Bridge weight limit

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Master Trams
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Bridge weight limit

Post by Master Trams »

This is an idea that I've had, which would be to have weight limits on bridges. If this is accepted, then once it's done, you could then extend it, so that tracks have various weight limits too! But for bridges, as we already have, you would drag to select placement of the bridge, then it takes you to a screen with two drop down menus, one with which you select the speed, and one with which you select the weight the bridge can handle. Then the game would take you to a second screen, which gives you the "most suitable" bridge type. This would be done by having the bridge parameters automatically set to a range of values, for example, a bridge type can cope with a speed limit of between 50mph and 80mph, and then a weight limit of 400kg to 750kg. Thus if the selected values fell within these ranges, the second screen would display this bridge type as a "suitable" bridge type. Graphically, these parameters may affect how legs the bridge has. If a train is longer than the bridge itself, then the weight of the train would be calculated by the length of the bridge. For example, if a train is 7 tiles long, but the bridge only 4, then if any 4 tile piece of the train is over the weight limit, then the train cannot cross.

If this is accepted, then I have already mentioned the possibility of adding this concept to tracks, however another feature you could have with bridges is clearance underneath, which would then enable the concept of having bridges go over and under each other. And also have boats only pass under bridges that are high enough.

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jfs
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Re: Bridge weight limit

Post by jfs »

Introducing weight limits would kind of also involve changing vehicles specs, since weight limits are typically axle load and not total weight. Vehicles currently don't have any way to specify their number of axles, so the game doesn't have any way to know each vehicle's axle load.

That said, you can already do something close just by using multiple railtypes and roadtypes, with the railtype/roadtype implicitly having a maximum axle load, and the vehicles requiring at least a railtype capable of supporting it.

Master Trams
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Re: Bridge weight limit

Post by Master Trams »

Well, maybe that can be an extension, but at first it would probably be best to keep it simple and just use total weight just whilst testing feasibility...

Eddi
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Re: Bridge weight limit

Post by Eddi »

jfs wrote:
20 Jun 2020 06:22
Introducing weight limits would kind of also involve changing vehicles specs, since weight limits are typically axle load and not total weight.
that is not entirely correct. axle load is typically about condition of the track/trackbed, but what bridges usually care about is metre load, which is weight of the wagon+cargo divided by its total length, independent of number of axles. if an individual wagon exceeds this load, it must be fit between two significantly lighter wagons to pass the bridge.
You might not exactly be interested in Ferion, but if you are, have fun :)

Master Trams
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Re: Bridge weight limit

Post by Master Trams »

Eddi wrote:
23 Jun 2020 12:14
jfs wrote:
20 Jun 2020 06:22
Introducing weight limits would kind of also involve changing vehicles specs, since weight limits are typically axle load and not total weight.
that is not entirely correct. axle load is typically about condition of the track/trackbed, but what bridges usually care about is metre load, which is weight of the wagon+cargo divided by its total length, independent of number of axles. if an individual wagon exceeds this load, it must be fit between two significantly lighter wagons to pass the bridge.
I don't know why, but that seems like it would be a whole load easier to implement than by axle load.

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MagicBuzz
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Re: Bridge weight limit

Post by MagicBuzz »

Eddi wrote:
23 Jun 2020 12:14
jfs wrote:
20 Jun 2020 06:22
Introducing weight limits would kind of also involve changing vehicles specs, since weight limits are typically axle load and not total weight.
that is not entirely correct. axle load is typically about condition of the track/trackbed, but what bridges usually care about is metre load, which is weight of the wagon+cargo divided by its total length, independent of number of axles. if an individual wagon exceeds this load, it must be fit between two significantly lighter wagons to pass the bridge.
In France, the weightlimit only applies to total truck weight.
I don't know how it was before 1980, but most of the restrictions now are not about weight (there are still few restrictions of weight, but most of the time it's only to force trucks ( > 3.5t) to avoid a road, mostly in towns) but the truck size itself :
https://www.google.fr/maps/@46.07977,4. ... 312!8i6656
=> Here vehicles > 4t can't cross the bridge, and vehicles heigher than 2,5 meters can't neither.

But something that is still frequent is single sided bridges :
https://www.google.fr/maps/@45.8452297, ... 384!8i8192
=> Trucks can't use this bridge, but there is also trafic lights to make car coming from only 1 direction at the same time. The previous bridge has also this restriction : when coming from west to east, you must stop and let vehicles from the oposite side to go first

So introducing bridge weight limits with current newgrf data is enougth for some countries.
If it requiers newgrf changes, please add also the width, length and height of vehicles too in order get keep a complete set of data to restrict bridges and tunnels.

Oh... and roads/bridges/tunnels (mostly tunnels) should also have restrictions by cargo. Many tunnels, but also some streets in cities in France are forbidden to vehicles transporting dangerous products (oil, petrol fuels, chemicals, etc.) :
https://www.google.fr/maps/@45.7634905, ... 384!8i8192
https://fr.wikipedia.org/wiki/Panneau_d ... _en_France

Eddi
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Re: Bridge weight limit

Post by Eddi »

MagicBuzz wrote:
10 Jul 2020 15:30
In France, the weightlimit only applies to total truck weight.
I was talking about rail, not road.
You might not exactly be interested in Ferion, but if you are, have fun :)

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MagicBuzz
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Re: Bridge weight limit

Post by MagicBuzz »

lol
After a good night I eneded to this conclusion :D

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