### Author Topic: Different loads = different axlepressure and speed  (Read 2998 times)

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#### Ves

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##### Different loads = different axlepressure and speed
« on: March 01, 2014, 02:19:46 PM »
Hello James,

I have an extension request that I hope you find interesting!  :
Were currently trying to get a pak in the north up and running, and some times also some whishes for some new features for the simutrans engine pops up.

In Sweden, goods cars have different axleloads and maxspeeds, dependent of how much is loaded on to the car. I dont know if this is present in england or other countries, but I asume very much that something similar is of existence.

Every goods car have a sign like this:

The upper row are the axle loads in tonnes
The left column are the speeds
And the centrum fields are the maximum loads in tonnes.

The entire sheet is variable with speeds and number of rows/columns, dependent of the nature of the car

A model train example of such a chart: http://www.svensktmjforum.se/forum/uploads/203/Mas-skyltar.jpg (number two from right)

The scheme would be visible in the depot and in the convoy details lists, either as a painted .png or some graphic interpretation by the Simutransengine.
When creating a shedule, in the shedule window, you specify a maxload (in tonnes, now it is in percent %) and the game would look in the .DAT-file where you have specified:

max_speed[X]=Y
max_spe.......
.......
Y=speed in kmh

.... and read the speed which match the load and apply it onto the car, reducing the maxspeed of the convoy. The axleload is calculated from whatever is loaded on to the car.

If the sheme is autogenerated by the engine, it will read the entries in the .dat and calculate all the entries, calculate the axleloads on the different entries and put it up in the layout, maybe rounding the axle loads up to two in order to get some space in the chart.

With this, one could use the same car and form it to ones needs instead of having multiple of the same cars with different loadings.
You are allowed to focus your good-trains to run fast with lesser load, or slow with heavier load, as well as you might use your cars on lighter tracks.

Is this or some of this possible and/or desired?

#### jamespetts

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##### Re: Different loads = different axlepressure and speed
« Reply #1 on: March 01, 2014, 03:50:56 PM »
That is an interesting idea. I am not familiar with this way of setting speed limits, because I do not think that we have that in the UK. The complexity that might make this difficult is the need to have partial loading of wagons, which would greatly complicate the loading algorithms as well as the associated GUI. Might it be easier just to have different versions of each wagon (upgradable to each other at no cost in the .dat files, perhaps) with different maximum loads, axle loads and top speeds? This would also have the advantage that this system would not need to wait what will probably be several years before a feature of this sort can be reached in the really very long queue that I have at present.

#### Ves

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##### Re: Different loads = different axlepressure and speed
« Reply #2 on: March 01, 2014, 04:26:53 PM »
Of cause such a system can be achevable with different cars upgradable into each other. It will just be a little confusing and create a little mes in the depot view And will not make a car convertible on the fly....

Ideally, you could specify the loading % pr. wagon, but that is probably quite teddious and not needed in the way it currently is...

If implemented, one day, to resolve the issues with different kind of cars, one could select a modus in the shedule:

* Fast as possible-modus = specify the desired spead and load as much as possible, while maintaining that speed, alternatively just fill up to absolute possible maxspeed or max track speed the train is currently on

* Max axleweight-modus = specify the desired axle weight/maybe an alternative to check the axleweight it is currently on and fill up to that point.
* Full load = yeah.. you guessed it

#### Sarlock

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##### Re: Different loads = different axlepressure and speed
« Reply #3 on: March 01, 2014, 05:37:07 PM »
Interesting.  What is the variation in load weights and speeds for?  Is this due to different grades of freight tracks requiring different load limits?

Rather than introduce such complexity, would it be best to make the pakset adhere to the most commonly used amounts?  Variable axleloads/weights and speeds is likely more than what the average player wants to contend with.  Either way, you can certainly achieve that through multiple types of rail cars-certainly easier than a coding solution.

#### Ves

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##### Re: Different loads = different axlepressure and speed
« Reply #4 on: March 01, 2014, 06:15:33 PM »
If the car is heavy, it may (in most cases ive noticed) not go as fast as an empty car, due to rail physics and because the tracks may not stand to it in curves etc. Also due to some cars beeing able to load very much and therefore get a too high load for some tracks. also the fact that different loads wheight different, again allowing the car to go faster

But I will try to manage it with different cars, upgradeable into each other and a BIG sheat somewhere to make an overview then :-)

#### Sarlock

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##### Re: Different loads = different axlepressure and speed
« Reply #5 on: March 01, 2014, 06:31:00 PM »
With the extra rail physics in Simutrans-Experimental, you may be able to simulate some of this effect.

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##### Re: Different loads = different axlepressure and speed
« Reply #6 on: March 01, 2014, 07:17:05 PM »
What about a general setting, that overweight vehicles are not banned from using a track/road, but can use it at limited speed. Perhaps some formula like for every ton of axle load over limit, the top speed is reduced by 10 km/h. And a notice should be displayed similar to no-route informing the player that the vehicle is slowed down because of weight limits.

#### Ves

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##### Re: Different loads = different axlepressure and speed
« Reply #7 on: March 01, 2014, 11:27:36 PM »
Something like that could also acheave something similar I guess.
In a transportation game/simulator, one should not be afraid to put some of the real life dilemmas and solutions for the player to solve

#### jamespetts

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##### Re: Different loads = different axlepressure and speed
« Reply #8 on: March 02, 2014, 01:13:19 AM »
The setting enforce_weight_limits=1 will give more or less the feature that Vladki suggests:

Code: [Select]
`# This setting allows the way in which weight limits are enforced to be customised.# If enforce_weight_limits is set to 0, weight limits are ignored entirely. If# enforce_weight_limits is set to 1, then vehicles can travel over roads, rails,# tunnels and bridges for which they are too heavy, but only at greatly reduced# speed. If enforce_weight_limits is set to 2, then vehicles cannot travel over# ways for which they are overweight at all. ## To revert to the behaviour of Simutrans-Standard, set enforce_weight_limits=0enforce_weight_limits=1`

#### kierongreen

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##### Re: Different loads = different axlepressure and speed
« Reply #9 on: March 02, 2014, 09:41:55 AM »
There are differential speed limits on UK railways - HSTs and DMUs often have higher speed limits than locomotive hauled trains on rural lines over certain structures.

#### jamespetts

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##### Re: Different loads = different axlepressure and speed
« Reply #10 on: March 02, 2014, 11:32:25 AM »
Interesting. Are those based on axle load or some other characteristic of the vehicles?