Topic: Weight limits for rail/road?

[Spike]

I saw some dat files which give weight limits for railroad tracks and roads. So far I thought this is an feature exclusively for Simutrans Experimental, but the dats seem to be derived from Simutrans Standard pak sets. So I want to ask, is the weight limit enforced also in Simutrans Standard? I might make use of it in pak48.Excentrique if it really is ...

[paco_m]

In the simutrans wiki the weight limit is described as "planned feature" so I guess that some paks contain the declaration because of this announcement. In the german board we had a discussion about that and suggestions how to implement it, prissi said there that he might implement it under certain conditions; probably not in the same way as it has been implemented in experimental to avoid some problems that occured there

[Spike]

Ok, thanks for the explanation I think I'll try to prepare sensible values then, in case the feature will actually be implemented some day soon.

[prissi]

After the next stable, hopefully still in January, weight limits will come; albeit in a little different way from experimental, i.e. always using the maximum load and calculating an axle load.

The other thing from experimental that will come are monthly maintenance for vehicles (so it also costs some money for having them standing around instead of waiting).

A certain percentage of the running costs will go back to track owner. That way it will be cheaper to operate on own ways. At the same time gaming as infrastructure company might become feasible.

[Zeno]

I find this quite interesting, also the axle load example, but I wonder wether we would need a "number_axes" property in all our vehicles for that... anyway sounds good. And month maintenance sounds even better.

[prissi]

Axles would be assumed 2 if nothing else given ... It will require a new makeobj version anyway.

In standard only some runways and some channels wilol be limiting what to drive there (and maybe some tram track, I have to check that).

[VS]

Hmmmmm, now that will be a way to keep ocean ships out of channels and metro from tram tracks... Even without way constraints...

[The Hood]

This will be a big improvement - I'm looking forward to it (except editing all of the dat files in pak128.Britain!)

[sdog]

it's not so bad Hood, you can just assume some default values based on broad vehicle categories and script the axles in. in a second long term step the axle numbers can be adjusted piece by piece without haste.

Prissi, do you already have an idea what you will call the entries for axle loads in makeobj/dat files?

[prissi]

Most sense actually to call them axle_load, as ships have zero axis and other vehicles may have very different axles loads on different axles. But I did not think into this deeply, as we want to finish the stable first.

[sdog]

you want to specifiy axle_load directly, or specify total weight and also axles? (value zero axle number would work for ships)

[prissi]

I think I would specify axle load directly.

[jamespetts]

Wouldn't it be much easier to specify the number of axles? That would be far easier for pakset maintainers to deal with, or else it would require them manually to run the calculations through the calculator for each vehicle! The other problem is: what happens if the pakset creator wishes to change the vehicle weight? It would be rather silly if the number of axles were assumed to change at the same time! Might I suggest a parameter specifying "axles=" in the .dat file, assuming, as you suggest, 2 if not otherwise specified?

[sdog]

specifying number of axles directly would have the advantage that total weight is specified already. If you would introduce axle weight directly should the total weight be kept?


@james
it's not that bad, since makeobj ignores not specified entries, pak-set maintainers could just keep axle count in the dat file and use a script to calculate axle load directly.

[ӔO]

you would still need total weight, because it's used for calculating top speed, and I think acceleration, in standard.

although, total weight isn't as much as an issue as it is in standard when compared to experimental.

[jamespetts]

it's not that bad, since makeobj ignores not specified entries, pak-set maintainers could just keep axle count in the dat file and use a script to calculate axle load directly.

This seems like a painfully tortuous way of doing it. One alternative might be to allow pakset authors to specify either axel_load= or axels=, although that would have the disadvantage that it would be difficult in cases where pakset maintainers (incorrectly) specify both - which should take priority?

[paco_m]

Why making it so difficult?
We have already the total weights defined so just divide them by the axels and that's the (average) axel load,
for Simutrans I don't think that it is important if one axel has 10% more or less load than the other one.
As for ships just use the pressure, total weight / length (everything already defined in the dats) or directly the total weight (would be axel count =1).

[Spike]

I'd also think that axle count is sufficient, since the total weight of a vehicle is already known.

[prissi]

The axle load of a certain vehicle in general is not total_weight/axle count.

For example any "Sattelschlepper" (MAC-Trucks?) where the towing unit is not very heavy but supports part of the trailer load. The trailer only has three axles at the rear, since half of its weight is actually supported by the two axis of the fron engine. Same problems for join streetcars or talgos which join axles between vehicles.

Also for a pak-set maintainer it would be very easy to define a axle load (and ignoring problem like new goods which are probably more heavy or miscalulation load). I could just specify the tram has 12t axle load (or way_load?) and the forget about any loaded weight etc. and define 18 for engines and so on.

