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Surveying Sunken WWI Ship USS San Diego

Sept. 13, 2017 | By Midshipman Nolan T. Brandon, U.S. Naval Academy
"You're holding onto a $500,000 sonar head. Don't drop it."

These were the words of encouragement I received from Tim Pilegard, a graduate student at the University of Delaware. At that moment, Tim and I were struggling to bolt the sonar onto the side of the R/V Joanne Daiber, University of Delaware's 46 foot research vessel.
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Photo By: NHHC
VIRIN: 170912-N-TH437-176

After several failed attempts, we finally got the bolts secured, and my risk of being heavily indebted to the University was momentarily over. As I looked over at a very large number of pelican cases containing more expensive equipment still resting on the dock, I realized it was going to be a long night, but there's no place I'd rather be.

My name is Nolan Brandon, a Midshipman in my final year at the United States Naval Academy. I'm working with team members from Naval History and Heritage Command, Naval Surface Warfare Center Carderock, the Office of Naval Intelligence, and the University of Delaware, to survey the wreck of the USS San Diego, help preserve the ship's heritage, and hopefully, to lay to rest the debate over its sinking. The story of this ship and its men is not well known. I had never heard of USS San Diego until I was invited on this mission. But now that I have learned of what happened on that day 100 years ago, I hope more Americans can hear the story too and be awed by the courage and skill of United States Sailors.

History of the Ship
San Diego was a 504 foot long armored cruiser commissioned into service on August 1st, 1907. San Diego, and the other ships of the Pennsylvania class, was a new breed of ships that were more heavily armed and armored than cruisers, yet still faster than the great battleships. San Diego served in a multitude of roles from testing the channel of the then brand-new Pearl Harbor to escorting convoys of merchant vessels against German U-boat attack during World War I.

Photographed 28 January 1915, while serving as flagship of the Pacific Fleet. Her name had been changed from California on 1 September 1914. Note two-star Rear Admiral's flag flying from her mainmast top. U.S. Naval History and Heritage Command Photograph.

It was during her WW1 service that San Diego met her sudden end. On the 18th of July, 1918, the ship was steaming towards her home port in New York through waters in close proximity to Fire Island known to be hunting grounds for U-boats. San Diego's commanding officer, Captain H. H. Christy, was well aware of this threat and took every precaution to safeguard his ship including stationing additional lookouts, zigzagging along his path, and closing additional watertight hatches. Unfortunately, these measures were not able to protect the ship from the explosion that rocked its port side below the waterline at 11:05 AM. No one knows for certain whether this explosion was caused by a torpedo, a mine, or a spy onboard (that's part of the reason why we're here), but it was enough to cripple the San Diego.

As the ship began listing to port, the captain kept his head and initiated evasive maneuvers while scanning for a suspected attacking U-boat. Despite the increasing list as San Diego took on water, Christy was reluctant to abandon ship in case a nearby U-boat could surface and take over San Diego. But as time passed, it became clear that the ship would soon capsize, and so, the call to abandon ship was sounded. Of the 1,183 men on the ship at the time of its sinking (including a few midshipmen), all but six safely escaped peril under the captain's skillful command, and four of those six died in or as an immediate result of the initial explosion. As per tradition, Captain Christy was the last to leave the ship. His actions, along with those of his men, reflect the competence, courage, and professionalism expected of United States Sailors.

The Prep
I'm excited and honored to be part of this mission, which, weather permitting will run until September 15th. In addition to the $500,000 side scan sonar head, our equipment includes a fully autonomous underwater vehicle (AUV) equipped with side-scan and bathymetric sensors, a remotely operated vehicle (ROV) with a video camera, a drop camera, a quadrocopter, and a vast multitude of all the cables, tools, computers, monitors, and spares necessary to support our operation. After many hours of wrench-turning and troubleshooting preparations on Sunday, the team ate dinner and returned to the hotel, ready to hit the water and start the surveying work Monday.

