A pair of Amtrak P42's pull down out of the yard at the 18th Street Shops, putting together a trainset for a night departure of one of Amtrak's long distance trains. The train is crossing the Chicago River on a lift bridge and diverges briefly towards the CN Joliet Sub at 21st Street Junction, where the train will pause before shoving back into the yard. The Canal Street Lift Bridge that Amtrak is using was built by the Pennsylvania Railroad in 1915, and at the time had the heaviest lift span of any bridge in the country, employing massive concrete counterweights to raise and lower the bridge, as well as a system of hanging chains to maintain a balanced load during operation.
