'Pensacola' was a US military transport convoy across the Pacific Ocean to deliver men, weapons and equipment for the strengthening of the forces in the Philippine islands group (29 November/22 December 1941).

The convoy had no official designation, and is generally known as the 'Pensacola' convoy after its primary escort ship, the heavy cruiser Pensacola, though to the US Navy it was the movement of Task Group 15.5 and to the US Army as the 'Republic' convoy for its largest transport vessel, the 17,886-ton Republic. Despatched before war had broken out between Japan and the USA, the convoy was designed to reinforce General Douglas MacArthur’s US Army Forces Far East command, which had been created to defend the US Commonwealth of the Philippines, with artillery, aircraft, munitions and fuel. The convoy was still at sea when the 'Ai' attack on Pearl Harbor and the 'M' (ii) attack on the Philippine islands group drew the USA into the war, and was then diverted to Brisbane on the east coast of Australia.

On 16 August the Department of War authorised a major reinforcement of the forces in the Philippine islands group, and MacArthur was informed that the first units would depart by sea during September. When General George C. Marshall, the US Army Chief-of-Staff, asked MacArthur if he needed a National Guard division for the USAFFE, MacArthur declined the offer on the grounds that equipment and the supply of existing forces were the essentials, and that he was confident that if these were improved speedily no further major reinforcement would be needed for the forces in the Philippine islands group to defend this US possession on the far side of the Pacific Ocean. Marshall responded that he had ordered that the US Army forces in the Philippine islands group be allocated the highest possible priority for men and equipment. Reinforcement convoys began in September and continued through to November 1941, each of them escorted from Pearl Harbor in the Hawaiian islands group by a naval vessel.

Pensacola's convoy included the gunboat Niagara, the US Navy transports Republic and Chaumont, the US Army transport ships Willard A. Holbrook and Meigs, the US merchant ships Admiral Halstead and Coast Farmer, and the Dutch merchant ship Bloemfontein.

The convoy was carrying a brigade of the US Field Artillery Corps comprising 2,000 National Guard troops in the form of the 2/131^st Field Artillery (Texas National Guard), 1 and 2/147^th Field Artillery (South Dakota National Guard) and 1/148^th Field Artillery (Idaho National Guard). The ships also carried 2,600 men of the USAAF, together with disassembled and crated aircraft. The last comprised 52 Douglas A-24 dive-bombers of the 27^th Bombardment Group (Light) in Meigs and 18 Curtiss P-40 fighters of the 35^th Pursuit Group (Interceptor) in Admiral Halstead; 48 fighter pilots of the 35^th Pursuit Group travelled in Republic and 39 newly graduated but unassigned pilots were in Willard A. Holbrook. The matériel transported included 20 75-mm (2.05-in) pieces of field artillery, anti-aircraft ammunition, 2,000 500-lb (227-kg) bombs, 3,000 30-lb (13.6-kg) bombs, 340 motor vehicles, 9,000 barrels of aviation fuel, 500,000 rounds of 0.5-in (12.7-mm) ammunition and 9,600 rounds of 37-mm anti-aircraft ammunition.

The ships departed San Francisco individually and reached Pearl Harbor on 27 November to constitute the convoy, which departed for Manila on 29 November by an indirect, southerly route. On 7 December, after news of the attack on Pearl Harbor had been received by the convoy, their crews and soldiers on board began to cover the ships' peacetime paint schemes with wartime grey paint; additional look-outs were posted to watch for Japanese aircraft, warships and submarines, all personnel were ordered to wear life jackets and carry full canteens of water, and life rafts were installed on deck.

Japanese forces landed in the Philippine islands group on 8 December, and the convoy was ordered to put in to Suva in the Fiji islands group while its final destination was decided.

It became clear over the following hours that the Japanese were rapidly overcoming Allied resistance in the Philippines islands group and many other parts of South-East Asia. On 9 December, at a meeting of the Joint Board, the chief planners of the respective services, Brigadier General Leonard T. Gerow and Rear Admiral Richmond K. Turner, agreed that the convoy should be recalled immediately. Turner wanted it to reinforce Pearl Harbor, and while Gerow agreed he added that if the convoy was not sent to the Hawaiian islands group it should be brought back to the continental USA.

The 'Pensacola' convoy was discussed in a meeting at the White House the following day, however, and at this time President Franklin D. Roosevelt suggested that the matériel should be delivered to the South-West Pacific and referred the matter back to the Joint Board, which decided at a meeting that same day to send the convoy to Brisbane in Australia via Fiji.