Day One - Learning how the AUV works 
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Photo By: NHHC
VIRIN: 170911-N-TH437-025

We got an early start Monday morning in order to get a full day of surveying in with the AUV. After the team's briefing with the senior Coast Guardsman at the base, Captain Kevin skillfully steered the Daiber through the shoals of the inlet and out to San Diego. As we made preparations to launch the AUV, I felt a little out of place surrounded by such capable individuals such Dr. Art Trembanis, an oceanographer from the University of Delaware with a PhD in Marine Science and one of our team's leaders, or Dr. Alexis Catsambis, an archaeologist with NHHC with a PhD in Nautical Archaeology and our team's other leader. However, I did my best to prove my worth as a deckhand and to suck up as much knowledge and experience as possible. 
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Photo By: NHHC
VIRIN: 210624-N-ZX259-6257

Launching the AUV from a moving boat was a much more controlled operation than I expected. Using the boat's A-frame, we lifted the AUV from its frame and steered it over the water with tenders. From there, it was a simple process of lowering the AUV down into the water, releasing the hooks, and slowly motoring away. Before launch, Dr. Trembanis programs a series of parallel tracks (like a lawnmower) with a preset depth below the surface or altitude above the bottom. The instructions are then transmitted to the AUV using a high-speed wifi connection. On Dr. Trembanis' command, the AUV slips beneath the surface and begins recording side-scan data.

While underwater, the AUV determines its position using inertial navigation and communicates back to the boat using a high pitched sonic device. The AUV's transmissions travel to a small metal torpedo-shaped object called a towfish that is connected to Dr. Trembanis' computer. This communication had very narrow bandwidth, so the operator only receives limited position information from the AUV during a mission. However, when the AUV finishes running the mission, it surfaces and comes in range of the wifi transmitter allowing for a much higher rate of data transmission.

We ran seven different missions over the course of the day at varying depths and frequencies allowing us to scan the wreck with very high resolution. Over the course of the next few days, the University of Delaware team will work to process this data into useful product for the NHHC, NSWCC, and ONI team members to analyze and manipulate.
"... you may be wondering what in the world a Midshipman is doing here. Don't worry, I've wondered the same thing many times..."
Day Two - Malfunction
The theme of Day 2 appears to be malfunction. The goal was to spend the first part of the day using University of Delaware's remotely operated vehicle (ROV) to get up close images of San Diego's hull. Pictures of the hull are critical so NSWCC, NHHC, and ONI can determine the cause of the explosion. Delaware brought several large monitors that would, in theory, display HD video from 100 feet below in real time for the experts to analyze. Once the ROV, monitors, and tether cable were ready to go onsite, I tossed the ROV over the side, and Dr. Trembanis piloted her below. Unfortunately for us, the camera feed chose that moment to act up. Dr. Trembanis described it as "driving a car with your eyes closed for 9 seconds, then opening them for one and trying to react in time." Needless to say, the issue essentially prevented the team from accomplishing any real imaging work.
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Photo By: NHHC
VIRIN: 170912-N-TH437-075

However, not all was lost. Delaware's vast amount of equipment also includes a camera-equipped quadrocopter. Before our misadventures with the ROV, we launched the little quadrocopter from the stern to get some footage of the boat, crew, and environment. I got a chance to pilot the drone for a short period and got a unique perspective of a large school of baitfish which had schooled on the surface to escape predators. From above, the school exhibits a distinct outline that constantly bulges and shrinks. It was beautiful. In addition to this footage, MC1 Eric Lockwood, our media specialist, used the drone to video the ROV launch. We anticipate using the drone more in the days to come for videoing AUV missions and side-scan sweeps.

After two hours of troubleshooting, the team called it an early day. A nearby boat had been unable to start its engines due to battery malfunction and had requested our assistance. Captain Kevin hooked up a tow, and we pulled them back towards shore. A local maritime towing company took over the tow half way back, but hopefully our small action will give us good karma for the work days to come. Once we docked at the Coast Guard station, University of Delaware's team began to systematically check and troubleshoot their ROV. Additionally, they were able to set up the side-scan sonar for use tomorrow. We may not have accomplished a lot of progress directly on San Diego today, but after a many hours of work on the dock, we're ready to make the most of the next two days.

