REFERENCE DOCUMENTS & RESOURCES - OFFICIAL ADMIRALTY DOCUMENTS
ADM 239/261: THE FIGHTING INSTRUCTIONS, 1939 (C.B.04027)
Updated 31-Mar-2007

This document is a modern transcription of a portion of Admiralty record ADM 239/261. This lengthy document contains the Admiralty's official fighting instructions. The original file is held at the The National Archives at Kew, London. This Crown Copyrighted material is reproduced here by kind permission of The National Archives.

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- Pages 74-79 -

FLEET ACTION
SECTION VIII.-NIGHT FIGHTING INSTRUCTIONS

CONTENTS

Clause Subject

430-439
430-432
433
434
435-437
438-439

440-444
440-441
442
443-444

445-450

451
452-459

GENERAL.
The policy of the fleet at night.
Factors essential to night fighting.
Action on sighting a strange vessel at night.
Manoeuvring the battlefleet and screens at night.policy signal.
(blank)

THE PLAN OF BATTLE.
Evasion and manoeuvre.
Recognition between the battlefleet and its screen.
(blank)

ENCOUNTERS BETWEEN CAPITAL SHIPS

USE OF SEARCHLIGHTS AND STARSHELL.
(blank)


SECTION VIII.-NIGHT FIGHTING INSTRUCTIONS

GENERAL

THE POLICY OF THE FLEET AT NIGHT
430.
Night action between heavy ships, for which a high degree of training is essential, must be regarded as a definite part of our policy.

431. If the enemy had not been brought to action or has not been defeated by nightfall, the Admiral will decide whether to seek a night action with capital shps or to rely on the light forces to maintain touch and attack during the night, in order to assist in bringing the enemy to action at daylight.

432. In any class of ship engaging an enemy at night, it is essential to develop the maximum volume of gun and torpedo fire before the enemy can do so, and all other considerations are of secondary importance. It must be remembered that the result of a night action may depend on the first minute or so and that, if the most effective action is not taken immediately, it is unlikely that there will be time ro recover. It must never be assumed that a ship with the advantage of light conditions, etc., has not been seen by an enemy sighted in a less favourable position. All enemy units should be engaged at once, except in the case of destroyers trying to slip through a screen to attack the enemy battlefleet, when their object at the moment will be to evade the screen.

FACTORS ESSENTIAL TO NIGHT FIGHTING
433. The following factors are vital to success:-

(a) Good look-outs. These can only be efficient if well placed and drilled.
(b) Alert gun, torpedo-tube and searchlight crews. This will only be achieved if the armament is exercised frequently in following the director or changing "look-out bearings."
(c) Prompt use of the helm and recognition signals. Correct knowledge of all methods of recognition and identification and the proper occasions when these should be employed, is essential.

ACTION ON SIGHTING A STRANGE VESSEL AT NIGHT
434.
When a strange vessel is sighted at night all ships should act as follows:-

(a) Train guns and searchlights on the vessel sighted, and bring the whole armament to the "Ready."
(b) Make an "Alarm" report (see Fleet Signal Book, Sections 8 and 9).
(c) If intending to attack or evasion is impracticable:-

(i) If in doubt as to the enemy character of the stranger, make the challenge when (a) is completed.
(ii) If or when the enemy character of the stranger is clear, open fire with guns or torpedoes. In capital ships, if the strange vessels are definitely identified as destroyers or M.T.B.;s and they are in a position to attack, they should be assumed to be enemy and fire should be opened simultaneously with making the challenge.

(d) If concealment is desired and evasion is practicable:-

(i) Turn away, switching off shaded stern lights.
(ii) Fire torpedoes if the stranger is known to be hostile.
(c) Disposition and movements of the battlefleet during the night.
(d) Morning rendezvous for detached units.

MANOEUVRING THE BATTLEFLEET AND SCREENS AT NIGHT
435. Night cruising order and night screens.
The considerations affecting night cruising dispositions and night screens are contained in Section II (see Clauses 108 to 121); an example of a night cruising disposition is shown in Diagram II on page 126.

436. Methods of altering course at night. An alteration of course of the whole fleet can be ordered by the Admiral in one of the following ways, according to the situation at the moment. It is assumed that the capital ships will be single line ahead, with gaps of about two miles between each division or squadron:-

(a) The battlefleet alters course and the night screen is ordered to preserve relative bearings. This is used to change the line of advance of the fleet when no enemy action is expected. The alteration may be made without signal in accordance with the previous orders or may be altered by W/T; ships of the battlefleet will alter course in succession.
(b) The battlefleet alters course and the night screen is ordered to preserve compass bearings. This is used when evading an enemy force reported at a distance. In this case, the divisions of the battlefleet alter course leading ships together, remainder in succession, in order that the ships may be unhampered in opening fire or taking avoiding action should an attack develop. The alteration will normally be ordered by W/T.
(c) The battlefleet alters course; the night screen continues its original course. This is used when it is desired to "slip the screen," in order to evade and mislead the enemy. The battlefleet may be ordered to alter course in succession. The signal ordering the alteration should give the necessary warning to the screen of the Admiral's intentions.

