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Vehicle capacities - max. weight/volume/area

Started by Vladki, November 21, 2020, 12:18:08 AM

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Hello all. I'd like to ask pakset creators who aim for maximum reality, how do you set the vehicle capacities for various goods, especially piece goods?

All vehicles have not only maximum weight, but also maximum volume and area. So if I set payload according to max weight (which seems quite reasonable for bulk goods, long goods and grain. Although for some agricultural products one can hit the volume limit earlier than weight limit. (E.g. malt is less than half ton per m3)

But using weight does not work well for piece goods. I ran into a small old wagon (10 m long) with 29 t allowance, but more modern wagon (14 m long) with only 25 t allowance (both have 20 t/axle when fully loaded). So I thought it would be better to use the area of the wagon - 23 vs. 33 m2. And use europallet as the metric - it has area of almost 1 m2. But then the weight allowance could be easily over loaded, as europallets can be loaded up to 2 tons. Even with 1 ton/pallet it would be too much for the bigger wagon.

What solution did you use for your pakset?

NB. I know proper solution would be to have multiple metrics for both goods and capacities, but that would be quite a big change for the game.

Leartin

Not that I'd aim for max reality, but there are a few notes.
Pak192.comic distinguishes between heavy bulk and light bulk. The main reason was to seperate agricultural produce from ores, but it somewhat made sense to frame it like that - even though plastic is rather light. When we did the seperation, we were discussing whether light bulk should be measured in volume. So a heavy bulk vehicle would transport X tons, and the light bulk vehicle would transport X cubic meter.
For whatever reason, we didn't, and you could certainly question whether two types of bulk vehicles is realistic in the first place.

You mention europallets can be loaded up to 2 tons. It can withstand 4 tons, but the max allowed load is 1.5 tons. But regardless - you know the goods in your pakset. You can check how heavy each pallet is - is there a pallet that weights 2 tons? Does it need to weight 2 tons, or can you just reduce it to one ton? Likewise, what are the lightest pallets available?

At some point, you'll have to make a decision between a few options, this list is probably not exhaustive:
1) Equalize Mass and Space. If for all goods, one full pallet weights one ton, you'd know the old wagon could hold 23 units (constrained by space) and the new wagon could hold 25 units (constrained by weight). It's still not realistic, as of course not all goods would weight a ton, but you moved the problem somewhere else where it might not be as important to you.
2) Disallow overloading. That means, you take the highest possible weight a pallet can have and use that as a limit. If that happened to be 1 ton, it would still be 23 and 25 units. If the heaviest pallet in the set is 1.5 tons, the old wagon could only load 19 units (by weight) and the new one just 16 units. Naturally, this is much less than you could normally carry with these wagons of lighter pallets, but at least you are never overloaded.
3) Use an approximation. Look at the array of different weights pallets can have, in pick some kind of middle ground - Mean, median or mode - and approximate that all pallets will weight that much. Both heavier and lighter pallets won't load correctly, but it will be about right most of the time.
4) Ignore weight. That's not for realism, but you know you can't get it right anyway. Weight influences the whole convoi even if there is no max weight on the vehicle, so using volume as sole determinator of capacity makes sense from a gameplay perspective.
5) Don't put vehicles in the game for which the space capacity is higher than the weight capacity. Never forget that you have that option to circumvent the entire issue - at least potentially, I don't know if real wagons actually allow that.

Lieven

Quote from: Leartin on November 21, 2020, 04:45:09 PMYou mention europallets can be loaded up to 2 tons. It can withstand 4 tons, but the max allowed load is 1.5 tons. But regardless - you know the goods in your pakset. You can check how heavy each pallet is - is there a pallet that weights 2 tons? Does it need to weight 2 tons, or can you just reduce it to one ton? Likewise, what are the lightest pallets available?
In reality, most pallets are loaded at 1t, but it's not rare to see some pallets loaded at 2 tons, I don't think that they're a reglementary maximum weight load for the pallets. I think that to represent the reality, you can use a average weight to 1 ton for the fresh / frozen goods and 700/800kg per pallet for standards goods. Some pallets are much heavier but that's not representative of the general cases.

