AND MOBILE COMMUNICATION UNIT
IN THE SOUTHWEST PACIFIC AREA
In the early years of the war in the Southwest Pacific Area the US Army Signal Corps utilised small boats mainly small schooners fitted with manual keyed, medium powere CW radio equipment plus small portable sets for ship to shore operation.
In the spring of 1944, Seaborne Communications was born, but was not officially authorized before January of 1945. In the post years of the war, many vessels of various types were pressed into service, such as the FP47 Communication Boat. The purpose of these floating Signal Centres was:-
to provide communications during assault phases
to provide communications during the period that fixed facilities were being set up ashore
to function as standby or emergency facilities in case of difficulty ashore
The immediate plan was to have invasion vessels and floating Army Command and Administrative Network ACAN stations on the spot right after a landing was secured. At this point in time a GHQ major radio communication station, so close to the action, was unheard of. Brigadier General Spencer Ball Akin obtained three ships to be under Army control - NOT Navy - but manned by the Navy. These three ships would be outfitted for the invasion of Leyte in the Philippines all equipped with Army Signal Corp units. The Seaborne Signal Corps echelon obtained:-
three US Navy vessels which were known as Patrol Craft Escorts (Rescue) PCE (R) 848, PCE (R) 849, and PCE (R) 850
a former revenue cutter / schooner "Apache"
a private yacht (1890 vintage)
a boat originally constructed from combined passenger and freight traffic in Alaskan waters FP-47
Three PCE (R)s
The three PCE (R) craft had their former large hospital area equipped with two AT / 20 Transmitters an Australian manufactured set rated at 500 watts. The Radio Receivers that were used were a mixture of Navy type shielded receivers, Super Pros and AMR 100s which was an Australian version of the HRO. This enabled operation of two CW manual radio circuits from each ship and provided extra receivers for intercept and monitoring. AN / TRC-3s with Teletype and telephone channels were also installed for ship-shore and Ship-ship communications. Additionally SCR-300s and SCR-284s were placed on board for miscellaneous uses as required. These small sets were frequently used for communication between ship and shore or reconnaissance parties and provided invaluable initial communication contact. Appropriate cryptographic equipment was also utilised.
The PCE (R) 848 went into the invasion with Brig. Gen. Akin aboard. PCE (R) 849 was backup for PCE (R) 848 and had Brig. Gen. Akin's deputy aboard. PCE (R) 850 had the 6th Army Signal Corp aboard.
The 50-year-old schooner, "Apache" which had many uses, was formerly President McKinley's yacht. The yacht was outfitted in Sydney, Australia with necessary gear. The good old faithful COMM. FP-47 was its backup. The "Apache" was mainly intended to be used as a Broadcast ship and it was equipped with a 10KW Amalgamated Wireless of Australia AWA transmitter. Power units were also included so that the transmitter was independent of the ship's power. A modern broadcast studio with recording equipment and a control room were installed. "Apache" was also provided with VHF, telephone and Teletype equipment as well as SCR-300s and SCR-284s.
The FP-47 was was used as a Press Ship for use by War Correspondents and was initially equipped for CW operation but was later converted to high speed Boehme equipment. Australian made AT/20 transmitters were also installed.
Three LCM's furnished by the US Navy had mobile communications equipment aboard to establish land terminals.
Ocean Lighters and a Paddle Steamer!!
For the construction of the floating ACAN stations, 7 ocean lighters (OL's) which were more or less barges, were ordered from a Sydney, Australia shipyard. They were 120' long with a 24' beam. They were new and were originally intended to carry cargo.
