‘Capturing’ the Mighty Mo
by Mark Evangelista
March 1, 2010
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| The
USS Missouri dwarfs a laser scanner ready to capture the historic ship that
served its country in World War II, Korea and the Persian Gulf. |
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Laser scans and holograms add a new dimension to the recently refurbished historic battleship.
When the USS Missouri was decommissioned in 1992,
the 887-foot-long Iowa-class battleship looked tired. Its worn and pitted teak
deck had supported hundreds of naval officers and their crews through three
wars spanning five decades. It was on this deck that Gen. Douglas MacArthur
accepted Japan’s
unconditional surrender in a ceremony on Sept. 2, 1945, ending World War II and
securing the USS Missouri’s place in history. However, the ensuing years and
battles had left multiple scars on the noble ship--particularly in the form of
rust.
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| The
Missouri’s
exterior hull, imaged from the inside, was taken just aft of the propellers and
rudders. |
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The
USS Missouri had actually been decommissioned once before, in 1955. Thirty-one
years later, the Missouri
underwent an extensive modernization of its weaponry. Equipped with four Tomahawk missile launchers, it was recommissioned and
called into action for Operation Desert Storm. Six years later, in 1992, “Mighty Mo,” the last
battleship built by the United
States, was finally allowed to rest.
For the next several years, the magnificent vessel remained docked at the Puget
Sound Naval Shipyard in Bremerton,
Wash. Then, in May 1998, the Navy
officially granted the battleship’s care to the nonprofit USS Missouri Memorial
Association Inc. The donation launched a new mission for the historic
battleship as a floating World War II museum, docked next to the USS Arizona on
Pearl Harbor’s Battleship Row.The museum
opened on Jan. 29, 1999, a testament to the vision and perseverance of the
association’s directors. But the directors had an even bigger vision in
mind--one that involved repairing and preserving the battleship for generations
to come.
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| A
point cloud shows the bridge and surrender deck of the USS Missouri, the site
of Imperial Japan’s unconditional surrender, which ended World War II. |
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A
War on Rust
That vision was realized in October 2009 when the Missouri was moved to Pearl
Harbor Naval Shipyard’s largest dry-dock facility for a three-month,
$18-million preservation project. The project included inspecting and
refurbishing the hull, sandblasting and repainting the ship’s exterior,
replacing rusted steel, and installing a system to monitor corrosion. It also
included a comprehensive documentation project that incorporated 3D laser scanning,
high-dynamic-range photography and traditional surveys. “Having the battleship
Missouri in dry dock provided a unique opportunity to completely scan the ship
while it was out of the water,” says Michael A. Carr, president and CEO of the
USS Missouri Memorial Association. “It was an opportunity we will not see again
for decades and certainly one we did not want to miss.”
A month before the preservation project began, Carr and other association
directors had met Richard Lasater, president of Smart GeoMetrics, a division of
Houston-based laser scanning firm Smart MultiMedia, at the Historic Naval Ships
Association conference in Alabama. Smart GeoMetrics had scanned the interior of
another historic battleship, the USS Texas, earlier in the year, and Lasater
was eager to demonstrate the results.
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| Scan
team member Donald Axtell positions a Leica HDS 6000 laser scanner near a
commemorative plaque on the surrender deck of the USS Missouri. |
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After
seeing the photographic panoramas and video flythroughs, the association
directors were impressed. The technology offered the potential to improve the
overall visitor experience at the museum. If they didn’t act then, they
probably wouldn’t have the chance in the future. “There is no way to complete
an accurate scan of an entire ship while it is in the water,” Lasater says.
“Not only is it impossible to image areas below the waterline, even on a calm
day, the tiniest movements of the water and ship would degrade scan
accuracy.”
The budget for the preservation project was already set. But the association
directors decided they had to make the documentation project work. Through an
extraordinary amount of teamwork, the project was funded at a level that was
acceptable to all participants, and Smart GeoMetrics began honing its strategy.
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| A
point cloud of the USS Missouri's port bow from below reveals a virtual
snapshot of the historic naval vessel. |
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Calling
in the Big Guns
The documentation effort would be the last part of the preservation project
before the Missouri was returned to its home on Battleship Row in January 2010.
