TYPE D TRAFFIC SIGNALS
The Type D signal was introduced sometime around
1936. This signal design was considered a new design
keeping with the trend of modern design. The four
illustrations on this page show the artistic lines of the
signal. The straight line motif is carried out in the entire
signal. Hinges and catches are concealed, and as a result,
the signal presents an excellent appearance when viewed
from any angle.

The casing, door and hood are made of a special silicon
aluminum alloy, cast in steel dies under tons of pressure.
Such construction insures a uniform and homogeneous
casting of great strength, capable of resisting corrosive
atmospheres, including salt air. Castings are extremely
accurate and all joints fit to a few thousands of an inch.
Similar parts are interchangeable on all signals.

The bodies of the type D signal are of unit, sectional
construction-an individual body casting being used for
each optical system. These individual body sections are
clamped between ornamental end plates by means of
two 3/8" through bolts, thus insuring a rigid, compact
casing which is dust and watertight. Signals of one, two,
three, four or five sections may be built up as desired.

This unit construction, with complete interchangeability
of parts, was of great benefit to cities using any quantity
of signals, since any desired combination and
arrangement of signal bodies can be made up locally. In
case of damage, there is considerably more salvage with
this unit, of sectional construction, than with any other
type. Door and hood are cast in one piece, which saves
assembly on the job. Doors with separate hoods of sheet
aluminum could have been furnished on special order.

After assembly, the complete body is finished with two
coats of baked enamel, thus affording additional
protection against the weather.
Click on a link below to view more information on a particular model.