Feature Request #3615

Use new track type label scheme

Added by oberhuemer over 8 years ago. Updated over 8 years ago.

Status:ClosedStart date:2012-01-27
Priority:NormalDue date:
Assignee:-% Done:


Target version:-


#1 Updated by dandan over 8 years ago

  • Status changed from New to Assigned

I appreciate the idea of bringing some order into the chaos of different rail type labels. But I cannot say I understand how this new system is supposed to work, specifically the part with axle weights. This will produce an awful lot of labels. And if I settle on some axle weight for the Japan Set tracks, say C, how will there be any compatibility with the French set that uses only A?

I was trying to follow suit with NuTracks for the most part, which still seems to be the most popular track set around. For now I'll wait and see what happens there.

#2 Updated by oberhuemer over 8 years ago

The plan is for NuTracks to start using the same scheme, though when I'll get to it is anyone's guess.
If you're not going to specify more than one axle weight, you can stick with A; and if the French track set uses "alternative labels" (see http://newgrf-specs.tt-wiki.net/wiki/Action0/Railtypes#Alternate_rail_type_labels_.281D.29), there's no compatibility problem.

#3 Updated by dandan over 8 years ago

Sounds reasonable. I'll probably do it then ;-)

#4 Updated by michi_cc over 8 years ago

The deal with the proposed label scheme is basically to somewhat abstract railtype sets from vehicle sets. At the same time, the main classification of track classes is switched to axle weight to align more with reality as speed is mostly a property of the track alignment and not the track type. (I'd consider the current NuTracks scheme more or less a work-around for the fact that OpenTTD does not allow vehicle orders with a speed limit.)

To achieve that, there's an initial system defined that assigns a meaning to each letter of the label (to be extended, e.g. for speed, if needed):

Gauge   Speed   Axle wt   Electrification
B       A       A         N
S       B       B         E
N       R       C         3

A vehicle set would, most of the time, define it's engines for a specific combination of gauge-axle weight-electrification (speed should be A unless there's some special reason like the (somewhat misused) R for rack rail). The sets would only check if these labels are available at all and might provide a fallback to RAIL/ELRL/NGRL if no track set at all is loaded, but should not attempt to provide fallbacks within this track scheme.

A track set then would pick a subset of these labels to offer to the player and use the alternative label list to map the other applicable track types to the provided types. So e.g. a track set that wants to provide only two axle weights might choose to map A and B to a light track and C, D and E to a heavy track. Mapping the gauge or the electrification makes seldom sense and the track speed is mostly internal to the track set (by appropriate compatible/powered masks).

See also http://www.tt-forums.net/download/file.php?id=153902 and the discussion starting at about http://www.tt-forums.net/viewtopic.php?p=987593#p987593

#5 Updated by dandan over 8 years ago

Thank you both for your explanations. I completely missed that debate on the forums.

So my plans for new railtype labels would be as follows:

JAPANESE MODE (used when Japanese trains are present)
ID    OLD    NEW    Speed in km/h
00    NLOW    NABN     80
01    NGRL    NBBN    130
03    ENLW    NABE     80
02    ELNG    NBBE    130
04    ENHI    NACE    160
05    ENUR    NUBE    130
06    RAIL    SACN    160
07    ELRL    SACE    160
08    ELUR    SUCE    160
09    EHIG    SADE    240
0A    HSTR    SBDE    320
0B    HSUR    SUDE    275
0E    750R    7ABN    ?
0F    750E    7ABE    ?
0C    MGLV    MGLV    -
0D    MONO    MONO    -

NON-JAPANESE MODE (as a general-purpose rail set)
ID    OLD     NEW    Speed in km/h (default)
00    RLOW    SABN     80
01    RAIL    SACN    150
03    RHIG    SAEN    200
0B    ELOW    SABE     80
02    ELRL    SACE    150
05    ELUR    SUCE    150
04    EHIG    SAEE    200
06    HSTR    SBEE    380
0E    3RDR    SAC3    130
0F    3RDC    SACZ    130
07    3RDU    SUC3    130
08    NLOW    NAAN     60
09    NGRL    NBBN    130
0A    ELNG    NBBE    130
0C    MGLV    MGLV    -
0D    MONO    MONO    -

SAAN, SABN, SBAN, SBBN                    ->    SABN
RAIL, SACN, SBCN, SADN, SBDN                ->    SACN
SAEN                                ->    SAEN
SBEN                                ->    SBEN

SAAE, SABE, SBAE, SBBE                    ->    SABE
ELRL, SACE, SBCE, SADE, SBDE                ->    SACE
SAEE, SBEE                            ->    SAEE

SAA3, SBA3, SAB3, SAC3, SBC3, SAD3, SBD3    ->     SAC3

NAAN, NBAN                            ->    NAAN
NGRL, NABN, NBBN                    ->    NBBN
ELNG, NAAE, NBAE, NABE, NBBE                ->    NBBE

Unsupported:    N**3, N**Z

New letters compared to the general scheme: =============================================
U - stands for "Urban". These are largely just for eyecandy and have concrete
background tiles. I chose to replace the speed letter (2nd) because it
seems the least important.
Z - dual-electrified (catenary + 3rd rail). The Z comes from MB who told me
this would be the label used in DBRails. Z=Zweisystem? Perhaps D for Dual
would be better?
7 - 750mm gauge (planned)

Any further comments or suggestions welcome.

