Metals in Planes and Trains
The U.S. currently has a 233,000 mile
network of railroad tracks. Trains are
mostly built out of a variety of steel
alloys, but they also use many other
• Body panels are of ten made of
• The wiring is made from copper.
•Bushings or bearings are sometimes
made of brass.
• Railway tracks were originally made
from wood, but today they are made of
iron or steel. In particular, high-carbon
steel is extremely durable.
Early airplanes that flew during World
War I were made from wood covered
in canvas. Planes today are usually a
mix of composites such as carbon fiber,
and aluminum alloys, titanium alloys
and steel provide the structure itself.
The airplane structure has to be strong
enough to sustain the force of its own
An airplane must also be strong enough
to deal with the force from lifting,
dragging, and twisting as the airplane
flies. The strength is in metal spars
covered by a thin metal outer skin. The
wings of an airplane are large, but they
are also light. The metal skin on an
airplane does more than make the wing
stiffer and stronger; it also forces air to
flow aerodynamically around the plane,
directing the air flow until it pushes up
on the wings with enough force to lift
the plane off the ground and into the air.
Landing gear must be extremely strong
and durable, and are built from high-
strength alloys of aluminum, titanium,