In a letter of March 20, [14] Admiral Bloch replied, stating that the
depth of water at Pearl Harbor was 45 feet and for this reason among
others he did not recommend antitorpedo baffles. Admiral Kimmel was in
agreement with this recommendation until such time as a light efficient
net was developed. [15]
However, in June of 1941, the Chief of Naval Operations directed a
communication to the commandants of naval districts as follows: [16]
"1. * * * Commandants were requested to consider the employment of, and
to make recommendations concerning, antitorpedo baffles especially for
the protection of large and valuable units of the fleet in their
respective harbors and especially at the major fleet bases. In paragraph
3 were itemized certain limitations to consider in the use of A/T
baffles among which the following was stated:
" "A minimum depth of water of 75 feet may be assumed necessary to
successfully drop torpedoes from planes. About two hundred yards of
torpedo run is necessary before the exploding device is armed, but this
may be altered."
"2. Recent developments have shown that United States and British
torpedoes may be dropped from planes at heights of as much as three
hundred feet, and in some cases make initial dives of considerably less
than 75 feet, and make excellent runs. Hence, it may be stated that it
cannot be assumed that any capital ship or other valuable vessel is safe
when at anchor from this type of attack if surrounded by water at a
sufficient run to arm the torpedo.
"3. While no minimum depth of water in which naval vessels may be
anchored can arbitrarily be assumed as providing safety from torpedo-
plane attack, it may be assumed that depth of water will be one of the
factors considered by any attacking force, and an attack launched in
relatively deep water (10 fathoms [16a] or more) is much more likely.
"4. As a matter of information the torpedoes launched by the British at
Taranto were, in general, in thirteen to fifteen fathoms of water,
although several torpedoes may have been launched in eleven or twelve
fathoms. [17]"
Page 160 PEARL HARBOR ATTACK
[12] Committee exhibit No. 9. This comment was made by Admiral
Richardson pursuant to a letter from Admiral Stark dated November 22,
1940, in which the latter had stated, among other things: "Since the
Taranto incident my concern for the safety of the Fleet in Pearl Harbor,
already great, has become even greater. This concern has to do both with
possible activities on the part of the Japanese residents of Hawaii and
with the possibilities of attack coming from overseas. By far the most
profitable object of sudden attack in Hawaiian waters would be the Fleet
units based in that area. Without question the safety of the units is
paramount and imposes on the Commander-in-Chief and the forces afloat a
responsibility in which he must receive the complete support of
Commandant Fourteen, and of the Army. I realize most fully that you are
giving this problem comprehensive thought. My object in writing you is
to find out what steps the Navy Department and the War Department should
be taking to provide additional equipment and additional protective
measures."
Page maintained by Larry W. Jewell, lwjewell@omni.cc.purdue.edu. Created: 11/28/96 Updated: 11/29/96