#6 Updated by michi_cc over 8 years ago

dandan wrote:

I chose to replace the speed letter (2nd) because it seems the least important.

Yeah, the "speed" letter is mostly for track set usage, so putting eye-candy into that spot seems best to me.

The Z comes from MB who told me this would be the label used in DBRails. Z=Zweisystem? Perhaps D for Dual would be better?

No preference here, that's mostly for track set authors to fight out (the same applies to 7 or whatever for 750mm gauge) :) The future CETS track set (which can be seen in the linked image) won't have much besides standard gauge.

I don't think you'd actually need that many redirections though. Unless there's some very good reason vehicles should always be defined for the 'A' speed grade (Shinkansen might qualify here if the trackside equipment is sufficiently different), so providing alternates for the other speed grades isn't needed. Just make sure to define proper compatible/powered masks (that applies to the axle weights as well of course).

And an addition via pm from Snail (the first author to actively use the scheme right now):

The notes you jolted down are correct, they just miss a couple of things: "a" (lowercase) for the axle weight, which I will use in the French set for really cheap tracks (axle weight <= 13t), and "T" for electrification, meaning threephase system, which is needed by the Italian set I have in mind (as well as any set modeling the Alpine region). The rest is ok though.

#7 Updated by dandan over 8 years ago

  • Status changed from Assigned to Feedback

I implemented the new labels as outlined above, with a few necessary corrections. Some typos in the above list, but mostly I realized that it's a bad idea not to replace the default labels RAIL and ELRL anymore. Since these are always defined, they cannot be redirected. So now I am using RAIL instead of SACN and ELRL instead of SACE.

#8 Updated by dandan over 8 years ago

  • Status changed from Feedback to Closed

#9 Updated by Snail over 8 years ago

I hope it's not too late to add a note...
To make this scheme even broader, I thought about some new letters that could be interesting for sets who might want to further differentiate the electrification system (i.e. DC as opposed to AC) as well as new gauges (750mm as opposed to 1000m, or dual gauges).
So how about this?

Gauge   Speed   Axle wt   Electrification
S        A        a        N
B        B        A        E
N        R        B        3
n        U        C        T
D                 D        Z
d                 E        D

The new letters would mean:
"n" = narrow gauge, <950mm (only to be used by sets supporting two narrow gauge systems; if a set only supports one, it should always be "N", regardless of the actual gauge, for simplicity and compatibility reasons)
"D" = dual gauge, standard + broad
"d" = dual gauge, standard + narrow

"D" = DC, "high" voltage (e.g. 3kV)
"d" = DC, "low" voltage (e.g. 1.5kV)
"A" = AC, "high" voltage (e.g. 25kV)
"a" = AC, "low" voltage (e.g. 15kV)

The values I wrote here are just examples and could be set to any actual value by set developers. The main idea here would be that any set that wants to provide a "generic" catenary-powered electrification (as I assume most current sets do) can and should still use "E" for compatibility reasons. Only those sets that want to be more granular and differentiate among many different catenary-powered electrification systems should use "D" and "A" first, and subsequently, if they want to go even deeper in detail, "d" and "a".

Any comments?

#10 Updated by dandan over 8 years ago

Thanks Snail. It's never too late as long as there is no release ;-) And I am in the middle of making some rather substantial changes to the track set anyway. Your suggestions make sense. I will definitely use the n instead of 7. I'll have to think about the electrification business. We currently have mostly DC and very few AC vehicles (except the Shinkansen). This will probably change at some point in the future, but whether we really want two different track types for that is not yet decided. So many track types already, I think this might be overkill (not to mention the problem of limited slots).

There won't be any dual guage track in the Japan Set. But just out of curiosity: How would you draw such track? It will have to be four rails instead of three (which would be more common, I believe) because you cannot distinguish the orientation. But with four rails, won't the tile look rather crowded?

#11 Updated by Snail over 8 years ago

I know, I also think that separating different voltage types might be too much for an OTTD game. OTOH, I saw other sets thinking about doing this (for instance, Emperor Jake with his Trains of Europe set) so I thought we could enlarge the scope of this naming scheme so that it's compatible with their ideas.
You have a good point that rails always have to be symmetrical, so a dual-gauge track with 3 rails wouldn't work. At the end, I guess that double gauge would end up having two kind of "thick" rails, which could be broken up by darker pixels here and there (especially in the diagonal views).
I think the largest obstacle in the way to have a more granular railtypes distinction is the 16-railtypes limit in a single game. Because of this, neither AC/DC distinction nor dual gauge will be in the French set tracks, so I haven't tried to draw them yet (and I'm not planning to, unless the number of slots is raised). But they might be useful for other sets...

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