American World War II Submarine Operations

World War II American submarine doctrine, Part 2

Posted Tuesday October 24th, 2006

This is the second article in a series on World War II American submarine doctrine. It is based on a declassified official U.S. Navy publication.

Each installment in this series will feature a different section from each of the publication's five chapters.

This installment features the publication's transmittal sheet and the second section from chapter 1.

Current Doctrine
Submarines
USF 25(A)
Prepared By
COMMANDER SUBMARINE FORCE, PACIFIC FLEET
FEBRUARY, 1944

SUBMARINE FORCE, PACIFIC FLEET
[Formerly] CONFIDENTIAL

This publication, Submarine Force, Pacific Fleet, Bulletin 25, is issued for the use and guidance of Submarines, U.S. Fleet, and is effective upon receipt.

USF 25(A) is a [formerly] confidential [but now declassified,] non-registered publication.

IT IS FORBIDDEN TO MAKE EXTRACTS FROM, OR TO COPY THIS PUBLICATION WITHOUT SPECIFIC AUTHORITY FROM THE CHIEF OF NAVAL OPERATIONS, EXCEPT AS PROVIDED IN ARTICLE 516 OF THE CURRENT EDITION OF THE REGISTERED PUBLICATION MANUAL. [Unlimited distribution of this document is authorized since its declassification.]

This publication is assigned Class C stowage. It is not intended for use in aircraft and shall not be transported therein.

It shall be handled and transported by the method prescribed in U.S. Navy Regulations, 1920, and the Registered Publication Manual, except that no accounting is required.

C.A. LOCKWOOD, Jr.,
Vice Admiral, U.S. Navy,
Commander Submarine Force, Pacific Fleet

Current Doctrine Submarines (USF-25(A))
Chapter I
Section 2
Doctrine for the Operations of the Individual Submarine

1201.   The primary objectives of submarines are enemy ships.

1202.   The primary weapon of the submarine is the torpedo; the secondary weapons are the mine and gun.

1203.   The ability of the submarine to deliver an attack successfully depends on remaining unseen and unheard until the attack is completed.

1204.   Having started an attack, deliver it as soon as a satisfactory firing position is reached. Waiting for an improved firing position almost invariably jeopardizes the satisfactory position already attained and increases chances of detection.

1205.   Attacks should be carried to as close a range as possible to insure hitting, keeping in mind arming distance of torpedo exploders.

1206.   The number of torpedoes fired should be sufficient to insure destruction or crippling of the enemy. (see paragraph 4614).

1207.   On attacks at short range a torpedo spread should be used to cover at least 80% of the target length.

1208.   Should a submarine be unable to reach a close firing position, the torpedoes should be spread so that the target cannot avoid all of them. This principle also applies to sound attacks.

1209.   In using multiple-speed torpedoes, the highest power setting that will insure the torpedoes reaching the target, should be used.

1210.   Empty tubes should be reloaded immediately if the noise made in reloading is unlikely to draw immediate counter attacks.

1211.   With radar operating, a submarine on the surface can usually detect enemy aircraft in sufficient time to dive to a safe depth. In clear water, in vicinity of the enemy, a submerged submarine must be particularly careful of periscope exposures, and running too shallow between periscope exposures.

1212.

(a) The basic defense of the submarine against aircraft lies in quick and deep submergence followed by evading action.

(b) Against surface craft, quick submergence plus information gained of enemy action from periscope observations and sound are basic for evasion if the contact is at close range. Silent running should be employed.

(c) At night, and in some conditions of low visibility when the contact is not at close range, evasion may be accomplished most successfully by use of high surface speed and evasive tactics.

1213.   With alert personnel and radars in operation submarines on the surface in reduced visibility are not subject to surprise attack.

1214.   Submarines are in diving trim and ready to dive immediately at all times when at sea.

1215.   Periscopes and periscope antennas should be exposed only at relatively slow speeds. After reducing speed, sufficient time should be allowed to permit the vessel to lose headway. This is one of the most important points in connection with the prevention of detection.

1216.   The handling of the submarine by section watches, during surface and submerged operations, is standard practice.

1217.   Vessels should take every opportunity to run "silent" at slow speeds. Development of sound apparatus will make such silent operations more and more essential in war.

1218.   Batteries and air banks should be kept as fully charged as operations will allow.

1219.   The necessity for efficient lookouts cannot be over-emphasized.

1220.   In rough weather, diving is facilitated by having the seam on the beam or slightly abaft the beam.

1221.   Before coming to periscope depth after running deep:

(a)  Thoroughly listen through 360° for external sounds.

(b)  Bring the submarine up smartly to periscope depth and quickly observe through 360° in low power.

(c)  If all is clear, follow this by a slower and more careful 360° search in high power.

In coming to periscope depth, control should be such as to permit immediate return to deep submergence.

1222.   While cruising on the surface in daylight, the highest periscope should be manned, as an additional lookout station.

1223.   Close at high speed to insure getting good firing position; at the same time, bear in mind possibility of sight and sound detection.

1224.   If possible, choose the firing side according to sun and weather conditions, but do not delay getting in on this account.

1225.   If water is clear and air screen is present or suspected, go deep between periscope exposures to avoid aircraft detection. This precaution is particularly important for vessels painted with the light camouflage paint. When the surface is choppy or in certain unclear northern waters this is probably unnecessary.

1226.   Time between exposures depends on visibility, speed of enemy, and expected air and screen surface ship menace. Learn to rely on sound gear and reduce number of exposures.

1227.   Get tubes ready for firing in plenty of time to avoid a last minute delay, but keep in mind the possibility of flooding torpedo afterbody.

1228.   Always parallel periscope data with sound data. It may be necessary to go deep for firing. Keep proper setup on angle solver for use in case of failure of T.D.C.

1229.   Firing bubbles must be avoided by efficient use of poppet valves. Too much, rather than too little, water should be allowed to enter the submarine.

1230.   Regarding the safe depth at which to fire torpedoes, see paragraph 1134.

1231.   Attention is directed to the following pertinent articles of F.T.P. 183, 188, and 143, which concern the employment of submarines:

F.T.P. 143, Articles 414(f), 825(b), 10142-10146, 1231-1233, 12129-12137, 12150-12154, 12209-12212, 12253, 12268, 12283, 12306, 12321, and 1254.

F.T.P. 183, Article 133.

F.T.P. 188, Chapter VI, Articles 1112, 1141, 1313, and the parts of the following applicable to submarine employment: Chapter VIII, Chapter IX, pages 9-1 to 9-27, Articles 1154-1159, 1323-1330, Chapter XIV and Chapter XV.