The convoy reached Suva on 12 December, and Australian warships were despatched in the same day to cover the convoy’s final approach. The heavy cruiser Canberra and light cruiser Perth departed Sydney for Brisbane, where on 15 December Rear Admiral J.G. Crace hoisted his flag in Canberra and departed for the New Caledonia area, where the two Australian warships were joined by the New Zealand light cruiser Achilles.

The convoy departed Fiji and steamed a zig-zag course at a speed set by the slowest ship. On 19 December, near New Caledonia the convoy’s escort was supplemented by the three Antipodean warships, and from 21 December land-based Lockheed Hudson patrol aircraft of the Royal Australian Air Force started to provide anti-submarine screening. The escort was later joined by the Australian sloops Swan and Warrego for the final part of the passage to Brisbane.

Meanwhile, the staff of Admiral Thomas C. Hart, commander of the US Asiatic Fleet, considered how the convoy could make its way from Brisbane to Manila. The Japanese advance in the Philippine islands group meant that a blockade by the Japanese navy was probable, and secondary plans to support Dutch and British commonwealth forces, in the Dutch East Indies, Malaya and Singapore, faced similar difficulties. When told of Hart’s concerns, MacArthur replied that the convoy could reach Manila with an appropriate naval escort and air support.

The situation changed however suddenly when Japanese forces began to land in Lingayen Gulf on 22 December, the day on which the convoy reached Brisbane and received an enthusiastic Australia reception as this was the first US military force to arrive on Australian soil at a time when Japanese forces were seen to threaten Australia. At this time the most capable and only battle-hardened Australian army formations were involved in the North African and Malayan campaigns.

It had been decided by this time that the most important items of equipment would be sent to Manila by air, and Major General George H. Brett of the US Army was on his way to Australia to establish the system whereby the forces in the Philippine islands group could be reinforced. The aircraft which had been sent with the convoy were assembled, but no engine coolant had been provided for the fighters and the dive-bombers lacked trigger motors, gunsight solenoids and gun mounts.

On 24 December Pensacola received orders to escort ongoing elements of the convoy as far as the Torres Strait before returning and rejoining the fleet. On 28 December, after six days of prolonged unloading because cargo had been loaded haphazardly under peacetime standards, two battalions of artillery sailed for Manila on Willard A. Holbrook and Bloemfontein, the two fastest ships. Japanese bases established in Borneo by this time made the blockade of the Philippine islands group so effective that most of the troops were unloaded at Darwin in northern Australia, whence some were sent forward to Soerabaja in Java.

Escorted by the US light cruisers Boise and Marblehead and the US destroyers Barker, Parrott, Bulmer, Stewart and Pope, Bloemfontein departed Darwin for Soerabaya with the 2/131^st Field Artillery and reached its destination on 11 January 1942, where it joined other Allied forces. After a general Allied surrender, most of its personnel became prisoners, but the headquarters of the 26^th Field Artillery Brigade left Java on 27 February 1942 and returned to Australia on 4 March 1942.

Seventeen of the 18 P-40 fighters shipped on Admiral Halstead were quickly assembled and allocated to the 17^th Pursuit Squadron (Provisional), formed 15 January with pilots of Major General Lewis H. Brereton’s US Far East Air Force sent from Luzon at the end of December 1941 to ferry the aircraft back to the Philippine islands group. The Japanese advances to the south into the Netherlands East Indies cut the ferry route and isolated MacArthur’s forces, however. On 16 January, the 17^th Pursuit Squadron instead flew across northern Australia to Darwin in the Northern Territory, where it remained until 24 January, when it moved via Kupang and Bali to its base on Java. On 1 March, the squadron evacuated Java, leaving its surviving aircraft to the Dutch military.

Eleven of the A-24 dive-bombers reached Java on 11 February, and were allocated to the 27^th Bombardment Group’s 91^st Bomb Squadron. All were lost in action. Several other aircraft of this type were later assigned to the 3^rd Bombardment Group, and most of them were shot down on 26 July while attacking Japanese shipping off Buna, New Guinea.

The battalions of the 147^th and 148^th Field Artillery were sent to Darwin to reinforce northern Australia. The 147^th Filed Artillery’s units were later reorganised as the 147^th and 260^th Field Artillery Battalions. The 148^th Filed Artillery’s units became the 148^th Field Artillery Battalion. Both battalions served in the South-West Pacific Area.