Feature #2763

track classes / railtype support

Added by planetmaker over 8 years ago. Updated over 7 years ago.

Status:NewStart date:2011-06-20
Priority:NormalDue date:
Assignee:-% Done:

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Target version:-

Description

See http://www.tt-ms.de/forum/showthread.php?tid=1284&pid=74868#pid74868 for an idea
  • Streckenklasse A: DBan (alt: DBNN) (max 16t, max 60/80 km/h)
  • Streckenklasse B: DBbn (max 18t, max. 100km/h)
  • Streckenklasse Be: DBbe (alt: DBNE) (analog B, elektrifiziert)
  • Streckenklasse C: DBcn (alt: DBHN) (max. 20t, max. 140km/h)
  • Streckenklasse Ce: DBce (analog C, elektrifiziert)
  • Streckenklasse C': DBCn (max 20t, max. 200km/h)
  • Streckenklasse C'e: DBCe (alt: DBHE) (analog C', elektrifiziert)
  • Streckenklasse D: DBdn (max 22.5t, max. 140km/h)
  • Streckenklasse De: DBde (analog D, elektrifiziert)
  • Streckenklasse D'e: DBDe (alt: DBHS) (max 22.5t, max 350km/h)

track_classes.png (26.2 KB) Eddi, 2011-08-04 20:11

History

#1 Updated by planetmaker over 8 years ago

  • Description updated (diff)

#2 Updated by michi_cc over 8 years ago

My idea to make the distinction for 18t axle weight more important.

The maximum speed is not set in stone and should be adjusted according to the engines that end up in the core set so that most engines will achieve top speed on the matching track type. It might even make sense to drop the speed limits all together or at least increase them to something like 120,160,200,inf.

  • A: max 16t, 100 km/h
  • B: max 18t, 120 km/h
  • Be: max 18t, 120 km/h, electrified
  • C: max 20t, 160 km/h
  • Ce: max 20t, 160 km/h, electrified
  • De: unlimited, electrified

#3 Updated by michi_cc over 8 years ago

Looking at the current DB timeline, the first engine with an axle weight > 20t would be the E10 in 1957 (max. speed 150 km/h). This doesn't really fit with the old proposals, where either the high-speed track would need to be available from 1957 onwards or the engines are 'cheated' into track class C. As a fix, track class D non-high-speed could be introduced in addition to or replacing the C tracks. Seeing that there are basically no competing engines for < 20t and > 20t at the same time, replacement is the better option.

Looking at the top speeds of the currently planed engines, especially the B track class needs to get a higher top speed, for example to cater for the BR 03.10. Partly this also applies to class A on which the BR 614 with a top speed of 140 km/h can run. As many tracks are likely going to be upgraded already by this time, limiting this particular engines to 120 km/h on class A tracks seems to be okay.

Thus, I propose the following modified track scheme:
  • A: max 16t, 120 km/h
  • B: max 18t, 160 km/h
  • Be: max 18t, 160 km/h, electrified
  • D: max 22.5t, 200 km/h
  • De: max 22.5t, 200 km/h, electrified
  • D'e: unlimited, high-speed, electrified

Additionally, to include the S-Bahn engines, there needs to be at least one 3rd-rail type. In order to allow mixing with non-eletric engines, providing a low axle-weight and a high axle-weight version should be considered, just like a 3rd-rail + catenary type. Those are not essential though, in case we want to limit the number of rail types.

#4 Updated by oberhuemer over 8 years ago

If you're bumping the top speed of class B so far, you should also include an electrified version of class A. As for third rail, I'd say make a such version for classes A and B and then one dually electrified track on class A. Then you can still have a narrow gauge electrified and non-electrified type, plus maybe one with rack rail, and a maglev/Transrapid type, leaving room for two more defined by other GRFs.

#5 Updated by Eddi over 8 years ago

There is really no (sane) electric engine with <16t axle weight. Even ones with <18t are rare, even in DRG times, most electrified lines were ready for 20t.

I have added a few proposals for track type schemes to the tracking table. For completeness here as attachment.

#6 Updated by michi_cc over 8 years ago

Eddi wrote:

I have added a few proposals for track type schemes to the tracking table. For completeness here as attachment.

The basic set needs An more than an (e.g. BR 614 with max 140 km/h, some limit to top speed in class A makes sense, but a limit to 80 not so much). Some for the E18 with 150 km/h on B axle weight.

oberhuemer wrote:

If you're bumping the top speed of class B so far, you should also include an electrified version of class A.

