WesWorld

This paper discusses the various engagements between the Bharatiya Nau Sena and Filipino Revolutionary forces. It highlights operational lessons with respect to ship and aircraft design, weapons, tactics, and strategy.

The Navy was involved in a total of twelve actions, beginning with the attack on SR Chandragupta by PRS Panay on 3 October 1928, and concluding with an air attack against SR Urumi on 15 June 1929. The Navy lost the destroyer Thimphu and three motor torpedo boats (M-22, M-35, M-42) sunk. Damaged were the monitor Chandragupta, cruisers Lucknow, Agra, and Bangalore, and destroyers Khulna, Gwalior, and Multan, as well as several motor torpedo boats.

In return, the navy disabled and captured the cruiser Panay and two MAS, and sank or caused to be lost two destroyers and eight MAS. Panay has been scrapped, one MAS was handed back to loyalist forces, and the other MAS was transported to Chennai for examination.

Note: the remainder of the paper will appear in this thread in parts over the next couple of weeks

1. Air to Surface Actions

-SR Urumi (6 Marut, 12 Toofani) vs. 2 DD, 9 MAS. 26 January 1929.

-Revolutionary Air Force (2 Aero A.24) vs SR Urumi. 15 June 1929.

-SR Urumi against various land-based targets. 27 January - 6 June 1929.

The attack by Urumi’s air group against the revolutionary strike force demonstrated the potential for Urumi to attrite enemy light and medium surface forces in support of battleline operations. The attack was well-executed, and the loss of two aircraft against a destroyer and an MAS is considered acceptable. Given additional time to locate and attack enemy MAS, it is probable that some of the later losses to the navy could have been prevented. This, however, speaks to a prematurely launched amphibious operation rather than a tactical error on the navy’s part.

The late raid against Urumi was singularly unsuccessful, with no damage or casualties sustained by the carrier and both attackers shot down by defensive aircraft after the attack. Level bombing attacks by slow aircraft at high altitude were not expected to be effective, and this one certainly was not. Nonetheless, the fact that the aircraft did have an opportunity to drop on Urumi suggests a shortfall in existing defensive fighter coverage operations that bear examination.

Ongoing support of ground operations cost Urumi several aircraft over the course of the Luzon campaign. Four Maruts and five Toofanis were lost - four aircraft to accidents, one to enemy aircraft, three to ground fire, and one to unknown causes. Generally speaking, the Urumi group functioned well, though heavier attack aircraft would have performed ground attack functions better than the Toofani. In general, both types demonstrated acceptable utility, damage tolerance and durability. However, the air group’s overall effectiveness was declining towards the end of the campaign as a result of accumulating pilot fatigue (despite some rotations) and maintenance requirements. Ideally, a second carrier would have been in place to alternate with Urumi, but this will evidently not be possible for some time yet.

A note on flight crews: three Marut pilots and eight Toofani crew were killed in flight operations, out of Urumi’s initial complement of twenty and thirty-two respectively. In total, however, thirty-one Marut pilots and forty-eight Toofani crew flew from Urumi over the course of the war, some replacing combat losses, others relieving fatigued crewmen.

Recommendations:

-Fighter coverage operations require further examination. Only two fighters were on station at the time, perhaps this should be doubled, with two aircraft orbiting the carrier and the other two orbiting along a likely threat axis outside the squadron.

-The Marut fighter should be modified to include racks for light bombs or grenades, for use in anti-MAS actions. Fighter crews should be trained to successfully engage MAS boats.

-The Toofani scout-bomber should be improved to carry a single heavy bomb in the 200 to 250 kg range, making the aircraft more effective against medium surface forces such as aircraft carriers, cruisers, and destroyers.

-The army and navy should investigate options to rapidly transport army air force units to distant shores aboard Urumi or other vessels.

-The navy should ensure that training operations provide an acceptable cadre of aviators to substitute for lost, injured, or fatigued aviators. Training methods should be updated to draw combat experiences wherever possible.