NARA Photo:- SWPA-SC-44-6656
Ocean Lighter OL-3 at Walsh Bay, Sydney on 29 April 1944
Useage of the Ocean Lighters was as follows:-
|1||Radio Teletype Receiver Barge, equipped with Radio teletype diversity receivers, AN/FCC-1 bays and one Western Electric single side-band receiver as well as miscellaneous testing and monitoring equipment and VF bays for single side-band operation.|
|2||Transmitter barges. These barges were equipped primarily with AT/20 (550 Watt) and Wilcox 96C (3KW) transmitters. One barge contained the single side-band transmitter as well as the amplifier stage of a Press Wireless 40 KW transmitter. Rack mounted frequency shifters for radio teletype modulation.|
|1||Tape Relay Center & CW Receiver Barge, equipped with CW receiver positions, Teletype typing reperforators and Teletype transmitting heads and an 80 line Western Electric manual telephone exchange for inter barge communication.|
|1||Press Barge, equipped with Press Wireless 15KW Transmitters, writing accommodations for correspondents.|
|1||Fitted at Bulimba in Brisbane with SIGSALY Classified equipment. This was OL-31. The SIGSALY equipment on board OL-31 had to be processed through the headquarters radio station single side-band equipment to the War Department in Washington D.C. This required wither a wire circuit of a VHF radio link to get the information from HQ's to OL-31.|
All the barges were fitted with AM/TRC-3 radio link equipment of communication between barges as well as radio keying and control lines. Terminal frames were provided so that cable and wire links to other barges and to shore could be easily connected. Each barge contained two each 50KW Diesel power units, modified with heat exchangers for salt water cooling.
NARA Photo:- SWPA-SC-44-9875
OL-22 midships, looking starboard, showing position
of Teletype Test Unit. Brisbane 17 October 1944
NARA Photos:- SWPA-SC-44-9884
OL-22 Starboard side, looking forward, showing 96-C
connections and cable runs. Brisbane 17 October 1944
NARA Photo:- SWPA-SC-44-9887
OL-28 aft, looking forward and starboard, showing
manual positions. Brisbane 17 October 1944.
The original plan called for 3 ACAN stations, using 6 of the OL's. The 7th, OL31, was equipped with a SIGSALY terminal at Bulimba in Brisbane. The first station consisted of OL22 receiver and OL30 transmitter.
Approximately seventy-five Army personnel were transferred to Seaborne to accomplish the task. In October of 1944, the OL22 and OL30 proceeded to Hollandia, Dutch New Guinea, and set in and handled traffic there for a few months, then moved on to Manila Bay in the Philippines. In early June 1945, OL23 receiver and OL29 transmitter arrived. George Sullivan could not locate any information on the other two OL's. He believed it was possible that they became Signal Corp supply and repair boats.
A support vessel for the Ocean Lighters was an Australian wooden paddle wheel steamer "Weeroona" (1910) which had previously been used for Australian coastal passenger traffic from Melbourne to Queenscliff. The paddle wheel steamer was fitted out as quarters for the men required to operate and maintain the communications equipment on the Ocean Lighters. Five high bunks were installed on the main deck with canvas to protect the men from the elements. The crew provided by the Transportation Corps to maintain and handle the Ocean Lighters had their quarters on board their individual ocean lighter. The Ocean Lighters and "Weeroona" were all relocated to new positions by being towed.
Mobile Communication Unit
A Mobile Communication Unit was formed to work in conjunction with the Seaborne Communication Unit to facilitate easily established highly mobile communication facilities in a minimum time. It also served on a temporary basis until such time as fixed semi-permanent facilities could be established under suitable cover.
The Mobile Communication Unit used for the Leyte landings was smaller than that used for the Luzon operations but the type of equipment and service provided were similar. The following equipment was used by the Mobile Communication Unit in the Luzon operation which included the landings at Lingayen Gulf:-
34 off 2.5 ton 6 x 6 WD trucks
|Quantity||Type of Equipment|
|5||Mounted with SCR-399s in HO-17 shelters|
|1||Mounted with a 2 position TC/2, Telephone Central Office Equipment|
|1||Message truck containing filing cabinets, typewriters, blank forms, stationary and miscellaneous items|
|1||CW Radio receiving truck with 12 each BC-779 (Super Pro) receivers and 8 each NC-86 typewriters mounted|
|1||Radio Transmitter truck containing 4 each AT/20 (500 watt) transmitters, mounted|
|1||Teletype and cryptographic repair shop truck with work benches, tools and spare parts|
|1||Teletype operations truck with 13 each EE-97 teletype machines, mounted|
|1||Radio Repair truck with tools, work bench and spare parts|
|1||Kitchen with gasoline field ranges, mounted|
