This is what a train wheel slip looks like
I’ve heard that this phenomenon can result in melted track. One more video below!
All the abandoned stations on the Park Avenue Main Line
This video is pretty cool. It shows a Metro North railroad train going south through the Park Ave Viaduct and then into the Park Avenue Main Line. If you ride the train and it just happens to be moving slow enough, you can see 4 abandoned stations (3 of which have platforms) that are now being used as Metro North storage points.
The video above shows these stations at 110th St, 86th St, 72nd St, and 59th St.
Here's what the train tunnels out of Penn Station look like
Here’s a video showing a very clear view from the front car window of a train leaving Penn Station and going underneath the East River into Queens and beyond.