2. Light Surface Force Operations

-Two revolutionary MAS against SR M-13, M-24, off Calapan, Mindoro, 26 February 1929

-Two revolutionary MAS against SR M-21, M-22, M-30, off Nasugbu, Luzon, 15 March 1929

-SR M-21, M-30, M-32, M-33 in support of a commando raid at Boac, Marinduque, 9 April 1929

-One revolutionary MAS vs SR M-13, M-32, M-38, off Roxas, Mindoro, 10 April 1929

-Interdiction operations, Sibuyan Sea, 8 March 1929 to present.

The Filipino Revolution was the first occasion in which Indian motor torpedo craft were used in combat. Eight motor torpedo craft were initially deployed, using a requisitioned Formosan ferry as a tender. Two additional torpedo craft were moved to the area of operations after the mid-March action.

The flotilla was charged with three missions. First, it was to search for and destroy revolutionary MAS craft rather than expose fleet destroyers to this risky task. Second, the flotilla was to investigate coastal traffic in the northwestern Sibuyan Sea and detain any vessels involved in transporting revolutionary troops or supplies. Finally, the boats were used to deliver army commandos on raids against land targets.

Events demonstrated that the motor torpedo boat, while the best available option for these missions, was not the best option overall. Configured for attacking larger vessels with torpedos, they were underarmed for combatting MAS craft with light cannons and machine guns - hence the loss of two MTB to one MAS in the three actions, despite having numerical superiority on both occasions where a boat was lost. The MAS, with a medium caliber gun and two twenty-five millimeter cannons, significantly outgunned the smaller MTB with their two fifteen millimeter cannons and two machine guns.

The raid at Boac was a dismal failure. Four MTB carrying two platoons of commandos were supposed to execute a high speed run into a wharf and then provide fire support to the commandos as they struck a rebel command post. Once detected - one assumes from the engine noise - and taken under fire by shore batteries, the boats lacked the firepower necessary to suppress protected gun positions, and lacked the protection and durability necessary to withstand much fire from those positions. The loss of one boat and a quarter of the commandos must be considered relatively light under the circumstances, and I approve of the quick decision to abort the attack by the strike leader.

In both situations, an exclusively gun-armed boat with some combination of eighty-eight, seventy-five, and thirty-five millimeter guns would probably have fared better against their opposition. On the other hand, in the interdiction role, the presence of torpedos was necessary as a real incentive for suspect vessels to submit to MTB command. This operation utilized two-boat patrols, sometimes guided by aircraft, to detect ships that might be trafficking men and material to Luzon to oppose the loyalist ground campaign. If a suspicious vessel was detected, one boat would circle at a distance while the other closed to make a visual inspection and provide verbal orders. If a vessel did prove to be under revolutionary control, it was either escorted to a friendly port or a destroyer was called in to take aboard prisoners and scuttle the vessel. In this fashion, seven successful intercepts resulted in the capture of approximately nine hundred soldiers, thirty artillery pieces, and a considerable amount of ammunition.

From the logistical perspective, the use of a tender was essential for operations. The flotilla commander has reported that the arrival of the Jagan Rane in early June has made for a huge improvement over the improvised ferry, despite Rane’s new condition and inexperienced crew. The accommodations are better and the fuel and munition transfer systems more efficient. Rane’s workshops sufficient to deal with light-caliber arms damage, and obviate the need for damaged MTB to journey to wherever the repair ship Otta happened to be - generally up near Iba, well away from the MTB’s usual operating area.

Recommendations

-The captured revolutionary MAS (the one supposedly destroyed on 19 March) should be extensively tested at sea and examined in drydock to gauge its capabilities. There should be an effort to maintain operational security as the capture of this boat is not public knowledge.

-The navy should develop a “motor gunboat”, geared specifically at the destruction of enemy light craft. These craft should train for aggressive hunter-killer operations.

-Operational experiences from the flotilla complement should be collected and incorporated in the training regime, and should also be used to guide future MTB design developments.

-The navy should continue acquisition of the Jagan Rane class tenders and practice the deployment of such vessels and their “flock”.

-Future exercises undertaken by the Navy should seek to integrate MTB operations where possible.