Aluminum has been an integral part of shipbuilding for more
than a century. Its structural strength and light weight make
it ideal for replacing steel in ships' superstructures.
In a century's time, the average weight of ships has more
than doubled, making the use of aluminum attractive to
shipbuilders despite the cost of the metal, which can run as
much as four times the cost of low-carbon steel. Now aluminum
might be coming into its own as a material of choice for a new
generation of U.S. Navy vessels designed to protect American
interests around the world.
At roughly one-third the weight of steel, aluminum has long
been used for the construction of lifeboats, motor launches,
patrol boats, yachts, cabin cruisers and search-and-rescue
vessels. Aluminum also has come into its own in the past
quarter-century in the cruise ship industry, used for such
structures as deckhouses, hatch covers, ladders, gangways,
stack enclosures, bulkheads, fuel tanks, lifesaving equipment
and deck plates.
With contemporary cruise ships exceeding 100,000 tons in
gross weight, more than twice the weight of the White Star
Line's RMS Titanic more than a century ago, naval
architects and shipbuilders have turned to aluminum as a
suitable replacement for steel without sacrificing strength.
The faster a vessel and the more weight it can carry translates
into a quicker return on investment, which has become one of
the main selling points for the use of aluminum in shipbuilding
in the 21st Century.
Less weight also means more speed. In 1895, a Scottish
shipyard built a 190-foot-long aluminum gunboat for the
Imperial Russian Navy that boasted a then-record speed of 32
knots. Later that year, the aluminum yacht Defender
won the America's Cup. In more recent years, Australia, with
thousands of miles of coastline, has pioneered the use of
aluminum for high-speed ferries. The country has built as many
as 85 fast ferries for use both in Australia and New Zealand
and for export to Europe, North and South America and the
In 1990, the shipyard of Australia's Incat Tasmania Pty Ltd.
built the first all-aluminum fast ferry, a 242-foot catamaran
with a speed of 39 knots. By 2010, Incat Tasmania was producing
365-foot fast ferries made of marine-grade aluminum that can
carry as many as 1,000 passengers and more than 300 vehicles at
speeds up to 40 knots. In the early 21st Century, Incat
Tasmania began successfully bidding for aluminum transport
vessels for both the U.S. Army and the U.S. Navy. Dubbed "wave
piercers" by the media, the transport vessels are typically
designed atop an aluminum catamaran hull and can deliver as
many as 350 combat troops at a time, plus their equipment, at
more than 40 knots.
In 2005, Austal Ltd.'s Benchijigua Express emerged
as the world's largest aluminum vessel. The 417-foot ferry
employed in the Canary Islands on the Tenerife to Gomera and
Palma run can haul nearly 1,300 passengers and more than 340
vehicles at speeds of 40 knots.
Speed, strength and weight were all considerations when the
U.S. Navy awarded bids in December for 20 Littoral Combat Ships
(LCS)-littoral refers to the shallow water between low and high
tide-capable of operating in shallow coastal waters. The first
of a total of 55 LCS are expected to enter service between 2012
In what might be a first, the Navy split the initial
contract between two shipbuilders. Lockheed Martin Corp.,
Bethesda, Md., in partnership with Italian shipbuilder
Fincantieri Cantieri Navali Italiani SpA, will build 10
conventional steel mono-hull vessels at Bay Shipbuilding in
Marinette, Wis., on Lake Michigan, while the other 10 will be
built by Austal at its shipyards in Mobile, Ala. The Australian
shipbuilder will build an aluminum trimaran LCS that one
observer likened to a Klingon warship from Star Trek. The
orders for the two vessels will provide thousands of jobs each
in northern Wisconsin and coastal Alabama.
The hull and superstructure of the Austal version of the LCS
will be marine-grade aluminum, while the superstructure of the
Lockheed-Fincantieri version also will be marine-grade
The LCS, able to operate in water as shallow as 20 feet,
will be designed for interdicting everything from Somali
pirates to Caribbean drug runners and North Korean patrol
boats. Armed with 2-inch guns and short-range missiles, the
417-foot LCS is designed to operate at speeds of up to 50
knots, more than enough to chase down almost anything afloat
anywhere in the world.
Critics, including Sen. John McCain (R., Ariz.), question
why the Navy has obligated itself to two competing versions of
the LCS. But the Navy counters that the competitive nature of
the contract will allow it to save as much as $100 million on
the cost of building each of the $600-million vessels. The Navy
also says it will use the two designs to determine which will
win the final contract for the rest of the 55-vessel fleet.