### Author Topic: Bridge-capacity versus trainweight.  (Read 2903 times)

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#### AvG

• Posts: 308
##### Bridge-capacity versus trainweight.
« on: March 28, 2014, 01:52:32 PM »
Running 11.22 with Pak128-Britain090 +DRC-paks.

I thought that the max trainweight should not exceed the capacity given in the bridge build buttons.

However I see that a 390 ton train is passing a wooden trestle bridge with a capacity of 200 tons. No problem at all. But I don't understand now EXACTLY the meaning of the numbers.

Can anybody help?

AvG
« Last Edit: March 28, 2014, 03:17:00 PM by AvG »

#### jamespetts

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##### Re: Bridge-capacity versus trainweight.
« Reply #1 on: March 28, 2014, 06:32:49 PM »
The maximum weight of a convoy permitted on a bridge is the weight of the maximum fraction of a convoy on a bridge at any one time. Supposing that a train is 3 tiles long and a bridge is 5 tiles long: the entire train would be on the bridge at the same time at some point, so the loaded weight of the convoy must not be more than the maximum weight for the bridge.

Now suppose that the train was 5 tiles long and the bridge 3 tiles long. In this situation, only 3/5ths of the train would be on the bridge at any one time. Accordingly, the train would only be too heavy for the bridge if 3/5ths of its total loaded weight is greater than the bridge's maximum weight.

#### AvG

• Posts: 308
##### Re: Bridge-capacity versus trainweight.
« Reply #2 on: March 31, 2014, 12:51:24 PM »
Ok, James, Thanks for your answer. This function is more sophisticated than I thought.

Now there is a new problem.
I try to fit the bridges into the DRC pricing system. (high prices, low maintenance)
However I can't compile any bridge for some reason.

I use:- latest version of makeobj from EXP11.22
- .dat and .png- files from your repositery.
My last trial is the steel-truss.
1 on 1 copy from your repositery but no result. I get constantly a pak-file of 1 K. And yes :the png-images are both in an folder named images.

Can you help me?

#### jamespetts

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##### Re: Bridge-capacity versus trainweight.
« Reply #3 on: March 31, 2014, 01:17:16 PM »
What is the output text that you get from makeobj? More recent versions of makeobj have much more helpful output text than older versions, so errors can fairly easily be seen.

#### AvG

• Posts: 308
##### Re: Bridge-capacity versus trainweight.
« Reply #4 on: March 31, 2014, 08:48:11 PM »

Following is the text of the 1k-pakfile:

Simutrans object file
Compiled with SimObjects 0.1.3exp
ë  ROOT

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#### jamespetts

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##### Re: Bridge-capacity versus trainweight.
« Reply #5 on: March 31, 2014, 08:56:23 PM »
I think that there might have been a misunderstanding: I was asking for the output text of makeobj when it runs. I do not recognise this text - what is it?

#### AvG

• Posts: 308
##### Re: Bridge-capacity versus trainweight.
« Reply #6 on: March 31, 2014, 09:20:32 PM »
That's the text you see if you open the the bad Pak-file.

But maybe I found the solution for the problem.

I make all the copiing and paste operations via Notepad. I think I opened somewhere a new file via notepad not realizing that you will get a txt-file.

What I did now is: copy a real .dat-file, remove the content and copy the wanred text for the truss bridge in it. Made sure that it was still a .dat-file.

And yes I get a pakfile of 217 kB for the trussbridge.

Tomorrow I will check if a simple rename also does the job.

Sorry to have bothered you with such a stupid thing!!!

AvG

#### jamespetts

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##### Re: Bridge-capacity versus trainweight.
« Reply #7 on: March 31, 2014, 09:27:28 PM »
I am still not sure that I understand - do you realise that a .pak file is a binary file and cannot be edited in a text editor?

#### AvG

• Posts: 308
##### Re: Bridge-capacity versus trainweight.
« Reply #8 on: April 01, 2014, 08:02:57 PM »
There is not a lot to understand.

I made a silly mistake by opening a new file with notepad, copy your .dat-file in it and save it. I did not realize that you save the content as a .txt-file. You can only save as a .txt-file.

Now I know it's working this way and I rename the extension from .txt into .dat.

AvG

#### jamespetts

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##### Re: Bridge-capacity versus trainweight.
« Reply #9 on: April 01, 2014, 09:57:32 PM »
Ahh, I think that I understand - sorry for being dim. Glad that it's working for you now.

(Incidentally, on an unrelated topic, you might be interested to know that I am working on testing early stage coach transport with the latest pre-release code, and the problems that you have reported in the past with passengers being unwilling to travel seem to be solved).