|1||2 each BC-339 (1 KW) transmitters, Assembled for operation on the ground.|
|1||2 each PE-85-L Diesel power plants capable of being operated on the truck but normally operated on the ground.|
|1||Petroleum truck mounted with 1,200 gallon tank for white gasoline (power units) and space for 12 drums of oil or grease. Complete with power pump.|
|2||Radio teletype receiving trucks. Each mounted with 2 each AN/FRR-3 Press Wireless radio teletype diversity receivers, two AN/FGG-1 bays patch panel. One Superpro receiver and one teletype machine for monitoring.|
|1||Shop truck with heavy tools. For repair of power units, electrical power installations, plumbing and carpentry etcetra.|
|4||Each mounted with 2 each AM/TRC-1 terminals including 2 each CF-1-A bays, 2 each CF-2B bays and four EE-101 ringers.|
|2||Miscellaneous cargo loaded equipment.|
|8||Cargo loaded with 45 days rations.|
Two Each 6 Ton Vans
|1||Cargo loaded with a complete three position TC-10 Teletype Central Office Equipment and 350 telephones, TP-8.|
|1||Cargo loaded with Teletype equipment for four radio teletype terminals and automatic cryptographic equipment.|
Two Each Four Ton Prime Movers
|1||Mounted with 1200 gallon water tank and pump.|
|1||With 16 ton flat bed trailer for transporting bulldozer.|
28 Each One Ton, Two Wheel Trailers
|20||Mounted with power units PE-95-H (10 KW)|
|6||Cargo loaded with miscellaneous wire and rubber cable assemblies.|
|1||Mounted with 250 gallon water tank.|
|1||Mounted with 300 gallon tank for Diesel fuel.|
Two Each Special 4-Wheel Trailers
|1||Mobile Kitchen with Wiles Steam Kitchen (Made in Australia).|
|1||Mobile 220 cubic foot refrigerators|
Twelve Miscellaneous Vehicles
|1||Four ton wrecker.|
|6||3/4 ton 4 x 4 weapons carriers with tools, equipment and wire and cable for five man light wire construction and maintenance teams.|
|1||K/43 pole line construction truck|
|2||DUKWI's with SCR-399's in shelters HO-17 and 2 Ea. PE-75's on rear deck.|
|1||K/44 Earth Borer.|
When Gen. MacArthur landed in Australia, he made a promise to the people of the Philippines, "I shall return". He specified that he wanted a radio broadcast ship in the convoy so that when he stepped ashore in the Philippines - which was 3 hours after the invasion started - he could broadcast that message to the people. It was also going to be used to broadcast to the guerrillas, plus press service to the world.
The combined and co-ordinated efforts of the Seaborne and Mobile Communication Units in the Leyte operation were very successful. General MacArthur was transported to Leyte on board the cruiser "USS NASHVILLE". Whilst communication silence was maintained during the voyage, a small detachment of Signal Corps personnel were able to get message to MacArthur by Naval "Fox" broadcasts. They used special cryptographic equipment for handling the Genera's traffic as well as a Willcox 96-C transmitter and VHF - carrier equipment.
Once communication silence was lifted at 1000 hours, communication by AN/TRC-1 and CW manual radio was established between USS NASHVILLE and vessels of the Signal Corps Seaborne Fleet. The APACHE sent out General Douglas MacArthur's communique which began with the words:-
"In a major amphibious operation we have seized the Eastern Coast of Leyte Island in the Philippines."
At 1400 hours a truck of the Mobile Communication Unit equipped with a VHF Radio Terminal and miscellaneous equipment rolled ashore from a landing barge. Within 15 minutes they had established contact with USS NASHVILLE and APACHE. Shortly after this General Douglas MacArthur waded ashore and after an inspection of the beachead he walked over to the communications truck and spoke those famous words into a waiting microphone:-
"I have returned. By the grace of Almighty God our forces stand again on Philippine soil - soil consecrated in the blood of our two peoples."
His words were relayed to USS NASHVILLE and broadcast to the people of the Philippines and later were broadcast by both APACHE and USS NASHVILLE and by pre-arrangement were received by stations in California and Australia for rebroadcast throughout the world.
The rest of the Mobile Communication Unit went ashore and setup the communications for MacArthur's new Advanced General Headquarters. Construction of new communication facilities at Leyte was slowed down by the rain, and muddy conditions. The Luzon operation was underway before permanent installations were completed at Leyte.
The Intercept Section in the Mobile Communication Unit was equipped with radio receivers and cryptographic equipment to intercept and decode traffic on pre-selected circuits of their own forces. After being decoded and screened this traffic was distributed to appropriate Staff sections in Advanced GHQ SWPA. This made it possible for staff officers to maintain a running and current account of selected tactical units.