[sdog]

Just thought about what prissi said, and formed some rough ideas, please correct me if i'm wrong.

This should not matter for the Jacobs-bogies in trams or emus, every carriage is on either end supported by one bogie shared with the adjacent carriage. Thus define two half bogies = one bogie. Only if the carriages have very different weights the axle weight would be underestimated. This should happen mostly at the head and tail of trains, those units have a bogie of their own there.

Semi-trailer i've looked up the weight of a Mercedes Actros tractor as about 8t. This leaves 32t for the trailer.
Only dividing the weight of each unit by its axles i get 4t for each tractor axle and 10.7 for the trailer. Putting half the trailers weight on the tractor has 12t for the tractor and 8 t for the trailer. Distributing the weight in a way that half of the total weight is on the trailer and hafl on the tractor gets the most reasonable result of 10 for the tractor and 6.7 for the trailer. It should be desirable to have a higher axle load on driven axles for better traction. An even distribution of the total weight over all axles would give us 8t per axle.

Code: [Select]

distr.     t/axle
 8 32    4   10.7
24 16    12   8
20 20    10   6.7
  40          8

If you want to use the axle weights to calculate the road maintenance the 20% difference between the last two cases should be quite relevant. If it's for way constraints, dividing the total weight of a convoy by it's total axles for road vehicles should be sufficient. For trains axle load of each unit of a convoy should be appropriate. The maximum allowed axle load is usually around 10t.

If maintenance will be based on cummulated axle load however, it's perhaps unavoidable to specify the axle loads directly. I don't think having both values in the dat file would really work. People tend to forget and there's no proper documentation, better keep things simpler.

[prissi]

That why I favour axle load in dat files, i.e. allowing light engines to run for instance medizine palette goods on tram tracks but disallow heavy tanker cars or heavy engines. Could even make an incentive to have some good trams ...

Therefore the axle load of the convoi must be the axle load of the heaviest car. An since a user should hardly need to calculate, he need to be shown the axle load in the depot window (where price etc.) is shown. But why do a probably incorrect calculation instead of directly use the axle load?

[sdog]

But why do a probably incorrect calculation instead of directly use the axle load?

I think main reason for some reservation against this is from pak maintainers. Adding a new entry for axle count is considerably less work than also calculating axle load. It should matter for a couple of thousand dat file entries?

For most vehicles
axle load = total_weight / axle_count
is a correct assumption?

[prissi]

pak file have no axle count entry either and no way of assuming the actual number of axles.

The most sensible way (and without breaking savegame compatibility) for me is to assume axle_load=0 for old pak. That way only paks, that want to use this feature, will use it. Old vehicles will be able to drive on any way, as it was intended at the time the maker built those.

[paco_m]

If I understood this right we are talking about a theoretic maximum axle load for the vehicles that is independent from the actual load (loaded/unloaded). In other words for european trucks we could just fill in the already mentioned 10t (legal limit?) and that is it?
And just for abnormal vehicles like this http://de.wikipedia.org/wiki/Liebherr_T282 I would enter 300t requiring a special "street" for this monster (just examples xD).
So, no need to calculate a real axle load for every vehicle.

In fact I think that is a good solution as this prevents any kind of problems like my unloaded vehicle can pass the bridge that loaded it can't return and so on, regardeless on what the pak maintainers are doing

[sdog]

pak file have no axle count entry either and no way of assuming the actual number of axles.

inforamtion is intrinsicaly there, just look at the pictures, or google. So this can be a fast thing to do. It is also the same for a broad range of vehicles. E.g. all 4-wheel carriages in pak britain have 2 axles :-). It's still a bit of work.

That would be a sensible default indeed.

Two more questions:
Do you want to use total weight for bridges? If yes there are several options: mass of heaviest vehicle in a convoy, mass on one square, total convoy mass, mass of part of a convoy on the bridge (several squares).


Second: When the axle load of the axle with the heaviest load of a vehicle is specified, how do you get the load for the other axles? While road maintenance scales quadratically or even worse* with axle load, the linear increase with number of axles couldn't be neglected either, when their axle load is similar. It's perhaps the whole point of road maintenance costs that damages accumulate.

*someone posted it a while ago (neroden?) i couldn't find it though.

ps.: thanks for discussing this upfront, i believe you are often a bit reluctant in the fear of projects being blocked by being debated ad nauseam (deutsch zerredet). I hope you consider this more fruitful.

[prissi]

Well, this should be kept as simple as possible. Thus displaying a number which a player can immeadiately relate with the game. If people want it complex, they can use experimental anyway.

Thus there is the maximum axle load a convoi needs, which is the maximum axle load of any of the vehicles in the convoi.

Max weight will be maximum axle load. Thus no max. weight for bridges; even more in reality on can do a lot byusing traffic light to have only on heavy vehicle on a light brige etc.