The important variable IMHO is the axle weight and not the top speed. The only reason to have a speed limit at all is for a) the distinction between high-speed and non-high-speed and b) to prevent "abuse" by running for example an ICE-TD at top speed over class A track.

Something that would make sense from a game play view is a decreasing curve speed for higher track class (even if that's not reality correct) to give some incentives to build more than just the fastest available track type. That would need a NewGRF spec extension to implement properly, but that could be solved easily :)

#7 Updated by planetmaker over 8 years ago

michi_cc wrote:

Something that would make sense from a game play view is a decreasing curve speed for higher track class

Railtypes have a curvespeed multiplier property since its introduction. Thus it's already feasible to penalize curves on slow railtypes more than on expensive ones: http://newgrf-specs.tt-wiki.net/wiki/Action0/Railtypes#Curve_Speed_advantage_multiplier_.2811.29

EDIT: the granularity is not very nice though

#8 Updated by michi_cc over 8 years ago

planetmaker wrote:

EDIT: the granularity is not very nice though

You can only increase the curve speed though and not decrease it. As the base speed for a normal 2x45° curve is already 88 km/h, there's not much you can penalize. And as for example NuTracks does define the existing property (though as 0 == default), changing it would mean some breakage or simply a new property, e.g. prop 'base curve speed' and prop 'additional speed per additional curve tile'.

#9 Updated by Eddi over 8 years ago

michi_cc wrote:

The basic set needs An more than an (e.g. BR 614 with max 140 km/h, some limit to top speed in class A makes sense, but a limit to 80 not so much). Some for the E18 with 150 km/h on B axle weight.

I disagree here, both from gameplay as well as realism point of view, such a high speed on branch lines not desirable. the "an" railtype is mainly meant to have some difference in the very early game, the speed limit will only affect trains much later. real branch lines often have even lower max speeds, between 40 and 60km/h. The "An" railtype is meant for the late period (in my Wagon proposal that would be the time when "(non-accelerated) Passenger" class goes 120km/h), and at that time you may as well upgrade to a faster track type, it's meant as a "basic" set, not covering every option. the speeds i have given in the table are imho a good compromise between your desires and my original intention, a speed limit that is not limiting anything does not have a lot of gameplay value.

let's look at a few selected engines that are affected by the current proposal: (Basic Set 2)
  • BR S1 (1885): could go 90km/h instead of 80km/h
  • BR 24/64 (1928): could go 90km/h instead of 80km/h
  • VT98 (DB, 1953): could go 90km/h instead of 80km/h
  • VT2 (DR, 1957): could go 90km/h instead of 80km/h
  • V100 (DB, 1958): could go 100km/h instead of 80km/h
  • BR 624 (DB, 1964): could go 120km/h instead of 80km/h
  • V100 (DR, 1966): could go 100km/h instead of 80km/h
    Only after 1970 some engines go significantly faster, but "Passenger" should go only 90km/h anyway until around 1990-2000.
For track class B, even fewer engines are affected:
  • BR E18 (1935): could go 150km/h instead of 130km/h. BR E04 (1933) goes 130km/h max.
  • VT04 (1935): could go 160km/h instead of 130km/h (or 80km/h)
  • BR 03.10 (1939): could go 140km/h instead of 130km/h
  • VT11 (DB, 1957): could go 140km/h instead of 130km/h
    Especially for express trains, there should be an incentive to use the more expensive track type.

Anyway, we should also provide an option to disable speed limits altogether (per parameter), maybe that can be a 3-way switch: "Speed limit: {low|high|none}"

#10 Updated by michi_cc over 8 years ago

I concur for B, but I would put A to at least 90 km/h because of the S1. I don't think we should force players to build B track in 1885 (where no engine needs B) just to use the top speed of the S1. And I'm not sure if a limit of dn to 160 km/h makes sense because would it counteract the purpose of the ICE-TD.

In general, I'm not much of a fan to "misuse" rail types as speed limiting device (i.e Nutracks, better do it via orders/timetable, for which I probably need to write a patch now :p). Construction cost, maintenance cost and curve speed (the latter two need OpenTTD support first of course) are more interesting variables IMHO. I do realise that having no limit at all is bad because of the modern MUs.

