This is an old revision of the document!
The industrial wood wagon is a logging wagon made by mbb. Its red colour matches the that of the Industrial Engine. There is no custom logic to change the model to have logs, but that would be a nice feature! Currently you can only have (visually, not dynamically) loaded wagons with the moretrains loaded wood wagon. It would probably be possible to make the model change to show inventory occupation in a custom_on_step.