German vehicles have special night-driving equipment
which compares favorably with that used by the
United Nations. The equipment includes the following:
a. Blackout Headlights
The headlight is mounted on the left-hand side of
the vehicle, about 3 to 4 feet from the ground. The
headlight-opening for passage of light is flat-shaped. A
35-watt bulb gives off light to the rear, against a
mirror which is half oval in shape. The mirror, in
turn, reflects the light forward through a glass panel
under the overhanging hood. The glass panel spreads
the light, which extends to the front a distance of 100
to 130 feet. The longest width of the light is about
80 feet. The light rays are scattered more on the sides
than in the middle.
The headlight will burn at three stages of brightness. A
three-stage switch will turn it on "dim," "medium,"
or "full." The Germans claim that at heights of over
2,000 feet the light cannot be seen while it is on "dim."
It is further claimed that it cannot be seen on "medium"
at heights of 3,400 feet or more, and while on
"full" it is not visible above 6,400 feet.
While in movement, the headlight of the leading
vehicle is turned on at the lowest possible stage to
permit travel. As a rule, the darker the night, the less
light needed. The danger of observation also is taken
into account in deciding the amount of light to turn on.
b. Interval-Judging Rear Light and Stop Lights
The panel containing the lights is divided into two
parts, the upper half and the lower half. The upper
half includes the interval-judging device itself, while
the lower half contains the usual red tail-light and a
yellow "stop" light, which goes on when the brakes
are put on. The interval-judging device has four
small windows, rectangular in shape and grouped in
pairs. When the device is working, a yellowish green
light shines through the windows.
The use of the interval-judging device is based on
the way the human eye sees lights at different
distances. When viewed from a certain distance, lights
close to each other appear to be just one light. For
instance, at 325 yards the lights shining through the
four rectangular openings in the interval-judging
device will seem to be only one light. At 35 to 40 yards,
the four lights look like two, and at about 25 to 30 yards
all four may be seen. In a convoy all drivers
except the first one keep an interval so that two of
the lights are always visible. In other words, they
maintain a distance of 35 to 40 yards.
On the under side of the housing which contains
the interval-judging device is a shutter, which, when
open, allows a dim light to shine down on the vehicle's
c. Additional Rear Lights
One is on the left side of the vehicle and the other
is on the right. German regulations require this
arrangement of rear lights to indicate the width of the
vehicle's rear as well as its front. Each of these side
rear lights has two windows, one above the other. The
upper one shows a dim light and the lower one
a normal light. A shutter is provided to shut out
either of the lights so that only one can show at a time.
2. USE DURING CONVOYS
Only the leading vehicle will normally use its
black-out headlight when convoys are close to opposing
forces. All the other vehicles will have only the
interval-judging rear light on. It cannot be seen from
the air, and cannot be seen on the ground at distances
of more than 325 yards.