Commander Alfred G. Howe, Commander, U.S. Destroyer Conner, to Rear Admiral Henry B. Wilson, Commander, United States Naval Forces in France
U. S. S. CONNER,
September 16, 1918.
From: Commander A. G. Howe, U. S. Navy.
To : Commander U. S. Naval Forces in France.
Subject: Formation of Two-Vessel, High-Speed Convoy.
Enclosures: Two diagrams, I and II.
1. The recent torpedoing of the U. S. S. Mount Vernon leads me to believe that there should be a reconsideration of the apparently established doctrine that line formation should be used at all times by vessels when practicable. It is my belief that with two fast transports and an escort of five or six destroyers, column formation is a better formation than line.
2. In the diagram, drawn approximately to scale, it is assumed that the transports keep a distance of 700 yards. From much observation on a number of escort trips it is my belief that this distance of 700 yards is rarely kept by the vessels of the convoy, and that it is generally 1000 yards or more.
3. The subject of the most desirable formation is treated under the following basic principles:
(a) Safety of transports as regards collision.
(b) Defense against submarine attack on the convoy offered by destroyers.
(c) Offensive opportunities offered to destroyers in case of submarine attack on convoy.
4. As regards safety of the transports as regards collision in mist, fog, or rough weather, or due to any derangement of machinery or steering gear, the advantages of the column formation are obvious and any arguments as to the desirability of this formation are superfluous.
5. With regard to the defense against submarine attacks on the convoy offered by the destroyers, it is believed that a comparison of diagrams I and II will show that the column formation for two fast ships is preferable. In both cases the arrows are designed to show the possible directions from which submarines may attack.
6. In diagram I a submarine may well, with whitecaps on the water, be able to attack from ahead, either bow, or either quarter, with an approach by microphones or one showing of a periscope without being seen by any of the destroyers, if the leg of the patrol on which they are standing happens to be away from the submarine’s line of approach, and the line formation, especially when the transports open out the distance, instead of keeping closed in to 700 yards, offers a submarine an excellent opportunity of getting between the two ships and having a large target at which to fire at close range. If the submarine does get between the ships in line both the defensive and offensive powers of the destroyers are practically a negative quantity. The line formation offers excellent protection against an attack from the beam.
7. Referring to diagram II, the distance to be patrolled by the destroyers is much less than in diagram I, and they can, from a defensive standpoint, have a much better chance of sighting a periscope than with the line formation. Furthermore if they do see it, there is no difficulty in making an attack caused by the necessity of keeping clear of a line of two rapidly approaching ships in case the attack comes from ahead or either bow. From an attack from right ahead the target offered the submarine is very small. From a defensive standpoint the attack from the beam appears to be more favorable for the submarine in column formation, but less of a target is offered to the submarine for a quartering shot in the column formation.
8. From the standpoint of offensive action the column formation appears to offer much greater opportunities for the destroyers under every direction of attack, and the possibility of attack without the destroyers being able to see the torpedo wake and know where to attack is greatly reduced. In the case of the torpedoing of the Mount Vernon none of the destroyers saw anything definite to attack.
9. The zigzag used, causing the formation to be a line of bearing instead of a true column, is not believed to be of great moment, or to in any way nullify the advantages of the column formation, and the fact that two ships are in exact column is not believed to give a submarine any better information than can be obtained from the line of masts and funnels of one ship.
10. It is realized that a two-ship convoy with an escort of six destroyers is an unusual condition, but it has occurred, and may occur again. It is my belief that the column formation is fully as favorable, if not more so, for the defensive action of the destroyers and offers much greater opportunities for offensive action.