We’re getting closer to our achieving our goal, but we still need your help to support the work on our hull. You can see the need below. Every dollar counts!
This week, we’ll get a little more – forgive the metaphor – in depth on cofferdams and how they work. Let’s start with the basics.
A cofferdam is simply an enclosure of some form which is pumped dry to permit construction or repair work for underwater structures. More specifically, a “surface piercing cofferdam” in our application allow us to access the upper several feet of the normally underwater hull.
This area of the hull is known as the “wind and water line” which is simply a descriptive term for the environment in that region of the hull where wind and water surface meet. In this area, the hull is subjected to mechanical wave action, additional oxygen and physical degradation of the coatings of the hull. This results in a highly corrosive environment which has long term consequences for the steel from which the hull is made.
(Image below NOT IOWA, but an example of potential consequences if we don’t take care of our hull.)
Our cofferdam is made of steel and weighs approximately 2,000 pounds. It is hung on steel “padeyes” which are welded to the hull in a specific form. Once installed, the water is pumped out and the hull is accessed for maintenance.
The particular area of the hull at which we’re working now is comprised of 1-1/2” thick armor which is riveted to the structure. Normally in good condition throughout the underwater portion of the hull, in the wind and waterline, the plates suffer from extensive corrosion damage.
Once cleaned, the rivets along with any localized degradation can be repaired through welding and grinding.
Pitting is also “clad welded” which restores the material to its original thickness. Some of the pitting is quite deep – some areas having over ¼” of material loss.
We are proactively addressing the wear of our hull to preserve the very foundation of our organization and museum. With your support, we can continue to welcome aboard and serve hundreds of thousands of students, veterans, and community members each year.
NMSN Gallery Highlight: Pathfinders of the Sea
Another preview of what you’ll experience when you visit the National Museum of the Surface Navy…
Navigating the world’s oceans and seas has long been an art as well as a science. The early Polynesians read celestial bodies, clouds, currents, and other elements in nature to determine where they were going. They memorized diagrams of the night skies and used stick charts to help them remember.
The Vikings used lead lines to determine water depth and sun compasses or sunstones to find their way around.
By the time the US Navy came on the scene in the late eighteenth century, instrumentation for navigation had progressed to compasses, sextants, chip logs, and paper charts, but sailors still guessed at the weather, using their experience to interpret cloud formations.
Today’s ships carry equipment that can pinpoint exact locations on the globe with incredible accuracy, and have access to satellite imagery and years of data to help predict weather.
Innovation has long been a part of the Navy’s operations. Our Pathfinders of the Sea gallery will bring navigational tools and concepts to life, and demonstrate how the Navy’s technological developments have benefits that reach beyond shipboard usage.
Save the Dates
Join Veterans Peer Access Network LA and Los Angeles Veterans Collaborative aboard Battleship IOWA Friday, April 8th for an event dedicated to helping educate veterans and military families about substance use and chemical dependency. Find out how to receive help for yourself or your loved ones in a judgment-free atmosphere.
Click photo for details. Sign up at Eventbrite to attend this free event.
And LA Fleet Week hits town May 27-30 over Memorial Day weekend for a fantastic summer kick off. (Click photo for details.)
Become A Plank Owner Today
Continue to be a part of all the incredible things happening at Battleship IOWA and the expansion of our mission to become the National Museum of the Surface Navy by signing up as a Plank Owner.
As a Plank Owner, your giving provides recognition and Haze Gray points to be redeemed for ship access, event space reservations, and more. Your name will be listed in the Quarterdeck of Honor, our living donor recognition display that lists your name more prominently as you support over time.
* Registering as a Plank Owner entitles you to a free digital certificate. Printed certificates are reserved for Plank Owners who donate $25 or more. As a Plank Owner, you will receive updates, invitations, and recognition as a museum Plank Owner. It may take up to 10 days for donations to reflect in your listing and upgrade your status.
The Haze Gray points system is in development to be released in 2022. All donations, volunteer hours, and numerated support will be applied to your Haze Gray account retroactively, dating back to Jan. 1, 2020. If you choose to donate without logging in, we will strive to match your donation up to an existing record. If we are unable to locate a record, we will create one for your contribution.