US Navy: Naval Aviation Doctrine: Introduction to Naval Aviation, 1946 - Torpedo Tactics

INTRODUCTION TO NAVAL AVIATION  - RESTRICTED - ISSUED BY AVIATION TRAINING DIVISION OFFICE OF THE CHIEF OF NAVAL OPERATIONS U. S. NAVY. * JANUARY 1946 * OPNAV 33-NY-85; Chapter IX. Tactics and Flight Operations.

5. TORPEDO TACTICS

Torpedo aircraft are the Fleet's heavy-weights. Per unit, they deliver a tremendous weight of offensive fire power in the aerial torpedo. Through their tactical uses they provide Fleet commanders with their most effective aerial weapon against major enemy fleet units. This is clearly demonstrated by the primary mission of torpedo tactics, the destruction of enemy capital ships.

The secondary missions of VT groups are almost as important - bombing, antisubmarine patrol, and scouting and search. In addition to the torpedo, with its 600 pounds of torpex, VT aircraft carry bombs for most forms of bombing, and rockets. VT aircraft also carry radar which readily adapts them to night missions of most types.

The torpedo attack is always coordinated with strafing and bombing attacks. Fighters and dive bombers customarily strike along with VT aircraft to knock out anti-aircraft fire, because the torpedo plane (despite its high-speed approach) is most vulnerable during the brief moment it is required to fly in straight and level flight to launch its torpedo; and because the attack must be made at close range, thus offering a favorable target to opposing gunners.

In addition to its attack functions against ships, the VT aircraft is the first line of defense for surface forces against submarine attack. Antisubmarine warfare and antisubmarine patrol (ASP) therefore constitute a primary function. An ASP is out at all times, often accompanied by a fighter to handle enemy snoopers which might attack the VT patrol. Antisubmarine attack is usually initiated with depth bombs and frequently followed up with rockets.

Prior to 1920, the aircraft torpedo and torpedo tactics were in their infancy. The Torpedo Mark 7, now obsolete, was used as an aircraft torpedo although it was designed originally for submarine use. Most important, it could only be launched from 10 to 20 feet above the water and at speeds under 100 knots. Until the development of high-speed, high-altitude launchings - which did not occur until 1944 - the torpedo pilot was considered to be something of a sitting target.

Today's Mark 13 type torpedo, however, can be launched from speeds up to 360 knots and at altitudes up to 2000 feet or more. The vulnerability of the VT pilot has thus been reduced almost to zero - to that brief moment in the approach when he levels out to make his drop before barreling away in high-speed evasive action.

Typical torpedo "anvil" attack pattern

The problems of launching torpedoes successfully from high altitudes was solved by use of the drag ring (sometimes called the "pickle barrel"). It improved the aerodynamic qualities of the torpedo during its air flight so that it now enters the water clean without making a "belly whopper." And in addition to stabilizing the torpedo, it reduced impact damage. Underwater performance was also improved late in 1944 by addition of a shroud ring, or "ring tail," which further stabilized it.

Under present limitations, torpedo attacks may be made at almost any speeds offered by modern aircraft, from altitudes in excess of 2000 feet, and into shallow water from 15 to 30 feet in depth. The importance of shallow water launching was emphasized during the Pacific fighting of World War II, when enemy vessels hid in shallow anchorages and around islands to protect them from torpedo runs.

The effectiveness of a torpedo attack depends upon certain aiming principles.

The most important factor is the dropping range, including the variable of the torpedo's air travel between the time it is dropped and the time it enters the water. Dropping range in turn is based on such factors as the dropping speed, dropping altitude, the speed of the target, and the angle between the plane and the target when the drop is made. The pilot is provided with minute sighting and launching data which assists him to correlate these factors without extensive on-the-spot calculations. Sighting tables apply to all standard attacks, obviating complex and time-consuming calculations.

The principal consideration on all torpedo attacks is a dropping range short enough to allow the target minimum time to take evasive maneuvers and yet give the torpedo time to arm itself. Only by coming in to a minimum range can a pilot assure himself of a hit. There is no problem in a sitting target, such as an anchored ship. A maneuvering warship, however. makes an elusive target. For example. in 90 seconds a major ship can change heading an average of 90 ° ; in the same time, a destroyer can change heading 180°. Once a torpedo is released, it will continue on the heading held at the time of its drop. Consequently, careful estimation of target angle, speed, and probable evasive action become essential; and the shorter the range. the less chance for evasion and a miss.

The "anvil" attack is the most common form of torpedo attack, the aircraft of the attacking group maneuvering so as to bring the target broadside to the attackers with torpedoes fired on both bows in a spread. The pattern thus made offers the target a minimum chance for "combing" the torpedoes - that is, avoiding them by maneuvering his ship to run parallel with them. There are a number of variations, but this is the most common tactic.

Through radar, night torpedo attacks are effective with smaller units being used.