Too much !

Leartin

Quote from: Lieven on November 21, 2020, 07:31:46 PM
In reality,[...] it's not rare to see some pallets loaded at 2 tons, I don't think that they're a reglementary maximum weight load for the pallets.
For Europallets, specifically EPAL1, it's specified to 1500kg.
Sure, in reality, regulations are often ignored. But remember that the max allowed load of a vehicle is also just a regulation, not the absolute maximum it could physically withstand. If we consider the max allowance to be a hard limit, we should equally consider the regulation for pallets a hard limit.
[Only if it's europallets. If it's non-standardized unknown pallets, anything goes, both in how much they can carry and how big they are.]

The weight allowance for pallets is not that important here. Piece goods (in simutrans) can be in pallets, barrels, sacks, or pieces in themselves (e.g. furniture, livestock, cars). All of them can have some weight assigned. Bulk goods/fluids may be defined in m^3 and also have weight assigned to it. But the weight is then used only for physics: acceleration, weight limits (and wear) of ways and bridges (in extended), but not while loading the vehicle. The loading capacity in dimensionless units, and each good may have different unit. What I'm looking for is to allow at least two (or three) dimensions for both goods and vehicles.  To be more specific:
all of bulk goods, fluids, grain, milk, long goods will have m^3 as the main unit, with weight assigned. The corresponding vehicles will have the current payload in m^3 and new option - payload_weight (or something). And neither of them could be exceeded. So for heavy goods, the weight would be the limit, for light goods, the volume might be the limit. But it may vary between vehicles (as in the first post - small vehicle with quite high weight allowance).
For piece goods, the main unit would be m^2 (assuming they cannot be stacked), and again the weight per m^2 would be defined. Of course if real life barrels of some stuff have smaller area than 1 m^2 the in game unit would represent more real world barrels. Ideally all three units (m^2, m^3, kg) would be specified to allow for stacking of barrels, pallets etc...

The question is how complicated it would be to add the weight allowance to vehicles.

Lieven

Quote from: Leartin on November 21, 2020, 07:31:46 PMFor Europallets, specifically EPAL1, it's specified to 1500kg.
After some researchs, they're no legal limitation of weight (or I didn't found them), but they're lots of recommandations, the max recommanded weigh of a pallet is generally about 1 ton, 1.4ton for the higest I've found, but they have the capacity to be stacked with a total charge of 5 ton, always following these recommendations.

I'm following you in the sense of the weigh that should be applied to Simutrans is about 1 ton, if you look in the way of the max charge capacity of the vehicules, you juste have to divide the nominal capacity of a standard lorry (generally about 29 tons) by 33 (the nominal surface capacity in pallets) and you got approximately 870kg, so, to set the weight of the pallets in simutrans at 2 tons is totally unrealistic, Im ok with that

Quote from: Vladki on November 24, 2020, 05:05:26 PMThe question is how complicated it would be to add the weight allowance to vehicles.
I think that, if you just set the max weigh capacity of each vehicle, it will be good, no ? But we probably don't have the sources for each vehicles ?

Too much !

Leartin

Quote from: Vladki on November 21, 2020, 12:18:08 AMHello all. I'd like to ask pakset creators who aim for maximum reality, how do you set the vehicle capacities for various goods, especially piece goods?
Just as a reminder what you originally wrote - you asked how to deal with what we have. Not sure why you go 180 and dismiss suggestions in favor of turning it into an extension request.

There are several issues with your idea.
To begin with, you claim pallets, barrels, sacks, furniture, lifestock and cars could/would all be piece good. In p192c, pallets are piece goods. Sacks are used for mail, a special good. Barrels are intended to become their own category for dedicated barrel cars. Furniture is transported in containers. Lifestock and cars are both special goods. By seperating categories, you never need to compare a car to a sack, never have the problem that any vehicle could load more sacks than it could load cars. Instead, you can indeed check the size of a pallet, it's approximate weight, and get close enough. So reducing the good categories would artificially blow up the problem in the first place.

