Warship Heralds Evolution in Weapon Technologies
By HUNTER C. KEETER
When the U.S. Navy’s first integrated power system (IPS)/electric
drive warship arrives in 2011 as the DD(X), the service will mark a technological
breakthrough that not only signals a new era for naval engineering, but
provides huge amounts of electrical power for uses once considered fanciful,
such as free electron lasers, high-powered microwaves and electromagnetic
Capt. Roger D. McGinnis, director of the Navy’s directed energy
and electric weapons program office, said that while the “lethality
mechanisms” of high energy weapons are classified, “Our bottom
line is that if we can put millions of joules of energy onto a target,
something will happen.”
In an interview with Sea Power, McGinnis described a variety of effects
from these weapons, including “the burning and blinding of an optical
system, or cutting an [airplane’s] wing off, or causing a fire
that results in an explosion.”
DD(X) is in development by the Navy, Northrop Grumman Ship Systems,
General Dynamics Bath Iron Works, Raytheon, Lockheed Martin and other
firms. When the new ship arrives in service it will be armed with very
advanced, but conventional weaponry, including two United Defense 155mm
Advanced Gun System cannons and an 80-cell vertical launch system for
various guided missiles. But these systems are stepping stones to greater
capabilities, according to Michael Collins, Navy IPS/electric drive program
manager. “This technology opens the door” to advanced weapons,
In January 2000, then-Secretary of the Navy Richard J. Danzig — now
chairman of the board at the Center for Strategic and Budgetary Assessments,
a Washington, D.C., think tank — announced the Navy would commit
to IPS/electric drive and associated technologies for the next generation
of surface warfare vessels.
Danzig’s commitment may influence the submarine and aircraft carrier
communities as well, if prominent leaders, such as the director of Navy
Nuclear Propulsion, Adm. Frank L. Bowman, have their way. So far, however,
the nuclear Navy, with its own approaches to power conversion and distribution,
has not embraced the DD(X)-type IPS/electric drive model.
An IPS/electric drive system takes raw power generated by engines (also
referred to as prime movers), and converts it to electricity, which can
be stored by devices such as flywheels or capacitors. The electrical
power can be distributed wherever it is needed on the ship, for example,
to weapons or sensors, or to electric motors which drive propellers.
That is an evolutionary improvement over present ship designs. Aboard
a modern Arleigh Burke-class destroyer, four main gas turbines are coupled
in pairs to huge reduction gears, providing power for propulsion. This
power is not accessible for any other function. Three additional gas
turbine engines are used to power an Arleigh Burke-class destroyer’s
generator set, delivering a total output of about 7.5 megawatts of electricity
for the ship’s systems.
By contrast, the destroyer-class IPS/electric drive would have four
prime movers, which are coupled through generators to an electrical power
conversion and distribution system, and to electric motors used for propelling
the ship through the water. The IPS/electric drive is capable of providing
10 times the electrical output.
Advanced weapon technologies may one day take advantage of surplus electricity
aboard ships, including free electron lasers, high-powered microwaves
and electromagnetic rail guns. The first two are directed-energy systems — directing
photons in the case of the laser, or radio frequency energy in the case
of the microwave — to damage or disrupt a target with variable
intensity. The rail gun concept would use electricity and magnetic fields
to accelerate a projectile, which attacks a target in much the same way
as conventional artillery, though with far greater kinetic energy.
IPS/electric drive has set the stage for these advanced weapon technologies,
but additional laboratory work and investment are required. According
to Fred Beach, a program manager in McGinnis’ office, advanced
electrical weapons are not going to “cost a few million dollars
and be developed overnight. These technologies require an investment
of $30 million to $50 million over several years.”
Potentially, the payoff for the investment is huge. In the case of laser
weapons, the lethal effect arrives at a target literally at the speed
of light. So today’s challenge of developing fire-control solutions — plotting
a target’s speed, maneuver and countermeasures against the capabilities
of the firing platform’s sensors and weapons — could be a
thing of the past for strike-group air defense.
“Now all we have to worry about is dwell time: how long do we
want to hold the beam on the target to get the desired effect?” Beach
said. That fact is particularly compelling to the Navy leadership struggling
with the increasing threat from proliferating antiship cruise-missile
While powerful lasers are not based on new technologies, their application
aboard ship remains in uncharted waters. The Navy was first to produce
a high-energy laser — the 1970s-era
MIRACL located at White Sands Missile Range, N.M. MIRACL is a megawatt-class
chemical laser with two serious shortcomings — it produces poisonous
fumes and lases at infrared wavelengths, which are neutralized by the
Electrically powered free-electron lasers may be tuned to frequencies
most effective for operating at sea. The Office of Naval Research is
funding development of a free electron laser at the Energy Department’s
Jefferson Laboratory in Newport News, Va. By changing frequencies, free
electron lasers could perform different functions, from target designation
to attack. Additionally, the ship’s crew could use the laser emitter
tubes — essentially powerful telescopes — as high-resolution
electro-optical sensors, for target identification and classification.
Other types of high-energy weaponry may appear sooner than lasers.
Ships could be equipped with high-powered microwave devices, such as
those being developed by Marine Corps Col. David P. Karcher Jr.’s
Joint Non-Lethal Weapons Directorate. Karcher’s command is working
with the Air Force on a product called the Active Denial System, which
is capable of causing pain that can be scaled up from mild heat to an
extreme burning sensation. The military wants the Active Denial System
to use as a force protection device.
