Not just trains, but train related. I built a big blast furnace with 13k bricks a while ago. It took several weeks to build it all in LDD. I tested the stability of the pipes i.r.l. with random bricks to be sure. When I posted those pictures, quite a few people asked for instructions so I decided to make a small blast furnace instead and enter it at Lego Ideas. It comes with all the main process features except the storage bunkers and crane. If you are interested in more pictures, please have a look at the linked page. https://ideas.lego.com/projects/7e689689-cd51-4f10-9e9f-ead01adae6b8 blast furnace by Yvonne Strijbos, on Flickr
Blast furnace front by Yvonne Strijbos, on Flickr
Blat furnace real built 2 by Yvonne Strijbos, on Flickr
Blast furnace real built 1 by Yvonne Strijbos, on Flickr