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“Bite-Size Bits of Local, National, and Global History”
“Bite-Size Bits of Local, National, and Global History”
Oxon Hill in Prince George's County, Maryland — The American Northeast (Mid-Atlantic)
 

Crossing the River

 
 
Crossing the River Marker image. Click for full size.
By Allen C. Browne, October 7, 2012
1. Crossing the River Marker
Inscription. In this age of technological innovation, the act of crossing a river may be taken for granted. And yet, there is always a magic to bridges: How is the river parted to lay the foundation? What stops the bridge from washing downstream? How are so many cars and trucks supported?

Let every man praise the bridge that carries him over. -- Anonymous

Redefining the arch

The design of the bridge, selected from among seven competing entries, reflects the arch tradition of other Potomac River crossings without actually using the classic arch. True Arches create large horizontal forces at the foundations -- a problem in the Potomac River where soils are particularly poor. An innovative system of V-shaped piers is used to transfer the load vertically through soft soil to firmer soils 200 feet below.

a balancing act

When tall ships approach, staff in the operator's House engage motors and machinery to open the drawbridge. The movable span -- called a bascule -- is a device that is counterbalanced so that it moves on a pivot, much like a seesaw. The bridge is so finely balanced that only small motors are needed to move the 34 million pounds of bridge, possibly the largest movable span in the world.

the construction process

This bridge, which replaced
Crossing the River Marker image. Click for full size.
By Allen C. Browne, October 7, 2012
2. Crossing the River Marker
a deteriorating, undersized bridge in this location, uses high-performance materials, pre-fabricated components, and innovative construction techniques.

Up to six-foot diameter steel pipe piles were driven into the soil to support the foundations. A cofferdam, or watertight enclosure, provided a temporary dry area to build the concrete foundations.

Concrete pile caps and pier pedestals were formed on the top of the piles.

Prefabricated segments of the V-piers were transported to the site by barge and lifted into place by cranes.

The segments were placed, alternating left and right to keep the pier balanced.

The tips of the V-piers were connected and held together by slender concrete tie beams containing tensioned steel cables.

Curved steel girders completed the arch appearance and a concrete deck slab provided the final roadway surface.
 
Location. 38° 47.614′ N, 77° 1.501′ W. Marker is in Oxon Hill, Maryland, in Prince George's County. Marker is on Interstate 95, on the left when traveling west. Touch for map. The marker is in a small park on the east (Maryland) end of the Woodrow Wilson Bridge. Marker is in this post office area: Oxon Hill MD 20745, United States of America.
 
Other nearby markers. At least 8 other markers are within walking distance of this marker. Woodrow Wilson Memorial Bridge
Crossing the River Marker image. Click for full size.
By Allen C. Browne, October 7, 2012
3. Crossing the River Marker
(a few steps from this marker); Shifting Sands: The Story of Rosalie Island (approx. 0.2 miles away); A Tale of Three Jurisdictions (approx. mile away in Virginia); The Race to Build Ships on Jones Point (approx. 0.8 miles away in Virginia); The Fitting-Out Dock (approx. 0.8 miles away in Virginia); Mountains of Materials and Massive Manpower (approx. 0.8 miles away in Virginia); The Alexandria Ford Plant (approx. 0.8 miles away in Virginia); The Civil War and Battery Rodgers (approx. 0.9 miles away in Virginia). Touch for a list and map of all markers in Oxon Hill.
 
Categories. Bridges & Viaducts
 
Crossing the River Marker image. Click for full size.
By Allen C. Browne, October 7, 2012
4. Crossing the River Marker
The Classic Arch image. Click for full size.
By Allen C. Browne, October 7, 2012
5. The Classic Arch
Illustration from the marker
System of V-Piers image. Click for full size.
By Allen C. Browne, October 7, 2012
6. System of V-Piers
Illustration on the marker.
Woodrow Wilson Memorial Bridge Pillar image. Click for full size.
By Allen C. Browne, October 7, 2012
7. Woodrow Wilson Memorial Bridge Pillar
 
 
Credits. This page was last revised on June 16, 2016. This page originally submitted on December 19, 2012, by Allen C. Browne of Silver Spring, Maryland. This page has been viewed 304 times since then and 26 times this year. Photos:   1, 2, 3, 4, 5, 6, 7. submitted on December 19, 2012, by Allen C. Browne of Silver Spring, Maryland. • Bill Pfingsten was the editor who published this page.
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