7. Rockets

Although rockets, like artillery, were not employed in sufficient quantity in Manila to be devastating, their potentialities were demonstrated. Rocket fire was almost always employed at night simultaneously with artillery fire, a circumstance which made accurate reports on its source and effect difficult. More extensive use of rockets in future Japanese city fighting may be expected.

Three standard kinds of rockets were found : the 447mm and 20cm naval spin-stabilized rockets, and the Army 20cm spin-stabilized rocket Model 4. Launching devices were of various types and included tube launchers, open troughs and rail launchers on single, double and triple mounts. Those used in Manila proper are believed to have been the Navy 20cm rocket with rail launchers, and possibly the 447mm rocket. Army 20cm rockets with tube launchers were used extensively in the fighting in the hills east of Manila.

In addition improvised rockets consisting of Navy 60kg Model 97 bombs with welded iron and sheet steel propelling devices attached were found, ready to fire, in Fort McKinley, and may have been used in the Manila area.

The 447mm (175/8") rocket (see Inclosure 37) is 68¼" long, weighs approximately 1500 pounds, contains a picric acid bursting charge, has a point-detonating fuse, and is estimated to have a maximum range of not over 2000 yards. Of 85 rounds found in a dump in Quezon City, Manila, the latest manufacturing date was in November, 1944. Observers' reports describing what is believed to have been the 447mm rocket in flight state that it left a trail of sparks approximately 150 feet long, and detonated with a terrific explosion, doing extensive damage to buildings.

Rockets for the 20cm rocket launcher Model 4 (see Annex 38 ) recovered in the Manila area were manufactured at the Osaka Army Arsenal in late 1944. The rockets are 20.2cm in diameter, 38¾" long, and are fused with a Type 100 mortar fuse. Japanese manuals give the range as from 360 meters at 10 degrees elevation to a maximum of 1800 meters at 50 degrees elevation. The launcher is similar to a large trench mortar. As stated in Japanese manuals and verified by experimental firing, the rocket must be fired by means of a long lanyard, since it shoots flame and showers powder particles to the rear, raising a cloud of dust as it leaves the launcher. It can be seen in flight by day and traced by its trail of sparks at night. Throughout its flight it makes a loud swishing noise. Its detonation is of a high order, greater in blast effect than in fragmentation. Instantaneous fuse settings used in the fighting east of Manila gave it a “daisy cutter” effect.


1. General

On the basis of experience gained in Manila, it may be stated that Japanese tactics and techniques in city fighting presented no radical departures from methods utilized by the enemy in other types of combat. Almost without exception, developments in Manila had ample precedent in previous campaigns.

It should be emphasized at the outset that the defense of Manila was influenced by certain factors which may not be present, either in part or in entirety, during future operations of a similar nature. Some of these circumstances complicated the defense: others facilitated it. In the first category were the following conditions: (a) the relative scarcity of weapons ; (b) the lack of training and inexperience of the majority of enemy troops: (c) the conglomerate nature of those troops ; and (d) the presence of essentially unfriendly civilians. On the other hand, the enemy's problems were simplified by: (a) the disproportionately large number of automatic weapons available as a result of the cannibalization of armament on planes and ships; (b ) the prohibition against aerial bombing by American forces; (c) the initial restrictions on our artillery fire, a procedure prompted by our desire to preserve property to the greatest possible extent: and (d) our efforts to protect the friendly civilian population and our consequent reluctance to proceed ruthlessly.

2. Conduct of the Defense

A partial reconstruction of the enemy's plans prior to our assault upon Manila indicates that he anticipated attacks either from the sea, from the south, or by airborne elements. When our true intentions became evident, the enemy was not able to redeploy his strength and to reorient his positions completely. In an attempt to salvage as much as possible from a difficult situation, the Japanese commander apparently decided to establish Intramuros as the core of his defense. This central installation was to be protected by an outlying belt of highly developed positions in earthquake-resistant buildings, which, in turn, were guarded by pillboxes, trenches and barricades (See Annex 39 and Annex 40) . These main defenses were situated south of the Pasig River. Units north of the river were seemingly given the four-fold mission of screening the principal positions to the south, of delaying the advance of our elements, of harassing our rear, and of guarding the approaches to the vital bridges across the Pasig until the moment of demolition.

Although fires set by withdrawing units and by artillery emplaced in the southern section of the city delayed the progress of our troops, the resistance offered by the northern Japanese forces was comparatively weak. Not until the passage of the river was completed did the nature of the enemy defense entirely reveal itself. Then it became clear that the defense was to consist, in the main, of independent centers of resistance which were well sited, well constructed, and fiercely held, but which were not coordinated in an overall plan.

