9. Crane Cars
New Yorkers are used to seeing cranes tower above the streets while building construction is in progress, but cranes are also used underground. The New York City subway employs a telescopic crane that folds up and fits inside the underground subway tunnels.
Crane cars, which again usually sport a bright yellow paint job, are pushed by another subway car. The cranes can move backward and forward along the bed of the car that supports it. They are usually used to aid in replacing stretches of subway tracks.