Smart GeoMetrics and its team would have a four-day window to scan the vessel
as scaffolding and protective covers were removed. The massive endeavor would
require three scanning crews, each equipped with a Leica HDS laser scanner, to
complete the project. A fourth crew was assigned to create and maintain the
survey control network. “The Missouri
is a very, very big ship, and we only had four days to complete an estimated 14
days worth of work among an army of shipyard workers,” Lasater says. “The
ship’s location in Hawaii
also made logistics a bit challenging.”
However, Smart GeoMetrics was up to the task. The firm quickly assembled a team
of HDS professionals from Meridian Associates in Houston
and As-Built Modeling Services Inc. in nearby Pearland, Texas,
with Houston-based Mustang Engineering Inc. providing special assistance.
The
team arrived onsite January 3 and established a control network of more than
400 points. Crews then captured scans at 160 locations on and around the ship’s
exterior and took thousands of photographs--5,400 in all. “The documentation
teams were really moving fast on this project, and not all of the ship was
accessible at the same time,” says Jonathan White, a senior project manager for
Meridian, who
headed up one of the scan crews. “We were working in and around dockyard
preparations to return the ship to sea.”
By January 6, one day before the Missouri was scheduled to leave dry dock, the
scanning and photography work was finished. “Ships such as the Missouri entail a great
combination of grace and beauty combined with an industrial structure that
comes out very well in scan data,” Lasater says. “This was an exciting project
that just would not have happened if such a great team of companies and
professionals had not been able to collaborate and contribute their expertise.”
With the scans in hand, the team turned its attention to the next phase of the
project--turning data into deliverables.
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| Workers
scramble to complete
the scan project while the USS
Missouri is in dry dock. |
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A
Lasting Legacy
The scans of the battleship generated billions of data points that the team
immediately began processing into point clouds, CAD drawings and 3D models.
The team also decided to take the deliverables one step further by adding
holograms, a capability provided by Austin, Texas-based Zebra Imaging. “The
technology from Zebra Imaging is so compelling,” Lasater says. “Zebra agreed to
provide the initial examples [at no charge] as part of the team. However, the
Missouri Memorial Association immediately realized the value of the technology
and is already working with us to provide specific exhibits and materials.”
This project marks the first time holograms have comprised part of an archival
record. The results of the entire documentation project will be used by the USS
Missouri Memorial Association as a historical record and for ongoing
maintenance and educational purposes.
On Jan. 30, 2010, the Battleship Missouri Memorial officially reopened to the
public looking much like the day it was first launched 66 years ago. The
freshly painted steel glistens in the sunlight. The teak deck gleams. Tours and signs have been
enhanced, and special touches have been added to improve the ship’s
capabilities as a venue for special events. But the Missouri Memorial
Association directors and the Smart GeoMetrics team are still working behind
the scenes brainstorming new ideas to create and maintain a fitting memorial
worthy of the battleship’s legacy. “I am very happy with what is being produced
and excited to start planning for how we can use it here to improve the overall
visitor experience,” Carr says.
Sidebar: Missouri Quick Facts
USS
Missouri (BB-63)
Class: Iowa-class battleship
Length: 887 feet
Height: 209 feet from keel to mast
Beam: 108 feet
Weight: 58,000 tons (full load);
45,000 tons (unloaded)
Speed: In excess of 30 knots (35 mph)
· Iowa-class battleships were
designed for speed and firepower.
· Designing the Missouri took 175 tons
of blueprint paper.
· The ship was built in three
years and required more than 3 million “man-days” to complete.
· Only four Iowa-class
battleships, including the USS Missouri, were built during World War II.
· The Mighty Mo is 5 feet longer
and 18 feet wider than the RMS Titanic.
· If you could stand the ship on
end, it would be 332 feet taller than the Washington Monument.
· Mighty Mo’s trademark feature
is its set of nine 16-inch guns. Each barrel is approximately 67 feet long,
weighs 116 tons, and can fire a 2,700-pound shell 23 miles in 50 seconds with
pinpoint accuracy.
· The Missouri was the last U.S.
battleship to be launched and the
last to be decommissioned.
Source: www.ussmissouri.com
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By: Barbara Brandt
Posted: March 6, 2010 6:44 PM