The special night-driving equipment which is fitted to German vehicles was designed by
the Nova-Technik G.M.B.H. of Munich in collaboration with the Army Mechanization Experimental
Department, Wuensdorf, before the outbreak of war. The equipment consists of the following parts:
(a) The black-out headlamp mounted on the left-hand side of the vehicle between 32" and 48" from the ground.
(b) The special interval-judging rear light and stop light, carried on the left-hand side of the vehicle.
(c) The additional rear light, fitted with a dimming device, and carried on the left-hand side of the vehicle.
(d) The additional rear light, fitted with a dimming device, carried on the right-hand side of the vehicle.
(e) A three-stage dimmer switch is installed.
The Head-Lamp is of a peculiar flattened shape, and makes use of a horizontal 35-watt lamp
emitting light rearwards against a semi-oval mirror. This mirror in turn reflects the light back
through a glass diffusion-panel under the over-hanging hood. A soft, almost flat-topped beam of
light results. The beam is projected for a length of 30-40 meters and a width of about 25 meters
and is particularly diffused towards the edges.
It is claimed that the beam from the head-lamp is invisible when on "low," from heights
exceeding 500 meters, when on "medium" above 800 meters, and when on "full" above 1500 meters. The
same distances also apply to ground observation, horizontally.
It should be noted that the vehicle's normal sidelights are also kept on in order to mark
clearly the breadth of the vehicle, but they are masked very thoroughly so that their light
is not visible beyond 500 meters.
The headlamp of the leading vehicle is switched down to the lowest possible switch position
compatible with the darkness of the night and the danger of observation. The rule is that the
darker the night, the less is the light to be used.
In convoys only the leading vehicle will normally use its blackout headlamp, and all the remaining
vehicles will switch to the H position (see above), using the interval-judging
panel to keep station.
It is possible that drivers are trained to follow a convoy with the switch in H position
and without sidelights, in which case each fifth vehicle would have its headlamp switched on.
It is emphasized that care is to be taken when negotiating gradients at night, as ground
observers may obtain a glimpse of the light source when the vehicle is climbing a hill or
just descending into a valley. The headlamp should be switched off when it begins to illuminate
the crest of a rise.
(Issue No. 43, G.S.I., G.H.Q., Middle East, Technical Intelligence Summary.)