NOAA Ship Thomas Jefferson completes 2018 survey work in the Approaches to Houston-Galveston

By Lt. Charles Wisotzkey

NOAA Ship Thomas Jefferson departed the western Gulf of Mexico in early August 2018 after completing scheduled survey operations on the Approaches to Houston project. Data collected for the project will update nautical charts for the approaches to the main shipping channel leading to the ports of Houston and Galveston.

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Thomas Jefferson‘s project area located southeast of the entrance to Galveston Bay.

The Port of Houston is the largest U.S. port in terms of foreign trade and petroleum products. The main shipping channel extends from Houston, down the Buffalo Bayou, through Galveston Bay, and into the Gulf of Mexico at the pass between Galveston Island and the Bolivar Peninsula. The approaches to Galveston Bay are heavily trafficked by all manner of commercial vessels. In fact, the anchorages outside of the entrance to Galveston Bay were among the busiest traffic areas the ship’s command had experienced.

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Automatic Identification System (AIS) traffic near the entrance to Galveston Bay. Each red, green, and blue symbol represents a separate vessel. Most of the offshore AIS symbols represent, in this instance, large commercial vessels (MarineTraffic 2018).
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A closer look at Thomas Jefferson‘s project area highlights its navigational characteristics.

Multiple safety fairways and numerous oil platforms with pipeline infrastructure are shown in the image above. The safety fairways are kept clear of oil and gas infrastructure and are used by large commercial traffic to transit around the Gulf of Mexico; however, obstructions are sometimes reported and charted within the bounds of the safety fairways. 

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An example of an abnormal traffic situation caused by the presence of position approximate (PA) obstructions in the safety fairway that leads into the entrance to Galveston Bay.

The image above shows two charted position approximate (PA) obstructions within the safety fairway to the south of Thomas Jefferson’s main project area. As seen in the image, two vessels favor the north side of the safety fairway in order to avoid the charted PA obstructions and passing nearer to each other than would otherwise be prudent. In this case, both PA obstructions were disproved by Thomas Jefferson and will be removed from the chart.

Overall, the Approaches to Houston project was highly successful. Thomas Jefferson was able to collect over 9,500 linear nautical miles and more than 500 square nautical miles of survey data. In addition to the two PA obstructions described previously, Thomas Jefferson corrected the position of five navigationally significant wrecks and obstructions, disproved the existence of one additional navigationally significant charted obstruction, identified two previously uncharted wrecks, provided updated Aid to Navigation data to the U.S. Coast Guard, and located numerous uncharted and/or exposed pipelines. This work will improve chart quality for an area of critical importance to our nation’s economy.

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The crew of the Thomas Jefferson, along with local Houston/Galveston NOAA partners, shared the positive impact of the ship’s work at a successful public relations event in Galveston, Texas, in July. From left to right: Ensign Sydney Catoire (Thomas Jefferson), Charles Rowland (Navigation Response Branch (NRB)), Alan Bunn (NOAA navigation manager), Erin Diurba (NRB), Katie Magee (National Weather Service (NWS)), Sarah Randall (NWS), Dan Jacobs (NRB), and Cmdr. Chris Van Westendorp (CO Thomas Jefferson). 

 

 

 

 

 

 

 

 

 

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