Local News

Barge hit sensors removed from U.S. 41 Twin Bridges

Barge hit sensors removed from U.S. 41 Twin Bridges

Bill Stephens

May 3rd, 2017


Sensors installed early in 2008

HENDERSON, Ky. (May 3, 2017) – The Kentucky Transportation Cabinet (KYTC) has removed a monitoring system aimed at detecting and monitoring the severity of barge hits on the U.S. 41 Twin Bridges between Henderson and Evansville. The sensors, installed in February 2008, were removed to accommodate the recent installation of solar navigation lights on the bridge structure.

“The sensors were an experimental effort to monitor barge hits, but in recent years it had become more difficult to retrieve information from the system in a timely manner,” said KYTC District 2 Chief Engineer Wade Clements. “There were a number of issues with the system that became more difficult to overcome.”

Clements noted that the transportation agency gets 1 to 3 calls a year indicating a passing tow boat has struck one of the piers on the bridges. When it was installed, there was hope the system could alert inspectors to help speed their arrival to run a safety inspection on the affected bridge.

As the system aged, it became more difficult to assure batteries were fully charged. Steel on the bridge structure blocked cell phone data signals used to control and monitor the system. As new solar powered navigation lights were being installed in recent months, it became apparent that solar panels and other equipment used to power and monitor the sensor system was taking up space needed for the new lighting system.

When the sensors were first installed, Dr. Issam Harik, professor of civil engineering and program manager for the Kentucky Transportation Center at the University of Kentucky, had hoped the system would provide engineers with specific information on the force of the impact from barge hits that could be analyzed and used to improve bridge pier design.

The 2008 installation was the first instrumentation of a Kentucky Bridge for the detection of barge/fleet hit incidents. The instrumentation was similar to seismic sensors used to detect earthquakes.

When a tow boat hits a bridge pier, federal law requires the Coast Guard to notify local authorities to stop traffic on the bridge until the structure can be checked by a certified bridge inspector. In the case of the US 41 Twin Bridges, it normally takes inspectors about an hour to run a detailed safety inspection on the bridge structure. During that inspection all vehicle traffic has to be halted. If no structural damage is found, the bridge can then be reopened.

When the system was installed it was one of only two in North America where sensors were being used to study the impact of barge hits on bridge piers.

The US 41 Twin Bridges were chosen for installation of pier sensors due to the number of barge hits. Tow boat pilots indicate wind and currents near the bridge piers can sometimes cause problems for down-bound tows on the Ohio River. The bridges are about a mile downstream from the confluence of the Ohio and Green Rivers. In particular, heavy outflow from the Green River can create tricky currents in the area.

The US 41 Twin Bridges, also known as the Bi-State Viet Nam Gold Star Memorial Bridges, are located at US 41 mile point 19.649 about a mile south of the Kentucky-Indiana State Line. They carry approximately 40,000 vehicles per day across the Ohio River between Henderson, KY, and Evansville, IN.

The bridges are located about a mile downstream from the confluence of the Green River and the Ohio River at Ohio River navigation mile point 786.8.

The northbound bridge was opened to traffic on July 4, 1932. The southbound bridge was opened to traffic in December 1966. Both bridges were painted and rehabbed during the 2007-2008 construction seasons.

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