Feature: Scanning D.C Post-9/11
Professional Surveyor Magazine - October 2011
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In part two of our “Remembering 9/11” series, the author recounts his experiences scanning the U.S. Capitol and Pentagon immediately after the 2001 terrorist attacks.
By Frank John Hahnel, III
mere two days after September 11, 2001, I drove from my home in Atlanta to New York City, trying to scan the debris from the World Trade Center wreckage (see the September issue for that article). While I was away, the senior vice president of my company had sent a heartfelt note of thanks to me and a dozen flowers to my wife, who was awaiting my return. The recognition meant a great deal to us both. After that long week I was trying to recover from the terrible things I had seen and learning to cope with nightmares.
While travelling home from the World Trade Center I received a phone call from the architect of the United States Capitol, and only a few weeks later, I was on a flight headed to Washington, D.C. As the architect had explained, scanning the Capitol was urgent because al-Qaeda had targeted it with Flight 93 that went down in Pennsylvania, and they didn’t quit once they’d targeted something. (The first attempt to bring down the World Trade Center is believed to have occurred during the basement bombing in 1993, and less than 10 years later the next attempt was tragically successful.)
Scanning the Capitol
The U.S. government urgently wanted a complete set of drawings in case rebuilding the Capitol became reality, and although the architect had bits and pieces of drawings from additions and renovations that had been performed over the years, he did not possess a full and complete drawing of the entire structure.
Prior to scanning, he asked to meet with us so he and his team could be fully informed of the process and understand the basics of the technology. The meeting would also provide us with the opportunity to walk the site and gain a better understanding of how many scan positions we were looking at with a 40x40-degree field of view.
We arrived in the mid-morning for that meeting, parking several blocks away from the Capitol (post-9/11, there was no easy way to get a vehicle on or near the Capitol campus). After answering security questions at the gate, we met our escort and crossed the threshold of the Capitol’s main entrance. We proceeded through a metal detector and had our laptop cases x-rayed, and then finally we met with the architect in his office to discuss our technology in detail and explain exactly what it could do to help in this time of need.
After the meeting, we took a walking tour of the campus to familiarize ourselves with some of the ornate features on the building. In addition to the ground level of the Capitol, the roof would also need to be scanned, along with the dome and its statue at the top. It quickly became clear that this was a large project that would take several days to complete.
After leaving the Capitol, we called our boss from a nearby coffee shop, filling him in on what we had learned and the magnitude of the project. He suggested we reach out to our local clientele for assistance with the project. They had worked with the government for several years and could provide manpower needed for scanning the site. This project needed to happen right away. We were under the gun in more ways than one.
The team descended upon Washington, D.C. quickly. We debated using known control for the site, and in the end elected to skip it because of the time constraints. We set our own nails and had the option to return using GPS to locate the points. The group of operators was divided into two teams of scanners, with the most-experienced operators running the scans. One team started on the House of Representatives side, while the other team began scanning on the Senate side.
Back then, our laptop had to be tethered to the scanner to collect the data. Color touch screens, on board hard drives, and memory cards didn’t yet exist. Neither did dual axis compensators. Yet we still made amazing progress. In all, we completed 80 scans over five days, just on the ground level.
On the fifth day, both groups began the tremendous task of scanning the roof and the dome. Shortly after my group started on the roof, we were interrupted by a frantic Capitol police officer bursting through the roof-access door.
“Don’t move!” he screamed.
It was a very windy day and extremely difficult to hear up there, so instead of freezing as ordered I walked over to him and our escort to find out what was going on. Our escort got on his radio, and the Capitol police officer got on his. Apparently we had caught the attention of sniper teams set up on adjacent roofs; thank God someone had the presence of mind to make sure we weren’t terrorists and to make direct contact with us.
I quickly learned that no one had informed any of the people in the surrounding buildings about our permitted presence on the Capitol’s roof that day. It seemed the appearance of 10 people walking around with two large gray “things” on tripods wasn’t an everyday occurrence and caused quite a panic.
I decided to wait to tell my team that they almost met their demise on the roof of the U.S. Capitol until we were safely down on the ground again. We were a trigger pull away from death. Who knew surveying could be so dangerous?
A newswoman had set up shop below us with a clear vantage point of our crews working on the roof. We all knew that something had to be said to her, but we had been instructed not to talk to anyone because the public hadn’t yet been told that the fourth plane had targeted the Capitol building. Instead, we explained to the reporter that we were working on the expansion and renovation of the Capitol, a project that had been planned for some time. Our government contractor gave a brief interview, and if you blinked early on Saturday morning, you would never have seen it. Success.
The next phase of the project included the process of registering all 94 scans together. Again, in those early days, data-collection software using overlapping points to register scans together simply didn’t exist. We had to compile the scans manually through the use of targets, and then we had to turn the layered images into a deliverable for the architect. With the scans and deliverables finished my part was done, and I handed the project to our qualified engineer for completion.
Scanning the Pentagon
Shortly after scanning the Capitol, I began working closely with the FBI on mapping the damaged Pentagon as the debris was being removed. On December 18, 2001, I flew yet again to Washington, D.C., along with a close friend, Cliff Culhane, PSM, formerly with the Pemberton Township police department of New Jersey. We met with our FBI escort and proceeded to the Pentagon site with our scanner.
My first impression was amazement at the absence of plane debris. The damaged area of the Pentagon had also been completely removed. All that remained was a huge scar carved through the building.
The site was noisy with construction equipment, and people were everywhere seemingly scrambling about. Off in the distance was a clock counting down to the one-year anniversary of the terrorist attacks on 9/11. The goal of those around the Pentagon was to have all repairs completed by that date. I had no doubt that it would be done, given the high level of activity on the site.
When we started to work we discovered that the hallways and doors of the Pentagon were boarded with plywood, and there was no way to place targets. On the phone our technical support group suggested I overlap the scans. I didn’t know at the time that our programmers were developing software for cloud-to-cloud registration based on the work we’d just completed on the Capitol building.
After a couple of hours I had completed seven scans of the open gash of the Pentagon. We boxed the equipment, left the site, and I burned the scan data to a CD and sent it overnight to my company’s headquarters. My company then tasked an engineer with working on my Pentagon scans for delivery.
Although I was finally able to return home quickly, December 2001 continued to be a very sad month for my wife and for me. My next job turned out to be helping pack our apartment to move to Orlando, our home before Atlanta. The company my wife worked for had closed its doors and laid everyone off, and we knew that we would need the support of our families for the next few months.
Then, for the third time since 9/11, I received a surprising and important work call. While driving our U-Haul truck out of the city, a contractor based just outside of Tampa called me. They had been working at the Fresh Kills Landfill (a 2,200-acre landfill in the New York City borough of
Staten Island; the name comes from the landfill’s location along the banks of the Fresh Kills estuary). The contractor was commissioned with measuring the volumes of debris from the World Trade Center towers, off-loading the piles from barges, and determining placement at the landfill.
They needed a fast and safe way to map the piles so as to determine how much more debris could be placed at each site. They had heard about the scanner and wanted a proof of concept. The best spot to do that, they said, was to meet them at the Fresh Kills site in New York. We agreed on a date in January, and I made flight arrangements, yet again.
The final part of this series details the author’s work at Fresh Kills.
Frank John Hahnel, III, was born and raised in Winter Park, Florida, and has worked in the laser scanning industry for 12 years. His background is in land surveying. He is currently working with local, state, and federal law enforcement agencies, as well as the military and private firms, in accident investigation and reconstruction.
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