Chapter XXVII
Gunfire Support

Index

Section 1. General
Section 2. Fire Support Ships
Section 3. Shore Bombardment
Section 4. Shore Bombardment Training
Section 5. LSM(R)
Section 6. LCS(L)(3) and LCI(G)
Section 7. LCI(M)
Section 8. LCI(R)(RCM)

Section 1. General

  1. The importance of Naval Gunfire Support in Amphibious Landing Operations in the Pacific Area is self evident. Heavier and longer preparation bombardments preceding the actual landing are standard practice. The technique of shore fire control is receiving wider use.

  2. Due to continuous patrol of the coast line, to the probability of 360° observation by the enemy, and to their use of radar, an amphibious landing operation against an enemy atoll or island amounts to a frontal assault with complete lack of surprise. This requires a landing practically "down the enemy's guns". There are two means of offsetting this initial disadvantage. One is air support, and one is naval gunfire support.

Section 2. Fire Support Ships

  1. The following ships are used to provide gunfire support:

    1. Battleships -- main battery -- counterbattery, and deep support fire for destruction, neutralization, smoke and illumination.

    2. Cruisers -- main battery -- counterbattery, and deep support fire for destruction and neutralization. AA battery for deep and close support fires for neutralization.

    3. Destroyers -- for deep and close support fires for neutralization, and for counterbattery and destruction.

    4. Amphibious Support Craft, LSM(R), LCS(L)(3), LCI(G), LCI(M) and LCI(R)(RCM). Close support fire for neutralization, harassing and destruction.

    5. Such other ships as may be assigned. In general, APA, AKA, LST, LSD, AGC, DE, APD and DMS are not employed for fire support or shore bombardment. However, they may be.

»XXVII-1«

Section 3. Shore Bombardment

  1. Shore bombardment is based on a military grid superimposed on charts or maps in accordance with pages 40 and 41 of CSP 734, (General Signal Book.) When the land mass to be covered is small the land areas may be marked off in numbered areas.

  2. Naval gunfire on shore targets may be classified as to:

    1. Effect.

      1. Destruction Fire -- requires heavy expenditure of ammunition, continuous observation, and considerable time.

      2. Illumination Fire -- permits own troops to observe enemy troops at night.

      3. Neutralization Fire -- destroys the combat efficiency of enemy personnel by causing some casualties, hampering movement, making enemy "Keep their heads down." Effect is only temporary.

    2. Tactical Use.

      1. Close Supporting Fire -- delivered in close support of the advance of own troops -- either in boats or ashore.

      2. Deep Supporting Fire -- delivered on objectives not in the immediate vicinity of own forces, against enemy reserves, supply dumps, etc.

      3. Counterbattery Fire -- directed against enemy batteries, control stations, etc.

      4. Harassing Fire -- delivered during quiet period (night) to prevent rest, interfere with movement.

      5. Interdiction Fire -- delivered against points, cross roads, areas, to deny enemy use of them.

    3. Selection of Targets.

      1. Prearranged or Scheduled Fire -- planned prior to the landing on known emplacements, beaches, etc.

      2. Call Fires -- on previously designated targets when called for by SFCP, spotting planes, etc. Targets are usually numbered areas on chart which may logically contain enemy emplacements.

      3. On Targets of Opportunity -- on known or suspected targets which suddenly appear during battle.

    4. Technique of Delivery -- Direct fire is delivered on target that can be seen from firing ships. Indirect fire is without benefit of visual observation.

»XXVII-2«

  1. Shore bombardment may be controlled in various methods. Prearranged fires may be delivered according to a schedule prepared and distributed with the Operation Order. Call fires may be at the request of shore commands through SFCP's or by plane spot, or at request of naval commands. Counterbattery fire may be at the request of any of the above agencies. Fire in close support of the troops are usually requested by SFCP's. Fire in close support of the landing boats may be given by DDs, LCI(G)s, boats themselves, etc. Attention is invited to PacFlt Confidential letter 13CL-44 of 1 May 1944 which contains further information.

