"Railroad Signals" is a PowerPoint for primary and secondary students. This presentation provides a history of train and railroad signaling, as well as highlights careers in the rail industry and transportation fields. Additionally, this lesson can be paired with an "Electrical Circuits" activity.
2. Used to prevent train collisions
Collisions are a major concern as trains travel
on fixed paths
A freight train travelling at 55 mph takes over a
mile to stop
A train will not be able to stop before hitting an
object after the engineer sees it
3. Early signals were flags
or lamps placed at a
predetermined
stopping distance from
an obstacle
Used before stations
and draw bridges
Only other control
system was by
timetables
4. Began in the 1830s
Balls of different
colors and shapes
were raised and
lowered to show
“Safety” or
“Danger”
5. Began in the
1840s
Several designs
Different shapes
or colors
described
specific
situations
6. Tracks divided into sections known as “blocks”
Used to space trains far enough apart so they
could not collide
Signalmen were stationed at the beginning of
each block and changed the signal
Signalmen sent telegraphs to confirm when
trains passed
Widely used after 1850
7. Often used to tell an
engineer they need to stop
and receive a telegraph
Common in 1870s
Downside was colors were
not standardized
Originally white used
instead of green as green
was difficult to produce
8. Allowed automatic signal
operation from long distances
Created closed-circuit tracks
by using the rails as
conductors
Original idea in 1872, but at
the time was not able to
power a signal
9. Previous signals hard to distinguish from long
distances and only able to be seen during day
Position signals
introduced in
1920s
Red, yellow
and green
lights added in
1950s
10. Electrical currents in
tracks determines if
block is occupied
Block lengths may be
variable and computer-
generated
Signal is green if next
two blocks are
unoccupied
Yellow if second is
occupied
Red if next is occupied
11. •Salary: $51,000 - $61,000
•Education: Bachelor’s
•Experience: 0-2 years
Civil Engineer
•Salary: $56,000 - $65,000
•Education: Bachelor’s
•Experience: 0-2 years
Electrical
Engineer
•Salary: $50,000 - $57,000
•Education: Bachelor’s
•Experience: 4 years
Geotechnical
Engineer
•Salary: $30,000 - $39,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Welder
•Salary: $26,000 - $34,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Heavy Assembler
12. Designs and supervises construction projects
such as airports, bridges, channels, dams,
railroads and roads
Responsibilities also include estimating costs
and personnel and material needs, preparing
proposals and establishing completion dates
13. •Salary: $51,000 - $61,000
•Education: Bachelor’s
•Experience: 0-2 years
Civil Engineer
•Salary: $56,000 - $65,000
•Education: Bachelor’s
•Experience: 0-2 years
Electrical
Engineer
•Salary: $50,000 - $57,000
•Education: Bachelor’s
•Experience: 4 years
Geotechnical
Engineer
•Salary: $30,000 - $39,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Welder
•Salary: $26,000 - $34,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Heavy Assembler
14. Designs, tests, installs and maintains large-
scale electronic equipment or machinery for
use in manufacturing or power generation or
transmission
May use computer-assisted engineering and
design software and equipment to perform
assignments
15. •Salary: $51,000 - $61,000
•Education: Bachelor’s
•Experience: 0-2 years
Civil Engineer
•Salary: $56,000 - $65,000
•Education: Bachelor’s
•Experience: 0-2 years
Electrical
Engineer
•Salary: $50,000 - $57,000
•Education: Bachelor’s
•Experience: 4 years
Geotechnical
Engineer
•Salary: $30,000 - $39,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Welder
•Salary: $26,000 - $34,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Heavy Assembler
16. Prepares and inspects projects involving
drilling and exploration
Responsible for geological mapping, report
writing, site characterization, numerical
modeling and analysis of excavations/supports
17. •Salary: $51,000 - $61,000
•Education: Bachelor’s
•Experience: 0-2 years
Civil Engineer
•Salary: $56,000 - $65,000
•Education: Bachelor’s
•Experience: 0-2 years
Electrical
Engineer
•Salary: $50,000 - $57,000
•Education: Bachelor’s
•Experience: 4 years
Geotechnical
Engineer
•Salary: $30,000 - $39,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Welder
•Salary: $26,000 - $34,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Heavy Assembler
18. Joins, fabricates and repairs metal and other
weldable material by applying appropriate
welding techniques
Interprets blueprints, specifications, diagrams
or schematics to determine appropriate
welding process
Inspects completed welds to determine
structural soundness
19. •Salary: $51,000 - $61,000
•Education: Bachelor’s
•Experience: 0-2 years
Civil Engineer
•Salary: $56,000 - $65,000
•Education: Bachelor’s
•Experience: 0-2 years
Electrical
Engineer
•Salary: $50,000 - $57,000
•Education: Bachelor’s
•Experience: 4 years
Geotechnical
Engineer
•Salary: $30,000 - $39,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Welder
•Salary: $26,000 - $34,000
•Education: High School Diploma/G.E.D.
•Experience: 0-2 years
Heavy Assembler
20. Assembles fabricated parts to relatively large
or heavy subassemblies and complete units
Tests and calibrates parts and mechanisms to
meet tolerances and product specifications
21. Characteristics of electrical circuits
have a closed loop
have a full, circular path
Today’s activity is to build basic circuits with
batteries, switches and lights
There are two ways to wire lights:
Series – if one lights go out, both go out
Parallel – possible for one light to work while other
does not
One will give you brighter lights than the other
22. The green screw on the
light switch is a ground,
do not use this screw
Don’t attach both wires
to the same end of the
battery
Turn the switch to off
until you are done
wiring, it makes it
easier to see how bright
the lights are