I started this page after completing a page for Detroit that covered the
majority of bridges and overpasses found in the metro area. This is an
introduction to the many varieties of railroad bridges that exist, and some
that are no longer with us. For further reading, check out some of the
links I have come across.
Bridge - Overpass - Viaduct.... What is the difference? The large
majority of the bridges mentioned below can probably be referred to as a
bridge or an overpass, and the terms are interchangeable. One fellow
who helped me with another page in PA is a "bridge guy", and may disagree.
Being that almost all bridges in
Detroit are "older", I don't think any
qualify as being called a viaduct, but some, like #8 and #9 going to Zug
Island, are bridges, and not overpasses or viaducts. I reference this
page in Detroit, because, as I said, this is what got me going on this page.
A viaduct is a specific type of bridge that consists of a series of arches,
piers or columns supporting a long elevated railway or road. Typically
a viaduct connects two points of roughly equal elevation, allowing direct
overpass across a wide valley, road, river, or other low-lying terrain
features and obstacles.
Open Railway Maps
Websites and other additional information sources of interest for the area:
covers railroad and automobile bridges, extensive descriptions, but no
pictures or diagrams to help explain
Trussed Through Arch
Here is one listing of railroad bridge types, however, it is for "modern"
bridges being built today, and doesn't include a lot of the "older" ones
found around any town of reasonable "old" age, like Baltimore, Detroit, and
Stuff in grey is from Strucsource
Trestle Type Bridges
Steel Girder Types
Steel Deck Girder
Steel Open Deck Girder
Steel Through Girder
Steel Through Truss
Bollman Iron Truss
GPS Coordinates: 39.13485, -76.82506
This is the only surviving example of this type of bridge, built by the B&O in 1852,
and moved to Savage MD in 1887.
I have a whole page dedicated to this bridge here.
Precast Concrete Double Box Girder
Precast Concrete Box Girder
Precast Concrete I-Beam Girder
CIP Concrete Trough
Precast Concrete Slab Girder
Prestressed Concrete Box Girder
Trussed Through Arch
Hell Gate Bridge
GPS Coordinates: 40.78269, -73.92219
A bridge (almost) in a class all of it's own. I used to sit up at night in the
60's and watch the New Haven trains come and go over this bridge.
Hell Gate is not the largest, but it was the first, completed in 1916.
It is 1,017 feet long, but 17,000 feet if you include the elevated
approaches, and clears the water below by 135 feet. It goes between
the Queens and the Bronx via Ward and Randall Islands. It was built by
the New Haven RR.
Sydney Australia has the largest of these: the Sydney Harbour Bridge - it
carries car, rail, and pedestrian traffic, and you can even climb to the top
of it! It was completed in 1932, and Hell Gate did provide the
inspiration for using this type. It is 1,149ft long, and sits 161 feet
above the water. It carries 8 car lanes and 2 streetcar tracks
electrified at 1,500 volts.