Section 4. Shore Bombardment Training

  1. The training of battleships, cruisers, and destroyers does not normally fall under the Amphibious Forces. However, their shore bombardment training is conducted with that of Shore Fire Control Parties, by Type Commanders working in close conjunction with Amphibious Commands. Shore bombardment practices are carried out which have all the elements of an actual landing, with gunfire support steaming areas, boat lanes, shore fire control parties operating on the beach, spotting aircraft, etc.

  2. Seven types of amphibious craft are used against enemy shore defenses, and their training and technique of employment are the responsibility of this command:

    (a) LSM(R) - mounting 5.0" spin stabilized rocket launchers, 4.2" mortars, 5"/38 D.P. gun, twin 40MM and twin 20MM.
    (b) LCS(L)(3) - mounting 4.5" barrage rocket launchers, twin 40MMs, 20MMs and .50 cal. MGs.
    (c) LCI(G) - mounting 4.5" barrage rocket launchers, 40MMs, 20MMs, and .50 cal. MGs.
    (d) LCI(M) - mounting 4.2" mortars, 40MM, 20MMs and .50 cal. MGs.
    (e) LCI(R)(RCM) - mounting 5.0" spin stabilized rocket launchers, 40MM, 20MMs, and .50 cal. MGs.
    (f) LCM(3) & LCVP - mounting .30 and .50 cal. MGs (Covered in Chapter XXV on Gunnery Instructions).

Section 5. LSM(R)

  1. Mission. The battle mission of an LSM(R) is to give harassing, and destructive fire before, during, and after an amphibious landing is made.

  2. Tasks.

    1. Support the landing of the assault waves with deep rocket or mortar and gun fire in order to neutralize the enemy beach defenses.

    2. Support the troops after landing, the initial beachhead, and the boat shuttle movement with deep rocket fire or mortar and gun fire against enemy positions on the beach which constitute a threat to this movement, and by fire against enemy aircraft.

»XXVII-3«

    1. Deliver harassing and destructive fire with rockets or mortar and gun fire prior to a landing to crack the enemy morale and destroy prepared positions.

    2. Deliver close support with long ranged rockets or mortars and gun fire to troops after the landing until the completion of the operation.

    3. Lay such smoke screens as may be ordered to hinder enemy observation and fire control, by means of smoke projectiles or fog generators.

    4. Assist the underwater demolition teams by covering them with supporting fire or smoke (when ordered) in order to permit the accomplishment of underwater reconnaissance and demolition.

    5. Make false demonstration (when ordered) using rocket fire, or mortar and gun fire, and smoke in order to divert the enemy away from the main landing.

  1. Armament:

    1. 10 Mk. 102 rocket launchers, 40MM twin mount with two rocket tubes, rockets fed from below -- capable of firing 30 rockets per minute. Rockets are 5.0" spin stabilized with maximum range of 5,000 yards; may be trained and elevated in local or director control.

    2. 4 Mk. 1 4.2" mortar mounts, 3"/50 mount capable of train and elevation in local control -- maximum range 4,400 yards.

    3. 1 5"/38 D.P. gun controlled by Mk. 51 director.

    4. 2 twin 40MMs controlled by Mk. 51 directors.

    5. 4 twin 20MMs.

  2. Organization: An LSM(R) Flotilla is composed of 24 ships. Two groups of 12 ships to each flotilla, and two divisions to each group. LSM(R)s usually operate in divisions or individually.

  3. Tactics: The employment of LSM(R)s is by the Standard LSM(R) Firing Plans. The officer ordering the attack specifies the type plan to use, target, and other pertinent information needed to carry out the standard plan.

  4. Training: In order to properly execute the assigned missions, LSM(R)s need extensive training in the use of their specialized equipment, standard firing plans, and operating and gunnery doctrines. Rehearsals in which all ships participate in a realistic action rounds out the training program and perfects timing schedules for each operation.

Section 6. LCS(L)(3)s and LCI(G)s

  1. Mission: The battle mission of LCS(L)(3)s and LCI(G)s is to support the LVT and boat group throughout an amphibious landing operation in order to permit the landing of troops and after the landing to furnish anti-aircraft screens for the radar pickets.

»XXVII-4«

  1. Tasks:

    1. Protect the LVT and boat group while in the rendezvous area, enroute to and at the line of departure from enemy automatic weapons fire from the beach and from enemy aircraft.

