A number-one product found on 1 in every 2.5 ships
The shipbuilding industry is concentrated in East Asia, with Japan, South Korea, and China together holding an 80% share of the world market. Many of the major engine manufacturers are also located in these three countries.
Kobe Steel estimates that its crankshafts account for about 40% of the world market in terms of units sold. This means that the main engines of one in every 2.5 middle-sized to large vessels with displacements from 10,000 to 20,000 tons or more use Kobe Steel's crankshafts. Kobelco's built-up crankshafts with cast steel crank throws have become a well-established brand.
A large crankshaft weighs as much as 380 tons. The crankshaft rotates in the ship engine room.
What crankshafts do
Much like a bicycle wheel rotates by pedaling, a
crankshaft's basic role is to convert piston movement into rotary
movement. Imagine a straight wire, bent back and forth several times.
This is what a crankshaft looks like. It is difficult to turn the
end of this wire smoothly by rotating it from one end.
A crankshaft may appear to be just an ordinary machinery component
at first glance, but it isn't easy to actually produce one. Many hurdles
must be overcome to produce fine quality crankshafts.
Kobe Steel's crankshafts are used in large diesel engines for ocean-going
ships and land-based generators. These big crankshafts can be as long
as 24 meters and weigh as much as 380 tons. As can be seen in the
picture below, crankshafts are directly connected to propellers. In
order to move ships with a displacement of tens of thousands of tons,
a few hundred tons of steel rotate at a speed over 100 rpm. This means
crankshafts must be processed to a high degree of accuracy and must
be exceptionally strong.
Piston movement in the engine is converted
into rotary movement by the crankshaft, which is directly connected
to the propeller.
The shipbuilding boom
Owing to the rapidly growing Chinese economy, the
shipbuilding industry is booming. High demand is outpacing supply.
There are three Japanese, two Korean, and two European manufacturers
of built-up crankshafts. Increasing their production facilities, Korean
manufacturers are gaining ground.
Meeting user needs
Kobe Steel has the top market share for large built-up
crankshafts. High quality is not the only reason why the KOBELCO brand
has earned the trust of the shipbuilding and diesel engine industries
all over the world.
Large crankshafts are manufactured at our Steel Casting and Forging
Plant in Takasago Works. Using advanced equipment and technologies,
as well as enhanced fabrication and processing lines, Kobe Steel is
capable of responding to wide fluctuations in demand. Marketing activities
both at home and abroad are also a big advantage in maintaining our
lead.
Cooperating with licensers
Diesel engine design does not end with the engine
manufacturers. Design companies, or licensers, of which there are
only three in the world, offer basic engine designs to manufacturers,
but the engines are not just manufactured as is. Kobe Steel works
in close cooperation with the engine manufacturers and licensers,
making proposals both in design and materials.
Looking ahead
Along with continuous development for more powerful
and compact diesel engines, crankshafts will increasingly need to
be made stronger. Kobe Steel is eagerly seeking the broader utilization
of new high-strength cast steel crank throw materials. We are also
actively pursuing further development in materials and design for
crankshaft applications.
The Kobe Steel Group is a global enterprise with businesses in metals, machinery, natural resources and engineering, construction machinery, and environmental solutions.
Iron and Steel Sector
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