NORFOLK, Va.-- A partnership between Norfolk Naval
Shipyard (NNSY) and Penn State University developed a tank cleaning tool
modification that saves mandays and money.
The new submarine oil storage tank cleaning tool replaces
the traditional manual process using pressure washers and solvents and cuts
cleaning time in half.
Thanks to a NAVSEA Technology Transfer Program and
Pennsylvania State University's Applied Research Lab (ARL) initiative, the
remotely monitored prototype tool blasts water at 20,000 psi, delivering 20
gallons per minute and creating a safe, cost-efficient way to clean and prepare
oil storage tanks for structural repair hot work, modifications, and
preservation. The NNSY-Penn State partnership developed the modifications using
an existing commercial product as a starting point.
The prototype was tested on USS La Jolla (SSN-701) and
then fine-tuned before use on USS Helena (SSN-725) in her Drydocking Continuous
Maintenance Availability (DCMAV), which completed its availability a day early
"Helena was a short availability, so we wanted to be
able to go in and attack it," said George Reed, NNSY Blasting and Painting
Shop Trades Manager. "We cut man hours out of the tank cleaning evolution
on the Helena project and took the workers out of the tank as much as possible,
which not only reduced cost but also increased the safety of our
Oil storage tanks are used to supply fuel to diesel
submarines and seawater is moved into the tanks as fuel is used in order to
maintain ballast for the ship. An
unpainted oil storage tank typically ends up with a multitude of structural
repairs and costs about 7,827 man-hours per availability. In the past, many of
these tanks were not painted because oil acts as a good preservative. However,
the seawater in the tank does not, and because oil and water don't mix, brine
becomes concentrated in the lower portion of the tank.
"We have to get the oils out of the metal so the
paint will adhere properly and to ensure we meet NAVSEA requirements. This
takes a lot of time," said Reed.
"The shipyard has never cleaned a tank as quickly
and effectively as we did Helena's," said Jonathan Simmons, NNSY Painter
Supervisor. "We completed this tank in 10 days. The typical tank takes
about 20 days. So you're shaving off a lot of time, which helps get the boat
back to the fleet."
Penn State's ARL fabricated the magnetic base prototype
and accessories, but these parts will be modified and manufactured by NNSY in
the future, and plans are underway to mobilize a team of painting/blasting
experts to train other public shipyards to properly employ the tool.
As for NNSY, the Painting/Blasting Shop will use the new
cleaning method for the USS Rhode Island (SSBN-740) availability and USS Boise
(SSN-764) when it arrives in 2016.
- NAVSEA -