437. During attacks, Divisional Commanders will manoeuver the divisions of the battlefleet as necessary, inside the screen. Alterations of course should be ordered by the method least likely to disclose the presence of the battlefleet, unless rapidity is essential. Course may be alteredand movements of the battlefleet during the night:-

(a) By leading the column clear with or without signal.
(b) By turning the ships in column together by W/T.
(c) By turning ships in column together by means of the Fixed Light Manoeuvring Signal (see Signal Manual, Chapter XIII).

438. (Blank)

439. (Blank)

ACTION BY THE BATTLEFLEET DURING ATTACKS BY ENEMY LIGHT CRAFT

EVASION AND MANOEUVRE
440.
When a warning og the approach of enemy destroyers is received, the Divisional Commander nearest the enemy should decide whether to evade the attack by an alteration of course or to stand on and repel the attack by gunfire. He should be guided by the Admiral's night policy signal or act in accordance with any special instructions issued by the Admiral. Evasion is the best policy, provided sufficient warning of the approach of enemy destroyer is received. Eveasion does not mean that fire is to be withheld. All enemy units sighted should be engaged with every gun that will bear, and opportunities for firing torpedoes seized.

441. When no warning is received, a torpedo attack will normally be frustrated if capital ships turn stern on to the enemy, using full rudder, at the samt time developing the maximum fire from all main and secondary armament guns that will bear. If, when the turn is completed, searchlights are switched off and firing stopped, the attackers will usually lose sight of the battlefleet, and the attack will fail. The judicious use of smoke may assist the evasion.

Note:- The instructions given above for countering destroyer attacks are equally applicable in the cvase of attacks by M.T.B.'s.

RECOGNITION BETWEEN THE BATTLEFLEET AND ITS SCREEN
442.
When a screened battlefleet is attacked by enemy destroyers at night, a danger will always exist of friend being mistaken for foe. Fighting lights or V/F lights should be switched on by screening vessels in a confused action, or if the battlefleet opens fire on a friendly ship ; otherwise it is better that no lights are shown. The instructions in the Recognition Manual (S.O. 02220) should be used as a general guide.

443. (Blank)

444. (Blank)

ENCOUNTERS BETWEEN CAPITAL SHIPS

445. If an encounter between capital ships takes place, success will depend upon rapid and intensive offensive action. While the element of chance in a night encounter must always remain, superior night training will probably decide the issue in the first few minutes.

446. Large alterations of course between sighting the enemy and firing the first salvo tend to confuse the control and delay opening fire ; they should therefore be avoided if possible. Even if all guns cannot fire, a well laid salvo from the forward guns would probably be more effective than a salvo fired from all guns in the middle of a large turn. Large turns may, however, he sometimes unavoidable to clear the field of fire for other ships and for other reasons.

447. As the effect of torpedo fire cannot be as immediate as that of gunfire, gunfire requirements should usually have priority when full offensive action is intended. Action taken to avoid enemy torpedoes must depend on the results of gunfire and the conduct of the enemy. It is desirable to turn away before the enemy's torpedoes arrive, but it is more important to ensure the disablement or destruction of the immediate opponent ; his gunfire is a certain and immediate danger, his torpedo fire a potential one.

448. From the nature of night encounters, divisions and ships will usually come into action in succession. A night encounter is thus likely to develop into a series of decisive actions between single ships, and any systematic form of concentration will be impracticable. Under these conditions, the initiative displayed by Captains, together with individual ship efficiency, will decide the issue. The first consideration of every ship must be to get into action ; this may often involved breaking away from single line and forming on a line of bearing which will enable fire to be opened. No Captain can do wrong if he engages one of the opposing ships effectively.

449. (Blank)

450. (Blank)

451. The following general rules govern the use of searchlights and starshell ; detailed instructions are given in the Firing Manual (C.B. 3026):-

(a) The use of searchlights in an action between heavy ships is dangerous and should be reduced to a minimum.
(b) Searchlights should not be switched on unless trained on the enemy. If a searchlight loses the target, it becomes a danger to the ship using it and must be switched off at once.
(c) The principal purposes for which searchlights may be required are-

(i) To illuminate the target before the first starshell takes effect and if starshell becomes ineffective.
(ii) To neutralise the effect of an enemy starshell.
(iii) Against enemy destroyers at short ranges.
(iv) By screening forces. (See (f) below.)

(d) Cruisers encountering enemy destroyers and attempting to ram may switch on searchlights ahead for this purpose.
(e) Destroyers attacking heavy ships may use searchlight if they are themselves illuminated by this method ; the beam should be directed, if possible, on the enemy's bridge. Destroyers which have been detected or have completed their attacks may be able to assist other attacking destroyers, by illuminating the enemy with searchlights in order to distract his attention and expose his movements.
(f) The area illuminated by searchlights is limited compared to that illuminated by starshell. Screening forces should therefore use searchlights in preference to starshell for illumination. Searchlights are more effective for showing up the enemy to friendly forces, and are less likely to show up other vessels on the screen, or the battlefleet. Discretion is necessary in the use of both searchlights and starshell to avoid the possibility of the main force being illuminated, or silhouetted to the enemy.
(g) Starshell should be used in preference to searchlights by heavy ships, or cruisers not forming part of a screen:-

(i) When a good point of aim in not available.
(ii) To assist in spotting.
(iii) To search a suspected area.

452. (Blank)

453-459. (Blank)

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