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Author Topic: Realism VS gameplay: a couple of balance issues  (Read 14881 times)

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Offline AP

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Re: Realism VS gameplay: a couple of balance issues
« Reply #35 on: April 19, 2010, 07:42:48 PM »
Here's an idea - if you could come up with a list, you could post it to the uk.railway newsgroup. They're a pretty knowledgeable bunch of rail enthusiasts (and very helpful for rail travel advice too!), and I'm sure some of them have bookcases full of the sort of information we need.

Presumably it's just weight, tractive effort, ?acceleration? we need (for locos), and (empty) weight for coaches.

Added bonus - if by chance there is an epic bible-type reference tome for all this information, they're the people likely to be able to give you its title, at which point it's just an inter-library-loan away.

Offline neroden

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Re: Realism VS gameplay: a couple of balance issues
« Reply #36 on: April 20, 2010, 02:39:33 AM »
Here's an idea - if you could come up with a list, you could post it to the uk.railway newsgroup. They're a pretty knowledgeable bunch of rail enthusiasts (and very helpful for rail travel advice too!), and I'm sure some of them have bookcases full of the sort of information we need.

Presumably it's just weight, tractive effort, ?acceleration? we need (for locos), and (empty) weight for coaches.
Also top rated speed.

I've actually seen some information about passenger coaches 1830-1870, because they were sometimes preserved in other forms and get restored as 'heritage' projects.  Goods wagons and locomotives are all long gone.
« Last Edit: April 21, 2010, 01:20:48 AM by neroden »

Offline jamespetts gb

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Re: Realism VS gameplay: a couple of balance issues
« Reply #37 on: April 20, 2010, 08:28:29 AM »
AP,

I did post a message here to the list - no responses so far. And I don't think that locomotives had top rated speeds in those days (they didn't even have speedometers until after the second world war); they just went as fast as they could with the load (which, in the early days, wasn't very fast most of the time) unless they had to go slowly for a particular reason (sharp corner, etc.).

Offline neroden

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Re: Realism VS gameplay: a couple of balance issues
« Reply #38 on: April 21, 2010, 01:20:25 AM »
AP,

I did post a message here to the list - no responses so far. And I don't think that locomotives had top rated speeds in those days (they didn't even have speedometers until after the second world war); they just went as fast as they could with the load (which, in the early days, wasn't very fast most of the time) unless they had to go slowly for a particular reason (sharp corner, etc.).
Oh yeah, you're basically right.  The top speed was determined by the track (you derail if you go too fast), and usually determined  by braking ability IIRC... you were most likely to go too fast and derail going downhill.

Offline sdog

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Re: Realism VS gameplay: a couple of balance issues
« Reply #39 on: April 21, 2010, 02:40:15 AM »
In experimental you don't have to care about the top speed. Bernd's physics engine will limit the top speed, and even display it in the depot window!

Offline neroden

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Re: Realism VS gameplay: a couple of balance issues
« Reply #40 on: April 22, 2010, 01:05:18 AM »
In experimental you don't have to care about the top speed. Bernd's physics engine will limit the top speed, and even display it in the depot window!

Yes, except for one thing....
...there's nothing modelling braking ability in the game.

I'm OK with that, it keeps things simple, and since the late 19th century both road and rail vehicles have had very powerful brakes, but it's worth noting that some of the earlier trains were genuinely limited in speed and tonnage by nothing more than their braking ability (early braking sucked).  This may require deliberate alterations to the numbers for the engines for the period, as their acceleration and pulling power may well have outstripped their braking power.  This is Britain, where every train had a "Brake Van" before the installation of air or vacuum brakes on every carriage. 

So if you find numbers which seem too high for some of the engines, it may be that the engines really were that good, but the brakes weren't.

Offline sdog

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Re: Realism VS gameplay: a couple of balance issues
« Reply #41 on: April 22, 2010, 02:28:59 AM »
perhaps the lack of braking can be simulated by seting the top speed for the carriages lower? that's probably even more guessing there.

Offline jamespetts gb

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Re: Realism VS gameplay: a couple of balance issues
« Reply #42 on: April 22, 2010, 10:07:38 AM »
I agree with Sdog's solution to this issue: the way to deal with speed having to be limited through poor braking is to limit the speed of the towed vehicles that have poor brakes, rather than altering the physics, which might have side-effects. However, I think that the carriages and wagons already do have appropriate speed limits set.

(Incidentally, very early freight trains did not have brake vans at all, and unbraked freight trains were only abolished in the 1960s, although they had always been limited to about 30mph).

Offline neroden

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Re: Realism VS gameplay: a couple of balance issues
« Reply #43 on: April 22, 2010, 04:45:35 PM »
I agree with Sdog's solution to this issue: the way to deal with speed having to be limited through poor braking is to limit the speed of the towed vehicles that have poor brakes, rather than altering the physics, which might have side-effects. However, I think that the carriages and wagons already do have appropriate speed limits set.

(Incidentally, very early freight trains did not have brake vans at all, and unbraked freight trains were only abolished in the 1960s, although they had always been limited to about 30mph).
It's so different over here in the US -- air brakes were mandated by law in 1900.

Incidentally, Wikipedia indicates that the Jenny Lind was an unusual success for the period with 70 manufactured, so perhaps it was better than its competition.  It also indicates that the "Crampton" locomotives were reaching speeds of 100 km/h - 120 km/h in the 1850s.... so I'm guessing the pak's early engines are actually underpowered compared to real life.

I wonder if freight cars from before the continuous-brake period (but after the "very early" period) should require a brake van, the way some of the passenger cars already do.  The 4t and several 7t brake vans are already there, with artwork (and apparently they are purely decorative!) This would be a rather elegant thing to do.  Or would those consist constraints be too complicated to program?


Offline jamespetts gb

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Re: Realism VS gameplay: a couple of balance issues
« Reply #44 on: April 22, 2010, 05:58:28 PM »
Neroden,

fascinating that freight trains required air brakes (air not vacuum - are you sure? It's harder for a steam locomotive to do air braking) as early as 1900. I know that, after the 1888 Armagh rail accident, passenger trains in the UK had to have continuous brakes, but there was no such requirement for freight trains, and many remained "unfitted" until well after the second world war.

The reason that the brake vans are just decorative is indeed that the constraints are too hard to program, because one needs to be able to combine any wagon with any other wagon of the same, a later, or earlier generation, and that would be an insane amount of work. I am hoping, however, to add a feature into Simutrans-Experimental 8.0 to allow a vehicle simply to have a constraint "must not be at the rear" (as The Hood requested some time ago) to enable this to be done - for Experimental at least.

Offline neroden

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Re: Realism VS gameplay: a couple of balance issues
« Reply #45 on: April 24, 2010, 05:52:15 PM »
Neroden,

fascinating that freight trains required air brakes (air not vacuum - are you sure? It's harder for a steam locomotive to do air braking) as early as 1900.
The law did allow vacuum and mechanical brakes, but air brakes were used.  Specifically, it required brakes *remotely operated by the engineer* on a certain (large) percentage of freight cars on all trains engaged in interstate commerce.   In fact most major railroads were already using air brakes on their passenger cars by this time.  Therefore, the very strong commercial requirement for interoperability of different locomotives and freight cars (there were a *lot* of handoffs between railroads, because there were a *lot* of relatively small regional railroads at the time) meant that air brakes had to be used for everything -- if one railroad went with vacuum brakes, they wouldn't be allowed to accept freight cars in interchange from a railroad using air brakes.

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The reason that the brake vans are just decorative is indeed that the constraints are too hard to program, because one needs to be able to combine any wagon with any other wagon of the same, a later, or earlier generation, and that would be an insane amount of work. I am hoping, however, to add a feature into Simutrans-Experimental 8.0 to allow a vehicle simply to have a constraint "must not be at the rear" (as The Hood requested some time ago) to enable this to be done - for Experimental at least.

Oh, that would be awesome.  :-)