Bridges on Bridges

[sparker]

One of the most unusual "road-over-rail" bridges around would have to be the Steel Bridge in Portland, OR.  The lower deck hosts a double-track main line actually owned by the Port of Portland but utilized by UP, BNSF, and Amtrak; Union Station is immediately west of the bridge, which crosses the Willamette River.  The upper deck was originally part of US 99W (and later OR 99W); it now is used by traffic to and from Interstate Avenue as well as the MAX LR lines, which split just east of the bridge into the main E-W line to Gresham and the Interstate Avenue line north to the Columbia River.  What is unique about this bridge is that the lift span of the lower deck (rail only) can be raised independently of the upper deck in order to clear mid-height river traffic; both spans must be raised when exceptionally tall ships must pass.  Since UP has an independent line through a tunnel under much of North Portland, only about a third of the rail freight traffic between Portland and the Seattle area needs to use the bridge (BNSF's freight hub is across the Columbia River in Vancouver); so the "default" bridge position is with the lower deck raised and the upper deck in a "normal" state allowing auto traffic and LR to pass.  However, with the addition of Amtrak's "Cascade" regional service between Eugene, OR and Vancouver, BC, the lower bridge is lowered into a traversable position several times per day to allow the passenger trains to access Union Station; the process, complete with bells and lights, is actually fun to watch.  The Steel Bridge, like its name implies, features construction robust enough to carry several times any momentary weight load -- which is why it was selected as the northern Willamette River crossing for MAX.  Worth a look -- and there's even an excellent (albeit a bit overpriced!) restaurant a couple of blocks north inside the old Union Station building, which is still used as the main city depot.