@mcnknopp It's so it looks like a worm.
Oh, and to easily connect multiple ones. The window inside the rubber is actually an entire driver unit. It swivels out of the way to create a corridor: https://mastodon.online/@Pepijn/110745124929906800
Attached: 2 images Some photos for passenger #train enthusiasts :-) The #danish IC3 and electric IR4 trains have an design where multiple units can be connected into one fully walkable tube worm. For this the entire front of a train, including driver controls, can swivel into a wall. Like many components the front is a fully modular unit. Here's a unit that was in a fire. Before and after photo. Rest of the train took a bit more work but it was also fully restored :-) Yellow structure is a transport frame.