[jamespetts]

If the reason to specify axle loading directly is that there are some cases in which the total weight divided by the number of axles will not give the correct result (as in articulated lorries), then there may be a good reason to give the pakset maintainer the option either of specifying the axle load directly or specifying the number of axles, and having the axle load setting take precedence if both are set for some reason. That way, pakset maintainers can take advantage of the greater ease of simply specifying a number of axles in the simpler cases (which is most of the time, saving a great deal of tedious work on a calculator), and use the direct specification of axle load only when the easier method would produce the wrong result.

[greenling]

Axle load for standard.
That it´s a no good idea!
It Makes many addon´s than be Worthless!
The Addon developeres In Japan, Aisa,Australia,dont working with new makeobj.
They have makeobj they be older the Makeobj 50!!

greenling

Mod note: moved & merged from exp. thread

[greenling]

I find that´s A Weight limits for Rails/Roads no good idea it!
A  Weight limits be get new problems and trouble.
I have many old pakfiles they i not can´t more be use on an new Simutransversion!
They all old Pakfiles have no enter of weight per axles.
A little example:
Many addons on Japanes.Simutrans.com site be are make with makeobj they older as an makeobj 51!
The pakfilesautors in Asia,Japan,Australia don´t know that´s here in Europe give a new makeobj!
And many Pakfilesautors forget to up date her pakfiles on a new System!

greenling
 

[Erik]

I don't see why it is so important to have the load for each axle.

If you have the total weight and divided it by the length of each unit.
Then you have enough information to calculate about the bridge will hold.

[paco_m]

I have many old pakfiles they i not can´t more be use on an new Simutransversion

Completely wrong:

The most sensible way (and without breaking savegame compatibility) for me is to assume axle_load=0 for old pak. That way only paks, that want to use this feature, will use it. Old vehicles will be able to drive on any way, as it was intended at the time the maker built those.

[colonyan]

If this thread is still in this section, I will assume this is still in consideration.

To be honest, not even the weight is needed.
 Forget the axle and all the fancy detail.
All you need is the simple weight class attribute such as "Light""Medium"and"Heavy".
It could be expressed even in number.
Different pack can have different number of weight class.
Add those attribute to vehicles and ways. Rest is obvious.
Heavy way can accommodate all types of weight type vehicles.
Light way is only accessible to light attribute vehicles.

It is (very) cumbersome to having to have to remember the number(s) each time
one encounters new vehicle and way types.

Other important element is making it visually very obvious in construction menu and
vehicle yard menu.

After all what is most important is the fact that it provides choice in degree
of investment, the money.

[sdog]

quite a good suggestion colonyan

@James,
Is route availability in the UK something similar?
http://en.wikipedia.org/wiki/Route_availability

[jamespetts]

I think that UK RA classes are a little more complicated than what Colonyan suggests here...

[sdog]

weight restrictions and the 'no route' resulting from it caused me quite a lot of grief playing. I'd like to suggest to let vehicles run on insufficient track at reduced speed and pop a warning when a convoy enters the first sqare. The no route should really be reserved for actualy broken ways only.

[ӔO]

@sdog
in simuconf.tab, set "enforce_weight_limits=1"

@james
10 settings doesn't seem so bad.

Vehicle weights would need to be kept for acceleration behavior, but this seems to be much simpler than an axle load number. Either would require another line in the depot display anyways. The best part is, a lot of the locomotives are already categorized.


I think roads would only need 3 or 5 settings, since all trucks and buses must fit within specific limits that are set by the department of transportation (or whatever it's called locally).
Early vehicles would get 1 to 3, while current vehicles would get 3 to 5

[jamespetts]

Hmm - it seems to me to be more complicated, rather than simpler, to have actual weight as well as a weight category. Vehicle weight and a weight limit is both more realistic and more readily comprehensible, I think.

[colonyan]

For those who know the numbers well might find it harder to assign weight class a new.
My proposal was from the player side point of view where they have no knowledge about the
vehicles details. As I noted, visual aide to obvious weight class information must be present to
what I propose to be truly effective.  

[paco_m]

Any news on this topic?

[prissi]

Nothing as I am still playing tetris (RL edition) to unpack boxes and assembling IKEA cupboards and the like from my recent move.

[jamespetts]

Nothing as I am still playing tetris (RL edition) to unpack boxes and assembling IKEA cupboards and the like from my recent move.

Does the RL edition come with the same theme tune?

Edit: Perhaps it does if you go here...

[greenling]

Hello paco_m
In simutrans exp gives the Weight limits for rail/road and there work it.
I Self have test the Weight limits for rail/road in Simutrans Exp with Self devlopment addons.
It was in the Beginning very hard to understand it.