Tuesday, April 26, 2022

1938,1998 Rainbow and 1991 Veterans Memorial Bridges at Port Arthur, TX

1938: (Bridge Hunter; Historic Bridges; HAERSatellite)

The cantilever truss bridge was built in 1938. The cable-stayed bridge was built in 1991. Then the truss bridge was closed and rehabilitated. In 1998, the two bridges became a couplet that share the traffic load. [HAER-data]

HAER TX,123-POART.V,1--11 (CT)
11. 3/4 VIEW FROM W - Rainbow Bridge, Spanning Neches River at State Highway 87, Port Arthur, Jefferson County, TX

Patrick Feller Flickr via BridgeHunter-1991, License: Creative Commons Attribution (CC BY)

Madison County, Texas Weather posted
On this day [Sep 9, 2022] in 1938, Port Arthur and Orange County were connected by what became known as the "Rainbow Bridge." The bridge replaced the Dryden Ferry.
[There are a lot of comments about how scary it was because it was so steep. Sue's comment is worth noting.]
Sue Newsom: Yes, I had a pinto that even with me speeding down the road to try to reach my highest possible and not get stopped by the law hoping to make it to the top without stalling out and coasting back wards. I would barely being doing 10 mph approaching the top. Finally gave up and took the more then an hour long way around Beaumont to get home from Bridge City to Port Arthur. Ha ha

Bridges Now and Then posted
The Rainbow Bridge nears completion, Port Arthur, Texas, 1938. (Port Arthur News)

Significance: The Rainbow Bridge, with its vertical clearance of 176'-0", became the tallest bridge in the southern United States and one of the tallest in the world upon its completion. Its height was needed to allow for the passage of ocean-going cargo ships and tankers, for it spans the Neches River linking the busy port of Beaumont with the Gulf of Mexico. The bridge features a 680'-0" central cantilevered span, one ofthe longest in Texas, and an overall length of 7,752! -0". The sixty-three-span structure includes a continuous deck girder, prestressed concrete girder approach spans, deck truss spans, continuous through truss spans, and a three-span cantilever unit. The construction of the bridge required innovative engineering methods not only because of its height but also because it had to be built to withstand hurricane-force winds. Triangular steel piers with V-shaped bracing on concrete pedestals support the deck girder spans, and were designed specifically to transfer up to 150-mile-per-hour winds to the foundations. [HAER]
This was Google Map's signature photo for the Rainbow Bridge. That looks like a rather steep grade for an 18-wheeler to climb. I found that the grade is 5%. [nomination, p10]
Ca P, Oct 2021

There is hardly any traffic on these bridges! John Weeks found a 2002 traffic count of 11,490 for the cable-stayed bridge.
Street View

That made me curious about what I-80 in Joliet, IL, looks like. Actually, this is a rather light traffic flow in my experience. Notice that there are only two through traffic lanes.
Street View

Both the Hartman Bridge and this bridge suffered from a vibration in the cables that occurred during a light rain and moderate wind. The problem was not understood, and threatened to shorten the service life of the cables. The problem was eventually solved by dampening the cables to counteract the vibrations. On the Veterans Memorial Bridge, shock absorbers were placed between the bridge and the cables very close to the base of the bridge. Despite the Hartman Bridge having the same problem, a different solution was implemented on that bridge, a series of cables were woven into the cable stay cables at a right angle to the main cables.

An inspection in 1995 found unexpected cracking in the concrete of the main bridge span. A repair had to be undertaken to change the fasteners holding the internal high-tension cables to better distribute the loads at the endpoints.

Note—The parallel steel arch truss bridge carries the westbound and southbound lanes, and is known as the Rainbow Bridge. The Rainbow bridge is over 170 feet above the water, the tallest bridge in Texas. The reason is that the US Navy wanted every ship in the inventory to be able to pass under the structure. The Navy had a single blimp tender ship that was nearly 170 feet tall, so the bridge was built just a little taller. Ironically, that particular Navy ship never sailed under the completed Rainbow Bridge.

[JohnWeeks]



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