TRACTOR STANDARDS THAT PROMOTE SAFETY
David W. Smith, Extension Safety Program
Can you imagine a world with no manufacturing
standards for the control and operation of
automobiles? What if the accelerator in one model
was controlled by the left foot, while in another
model the accelerator was controlled by the right
foot? What if every manufacturer had their own
color coding and symbols for turn signals or for
shifting gears? Not only would drivers need to read
the user manual for each vehicle, but every driver
and passenger would be subject to a higher degree
risk while on the road. Standard vehicle controls
make it easier for us to drive, making everyone on
the road safer. This also holds true in tractor
operation.
Farm tractors have evolved from a relatively simple,
stationary engine that provided power to pulleys
and shafts, to a highly-mobile, highly-sophisticated
power and transport machine capable of pushing,
pulling, and lifting attached implements, providing
power through mechanical and hydraulic energy to
perform almost all farm tasks. If you have ever tried
to operate an old tractor with missing decals, no
color coding, and unfamiliar control levers, you can
appreciate the tractor industry’s efforts in
developing standards for uniform and safe tractor
operation. This fact sheet will discuss the current
standards for color coding, operation of controls,
and graphic symbols for tractor operation.
COLOR CODING
Responding to the need for a standardization of
tractor controls, the Farm and Industrial Equipment
Institute proposed using color codes to represent
common functions of tractor operation. In February
1984, the Power and Machinery Division Standards
Committee of the American Society of Agricultural
Engineers (ASAE) approved and adopted the color
code system.
ASAE EP443.1 FEB 04 – Color Coding Hand
Controls defines a voluntary system of color coding
hand controls which will aid in identification by
operators. Hand controls include, but are not
limited to, levers, switches, knobs, handles, and
buttons, which the tractor operator manipulates to
activate or control machinery functions. Following
is a summary of this standard.
RED – Indicate single-function engine stop
controls. Where key switches, ignition switches or
hand throttles are used to stop the engines, the “off”
or “stop” positions will be indicated with red lettering
and/or symbols.
ORANGE – Designates machine ground
motion controls, such as engine speed controls,
transmission controls, parking brakes or park-locks,
and independent emergency brakes.
Where the engine speed and engine stop controls
are one, the controls may be red.
Steering wheels or other steering controls may be
black or any other color than red or yellow.
YELLOW – Indicates function controls
which involve the engagement of mechanisms such
as power take-offs (PTOs).
Yellow is also used to designate controls on other
farm machinery that operate separators,
cutterheads, feed rolls, picking units, elevators,
spray pumps, winches, and unloading augers.
