Last Updated：2022/12/24
One of the first standard types of automated visual grade-crossing warning was the automated flagman, a signal commonly known as a wigwag.
According to Santa Fe documents, the wigwag was adopted as a standard crossing device by the American Railway Association in 1923. A standard wigwag is actuated by a track circuit and consists of a paddle with a red lamp that gracefully swings back and forth in a horizontal pattern when a train approaches. A wigwag is usually accompanied by a bell.
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One
of
the
first
standard
types
of
automated
visual
grade-crossing
warning
was
the
automated
flagman,
a
signal
commonly
known
as
a
"wigwag."
According
to
Santa
Fe
documents,
the
wigwag
was
adopted
as
a
standard
crossing
device
by
the
American
Railway
Association
in
1923.
A
standard
wigwag
is
actuated
by
a
track
circuit
and
consists
of
a
paddle
with
a
red
lamp
that
gracefully
swings
back
and
forth
in
a
horizontal
pattern
when
a
train
approaches.
A
wigwag
is
usually
accompanied
by
a
bell.
