Portland Branch Library
U. S. Dept, of Agriculture
UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
CAMOPFLAGE
for
FOREST SERVICE STRUCTURES
Part I
PAINTING
UG
449
G7G
v.l
Division of
Engineering
V. a. OOV*RNM*NT PHINTINO OPFIOa
8—7417
Univ. of Washington Libraries
For
FOREST SERVICE STRUCTURES
P&rt I
P A I N T I N 0
1942
Prepared by
W. Ellis Groben
Architect
T. W. Norcross, Chief
Division of Engineering
pacific roiTirv^r and
CAMOUFLAGE
For
FOREST SERVICE LOOKOUT TOWERS
Part I - Painting
Forest Service lookout towers are located
so as to function most efficiently in the prompt
detection of forest fires. The existing state of
war increases their usefulness beyond that of
normal peace times because they serve, 1) to spot
any fires deliberately set by dropping incendiary
bombs and, 2) as interceptor stations.
Of necessity they must occupy conspicuously
outstanding locations on mountain peaks and ridges
throughout the forested areas of the country. Un¬
less camouflaged, they are easily recognized from
the air because of their location and standardized
shape and construction. In two Regions the direct¬
ional numbers, which have been placed upon the cab
roofs as a guide for aviators, should be removed
promptly.
A few months ago any discussion of the sub¬
ject of camouflaging them would have appeared to
be premature or, perhaps, the result of undue
alarm. By being forehanded in this important
matter of maximum concealment in the contingency
of aerial attack, the Forest Service will be in a
practical position to protect and operate its
numerous lookout towers without interruption.
Hfhile not easily destroyed from the air nor
worthwhile targets for bombing on account of theia
small size, nevertheless, they serve as excellent
beacons to guide enemy planes during daylight, as
shown on the diagrammatic map herewith, Fig. 2.
Although, in this respect, their potential
value would be much less during darkness, especial¬
ly in obscure, hazy weather, yet in bright moon¬
light or starlight the sheen from the roof slopes
against which such light strikes is reflected with
sufficient clarity and shape definition to cause
them to function adequately as directional beacons,
unless concealed, Fig. 1.
Fig. 2. Fire Towers
as possible direc¬
tional guides, r (2)
-2-
Despite the fact that the enemy have accurate maps, photographs,
and other intelligence, visual identification of a target still remains
a necessity for effective bombing. Hence, a particular tower may be
the landmark for.releasing bombs on some target of military importance
or such vital civilian installations as power houses, railroad yards,
bridges, important highway intersections, adjacent to, or beyond it.
The rapid developments of today call for immediate action by
initiating a definite program to prevent lookout towers from being
utilized by the enemy for purposes of orientation. Let's not have it
said, "Too little and too late" in this instance.
Camouflage
Camouflage is deception based upon 1) painting, 2) screening
or garnishing, and 3) planting. Any concealment which tends to reduce
the visibility, deceive or confuse the identity, or completely hide an
outstanding landmark is of inestimable value as a measure of protection.
Painting, herein discussed, will be followed by subsequent releases on
the other phases of canouflage.
Painting, or "first stage" concealment, should be undertaken at
once to obliterate the conspicuous colors with which many of these
towers have been purposely painted in the past.
Lookout Towers
The variety of lookout towers on our national and State forests,
comprising those from about 30 to 120 feet in height and with either
7x7 foot or 14 x 14 foot cabs, and still others consisting of a single
small building at ground level in a high and isolated location, call
for different treatments which, nevertheless, fall within a limited
range of patterns.
Perfect camouflage is neither contemplated nor essential because
absolute conceealment is a difficult undertaking which, under varying
seasonal and climatic conditions, requires alteration from time to time.
It is recommended, therefore, that Forest Service lookout towers
be concealed only enough to create confusion and uncertainty concerning
them, thereby n JLlifying their use as directional guides to more impor¬
tant objectives.
Metal lookout towers and cabs,and especially the higher ones,
present our most troublesome problem of concealment. In addition to
suppressing their visibility by painting, other effective supplementary
means will be discussed in a subsequent release dealing with Screening
and Garnishing.
FIQ.3- TONIUG DOWM THE. LiqHT COLOTC
-3
Many towers are located amidst the trees which effectively con¬
ceal the lower portion. Only the cab is exposed to aerial observation,
attracting special attention when of a light color. Again, others have
creosoted, dark-colored wood supports surmounted with cabs painted in a
light conspicuous color. In both instances the cab only need be camou¬
flaged by painting; 1) toning the light color down, and 2) applying dull
drab colors to simulate the surrounding natural conditions of earth or
trees as the occasion demands. These instances, as well as where the
cabs and their roofs are already a dark color, require the minimum of
effort and labor for concealment.
First Stage or Toning Down
Painting cannot be depended upon always as the sole means of
concealment. It is, however, one of the most important first steps
in suppressing light colors, reflective aluminum-painted or metal sur¬
faces, and sharp contrasts. Where lookout towers have been painted in
this manner they should be toned down promptly with dull paint to
reduce visibility,' Fig. 3.
Glossy paint and varnish act according to the laws of specular
reflection under the effect of light. When applied on smooth surfaces
their reflective coefficient, under certain conditions, is equivalent
to that of a mirror.
Ordinary flat paint reflects less light than glossy paint. By
increasing the roughness of the surface the reflective qualities may
be reduced very decidedly, approaching the irregular, broken up, non¬
reflecting qualities of foliage and landscape. Therefore, by scattering
grit, consisting of particles of gravel, ground slag, or similar
material, not over 1/8 inch to insure adhesion, over freshly painted
roof surfaces, excellent effects in camouflage are assured.
Camouflage paint is not used as a preservative against deteri¬
oration - the purpose of ordinary exterior paint - and, consequently,
good quality paint is not essential. The paint should be a quality
to produce a dull matt finish; that is, to dry without gloss or re¬
flections, be cheap, easy to apply, have large coverage capacity, and
produce results with the application of one coat.
Roof surfaces require darker painting than walls because they
receive more direct sunlight. Also dark paint is more efficacious in
counteracting the reflecting powers of roof surfaces.
Second Stage or Disruptive Patterns
Existing tower roofs have been finished with wooden shingles,
canvas, and the metal towers with copper.
1. Aerial photograph of Lookout
tower site.
2. Diagrammatic tree top pattern
of area surrounding look-
oul Tower.
3. Blending camouflage pattern
on roof, with adjoining tree
top pattern.
4. Disruptive pattern simulating
foliage of tree tops for roof
itself.
PROGRESSIVE STUDIES OP A CAMOUFLAGE PAINT
DESiGNI TO SIMULATE ADJACENT FOREST COVER
FIG.4.
Shingles are usually stained a dark color and, often, variegated;
all of which is a great help. At most, a darker stain and disruptive
pattern treatment are all that is needed.
For canvas roofs, the disruptive pattern treatment and the paint
may be the same as that for wood. The following table illustrates why
darker colors are essential in camouflage.
{ -Reflecting Power
Color of canvas: Photographic Visual
White 56.0 64.8
Gray 17.5 20.1
Black 6.7 7.5
The copper roofs of the metal towers, when new, attract more
attention than any other sort of roofing, because of their reflective
power. Fortunately, they oxidize quickly so that the older ones may
have become irregularly corroded sufficiently with verdigris, a mottled
greenish gray rust, to require no further treatment.
The paint should not be applied uniformly because surfaces of
uniform color do not conform with natural surroundings. Disruptive
effects add confusion and aid concealment. In order to eradicate sloping
roof surfaces from aerial view as much as possible, any scheme of painting
should conform in a general way with the patterns of the natural sur¬
roundings, such as rocky, bare ground, or the forest cover, Fig. 4«
"Dazzle” painting of flat surfaces, as used in World War I, is
not as effective as simulating the shapes and patterns of the immediate
locale.*
Also the change of seasons is a consideration in the problem of
complete concealment. It is recognized that this difficulty cannot be
overcome without repainting several times a year. Therefore, dull
neutral, or drab colors, are the best compromise for all-year camouflage.
For this reason, it has been adopted by the Army in the painting of its
equipment.
The Darker colors, such as the greens, earth browns, olive or
field drab, and dark grays, without gloss to eliminate reflections and
thereby effectively reduce visibility from the air, may be had in stock
paints made for the special purpose of concealment by the manufacturers
of standard paint products.
Natural foliage registers white in infrared photographs because
of the chlorophyll in green leaves. On the contrary, evergreens, being
*The coloring of strips of cotton fabric will be given in the release
on Screening and Garnishing.
-5-
deficient in chlorophyll, are like artificial foliage or withered
natural foliage which lack infrared reflectance and register black
like ordinary commercial green paint.* Therefore, any disruptive
painted camouflage patterns used in connection with the painting
of buildings located in evergreen forests may be done with ordinary
paint instead of especially prepared infrared paint.
Painting of earth and grass
This phase of camouflage painting is of considerable importance
for air fields in connection with which it will be discussed in
Part III.
Imitation hedges, paths, roads, runways, and other ground patterns
may be painted upon grass or earth with emulsified asphalt, pigmented
or unpigmented depending upon color required, coldwater protein paint,
and iron sulphate and tannic acid. The latter is applied in two coats
and all may be sprayed applications. A list of paints has been given
on page 7.
Unpigmented bituminous emulsions and coldwater protein paint
must have dried from l/2 to 1-1/2 days before rain to prevent washing
away.
Painting concrete
For this information see Part III in connection with Highways
and Roads.
Sunshades
The retention of the double purpose wooden sunshades, or storm
enclosures for cabs when not in use, seriously handicaps aerial obser¬
vation where the towers function jointly as interceptor and fire de¬
tector stations.
Furthermore, in camouflaging lookout towers the removal of the
sunshades is very essential in order to simplify the problem by re¬
ducing the quantity of solid screening required, the labor of cutting
it to shape, and its painting and erection - with the resultant saving
in time and cost.
W. ELLIS GROBEN
Architect
May 15, 1942 U.S. Forest Service
*S'ee al'so PART' II - SCREENING 'ANITUaMISHBIG'
(Extract from. "Protective Concealment”, issued by U. S. Office of Civilian Defense.)
Type and specifications
Colors
available
Coverage
per unit
quantity
. 'Cost
per unit
quantity
Durability
(approxi¬
mate)
. Remarks
Oil paints#
Full range
Sq.ft.
200/gal.
i ,
1.00-2.00/gal.
1 year
Bituminous emulsions#
Dark colors only
(browns, reds,
greens;
200/gal.
.S5-1.60/gal.
1 year
Fibrated type should be
used on surfaces subject
to wear. Dilute with
water according to manu¬
facturers directions.
Lusterless enamel#
Full range
300/gal.
2.50-3.00/gal.
1 year
Emulsified resins #
Full range
300/gai.
1.00-2.00/gal.
1 year
Dilute with water according
to the directions of the A*
manufacturer *
Cold water proteins#
U.S, Army, Corps of
Engineers, T 1093 A
(paste or powder)
Full range
300/gai.
1.00-1.75/gai.
.10-.15/ib..
6 months
Includes any protein binder
Dilute with water according
to directions of manu¬
facturer. (Tinting colors
blue and deep green cost
about 6 times the prices
quoted.)
Oleo-resinous
Full range
300/gai.
1.50-2.50/gal.
1 year
Hydrocarbon thinner.
Adhesives
Bituminous emulsions*
Black
50/gai.
.20/gal.
1 year
For adhesive use this
material is not diluted.
Follow directions of manu¬
facturer as to proper in¬
terval between application
of the adhesive and the
granules.
Bituminous adhesive*
Black
36/gal.
.50/gal.
1 year
(Rejuvo - as made by Philip
Carey Co.. Cincinnati, 0.)
#ADnlied by brush or spray,
, ^Applied only by brush.
PAINT FOR EARTH AND GRASS
(Extract from ’’Protective Concealment”,issued by U. S. Office of Divilian Defense)
Type
Color
Mix
Coverage
Cost Durability
Sq.Ft.
Eituminous
emulsion, not
pigmented
Black
Dilute with water
per manufacturer’s
directions
20-30/gal. (earth)
O.llJ/ gal. 3 months
Emulsified
asphalt paint
pigmented
Dark colors
(browns, reds,
greens)
2 gals.paint plus
1 gal. water
50-150/gal.(earth)
100/gal. (grass)
•40-.90/gal. 3 months, if not
subject to wear
Coldwater
protein
paints
Full range
4 lbs. powder to
2/3 gal. water =
1 gal. mixture
50- 150/gal.(earth)
100/gal. (grass)
1.00/1.75/gal* 3 months (earth if
not subject to wear)
2 months (grass)
Iron sulfate
plus tannic
acid
Blue-black
(8 oz. iron sulphate + 72/lb. (grass)
(2 gals, water* )
( or )
(1 oz. tannic acid + 576/lb. )
(2 gals, water* earth)
.05/lb. (in
50-lb.lots) 3 months
♦Each mixture applied as a separate coat. Ground to be moistened slightly first to receive iron sulphate
solution followed by application of tannic acid solution, all sprayed.
T1TLEJIC
University of Washington Library
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