Graphics Development • Re: [OTTD] 2cc TrainsInNML

It suggests a durability formula for steam engines.

Sorry but I don't think this should be automated. The formula is not realistic and at the end of the day it mostly anticorrelates everything with horsepower once horsepower goes orders of magnitude above the total weight. It only gives a bonus of >10 years to like 4 locomotives, which means almost all of them are <40 years total lifetime -- once again not consistent with real numbers.

In Iron Horse for instance, the model life is 40 or 60 for trains (unless they have a replacement, then it takes into account the date of the next generation engine with the same role). But here we are talking real-life trains so we do have the information of their lifespans most of the time! And i don't know why we'd try to be historically accurate with horsepower/tractive effort/intro year but then just use nonsensical values for the model life when it's right there online

Why not just have a WITHDRAWAL_YEAR column in the spritesheet, that we agree is either the earliest withdrawal or refit/rebuild year (to be consistent with taking the INTRODUCTION_DATE as the earliest build date)? Then compute the model life as WITHDRAWAL_YEAR - INTRODUCTION_YEAR, and use the default of 40 for all those without a WITHDRAWAL_YEAR set?

This way we can just collaboratively fill the missing dates, I'm happy to spend some time researching that, and you can use the above list for like 20 early locomotives already. That's what development on GitHub is about (though Excel spritesheets are not great with that !)

Statistics: Posted by althonos — 26 May 2026 09:41