(Via Ho’okele News)
Story and photos by MC3 Johans Chavarro
Navy Public Affairs Support Element West, Detachment Hawaii
Every year, millions of people walk through the gates of the World War II Valor in the Pacific National Monument in Pearl Harbor, Hawaii to look back on Dec. 7, 1941— the day that has lived in infamy. The USS Arizona Memorial draws more than 1.8 million visitors each year to its site.
Above the water’s surface, the protruding remnants of Arizona’s rusted hull provide visitors with the chance to remember those who gave the ultimate sacrifice in protecting their brothers and country—a chance to honor those who may be sometimes forgotten.
On Oct. 21, divers under the surface were working to bring history back to life.
Just a few feet under the surface, Shaan Hurley, a technologist in the office of the chief technology officer at Autodesk, a software company, carefully maneuvered through the silty waters surrounding the Arizona, navigating his way to key structures and components mapped out on a waterproof map of the ship.
Hurley’s objective in photographing these important structures was so that eventual 3D models and printouts can be made to study, a technique referred to as photogrammetry.
Today, the corroded and twisted passageways and bulkheads of the Arizona are, to the surprise of some, teeming with marine life. Such an occurrence should, in reality, not even be happening given the harbor’s harsh environment, but nature has found a way and, in doing so, may have potentially put the ship’s structural integrity in danger, according to Scott Pawlowski, chief of cultural and natural resources at the WWII Valor in the Pacific National Monument.
“In the first surveys done in the early ’80s, coral did not exist on the ship, and one of the models that we have created to help us measure the longevity determined that coral was not a significant contributor to the model’s accuracy,” said Pawlowski.
“All growth happens in a logarithmic scale and what we’re trying to do is find out where along the growth scale we are, so we can double check our work from the past and be ready for questions about whether we should or should not manage it in the future,” he said.
Since then, the National Park Service (NPS) has begun an extensive surveying project to develop high-resolution surveying data and models through the use of state-of-the-art technology, like photogrammetry, underwater acoustic mapping and light detection and ranging (LiDAR). This is being done in an effort to better understand how the sunken remains of the Arizona and Utah, as well as various historic sites throughout Pearl Harbor, are changing with time.
“What’s driving this project, at its core, is our desire to have high-fidelity measurements of the ship that we can then repeat over time and determine if things have shifted, changed or settled,” said Pawlowski.
“But along with that, ours and the [National] Park Service’s mission is also to help people develop a connection with the ship and explain why it’s important, what’s down there, and what the crew who were aboard the ship on Dec. 7 must have gone through. [The] 3D models and data, presented well to the public, allow that connection to be made at a level that 2D or black and white can’t,” Pawlowski explained.
To accomplish this goal, the NPS has teamed up with a number of professionals and subject matter experts located throughout the country in its latest week-long effort, with each team bringing its own expertise and skill set, at no cost to the Navy or NPS.
“This project is very special in that it’s a partnership with a number of different companies and partners, as well as other government agencies, that have all come together and donated their time and energy, free of charge, to do this work,” said Pawlowski.
“These are companies that believe in the importance of preserving cultural heritage and maintaining national monuments, like the USS Arizona.”
According to Navy Diver 1st Class Ryan Crider, assigned to Mobile Diving Salvage Unit One, who was present during the surveying dives, poor visibility, razor sharp edges and structurally vulnerable overhangs maintain a clear and present danger to those who dive too close or unknowingly,
“One of the biggest concerns when guys are diving around the memorial is the visibility,” said Crider. “The visibility can get so bad out here that the chance of them getting lost is greatly increased.
“Another thing is the deterioration of the ship. Guys can get cut a lot easier or something can break off and fall on them. Also, with the oil leaking out the way it does, it takes a toll on the equipment and shortens its lifespan greatly,” Crider said.
As Hurley carefully found his way along the ship’s exterior, technicians from R2Sonic, an underwater equipment manufacturing company, trolled a 17-foot dinghy above the surface and a safe distance away from the dive site.
The advanced technologies being used by R2Sonic today are a far cry from the real-time surveys of the past, which consisted of NPS rangers strapping on their dive gear, and working with only a pencil and pad.
“The advances in technology allow us to not do what they used to in the past, where divers used to have to go down with pads and in-depth measurements to map out a few points on a ship,” said Jens Streenstrup, president of R2Sonic.
“Now, we, in a single day, can generate millions of points with super high precision within an inch.”
But aside from the poor visibility, the piercing metal and dangerous overhanging structures, surveying the Arizona still comes with additional challenges.
“Because the memorial goes over the ship, it has a low ceiling,” said A.J. Cecchettini, sales manager at Deep Ocean Engineering. “The depth of the water above the USS Arizona is very shallow, so you can’t get in there with a boat and run multi-beam survey.”
And that’s where the unmanned surface vessel (USV), USV H-1750, came into play.
At only approximately two feet tall in the water, the H-1750 provided a method of collecting multi-beam survey data where its much larger, manned, brethren (the 17-foot dinghy) couldn’t. Wirelessly controlled, the H-1750 fits into the nooks and crannies of the exposed wreckage, traversing underneath the USS Arizona Memorial with ease.
On land, John Tocci, director of virtual design and construction for Gilbane Building Company, set up LiDAR equipment to scan the terrestrial portion of the memorial.
According to Tocci, the technologies being used at Pearl Harbor provide the opportunity to experience the wreckages and historic sites in dramatically new ways.
“Growing up and reading about (WWII) in fifth grade, the only thing you got was a black and white photo of Pearl Harbor and the current state of the memorial,” said Tocci.
“But the fact that we can take this data and turn it into a three-dimensional walk-through and show [the current generation] both the above and below water components of the Arizona and the Utah, I think is going to be really exciting. It’s going to take history, and it’s going to make it come to life for a new generation,” Tocci said.
However, in the end, beyond the science, beyond the computer modeling and algorithms, remains the sentiment—the human connection.
“I think the thing that has surprised us the most about this project so far is the visceral personal experience that working on such a place has on every member of the team,” said Pete Kelsey, Autodesk strategic projects executive.
“Whether it’s putting a [reconstructed] artifact in the hands of a 92-year old survivor who was here on Dec. 7, 1941, or showing it to kids in grade schools, [we’re,] basically using this three-dimensional data to ensure that what happened here, that story, this history, will not end.”
According to Pawloski, the ongoing project is estimated at a value of more than $400,000, with the NPS contributing approximately $10,000 of its own money toward acquiring the goods and services of those involved.
In addition to the computer 3D models being developed, a 3D model printout of the Arizona in its current condition is also expected to be produced and displayed at this year’s Dec. 7 commemoration.