Feature 4 | SIGNATURES & COUNTERMEASURES
ONR trials superconducting degaussing
system
A revolutionary high-temperature superconducting degaussing system has
been installed on the destroyer USS Higgins in order to test the eff ectiveness
of the technology over a two-year period.
he new degaussing coils – the fi rst
of their kind – were installed on
Tthe destroyer earlier this year by
the Offi ce of Naval Research (ONR) and
the Ship Engineering Station Philadelphia
(part of the Naval Surface Warfare Centre,
Carderock Division) in the US, and
‘went cold’ on 11 July. Initial magnetic
performance measurements will begin in
December 2008 and continue for the test
and evaluation period.
The new system replaces the heavy
copper cables used in conventional
degaussing systems. Instead of copper
cables, the revolutionary system uses a
single cable made from high-temperature
superconducting (HTS) wire that
signifi cantly reduces overall weight and
installation costs. A HTS degaussing system has been installed on board the USS Higgins and will now
Conventional degaussing systems undergo two years of trials.
require many tons of copper wire to be
installed on a warship in order to generate
magnetic currents that ‘cloak’ a ship’s amphibious ships, the Littoral Combat the naval architect in planning out the
magnetic signature and make it more Ship (LCS), and surface combatants such degaussing system to meet the platform’s
diffi cult to detect using magnetic sensors as the CG(X), DDG-1000, and CVN-21 signature requirement. The US Navy’s
on magnetically activated sea mines. could provide a 50-80% reduction in adoption of the technology is a result of
In a typical conventional arrangement, total system weight, and a reduced total many years of hard work in developing
a degaussing system uses a network ownership cost compared to current HTS wire and demonstrations funded by
of copper cables installed around the systems. In addition, says the ONR, using both the Department of Defense and the
circumference of a ship’s hull, running HTS degaussing systems could result in a Department of Energy,” he explained.
from the bow to the stern on both sides 90% reduction in the total installed cable Industry in the US has played a key
of the vessel. lengths for all US Navy ship classes. role in the development of the HTS
HTS wires cooled to cryogenic “Th e work on the Higgins represents a degaussing technology, including
temperatures can be operated at current true leap ahead for the US Navy magnetic American Superconductor, Nexans
densities up to 200 times higher than silencing and HTS communities that GmbH, PHPK Industries, Cryomagnetics
conventional conductors. This allows takes advantage of two decades’ worth of and Cryomech.
the magnetic flux generation from the research,” said ONR programme manager Future HTS degaussing systems could
degaussing loop to be generated with HTS George Stimak. “HTS degaussing brings also incorporate components currently
wires that are a fraction of the weight of with it a new capability in not only being under development through the US Navy
copper wire systems producing equivalent able to perform the same functionality Small Business Innovation Research
magnetic fl ux. that copper-based degaussing systems can (SBIR) programme under ONR and Naval
Th e ONR says that this reduction in accomplish, but being able to do the same Sea Systems Command sponsorship.
the number and weight of cables required task in a much more effi cient manner that These include an HTS connector for
suggests that HTS degaussing systems is less invasive.” attaching HTS cables to each other, an
fitted onboard the US Navy’s LPD-17 “It opens up the design trade space for advanced HTS junction box incorporating
38 Warship Technology October 2008
WT_Oct08_p38+39.indd Sec1:38 10/10/08 4:40:28 PM
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