    2. Support the landing of the assault waves with automatic weapons fire and rocket fire in order to neutralize the enemy beach defenses.

    3. Support the troops after landing, the initial beachhead, and the boat shuttle movement by automatic weapons fire against enemy positions on the beach which constitute a threat to this movement, and by fire against enemy aircraft.

    4. Lay such smoke screens as may be ordered to hinder enemy observation and fire control, by means of smoke rockets and fog generators.

    5. Assist the demolition teams by covering them with supporting fire or smoke, (when ordered) in order to permit the accomplishment of underwater reconnaissance and demolition.

    6. Make false demonstrations when ordered, using gunfire, rocket fire, and smoke in order to divert the enemy away from the main landing.

    7. Perform direct support and harassing missions in support of the troops after the landing and until the completion of the operation.

    8. Provide AA screens for radar pickets.

    9. Provide flycatcher screen for suicide boats and swimmers.

  2. Armament of LCS(L)(3):

    1. 3 - 40MM twins controlled by Mk. 51 directors.

    2. 4 - 20MM.

    3. 10 - Mk. 7 rocket launchers -- Mk. 7 Launcher fires 12 4.5" barrage rockets from one rail (automatic feed) in salvo in about 4 seconds -- single shots also may be fired -- maximum range 1,120 yards.

    4. 4 - .50 cal MGs.

    Armament of LCI(G):

    1. 40 - Mk. 7 rocket launchers.

    2. 3 - 40 MMs.

    3. 4 - 20 MMs.

    4. 4 - .50 cal. MGs.

      Note:
      1. Bow Nos. under 351 have only 2 40MM., and 5 20MMs.
      2. Additional LCI(G)s converted without rocket launchers for radar picket screen and flycatcher duty. Interim armament as above. Ultimate armament has 2 40MM twins with Mk. 51 directors and 3 or 4 20 MM twins.

  3. Organization: LCS(L)(3)s are organized in Flotillas of 5 ships. Each Flotilla consists of 3 groups of 12 ships each. Each Group consists of 2 divisions of 6 ships each. On supporting landings, LCS(L)(3)s usually operate in groups or divisions. Identical for LCI(G)s.

»XXVII-5«

  1. Tactics: LCS(L)(3)s form a line abreast a few hundred yards ahead of the line of departure. They then proceed toward the beach covering the waves with automatic weapons fire. At 1,000 yards range they commence their rocket barrage and cease at 500 yards. Here they lie dead in the water covering the assault waves with automatic weapons fire. The LVT waves pass between the ships. Usually after the LVT waves have passed and before the boat waves hit the beach the LCS(L)(3)s vacate the boat lanes by proceeding in column to the flanks. On radar picket AA screen four ships usually form a station and maneuver around a tight square offering each other the maximum AA coverage. Identical for LCI(G)s.

  2. Training: In order to properly execute their battle missions LCS(L)(3)s and LCI(G)s need extensive training in radio communications, shore bombardment, and anti-aircraft firings. Firings, especially AA, should be made at every opportunity. Rehearsals in which all ships carry out a complete rehearsal is necessary to perfect timing schedules for each operation.

Section 7. LCI(M)

  1. Mission: The battle mission of an LCI(M) is to support the LVT and boat group by anti-personnel and neutralization fires on the beachhead prior to and during the assault landing and later furnish supporting and harassing fire.

  2. Tasks:

    1. Support the landing of the assault waves with mortar and automatic weapons fire in order to neutralize enemy beach defenses.

    2. Support the troops after landing, the initial beachhead, and the boat shuttle movement by automatic weapons fire against enemy positions on the beach which constitute a threat to this movement, and by fire against enemy aircraft.

    3. Lay such smoke screens as may be ordered to hinder enemy observation and fire control, by means of smoke mortar shells and fog generators.

    4. Assist the demolition teams by covering them with supporting fire or smoke (when ordered) in order to permit the accomplishing of underwater reconnaissance and demolition.

    5. Make false demonstration when ordered, using gunfire, mortar fire, and smoke in order to divert the enemy away from the main landing.

    6. Provide flycatcher screen for suicide boats and swimmers.

    7. Perform direct support and harassing missions, employing mortar fire, in support of the troops after the landing and until the completion of the operation.