To expand a bit more about the curve speed: The normal speed limit in a 2x45° curve is 88 km/h (actually, if only one wagon is on the curve, so for 4lu wagons, the speed limit is already 110 km/h). If a set uses realistic wagon speed limits for freight trains, the curve speed limit is totally unimportant from two or three tile long curves on. My idea here would be to lower the curve speed for tracks with higher speed/axle limit ("simulating" the bigger space needed for the better subgrade) to keep a niche for lower axle weight tracks and engines in more difficult terrain.

#11 Updated by Eddi over 8 years ago

Hm, austrian railways seem to have a very low requirement of 14,5t axle weight, so those might even benefit from 100km/h on track class A.

so how about this: for the "Basic Set 2" and "Extended Set" with only one class A type, make the limit 100km/h, and for "Full Set" keep it at 80/120 km/h.

I agree that the curve speed limit should be drastically reduced, maybe something like this for 2x45° Curves:
  • 30km/h for narrow gauge (not necessarily included in this set)
  • 25km/h for track class A
  • 20km/h for track class B
  • 15km/h for track class C
  • 10km/h for track class D

PS: planetmaker opened a project here: http://dev.openttdcoop.org/projects/ce-tracks

#12 Updated by michi_cc over 8 years ago

Eddi wrote:

so how about this: for the "Basic Set 2" and "Extended Set" with only one class A type, make the limit 100km/h, and for "Full Set" keep it at 80/120 km/h.

Yeah, that sounds quite okay for the base set. The full set can of course fill the 16 rail type slots with whatever wanted :)

"Proper" curve speed handling needs some larger rewrites of OpenTTD unfortunately, thanks to instant breaking, no look-ahead at all and curve speed limits also depending on train length. But yes, something like your list would be very nice.

#13 Updated by Eddi over 8 years ago

michi_cc wrote:

"Proper" curve speed handling needs some larger rewrites of OpenTTD unfortunately, thanks to instant breaking, no look-ahead at all and curve speed limits also depending on train length. But yes, something like your list would be very nice.

in my imagination it always worked like this:
  • the train reserves a minimum of N tiles (some estimate of braking distance) regardless of path signals nearby (and from that point until the next signal)
  • signals within this distance are forced to green
  • path will also be reserved near block signals, a reservation in a block forces all signals to red, like if there was a train on that reservation
  • the curve speed is calculated based on the path reservation, not the train length
  • if reservation fails, or limit is lower than current speed, the train decelerates similar to how it is done when approaching a station

#14 Updated by oberhuemer over 8 years ago

I thought about how narrow gauge (both electrified and not) could be integrated into the "full set". Right now, I'd support removing the An and d3 types and moving the third rail track type from class "a" to class "c", leaving one slot for maglev or anything else.

#15 Updated by Eddi over 8 years ago

i'd not do that, you can't have everything. the "full set" has one slot free, in case you want to add an extra grf with either planning tracks, narrow gauge, maglev, universal railtype [like combined 3rd rail and catenary] or whatever else you can think of. if you want more than that, you're better off using the "extended set".

the sense of the "d3" type is that you can either use "a3" for separate metro lines, or "d3" for combined main/metro lines (like the long distance rails on the "Wannseebahn")

#16 Updated by oberhuemer over 8 years ago

I'm just thinking a3 is a bit slow and d3's utility is sharply limited by it not allowing regular electric trains - except, of course, if overhead wires are added, which doesn't seem to be the plan.
As for "having everything", I'm trying to show exactly that it can work. Of course, there need to be trains for all those tracks too...

#17 Updated by oberhuemer about 8 years ago

I've read up on the German narrow gauge engines, and all I'll say is that I understand why the Bundesbahn wanted to get rid of them. Narrow gauge tracks might still be nice for Austria and Switzerland (haven't checked them out), but that's clearly a long way off.

#18 Updated by Eddi about 8 years ago

there is a quite major network of narrow gauge railways in saxony and in switzerland, but the general consensus was "if we do that, probably in a separate GRF"

#19 Updated by oberhuemer almost 8 years ago

Out of date, new labels at https://docs.google.com/spreadsheet/ccc?key=0AkXAVZqXTFQxdHM3UlpWM1hPZWpfeTlkdnZsMldjSkE&hl=de&pli=1#gid=9. That famous Someone really needs to write some documentation files so everything's not just randomly flying around.

#20 Updated by Eddi over 7 years ago

i haven't gotten around to updating the railtype code yet. it can probably be simplified a bit now that we actually got to a sane common standard

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