Over the next year, the Active Denial System will be packaged and tested
in a vehicle configuration aboard a military Humvee. It could officially
be deployed after 2005. A shipboard application could follow — perhaps
useful in future scenarios such as the October 2000 attack on the destroyer
USS Cole, when a terrorist bomb killed 17 sailors and crippled the ship.
McGinnis’ office also is working on a rail gun that could draw
powerful pulses of electricity from a modified IPS/electric drive system
to launch projectiles. Propellant is not needed in the rail gun concept
because clean electricity launches each round down a rail or through
a magnetic coil. The speed with which a rail gun’s projectiles
travel may deliver thousands of times the kinetic force of a conventional
artillery shell, making explosive warheads unnecessary.
Chief of Naval Operations Adm. Vern Clark, told a Navy League of the
United States Sea-Air-Space luncheon audience April 8: “the rail
gun is in our mind and we are investing in it.”
Make A Real Difference
While rail guns, high-powered microwaves and lasers are unlikely to
replace conventional munitions outright, McGinnis noted that these technologies
would likely co-exist on the ships of the future. “If there is
no danger of collateral damage and the objective is to blow a target
up, then conventional weapons do a great job,” he said.
Once operational, however, directed energy weapons could make a real
difference for the Navy. McGinnis noted that, despite the range and line-of-sight
limitations that make them unsuited for long-range strike, lasers deliver
very fine beams that can be precisely controlled. Lasers could be called
upon in cases with a high probability of collateral damage, for example,
if a small enemy vessel attempts to hide among friendly vessels or other
With the potential to cause horrific damage against a target exposed
to full power emissions, directed energy weapons could also emit power
on low settings to drive targets away from a conflict area, with no loss
“The military likes having the option that does not cause collateral
damage. That lets us engage units that are close to friendly forces and
where we don’t have to kill, but can simply make the enemy go away,” McGinnis
Whatever investment decisions are made for weapons the next several
years, the Navy already is engineering the potential these technologies
require, according to Collins and his IPS/electric drive team for DD(X).
That team is helping to make practical what Danzig and other Navy leaders,
such as Rear Adm. Charles S. Hamilton II, program executive officer for
ships, have said: that the acquisition of a IPS/electric drive is like “the
shift from sail to steam.”
On Oct. 29, 1814, the first U.S. steam-powered warship, the 32-gun Demologos,
designed by Robert Fulton, was launched in New York. The Demologos — scuttled
when its magazine exploded in 1829 — contrasted sharply with the
most advanced sail frigates of its day, and though under-appreciated
by the naval establishment, lit the way to the future.
It took almost two generations for James Watt’s practical improvements
on Savery’s and Newcomen’s steam engine in 1769 to inspire
the first steam-powered warship. IPS/electric drive, itself not a new
concept, may have come of age, according to Philip A. Dur, president
of Northrop Grumman Ship Systems.
“The beauty of it is that we will have this ‘power surplus’ on
the ship so that we develop the weapon suites on these ships spirally,” he
said. “The power surplus is integral to the advantage we have in
Cruise ships have long employed electric drive because it is less costly
to operate than more conventional propulsion systems. In a conventional
propulsion system, the engines are accelerated or decelerated to increase
or decrease speed. IPS/electric drive de-couples the prime mover from
the propeller shaft. Because gas turbines operate more efficiently at
higher shaft revolutions, prime movers in an IPS/electric drive can be
revved up to their most efficient level of operation and remain there.
Electric motors are used to change the ship’s propeller speed.
Fuel economy is a key reason why the Navy is investing in IPS/electric
The U.S. Navy experimented with electric drive in 1911 with the ex-USS
Jupiter — converted in 1913 as USS Langley, the first aircraft
carrier. Other military vessels are operating today with forms of electric
drive. For example, the U.S. Coast Guard Cutter Healy, built in 1993,
is an electric drive vessel powered by diesel prime movers. The British
Royal Navy’s Type-23, new Type-45 and new aircraft carrier programs
are designed with IPS/electric drive-type systems in mind.
The Naval Surface Warfare Center, Carderock Division’s, Ship Systems
Engineering Station in Philadelphia has been putting Danzig’s vision
for a new, state-of-the art IPS/electric drive design into action.
The engineering development model for the DD(X) IPS/electric drive is
to be assembled there by April 2005. Testing of the model is to continue
from June to September 2005. DRS and General Atomics have developed permanent
magnet motor technologies the Navy will evaluate at Philadelphia.
Additionally, other approaches — such as Alstom’s advanced
induction motor, American Superconductor’s high-temperature superconductor
and General Atomics’ superconducting DC homopolar motor — have
attracted naval interest.
Northrop Grumman Ship Systems and its partners are working with the
Navy under a $2.9 billion contract for DD(X) that includes the design,
manufacture and test of 10 engineering development models.
IPS/electric drive is one of those models. The system will provide 78
megawatts of power to produce electricity for propulsion and all of the
ship’s systems, including advanced sensors and weapons.
Though significant technological and funding challenges remain, additional
available electrical power in the DD(X) design has already made it possible
for the Navy to embrace and re-invigorate its programs for advanced weapon
and sensor technologies.
As Collins put it: “If you back off on how much electric power
you have on board [new ship designs], then you are almost backing away
from the future.”