Anyway - assume you have a good that requires a larger space/more weight per unit than a vehicle that transports the type of good can offer. Would it stay empty while there are goods waiting in the station? How is "full" defined for wait on load? Can it never be filled, or is it full as soon as it tries to load something, but does not have the required space/carry capacity? Or would you scrap other units and simply have a few square meter of rum barrels?
What happens if both heavy small goods and light large goods are waiting for the same destination, will Simutrans automatically optimize usage of each car, or will they just load whatever, requiring more of them in total?
Would stations follow suit, even though their capacity is occupied by several goods simultanously anyway?
If you had lightweight vehicles that can carry a lot of space, but not a lot of weight, and bulky vehicles that can carry a lot of weight, but not much space, and want to transport very light feather pillows and very heavy gold bars both from A to B, how could you prevent the lightweight vehicle from unprofitably transporting gold?

And then, of course, someone will tell you that a specific vehicle had only 1.4 times 1.4 area of space in reality, which is a bit more area than two europallets, yet two europallets wouldn't fit. So why would they fit in the game? So unrealistic- then we need a way to solve that problem too.

All in all, it would be a pain to find a solution that could work in theory and be enjoyable for players - long before someone would actually start coding it.

Quote from: Lieven on November 24, 2020, 06:28:31 PMAfter some researchs, they're no legal limitation of weight (or I didn't found them)
I can only provide it in German source, but it's directly from EPAL. "Tragfähigkeit 1500 kg" (it's not 1.5, German uses dots as seperators for large numbers). Not just a recommandation.

@Leartin, thanks for your ideas and suggestions. I  know I diverted from the original question. That "feature request" was occupying my mind and I wanted to discuss it with others.

Quote from: Leartin on November 24, 2020, 07:48:59 PMAnyway - assume you have a good that requires a larger space/more weight per unit than a vehicle that transports the type of good can offer. Would it stay empty while there are goods waiting in the station?
If the pakset contains so small vehicle that it could not load at least one unit of any good, I would consider that a pakset bug. But the problem will be that the wight_allowance may be for non-integer number of units of some goods.  That's a very good point. Also the mix of pillows and gold bars. I agree this will be hard to solve.

So far I'm considering two options:
1. weight based approximation: 1 pallet = 1 ton, but reducing the weight capacity for older vehicles. In the original example both wagons have 20t/axle when fully loaded. I can reduce it to 18 or 16 t/axle as the old railways had often lower permitted axle load.
2. space based approximation: 1 pallet = 1 m^2, and ignore the overweight. But that might cause problems in extended, that the wagon would exceed the axle load of any available track. So the first option is probably more practical.
3. take the lower value of both weight and space limits.

Leartin

Quote from: Vladki on November 24, 2020, 11:06:36 PM
If the pakset contains so small vehicle that it could not load at least one unit of any good, I would consider that a pakset bug.
Not "any" good, but a specific good of the category it's supposed to carry.
With your idea, consider three different piece goods: A weights 500kg and needs 1m², B is very heavy, 2t on 1m², while C is eg. a car, 1t, but needs 8m². An early ox cart might realistically carry good A, but not goods B or C. However, it would still be a piece good vehicle, with B and C being piece goods, and you get to a situation where a piece good vehicle can't carry a single unit of a piece good.
In order not to create what you call a "pakset bug", the pak creater would be forced to make the ox cart capable of carrying 2t weight and 8m² space. Which, beside allowing one unit of B or one unit of C, also allows four units of A. Quite the ox cart! [and an extreme example]

Anyway - don't dismiss the option of additional good categories. If you had two piece goods categories, you could still make sure that real vehicles play to their strenght. If in reality it can carry a lot of weight but doesn't offer much space, it's in the "heavy" category. You get the gameplay element of needing to use different vehicles for gold bars and pillows without a danger that they accidentially ruin you while transporting the wrong thing, so it's much friendlier to beginners. Meanwhile, nothing about the program has to change. It's unexpected, some might say unrealistic, but it's no more an approximation than the category system as a whole (EVERYTHING is piece good if you put it in a box - eg. tank containers)

prissi

Howing both a weight and capacity limit to obey would make a 100% load calculation somewhat more challenging.