Longer Convoys

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Longer Convoys

March 24, 2009, 11:24:16 am

We've been discussing this in the pakBritain subforum - http://forum.simutrans.com/index.php?topic=1758.msg18420;topicseen#msg18420

To summarise, Is it possible to increase the limit of vehicles in a convoy? We are having problems with short freight wagons early in the game which mean that even the longest convoys aren't very long. I know there would be a possible issue in the depot window, but would it possible to add a scroll bar to view longer trains (maybe up to 64 vehicles?)

Re: Longer Convoys

Reply #1 – March 24, 2009, 11:42:11 am

It's possible, but I'm afraid you need to modify the source code. Maybe you're interested on this topic Increasing maximum rail length

Re: Longer Convoys

Reply #2 – March 24, 2009, 11:48:11 am

That's pretty much what I was thinking. Question is, if someone writes a patch for this, how likely is it to get in trunk? If it doesn't stand a chance, then I need to use a different solution to the balancing problem in pakBritain.

Re: Longer Convoys

Reply #3 – March 24, 2009, 12:01:17 pm

Why don't you test it in Simutrans experimental first? Talk with jamespetts.

Re: Longer Convoys

Reply #4 – March 24, 2009, 12:04:54 pm

He's already keen - I suspect it will be in simutrans-experimental before too long if it isn't very hard to code (presumably not compared to things like replacements!)

Re: Longer Convoys

Reply #5 – March 24, 2009, 12:14:06 pm

Although there is a 24 car limit on real world consists in europe ... as discussed in said thread. In older days, due to weaker engines and couplers this limit was even less.

Moreover, most sensible combinations of engine and cars will never reach full speed with 24 cars.

Re: Longer Convoys

Reply #6 – March 24, 2009, 12:35:52 pm

Just edit a constant in simconvoi.h

Code: [Select]

#52	enum { max_vehicle=4, max_rail_vehicle = 24 };

Apparently the size of depot window is adjusted according to the maximum length... So if you set the value too large, the depot window might not fit into your display. But anyway, it's possible here, although there might be other possible problems. I don't know.

Re: Longer Convoys

Reply #7 – March 24, 2009, 08:41:39 pm

Prissi,

the 24-car limit is by no means universal, even in Europe. See here for an example of trains in the UK many years ago consisting of 70 (albeit rather small) wagons, hauled by a single locomotive.

Re: Longer Convoys

Reply #8 – March 25, 2009, 06:11:15 pm

I highly doubt these numbers for the 19th century, for many reasons. One are the brakes of those trains. For other than shunting, moving so many cars (each 8-10t empty) would result in an 800t trains of those typically only one third would be with brakes or brakemen. Running with 30 miles per hours such trains could hardly stop in front of a signal in such cases. Also in Simutrans economy five seperate trains would make more sense than put them together, as station maintenance will kill you for those monster trains ...

Re: Longer Convoys

Reply #9 – March 25, 2009, 08:13:13 pm

Prissi,

I can only go with the research that I have unearthed - a Google search for "hauling xx wagons" with numbers > 24 in place of "xx" yields a goodly number of results, all from sources independent of each other, some from the UK in early years, some from all over the world in modern times. It seems highly improbable that they are all wrong. (Incidentally, they may well have gone considerably slower than 30mph in the old days).

In any event, if station maintenance is an issue for stations that long, the pakset authors can simply reduce the station maintenance cost for certain sorts of freight stations (perhaps allowing low capacity length extenders at a low cost) to remedy that.

Re: Longer Convoys

Reply #10 – March 25, 2009, 10:49:28 pm

One reason for the wish to increase train lengths is the fact that certain expensive locomotives cannot be fully used, due to the limitation to the number of wagons, which may be low-capacity ones. This is more a pak-set problem.

To be able to use the depot dialog with longer trains on a standard screen, the train could be displayed in several rows (perhaps overlapping).

Quote from: prissi – on March 25, 2009, 06:11:15 pm

I highly doubt these numbers for the 19th century, for many reasons. One are the brakes of those trains. For other than shunting, moving so many cars (each 8-10t empty) would result in an 800t trains of those typically only one third would be with brakes or brakemen. Running with 30 miles per hours such trains could hardly stop in front of a signal in such cases.

For non-standard trains like these, the network would have to use an exceptional mode of operation, e.g. by clearing and securing several blocks ahead of the train, allowing much longer braking distances. Having substantially more time to brake means that less brakemen are needed, each of them responsible for several wagons.

Re: Longer Convoys

Reply #11 – March 25, 2009, 10:52:48 pm

Quote from: jamespetts – on March 25, 2009, 08:13:13 pm

In any event, if station maintenance is an issue for stations that long, the pakset authors can simply reduce the station maintenance cost for certain sorts of freight stations (perhaps allowing low capacity length extenders at a low cost) to remedy that.

What use would that be (adopting station maintaince to stations for such long trains)??
Why would one ever need such a long train instead of many short trains?

Re: Longer Convoys

Reply #12 – March 26, 2009, 10:05:03 am

Station maintenance wouldn't be much of an issue - the point is that there are many short wagons, e.g. in current pakBritain a loco + 22 wagons is only 5 tiles (or less with some of the even older wagons). Obviously running really long convoys with long wagons as well is not so sensible, both from maintenance and also clogging up the network!

As far as I know, for these old goods trains, 30mph (50kmh) was a real achievement, and average speeds for whole journeys were usually well below 10mph!

Re: Longer Convoys

Reply #13 – March 26, 2009, 12:13:51 pm

It's actually pretty common to have more than 24 cars even in Japan, where the infrastructure is relatively weak. For instance, this freight waggon
http://ja.wikipedia.org/wiki/%E5%9B%BD%E9%89%84%E3%83%AF%E3%83%A080000%E5%BD%A2%E8%B2%A8%E8%BB%8Aused
can be coupled up to 45 cars, although the length of each car is rather short (less then 10 metres). And such trains are operated under the usual signalling and the speed (up to 75 km/h).

In Australia, the standard freight trains, operated on Melbourne - Adelaide route, consist of 4 locomotives + 40 freight waggons, which length is about 1 km. Trains are even longer on Adelaide - Perth and Darwin routes.

Of course, this doesn't mean Simutrans should have longer trains. This is another issue.

Re: Longer Convoys

Reply #14 – March 27, 2009, 12:57:55 pm

Probably one should limit the length than rather by tiles than by the dialoge since in most places the length and not the number is limited. (Central Europe 700m or 252 axles due to axle counters). This would mean like 7 tiles in Simutrans ...

Re: Longer Convoys

Reply #15 – March 27, 2009, 01:02:30 pm

That sounds like a better idea. Maybe slightly longer - full length Eurostar / Pendolino sets take up longer (10-11 tiles) in pakBritain. I think 10 tiles would be a sensible limit - otherwise it is too long and looks silly.

Re: Longer Convoys

Reply #16 – March 27, 2009, 02:03:45 pm

Maybe the issue is that size of the wagons are not realistic in the map to begin with? 2 wagons taking up a mile/tile?

If you think of current "individual wagons" as a group of x (2, 4, 8?), does it make more sense? Keep the weights and powers realistic, but increase the number of wagons per tile, tweak the ui, and you may have a better solution, then 15 mile trains.

Re: Longer Convoys

Reply #17 – March 27, 2009, 03:56:06 pm

Hmm, but wouldn't that require each vehicle's .dat file to specify the number of axles? (If so, that might be of some use in more sophisticated weight limit algorithms, but the question is whether it is really worthwhile).