Escort Duty Doctrine of Vice Admiral Henry B. Wilson, Commander, United States Naval Forces in France
Confran’s File 240
7 November 1917.
DOCTRINE FOR ESCORT DUTY
The primary mission of the escort is to insure the safe transit of convoy through the danger zone.
The secondary mission is to save life in the event of the sinking of a vessel, and to assist disabled vessels.
Vessels on this duty should be prepared –
(a) For offensive action against submarine with ram, gun and depth charges;
(b) To rescue crews of torpedoed vessels;
(c) To tow disabled vessels.
INITIATIVE OF ESCORT COMMANDER:
Because of unforeseen conditions which may be encountered, and of new information which may be received at any moment, the Escort Commander is given discretionary authority as to course to be steered, formation and disposition of escort and convoy.
This discretion will be used consistently with such instructions as may be given Commanding Officers from time to time.
Conferences attended by the Commanding Officers and Masters of escort and convoy shall be held before sailing, whenever practicable.
At these conferences there shall be thorough indoctrination as to hour of sailing, formation, speed, zigzags, signals, procedure in case of fog, darkening of vessels, procedure, in the event of submarine attack, and other relevant matters.
Signaling shall be reduced to a minimum consistent with imperative necessity.
All officers shall be impressed with the absolute necessity of completely darkening ships; of avoiding the use of night signals, and the restriction of the use of radio to low power, and to messages which are necessary.
Armed merchant vessels, except when the armed guard is commanded by a Naval Officer, should not use the guns at night when under escort, except to fire one shot when a submarine or torpedo wake is first seen.
The importance of water-tight integrity must be impressed on Masters. The bulkhead doors, except those absolutely necessary for the operation of the vessel, must be closed and sealed. Bunker doors must be kept habitually tightly closed, except for short periods, once in a watch, during which coal for the watch is gotten into the firerooms.
Get underway by prearranged instructions, without signals.
FORMATION OF CONVOY:
When in free route the depth of formation should be as small as is practicable. If convoy is of four or less vessels, form in line as soon as sea room permits. If more than four vessels, line or line of division, but the number of vessels in a division should not exceed the number of divisions. Vessels of less value shall, as a rule, be on the flanks.
FORMATION OF ESCORT:
This must depend on the strength of escort available. The position sought by the submarine will be forward of the beam of the target ship, distant not more than six hundred yards; therefore the protection of the flanks is of primary importance.
With three vessels in escort, deploy ahead and on both flanks. With four vessels in escort, deploy ahead, oh both flanks, and astern. Additional escort shall be employed as protection to flanks.
Flank guards shall be about eight hundred yards from the convoy, vanguard about one thousand yards, and rear guard well astern, to prevent trailing.
Zigzagging shall obtain whenever conditions of light are such that a vessel in convoy can plainly see the vessel on either beam. Escort vessels shall zigzag so as to give large changes of course at best speed, with due consideration to steaming radius; in the case of destroyers, this speed should be not less than fifteen knots. Escorts zigzagging independently of convoy.
The convoy, if steaming at eight knots or better, should zigzag according to orders, ships changing course simultaneously. If convoy is making less than eight knots, instead of zigzagging, the course should be altered every 1-1/2 or 2 hours by not less than two points.
When attacked by a submarine, make signals, blow whistle, and open fire on submarine if sighted, or in direction of submarine, if that be known. A portion of the escort nearest to the submarine remains in the vicinity of the position, uses depth charge and keep the submarine submerged until convoy is on the horizon, and then rejoins convoy.
In the meantime the convoy shall make radical change of course.
CONVOY SHIP TORPEDOED:
The two nearest escort vessels proceed to rescue – one to pick up survivors, the other circling about and acting as guard.
Westbound convoys will be dropped one hour after dark the third night after sailing. Before dropping convoy, give commander latest information and advice as to best course.
If sea becomes too rough for the escort to maintain speed of the convoy, inform convoy commander. The Senior U. S. Naval Officer Present shall then decide whether convoy will proceed at Full speed without escort, or slow down to speed of escort.
Senior Officer of Escort, upon completion of duty with convoy, will submit report giving number of ships in convoy, names of U.S. vessels, and the name of all escorting vessels, number of miles and number of hours that convoy was under escort, events of interest, difficulties encountered.
These reports should avoid statements of positions, routes or courses.
SUGGESTIONS AS TO DOCTRINE.
Suggestions for the development of a doctrine for escort and convoy shall be made after each escort returns to port, to the end that all experience gained by the operations of all the vessels of this force shall be available for use by each individual vessel.
Source Note: Cy, DNA, RG 45, Entry 517B.