As soon as the first Japanese positions in the southern part of the city were encountered, it was evident that, in constructing defensive installations the enemy had brought all his acknowledged ingenuity to bear. Demonstrating once again his ability to adapt his defense to the existing terrain, the enemy took excellent advantage of the specialized topography of the city. Virtually every street was barricaded. Reinforced pillboxes, carefully placed to allow assaulting troops only severely limited aproaches, commanded critical points. Chosen for their strength as well as for their location, buildings took on many of the aspects of fortresses. Minefields, although generally inexpertly laid, were a constant hazard and acted as a delaying element. (Specific instances of the skill shown by the enemy in siting and constructing defenses may be found in Section IV, Defensive Installations.)

In these positions the enemy emplaced a considerable variety of weapons, standard, modified or improvised. The Japanese have always been reasonably proficient in the use of infantry weapons or weapons adapted for use by infantry. The defense of Manila produced no significant exceptions to this general rule. Inasmuch as this subject is discussed in some detail in Section V, Part One, only a summary of the salient features is presented here :

a. On the whole, rifles and automatic weapons were employed conventionally.

b. Fields of fire were chosen with care and permitted good coverage of critical areas.

c. Within each center of resistance the fire plan was characteristically thorough ; coordination between positions was, however, generally imperfect.

d. Fire discipline was good ; fire was withheld until assault troops were at very short range.

e. Snipers, as such, were not used to any important extent.

The troops manning the pillboxes and serving the weapons were a variegated lot, poorly trained and inexperienced. What they lacked in skill, however, they redeemed by their suicidal tenacity. The vast majority was resigned to defending the positions until death, and there were no satisfactory indications that plans for withdrawal from outlying buildings to Intramuros were ever made. Within the buildings themselves, however, the Japanese retired to successive positions in the interior until trapped and exterminated.

In spite of excellent positions, good employment of weapons and fierce resistance by his troops, the enemy's defense was seriously impaired by his failure to coordinate centers of resistance. This common enemy weakness was perhaps attributable to inadequacies of the command, poor communications and the heterogeneity of the units available. The absence of an integrated fire plan has already been noted. In addition, there was little evidence of echeloned defense. Although concentrations of installations in certain areas gave the effect of depth, this seems to have been incidental and inadvertent rather than the result of a deliberate plan. The lack of coordination inevitably caused the enemy defense to become inelastic, in that centers of resistance became isolated and susceptible to destruction in detail.

The enemy employment of artillery also gave evidence of the Japanese inability to coordinate elements in the defense. Artillery fire, although accurate, was never delivered in heavy concentrations. For the most part, the enemy seemed content to undertake harassing missions, never involving more than three pieces against a target. It should be pointed out in this connection, however, that this enemy policy may have been dictated by the necessity of protecting his guns from our counterbattery fire.

3. Counterattacks

Concerted counterattacks, in the usual sense of the term, were never launched. That at least one abortive attack was made is evidenced by a captured document, the translation of which appears below :

"Ultra Secret Central Force Op Order No 4               15 Feb 45

     Central Force CO, Iwabuchi, Mitsuji (or Sanji)

          Central Unit Order

1. The city has fallen into hand-to-hand fighting since this morning, and 5 tanks and 9 armored cars are appearing and disappearing at every turn.

2. This unit will make preparations for an all-out suicide attack to annihilate the enemy to our front. On the night of the 15th each unit will carry out as many daring suicide attacks on the enemy to our front as possible. Although the time of the all-out suicide attack will be indicated in a separate order, preparations will be completed beforehand.

a.  In addition to annihilating the enemy to the front, the suicide unit will plan to wipe out the enemy in the Malacanan Palace.

b.  Prior to the all-out suicide attack, wounded will be made to commit suicide and documents and material will be burnt.

c.  In the all-out suicide attack every man will attack until he achieves a glorious death. Not even one man must become a prisoner. During the attack friends of the wounded will make them commit suicide.

d. The Suicide (Nikko) Section will be at the head of the attack and will destroy the enemy tanks.

e.  /Personnel/ will be lightly garbed in the attack and carry as much ammo as possible. Personal belongings and unnecessary articles will be burnt."

 The only indication of this attack was an increase in enemy infiltration attempts on the night of 15-16 February,

Occasionally, when a position became untenable, isolated groups, usually composed of twenty to thirty men, executed frontal suicidal attacks which were easily repulsed.

Highly valued by the enemy but hardly worthy of the title "counterattacks" were infiltration raids by groups normally consisting of from ten to fifteen men carrying demolition charges. Missions were assigned in very general terms, such as "to destroy enemy installations in the rear areas paying particular attention to artillery". These infiltrators, operating within the built up section of the city, usually because separated or lost and were destroyed by our forces before they fulfilled their purpose.

4. Espionage and counter-espionage

The enemy frequently employed pro-Japanese Filipinos on intelligence Interrogation of captured spies disclosed that they were not directed to gather any special or unusual intelligence but were instructed to report on the locations of troops, installations, movements, and strengths.

