800 should be able to have the Virgin Trains livery and also to have the same acceleration rate as its no different in real life whether its on diesel or electric. So can that be a possible fix please?

With the acceleration corrections imminent, will it be possible to allow both the class 800/801's to be able to be liveried into either the LNER (then VTEC) livery and the GWR liveries please?

[Vladki]

I have got to try the class 801 (800) and found some discrepancies. (and this old thread).
Diesel engine has correct power 700 kW, but electric has 4x 226 = 904 kW, according to http://www.hitachi.com/rev/pdf/2014/r2014_10_105.pdf

Power and weight is also here (for the whole train). Power agrees with the above.
https://web.archive.org/web/20181005071852/https://www.railengineer.uk/wp-content/uploads/2017/10/Table-1-Hitachi-800-802-orders-V3-Avenir.pdf
Weights in simutrans are a little bit different, and to not sum up exactly. Was there any specific reason? Comparing the weights of 5 and 9 car trains, it seems that all powered or unpowered cars have almost the same weight (difference less than 1 t).

Also the constrainsts and upgrades are not real. There is not composite trailer but a composite motor...

Also the above document states acceleration at 0,7 deccelration 1 m/s^2.
Brake_force is set to 49, which slightly higher, than my claculation: 46.60 kN for electric, and 48.60 kN for diesel. (But I think it should be the same). So 49 kN is OK.

tractive effort: electric 77 kN, my calculation for 5-car unit is 68 kN, 9-car unit 73 kN, soooo OK... (already with gear accounted for)

But for the diesel unit it seems too low (62 kN) - with 50% gear... Given the fact thet the traction motors are the same, just the power supply is limited, we could assume that the starting acceleration could be the same (maybe only for short while). Tractive effort for 9-car diesel unit and 0.7 m/s^2 is in my calculation 61.24 kN, but without gear. So to get the same acceleration we have to multiply by 2 -> 122 kN.

Also there is a clear typo in br800-rear fixed cost (+10000 compared to others). Also I don't understand why trailers have so high fixed cost compared to motor cars? Are there any approximate rules - how much are fixed costs of staff (driver, conductor, buffet) ?

As I have finished the electrostars I will continue with these.

[[C] Ranran]

Diesel engine has correct power 700 kW

Yes, it is the engine for power generation. It is driven by a motor with the generated power and the stored power.
Motor performance is as written by Valdki.

Also, as I reported in some thread before, the spec of Scott's class 385 made by inspire the next Hitachi is also different, so it would be helpful if someone fix it.
The 3-car unit and the 4-car unit are different.
The seats are different. There is no 1st class for 3-car one.
The number of motors is different. In order to have the same acceleration performance, the three-car train is a mixture of vehicles with half the number of motors. This is the method often found in Jalapagos. Feel Jalapagos.

You can check it on Hitachi's website. I think there was an English pdf somewhere. please look for it.
http://www.hitachihyoron.com/jp/archive/2010s/2016/10-11/pdf/2016_10_11_08.pdf
(This is in Japanese.)

[jamespetts]

Thank you for looking into this: it is very helpful to have good research on accurate data for the tractive effort of modern multiple units, and especially helpful to have implementation of this.

For the tractive effort, may I ask how you are calculating this; are you using the Simutrans physics engine and testing actual acceleration rates in-game with the parameters in question? This may be the best way to do it if we have acceleration rates but not base data and we need to infer the data from the acceleration rates.

The costs I did not set up - that was Dr. Supergood's interim balancing from a while ago; it may be that there are typing errors here.

[Sirius]

(starting) force is calculated using simple physical rules of mechanics:
F=m*a or in units 1N=1kg*1m/s²

Simutrans actually implements real-world physics, so apart from rounding that formula fits to simutrans as well.

Usually acceleration is given, which refers to force on tracks. Simutrans applies gear to force, thus we have to divide force by gear.

[[C] Ranran]

When tested on a Japanese train example, the acceleration display in the current in-game GUI generally shows the "theoretical" acceleration value correctly.
In theory, the nominal value may differ from the theoretical value as it may actually increase or adjust the current as the vehicle loads.
Class 800 uses such an AC induction motor.
https://en.wikipedia.org/wiki/Squirrel-cage_rotor.

[Vladki]

For the tractive effort, may I ask how you are calculating this;

F=m*a or in units 1N=1kg*1m/s²

Exactly as Frahk says, so for example:
BR class 801, 5-car unit, 233 tons, acceleration 0.7 m/s^2 -> 233 * 0.7 = 163 kN (tractive force for the whole train). Only 3 of 5 cars are powered, so 163/3 = 54.36 kN per car. Divide by gear 54.36/0.8 = 68 kN to be written in dat file.
Decceleration 1 m/s^2 -> 233 kN / 5 cars (all braked) -> 46.6 kN per car, gear does not affect brake_force.

I used the same method for trams. This can be IMHO used for all EMUS, trams, and buses, that are not expected to pull any wagons. Calculation has to take powered/braked axles in account, not whole cars.
Also note that maximum accleration/decceleration (to avoid wheelslip) is given by weight * g (gravitation acceleration = 9.81) * steel to steel static friction coefficient. Depending on weather it cen be 0.3 (dry) to 0.1 (wet). At least czech rail design rules assume 0.15 for braking calculation purposes. For the above unit it will be 68 kN (seems like coincidence, but I don't have the numbers at hand to compare). So far all vehicles I fixed have the brake_force safely below this limit, but tractive force is sometimes higher, so the driver must be careful when accelerating in wet weather.

[jamespetts]

That is helpful - it is good to know that the physics engine works as intended!

[Sirius]

it is good to know that the physics engine works as intended!

Well, apart from serious rounding troubles at low power, force or speeds at least.
The physics engine is quite impressive anyways.

[jamespetts]

Well, apart from serious rounding troubles at low power, force or speeds at least.
The physics engine is quite impressive anyways.

This was the work of Bernd Gabriel back in the early 2010s.

[Vladki]

That is helpful - it is good to know that the physics engine works as intended!

To be honest, I did not check if it works as intended. For that one would need data in form like: acceleration from 0 to 100 km/h in 10 seconds. Then one could compare if it makes it in the game.
I hope you would agree, that the values in dat files should be as close to reality as possible, and if it does not work well, then the engine has to be improved, or a global power/force factor (gear) be changed.

This is what we look for: https://eversholtrail.co.uk/fleet/class-802/
Acceleration graphs for both electric and diesel. Clearly the performance on diesel is worse...

[Sirius]

Clearly the performance on diesel is worse...

...above roughly 30 km/h.
What's the rated speeed? Is it somewhere between 20 and 40 km/h?

If you want to validate the physics engine:
DesiroHC 4 cars RRX (class 462)
starting acceleration: 1.1 m/s²
short time power: 6000 kW
weight (empty): 200t

0-160 km/h: 72,5s


ICE3 (class 403)
starting force: 300 kN
power: 8000 kW
weight (empty): 384t
0-100 km/h: 49s

[jamespetts]

Having found by chance one datum related to acceleration of electric multiple units, I thought it sensible to post that here.

The Metropolitan District Railway's "F" stock trains, in their originally built condition, are reported as having a rate of acceleration of 1.5 miles per hour per second (or 2.4km/hour/second) by the author of "Steam to Silver", written by J. Greame Bruce and published by London Transport in 1970.