Maritime Operations Archives | Page 3 of 9

VIDEO: Study of line-throwing technology demonstrates importance of the Council’s independent research

January 15, 2024August 19, 2020 by Amanda Johnson

Photo shows Coast Guard officer firing a messenger shot line from one Coast Guard vessel to another. This is one method of connecting tow lines between a tug and a tanker. — In this 2016 photo, a U.S. Coast Guard officer fires a messenger line from one military vessel to another. This is one method of connecting tow lines between a tug and a tanker. Photo by Pasquale Sena, U.S. Coast Guard.

A new study evaluating methods of establishing tow lines between an escort tug and a tanker in distress is a prime example of why the Council’s studies are vital.

The Council often hires experts to review equipment technology used in the Prince William Sound oil transportation industry. Sometimes these studies fill a hole or gap where independent research is lacking.

“Very little has been previously written on this topic,” said Alan Sorum, who managed this project and other similar technology reviews for the Council. “In a literature review it conducted, the Council’s contractor, Glosten, found that there is a general lack of published material on this subject and in particular, little guidance on best use practices or what is the most appropriate device to use for a given situation.”

Watch the new video released in 2022

Study evaluates places of refuge

January 9, 2024December 7, 2019 by Contributing Author

By Alan Sorum
Council Project Manager

Some locations won’t work for Prince William Sound tankers

A recent Council-sponsored study reviewed eight “potential places of refuge,” or PPOR, which are locations where an oil tanker in distress can anchor and take action to stabilize its condition. Of the eight reviewed in the study, none were found to be safe for use by tankers. However, several safe alternates were identified, analyzed, and proposed for future consideration.

Identifying these sites in advance allows decision-makers to save time during their critical initial response to a potential oil spill. Establishment of these places of refuge is recognized by the International Maritime Organization and other governmental agencies as an important marine safety and pollution mitigation measure.

New study analyzes weather at Hinchinbrook Entrance

January 9, 2024March 15, 2019 by Amanda Johnson

A recent Council-sponsored report found that wind and waves at Hinchinbrook Entrance may be under reported as observed by the Seal Rocks weather buoy.

Researchers from Tetra Tech analyzed wind and wave data to better define weather conditions at the Entrance, as well as how these conditions might affect rescue operations by the escort tugs. To do this, researchers looked at the frequency and duration of weather events when the Entrance was closed to laden tankers.

Average closure conditions

A "wind rose" graphic that shows the speed and direction of wind as recorded at Seal Rocks. — This “wind rose” graphic shows the speed and direction of wind as recorded at Seal Rocks.

Wave height alone was found to be the cause of most of the closures, occurring 10 to 26 times a year on average. Average wave height during closures was over 17 feet and the highest recorded wave was over 26 feet. Wind speed closes the Entrance one to three times annually, as do closures for both wind and waves. Winds average just over 54 miles per hour during closure and the highest recorded wind speed was over 61 miles per hour.

Closures for winds typically last less than two hours, while waves close the Entrance for an average of just over six hours.

Seal Rocks buoy’s data may not be precise

Out-of-service buoy and winter storms raise concerns

July 24, 2023March 10, 2019 by Amanda Johnson

An out-of-service buoy and a series of recent storms have combined to raise concern at the Council about tanker transit procedures during period with the high wind speeds and wave heights in which tankers are allowed to travel through Prince William Sound.

Seal Rocks buoy out of service

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From May until December of 2018, a critical buoy located near Hinchinbrook Entrance was out-of-service. This buoy, referred to as “Seal Rocks buoy,” collects wind speed and wave height data. That information is used by the U.S. Coast Guard to make decisions as to whether Hinchinbrook Entrance is open or closed to outbound laden oil tanker traffic. When this buoy is inoperable, the U.S. Coast Guard uses data from two nearby buoys, Cape Cleare and Cape Suckling, along with reports from Edison Chouest Offshore, or ECO, tug crews that are sent out to observe wind and waves to make Hinchinbrook Entrance open and closure decisions.

In November and December, several winter storms came through Prince William Sound that raised concern about these alternate methods for reporting weather conditions at the Entrance.