Endeavoring to make the most of their physical resemblance to the Filipinos and to take advantage of the American inability to distinguish between Orientals, Japanese members of special intelligence units allowed their hair to grow long and adopted civilian disguise to facilitate entry into our areas. It has been impossible to determine the degree of success achieved by these units. A pertinent document is set forth below :


"Ultra Secret 4th Bn Daily Order No 2 28 Jan 45, MANDA HILL

From : 4th Bn Co, OGAWA, Sautami

"To : All Co COs and Plat Ldrs

In accordance with Manila Naval Defense Force Op Order No 25, special reconnaissance units will be organized.

1. CO : Naval Lt (legal) ANDO, Masafumi.

2: Organization : Two teams (or less ) of three men each will be sent by all Bns of the Manila Naval Defense Force from each of their pIts.

3. Duties : Observation, reconnaissance, demolition, burning, surprise attacks, and stratagems as ordered.

4. Selection of personnel : Personnel for these units will be carefully chosen and appointed with attention to the following points :

a. Firmness of purpose (keeping secrets, avoidance of improper actions).

b. Bodily strength.

c. Build and features.

d. Consideration must be given to personnel fluent in English.

5. Equipment : Pistols, hand grenades, etc., as required.

6. Clothing : As required, but mainly civilian clothes.

7. Performance of duty :

a. For the present the personnel will be on duty in their plats, and the Plat Ldr may use them in the patrol duties of his own unit.

b. Except when carried out directly under the control of the /Force/ CO, training will be carried out by each unit CO, for his own men.

c. The /Force/ CO will use the teams either individually or in conjunction with one another.

8.     Miscellaneous : Unit personnel may grow long hair if they have obtained permission. 

A nominal roll of personnel selected will be immediately submitted."

 Goaded by their failure to put an end to guerrilla activity in Manila, the Japanese, in desperation, determined to take positive action by declaring that all Filipinos,, women and children included, found in the battle areas were to be considered guerrillas and were to be exterminated. This decision was carried out in part. Below appears a translation of the document which directed this mass murder :

"KOBAYASHI Group (HEIDAN) Order              13 Feb

1.         The Americans who have penetrated into Manila have about 1,000 army troops, and there are several thousand Filipino guerrillas. Even women and children have become guerrillas.

2.         All people on the battlefield with the exception of Japanese military personnel, Japanese civilians, Special Constr Units (GANAPS in the Filipino language ) will be put to death. Houses---" (Order breaks off here) .  

5. Chemical Warfare  

One authenticated instance of the use of gas was reported on 12 February. During the house to house fighting in the Singalong District of Manila, a self-projecting vomiting-gas candle exploded in a room occupied by American troops. The soldiers, having immediately felt a stinging sensation in their eyes, withdrew and later became violently ill. Vomiting gas candles and frangible glass HCN grenades were discovered in dumps in the city and are known to have been in the hands of troops. This isolated instance, however, is believed to have been a lapse in command discipline rather than an authorized resort to chemical warfare.

A very few flame throwers were found in Manila, but none appeared to have been used.

6. Armor

One tank was encountered in Manila and it was destroyed by our tank destroyers on Faura Street on 16 February. On the same day, one armored car was observed on Dewey Boulevard.

7. Summary

In recapitulation, it may be said that the Japanese defense of Manila produced no innovations of consequence. The enemy's tactics and techniques gave evidence of the same strengths and weaknesses which have been apparent in his methods in other operations. In his favor were : his shrewd use of terrain ; his excellent location and construction of individual positions ; his ingenuity in improvising and adapting weapons ; his skilled employment of individual weapons ; and, above all, his great tenacity in defensive combat. He was guilty on the other hand, of several basic errors, among them; his inability to develop any degree of overall coordination in the plan of defense; his weak and ineffective employment of artillery; and his lack of appreciation of the potentialities of mines as defensive weapons.

The enemy, notwithstanding his deficiencies, proved himself a formidable opponent in the defense of a heavily populated area. Unquestionably he will profit by experience gained during the fighting in Manila, and, in consequence, it may be expected that some or all of his shortcomings will be corrected in the future.








Sketch No. 20







The 447mm (17
5/8") rocket is 68¼" long, weighs approximately 1500 pounds, contains a picric acid bursting charge, has a point-detonating fuse, and is estimated to have a maximum range of not over 2000 yards.


Of 85 rounds found in a dump in Quezon City, Manila, the latest manufacturing date was in November, 1944.

Observers' reports describing what is believed to have been the 447mm rocket in flight state that it left a trail of sparks approximately 150 feet long, and detonated with a terrific explosion, doing extensive damage to buildings.

The crater left by the rocket was the equivalent of a 1000lb aerial bomb.

The cart, with its 4-foot wooden wheeels and 12-foot launching platform was of crude but effective design and construction, suggesting it had been locally fabricated.



20 cm Army Rocket


Side view of 20-cm Army Rocket Launcher



Front view of Launcher
(Showing TraversingMechanism)



Rear view of Launcher
(Showing method of loading)