  3. Armament:

    1. 3 - 4.2 Chemical Mortars (fixed train and elevation).

    2. 1 - 40MM.

»XXVII-6«

    1. 4 - 20MM.

    2. 4 - .50 cal. MGs.

      Note: The 3 fixed mortars are being replaced by 2 4.2" Mk. 1 mortar mounts which is a modified 3"/50 mount capable of train and elevation.

  1. Organization: LCI(M)s are organized in Flotillas of 36 ships. Each Flotilla consists of 3 Groups of 12 ships each. Each Group consists of 2 Divisions of 6 ships each. On fire support missions LCI(M)s usually operate in division strength.

  2. Tactics: Employment of LCI(M)s is by the standard LCI(M) Mortar Fire Plans. The officer ordering the attack specifies the type plan to use, target, and other pertinent information needed to carry out the standard plan.

  3. Training: In order to properly execute their battle missions LCI(M)s need extensive training in radio communications and in mortar shore bombardment. AA firing should be made at every opportunity. Rehearsals in which all ships carry out a complete rehearsal is necessary to perfect timing schedules for each operation.

Section 8. LCI(R)(RCM)

  1. Mission: The battle mission of a LCI(R)(RCM) is to support the LVT and boat group by anti-personnel and neutralization fire on the beachhead, prior to and during the assault landing, and later furnishing supporting and harassing fire.

  2. Tasks:

    1. Support the landing of the assault waves with rocket and automatic weapons fire in order to neutralize enemy beach defenses.

    2. Support the troops after landing, the initial beachhead, and the boat shuttle movement by automatic weapons fire against enemy positions on the beach which constitute a threat to this movement and by fire against enemy aircraft.

    3. Lay such smoke screens as may be ordered to hinder enemy observation and fire control, by means of smoke rockets and fog generators.

    4. Assist the demolition teams by covering them with supporting fire or smoke (when ordered) in order to permit the accomplishment of underwater reconnaissance and demolition.

    5. Make false demonstration, when ordered, using gunfire, rocket fire, and smoke in order to divert the enemy away from the main landing.

    6. Provide flycatcher screen for suicide boats and swimmers.

    7. Perform direct support and harassing missions, employing rocket fire, in support of the troops after the landing and until the completion of the operation.

    8. Radar countermeasures, when ordered.

»XXVII-7«

  1. Armament:

    1. 6 - Mk. 51 Rocket Launchers -- Mk. 51 launcher fires 12 5.0" SSR from one rail (automatic feed) in ripple salvo of about 4.5 seconds -- single shots may also be fired -- maximum range 5,000 yards.

    2. 1 - 40MM.

    3. 4 - 20MMs.

    4. 4 - .50 cal. MGs.

  2. Organization: LCI(R)(RCM)s are organized in Flotillas of 36 ships. Each Flotilla consists of 3 Groups of 12 ships each. Each Group consists of 2 Divisions of 6 ships each. On fire support missions LCI(R)(RCM)s usually operate in Division strength.

  3. Tactics: Employment of LCI(R)(RCM)s is by the standard LCI(R)(RCM) Rocket Fire Plans. The officer ordering the attack specifies the type plan to use, target, and other pertinent information needed to carry out the standard plan.

  4. Training: In order to properly execute their battle missions LCI(R)(RCM)s need extensive training in radio communications and in mortar shore bombardment. AA firings should be made at every opportunity. Rehearsals in which all ships carry out a complete rehearsal is necessary to perfect timing schedules for each operation.

»XXVII-8«

LCS(S) Diagram No. 2 -- Employment from Rendezvous Area to Line of Departure

LCS(S) Diagram No. 2 -- Employment from Rendezvous Area to Line of Departure

»XXVII-9«

LCS(S) Diagram No. 3 -- Employment from the Line of Departure to the beach Assault Firing Run

LCS(S) Diagram No. 3 -- Employment from the Line of Departure to the beach Assault Firing Run

»XXVII-10«

LCS(S) Diagram No. 4 -- Employment with LVTs at Line of Departure

LCS(S) Diagram No. 4 -- Employment with LVTs at Line of Departure

»XXVII-11«

LCI(L) Gunboats Assault Firing Run

LCI(L) Gunboats Assault Firing Run

»XXVII-12«

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