Day Three - Gigabytes of success!
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Photo By: NHHC
VIRIN: 210624-N-ZX259-6224

I have never had a more productive day on the water. We left the dock this morning loaded down with the remotely operated vehicle (ROV), the autonomous underwater vehicle (AUV), and an Edgetech side-scan and bathymetric sonar (all of which were fully functional!). All the gear, combined with the entirety of our team, made for a packed boat, but we made it through the rough waters of the inlet and out to the wreck in one piece.

Once we arrived, we had our choice of survey instruments and began with the side-scan sonar. This device, mounted to the side of the boat, gives us both 2D and 3D datasets which reveal the contour of the sea floor and any objects resting on it. After making several passes over San Diego, the computers revealed the current state of the wreck. San Diego lies upside-down with a scattering of debris off either side. The hull exhibits signs of both battle and decay. An extensive section of the hull amidships has collapsed into the wreck, forming a large concave depression. Other scattered portions of the outer hull are also missing which could have been caused by depth charging when US ships mistook the San Diego for the submarine that sank her. We followed up our side-scan passes with another ROV deployment.

Yesterday, we spent over two hours attaching a new camera to the ROV in order to fix the spotty video feed problems we experienced on day two. The effort entailed wrapping at least four whole rolls of electrical tape around the separate ROV and camera cables as well as zip-tying the new camera to the ROVs frame. I'll admit that it looked jerry-rigged, but it actually gave the ROV a better video feed than before the problems, so that's a win in my book! When we deployed, the ROV's camera displayed rather nasty bottom conditions. Visibility was less than half a meter, and a stiff current was flowing over the wreck. Despite these obstacles, Dr. Trembanis managed to record video of several of the more significant cracks and gaps in the ship's hull that the historians and archaeologists will analyze in greater depth. 
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Photo By: NHHC
VIRIN: 210624-N-ZX259-6236

Our final deployment was the AUV. The seas had slowly been growing rougher and rougher over the course of the day, so getting the seven foot long metal tube of the AUV over the side safely proved challenging, but besides some soaked graduate students, we were successful. The University of Delaware's team programmed the AUV to run passes over the wreck perpendicularly to its long axis so we could fill in the gaps of our previous side-scan and bathymetric data sets. At the end of the day, the team had gathered gigabytes and gigabytes of data covering the entirety of the wreck at high resolution. We have more than made up for the many malfunctions and lost survey hours that we experienced yesterday. 

USS San Diego (Armored Cruiser No. 6) Painting by Francis Muller, 1920. It depicts the ship sinking off Fire Island, New York, after she was torpedoed by the German submarine U-156, 19 July 1918. Courtesy of the Navy Art Collection, Washington, D.C.

After reading about all this complicated high-tech equipment and the experienced and well-educated members of our team, you may be wondering what in the world a Midshipman is doing here. Don't worry, I've wondered the same thing many times. However, I promise there is a purpose, and I do my part. During my third year at the Academy, one of my professors offered me the opportunity of a lifetime, the chance to work on a Bent Prop expedition in the Pacific. Bent Prop is an organization devoted to locating aircraft lost during World War 2 in the hopes of initiating the recovery of the remains of crew members who have been missing in action for over 70 years. I flew to a small island in the West Pacific and helped the team locate several aircraft using similar equipment to what we're using on the wreck of San Diego. In fact, University of Delaware supplied that equipment and the personnel to operate it. In the months following, I've continued to support Bent Prop's mission with another trip to the Pacific and work at the Dulles Air and Space Museum.

These experiences have humbled me and have been a true blessing. With Bent Prop, I?m working to honor those who have gone before me and often find myself hovering underwater over their final resting place. It's a surreal experience to find oneself 70 feet under the surface in the West Pacific staring at a yoke that some US pilot, who was probably the same age as me, wrestled to save his crew until their final moments. If I had been born in that era, I very much could have been that young pilot. After being given these fantastic opportunities, I've searched for a way to contribute more than my hands to the effort.

