Coast Guard establishes PDL ranges to support post-Panamax vessels

The U.S. Coast Guard has established radio-activated, solar-powered Precision Directional Light (PDL) Ranges to support larger ships navigating into American ports.

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Glen Brumby from SPX Technical Support and Petty Officer 2nd Class Shawn Blake (red hat) from ANT Oak Harbor climb the range tower.  U.S. Coast Guard photo by Ethan Coble.
Glen Brumby from SPX Technical Support and Petty Officer 2nd Class Shawn Blake (red hat) from ANT Oak Harbor climb the range tower. U.S. Coast Guard photo by Ethan Coble.

Written by Walter T. Ham IV 

The U.S. Coast Guard has established radio-activated, solar-powered Precision Directional Light (PDL) Ranges to support larger ships navigating into American ports.

Known as post-Panamax vessels, supertankers that did not fit the original Panama Canal locks are visiting East Coast and Gulf Coast ports following the recent expansion of the Panama Canal.  

Part of the U.S. Aids to Navigation (ATON) System, a range indicates a specific bearing by lining up a pair of lights or dayboards, typically the bearing is the centerline of a channel.

With a traditional range, mariners can determine their position in the channel by looking at the marks.  Instead of using a specific bearing, a PDL range uses white, red and green light sectors to let mariners know where they are in the channel. Activated by radio when needed, a solar-powered PDL range light system doesn’t require shore power.    

From the left, Albert Grimes and Ethan Coble from the Fifth Coast Guard District Waterways Management Branch survey the projector alignment. U.S. Coast Guard photo by Ethan Coble.
From the left, Albert Grimes and Ethan Coble from the Fifth Coast Guard District Waterways Management Branch survey the projector alignment. U.S. Coast Guard photo by Ethan Coble.

The Fifth Coast Guard District recently set up a Mariner Radio Activated PDL range for mariners in the Cape Fear River.

“The PDL was installed to support the Cape Fear River pilots sailing larger vessel outbound on Southport Range that had no prior visual range,” said Ethan J. Coble, a marine information specialist in the Fifth District Waterways Management Branch.

The Coast Guard Office of Navigation Systems, Waterways Operations Product Line, U.S. Coast Guard Cutter Smilax (WLIC-315), Aids to Navigation Team Oak Island and Oak Island Water Rescue teamed up to establish the PDL range at the Cape Fear River entrance.

Near the Port of Corpus Christi, Texas, in 2018, the U.S. Coast Guard installed its first two Mariner Radio Activated PDL Ranges in the La Quinta Ship Channel near a new Liquefied Natural Gas (LNG) facility. The pilots requested the new ranges and Cheniere LNG paid for them via a Gratuitous Service Agreement.  

“There is a small percentage of time that the front ranges are covered by the pilot house of a moored ship and the pilots can activate the PDL range,” said George Rau, who led the Federal Projects staff at the Eighth Coast Guard District during the project and now serves a Coast Guard commercial fishing vessel examiner based in Houma, Louisiana.  

U.S. Coast Guardsmen from Aids to Navigation Team Oak Harbor, N.C., work on the PDL range at the Cape Fear River entrance. Petty Officer 2nd Class Shawn Blake climbs the range tower while Petty Officer 2nd Class Jonah Warren (red hat) and Seaman Brittany Hodson (blue hat) work on the lower platform. U.S. Coast Guard photo by Petty Officer 1st Class Christopher Fuentes.
U.S. Coast Guardsmen from Aids to Navigation Team Oak Harbor, N.C., work on the PDL range at the Cape Fear River entrance. Petty Officer 2nd Class Shawn Blake climbs the range tower while Petty Officer 2nd Class Jonah Warren (red hat) and Seaman Brittany Hodson (blue hat) work on the lower platform. U.S. Coast Guard photo by Petty Officer 1st Class Christopher Fuentes.

Before they were established, Rau said the La Quinta PDL range lights were tested at the Maritime Institute of Technology and Graduate Studies-East, a simulation facility in Linthicum Heights, Maryland.

Establishing the La Quinta Ship Channel PDL Ranges was a team endeavor that brought together the Eighth District, Sector Corpus Christi, Aids to Navigation Team Corpus Christi, U.S. Coast Guard Cutter Mallet (WLIC-75304), and Construction Engineering Unit Miami.

In Bayport, Texas, off the Houston Ship Channel, the Eighth District, Sector Houston/Galveston and CEU Miami also set up a 190-foot-tall PDL range that could be seen over the pilot house of a moored ship.  

Rau said pilots were initially reluctant to accept the new PDL ranges until they used them for a year.

“As the ship handlers see more of them and get more comfortable with them, I think they will become more widely accepted,” said Rau.  “In other parts of the world, they are very common.”

Across the 25,000 miles of American waterways, the Coast Guard maintains more than 48,000 Aids to Navigation, the buoys and beacons that help mariners to chart a safe course.  

The U.S. Aids to Navigation System guides millions of mariners and trillions of dollars of trade into U.S. ports every year.  In 2018, American waterways generated $5.4 trillion in economic activity.  

The Coast Guard established a radio-controlled, solar-power Precision Directional Light (PDL) range in the Cape Fear River to help guide larger post-Panamax ships out of Wilmington, N.C. U.S. Coast Guard photo by Ethan Coble.
The Coast Guard established a radio-controlled, solar-power Precision Directional Light (PDL) range in the Cape Fear River to help guide larger post-Panamax ships out of Wilmington, N.C. U.S. Coast Guard photo by Ethan Coble.

The Coast Guard charted the way ahead for its missions that support U.S. waterways in its first ever Maritime Commerce Strategic Outlook.  Modernizing Aids to Navigation and marine safety information systems are among its main lines of effort.“The Coast Guard is committed to working with our port and industry partners to develop an ATON scheme that results in the safest possible waterway,” said Dave Merrill from the U.S. Coast Guard Aids to Navigation and Position, Navigation and Timing Division.  “We look at every available technology to accomplish that and PDLs are one of the newest technologies.” 

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