New industries.

[Born Acorn]

Im thinking of loads, also industries assinged to specific periods.

eg Slate quarry.

1800 - 1950

message, all slate mines close because of new roofing materials.

or even the coal mines already to TTD closing due to no more steam engines and coal fires etc.

[Bjarni]

or even the coal mines already to TTD closing due to no more steam engines and coal fires etc.

Coal are still used on large scale. The difference from 100 years ago and now is that you don't see the coal burning anymore.
Today we use electric engines instead, but a lot of powerplants are in reallity highly advanced coal powered steam engines

The idea of having industries to fit certain time periods are good, but we have to expand OTTD to handle 18xx first to make it really good. AFAIK nobody are currently working on that

[Born Acorn]

Thinking about a stephensons rocket?

[mnorman]

No, has to be Locomotion or Pen-Y-Darin (think I got the speeling right) which were several years earlier.

[Born Acorn]

yes but the pen y darren loco, kept breaking the rails with its weight and only carried passengers once, as a trial run.