I was building a route using DEM (my first one too) and was watching a TV show about engines. That show reminded me of this website. I had to do a little digging around the internet to find it, but I found it. It's a really interesting website that explains how various types of engines made. The four-stroke, two-stroke and diesel engines, along with how a steam locomotive works, is shown along with engines used for other purposes. Here's the website:
http://www.animatedengines.com/
http://www.animatedengines.com/
Last edited: