Ship Camouflage Instructions
United States Navy
Ships - 2
Bureau of Ships
January 1941

 

Chapter 4
Experimental Background

 

Results of Surface Ship Experiments.

Investigation of many aspects of surface ship camouflage initiated in 1935 by the bureau of Construction and Repair and continued since that time is described in References 1 and 2.  

Reference 1

Naval Research Laboratory Report H-1585, January 12, 1940, "Naval Camouflage, Tests at Sea June to September, 1939," and references therein.

Reference 2

Comdesbatfor Conf. Ltr. to BuShips 25 October 1940, S19-Ser. 4888, "Camouflage of Destroyers - Low Visibility Paint."

The references summarized the results of long continued tests  at sea on low visibility painting, graded painting,  dazzle painting, and various miscellaneous experiments.  In the matter of low visibility colors it was established that no one color was the best under all conditions of weather and illumination and that any color finally selected would be a compromise.  The observed facts are summarized in Table 1; the notes appended to Table 1 bring out certain facts which are readily reduced to tabulation.  Other conclusions reached were,

  1. that graded painting produced some range deception,
  2. that a painted bow wave produced some speed deception,
  3. that bold dazzle camouflage was undesirable because of enhanced visibility,
  4. that unobtrusive dazzle camouflage yielded some deception without too great enhancement of visibility, but was limited in its application. 

Visibility of Wakes.

When a ship has been painted to achieve low visibility, the visibility of the wake becomes important.  In the case of destroyers making speeds above 20 knots the wakes are so apparent that little advantage can be had from camouflage (see note 6, Table 1).  In the case of other types of ships, the speed at which visibility of the wake becomes of paramount importance is not known.

Discussion of Measure 1.

The Dark Gray System of Measure 1 is the system which appears to offer the best compromise color for low visibility under various conditions of weather and illumination.  This came about in the following way:

In the experiments of Reference 1, ships painted Light Gray, Ocean Gray, Dark Green and Black were observed, the results being summarized in Table 1.  In view of the fact that a black color increased the visibility of the ship as an object to a surface observer, although it possessed desirable features of a low visibility to aerial observers and of range and course deception, Reference 1 suggested that the Dark Gray 5-D might be the best compromise low visibility color for combat ships.

Further experiments during Fleet Problem Twenty-One with destroyers painted Light Gray and Black, described in Reference 2, verified a number of the conclusions of Table 1 and recommended that all destroyers attached to Destroyers, Battle Force, be painted Dark Gray.

This Dark Gray System, Measure 1, which is the most important measure of Chapter 2 is a system which has never been tested.  It must be kept in mind that THE EFFECTIVENESS OF THE DARK GRAY SYSTEM IS NOT KNOWN.

Reference 1 states, "Laboratory tests show the in the dark under searchlight illumination the Dark Gray color is distinctly more visible than black, but whether the difference is important can only be determined by tests at sea."

It is important to remark that a pure intense blue color possesses desirable low visibility features perhaps to a greater extant than those of Dark Gray.  The reasons for the low visibility of a vivid blue color are fully described in Reference 1.  However, attempts to prepare a stable ultramarine blue paint which does not fade have been unsuccessful, and, therefore, tests of the color on a ship have not been made.

Discussion of Measures 2, 3 and 4.

By consulting References 1 and 2 and Table 1, it will be found that the Graded System, the Light Gray System and the Black System of Measures 2, 3 and 4, Chapter 2, respectively, have been tested.  Therefore, the effectiveness of these measures can be said to be known from direct experiment.

Discussion of Measure 5.

As described in a reference cited in Reference1 the painted bow wave of Measure 5, Chapter 2, was tested only once on a destroyer in 1935.  The bow wave designs of Plates 4, 5, 6, 7 and 8 have not been tested and their effectiveness is not known.

Table 1
Color for Low Visibility

Position of
Observer

Conditions

Color for Lowest 
Visibility

Day Night Weather, Illumination, etc. Vertical
Surfaces
Horizontal
Surfaces
On Surface Day   Clear sky, sunny, no haze. Ocean Gray Usually not seen
  Day   Cloudy sky, no sun, no haze. Light Gray  
  Day   Haze or fog. Light Gray  
  Day   Black smoke screen. Dark Colors  
  Day   White smoke screen. Light Colors  
    Night Natural illumination, stars or clounds,
no moon.
Black  
    Night Clear sky, moon behind observer. Black  
    Night Moonlight diffused through clouds Ocean Gray  
    Night Searchlight illumination from observing
ship, or from behind observer.
Black  
    Night Far side of target from observer illuminated
by searchlight, flare, or star shell.
Target in silhouette
all colors alike.
 
In the Air Day   All conditions of weather and illumination. Black Black
    Night All conditions of weather and illumination. Black Black

Notes on Table 1

Note 1. In silhouette against the sun, moon, searchlight or other source of light all colors look alike and camouflage is of no effect.
Note 2. No color affects appreciably the accuracy of stereo-ranges.
Note 3. Gloss is objectionable in any color.  It is most apparent on stacks and gunshields.
Note 4. Dark Green is almost the same as Black but not quite as satisfactory.
Note 5. In the daytime black ships are visible at long ranges as objects but target angles and ranges, because of indistinctness of shadows, are much more difficult to determine than with lighter paints.
Note 6. When observed from the air at distances 1 to 8 miles, altitudes 1000 to 2000 feet, the black ships of DIVISION FOUR were not visible over two or three miles, while the Light Gray were visible at all distances.  The Black ships were less visible than the Green.  Sun glints and light spots aided in locating the destroyers.  The visibility of the dark ships was 1/3 to 1/4 that of a Light Gray ship.
Note 7. All surfaces visible from the air should be black or a color approaching black.  These include canvas of all kinds.
Note 8. Exposed life ring buoys should be the same color as the surrounding surfaces.

 

Note 9. Black masts and similar high structures are very revealing when they alone protrude above the horizon.  The Light Gray color is believed to be the best for them.
Note 10. At Speeds above 12 knots the white wake of a destroyer becomes important.  At night and from aircraft at any time when destroyers are making speeds above 20 knots and above the wakes are so apparent that little advantage can be had from camouflage.  At night under searchlight high speed wake is clearly visible and readily discloses the presence of a destroyer regardless of painting.

Back Page ] Table of Contents ] Next Page ]