As a Midshipman studying to achieve an Honors Oceanography degree from the Academy, I must complete an independent research project during my senior year. My intention is to use side-scan and bathymetric data from my trips, primarily from San Diego, to provide organizations like Bent Prop and NHHC with better techniques to locate and identify underwater wreckage. In order to earn this data, I have to do my part as essentially a deck hand aboard Delaware's R/V Joanne Daiber. But the USS San Diego means more to me than just data. There were 9 Midshipmen aboard the day she went down. Just as I could have been that young pilot, I could have been one of those Midshipmen. Experiences like these help remind me of the gravity of the profession I will soon fully be part of and help motivate me to prepare as best as I can. I'm also using this mission as an opportunity to learn from the experts, whether it's processing sonar data with Delaware's team or learning the intricacies of underwater archaeology from NHHC's professionals. I'm just doing what I can, and I hope it makes a difference however small.

Day Four - That's a Wrap! For Now
"After more discussion, I realized just how much more work is to be done on this project. Coming out to the wreck and collecting the data seems to be the least time-consuming part of this effort."
Today was the final day of boat work for our team, but we never left the Fire Island Inlet. We amassed so much data yesterday that we essentially exhausted our survey options. So instead, the team leaders decided that we should show our appreciation to the crew of US Coast Guard Station Fire Island by taking them out on the boat and demoing our equipment. Six Coasties, including the ranking chief, came aboard for the short cruise. We deployed the Edgetech side-scan sonar and gathered bathymetric data for the Fire Island inlet, which is known for its rapidly shifting shoals. Next up was an autonomous underwater vehicle launch and recovery with video from the Mavic Pro drone. In between these tech demos, I had the opportunity to chat with several of the junior Coasties.

As we discussed our backgrounds, all of them mentioned their college education in one way or another. This struck me as a strong reminder that in today's military, the enlisted force is becoming more and more educated. Potentially all of the Sailors that I may lead will have the same level of higher education as myself. Some of them may even hold masters. This situation presents both a challenge and an opportunity. I look forward to the distinct honor of leading these people.
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Photo By: NHHC
VIRIN: 210624-N-ZX259-6200

Upon arrival back at the station, our team commenced breaking down, cleaning, and packing up every piece of equipment from the boat. After several hours of work, we got all of University of Delaware's gear into Pelican cases and into their trailer. Next up on the schedule was a final team meeting to discuss the outcome of our mission. Dr. Trembanis, Peter Barron, and Kenneth Haulsee displayed their rough first products from the different side-scan and bathymetric datasets. Just one of these products contains a 3D point cloud of over 3.4 million points which depict the current state of San Diego and the surrounding sea bed. The team from ONI also had created a comparison between the ship's original hull and the current state. Both of these products indicate that wreck has experienced a significant amount of collapse amidships where the boiler rooms were. Additionally, San Diego appears to have sunk into the surrounding sediment by at least several feet.

After more discussion, I realized just how much more work is to be done on this project. Coming out to the wreck and collecting the data seems to be the least time-consuming part of this effort. In the coming months, teams from U Del, NHHC, NSWCC, and ONI will work together to analyze all the data we have recovered, study primary sources regarding the ship's operational history, and run calculations to determine what damage can be attributed to the explosion, and just what caused it. All of this work will be in preparation for the 100 year anniversary of the ship's loss. Hopefully by then, we'll have a better understanding of what happened to those young Sailors on July 18th, 1918.

It's been an honor for me to be a part of this team. Over the past four days, I learned so much from the experts around me from running AUV operations, to troubleshooting sonar malfunctions, to the detective-like process of underwater archaeology, to simply coordinating a multi-disciplinary team of professionals. This team has exhibited such expertise and leadership that I never saw anything other than full cooperation and teamwork. With their hard work, San Diego's story and reputation will spread and grow.