The Intercept Section had been started in Port Moresby and was used throughout the northward advance. The Intercept Section used a large six-ton van with receivers mounted at operating positions. The six-ton van proved impractical in the Philippines due to the poor roads and extreme muddy conditions.
Japanese Air Raids
On 25 October 1944 four Japanese bombers made one of many raids over Leyte Gulf. One of the PCE (R) boats was hit by fragments of a Japanese bomb. The ships gunners managed to shoot down the bomber which hit the water about 1,000 yards off the port bow. The bomb fragments pierced the first superstructure deck entering the Captain's cabin and wardroom. Two crew members were killed and 10 others were wounded. Signal Corps members were not amongst the dead or injured.
On 28 October 1944 another one of the PCE (R)'s was straddled by three Japanese bombs, with the nearest hitting about 20 yards away. Bomb fragments put about 80 holes in the starboard side and 20 holes on the port side of the ship. Six crew members were killed and 25 including the Captain were wounded. Some communications equipment was damaged but the ship continued to operate until it was sent to a rear area for repair and re-equipping.
"Voice of Freedom"
Whilst at Leyte, APACHE sent out a daily 30 minute broadcast to the Philippines known as the "Voice of Freedom". When APACHE needed to move forward and maintain radio silence, a Wilcox 96-C transmitter was set up ashore to facilitate the daily broadcasts.
By Christmas Day 1944, most of the major preparations for the Luzon operation were completed. the Mobile Communication Unit started to load their equipment on to LST's and other boats. Portions of the Mobile Unit joined the Seaborne Unit for the trip to Luzon to take part in the early landings. Another portion of the Mobile Unit accompanied the assault troops so they could be placed ashore early in the landings.
APACHE experienced some engine problems enroute and had to be towed for a short while. Once it was determined that the issue was water in the fuel supply, they used fuel from the Signal Corps tanks on board to get underway again allowing APACHE to arrive off Lingayen with the rest of the convoy.
Once communication silence was lifted, the Seaborne Signal Corps Fleet went on the air and was soon working solidly with channels to Leyte and ship to ship circuits. The FP-47 operated a Boehme circuit back to Leyte where commercial press facilities were available back to the USA. The APACHE commenced its broadcast routine again and before too many hours the news of the landings had been spread around the world.
The day after the landings the first trucks of the Mobile Unit went ashore on White Beach, near the town of San Fabian. The trucks were equipped with VHF terminals and they were also carrying SCR-300's for miscellaneous communication. Within an hour the trucks were in communications with elements of the Seaborne Unit and also with the Cruiser USS BOISE which had taken General Douglas MacArthur to the operation. These first trucks of the Mobile Unit reconnoitered suitable sites to set up the remainder of the Mobile Unit equipment and to select road approaches and to provide communications for General MacArthur whilst he was ashore and for other members of his staff.
MacArthur established an Advanced Echelon of GHQ at the town of Dagupan. The rest of the Mobile Unit came ashore over the next two days. With road and bridge problems a good portion of the Mobile Unit came under Japanese fire on the beach while critically needed trucks were moved into Dagupan on LCM's.
A TC/2 switchboard for MacArthur's Advanced Echelon GHQ was established from a truck and later replaced by a TC/10. CW contact with San Francisco, using a BC 3339 transmitter (1 KW) was soon in service and circuits back to Leyte and other units in the area quickly established. A Signal Centre was established in an old two story building across from the market place in Dagupan. A semi-permanent installation was operating within five days of arriving in the town.
The men and equipment of the Mobile Communication Unit continued to support General Douglas MacArthur on his push forward to Manila.
Signal Corps "Mariners" sail into Manila Bay
The six steel ocean going lighters of the Signal Corps Seaborne Communications Unit were towed from Hollandia accompanied by a wooden paddle wheel steamer. They sailed into Manila Bay past Corregidor. They were dubbed, "Gen. Akin's Grand Fleet."
At about 0900 hours Manila time, on 15 August 1945, a routine Teletype Conference in the Signal Center in the former Manila Water Works building was underway with "WAR", which was the Teletype Conference Room in the Pentagon, Washington D.C. The conference was interrupted and Manila was advised to stand by to receive an important message. The following message was received:-
"NR 1408 WITH REFERENCE TO PARAGRAPH TWO OF WARX FOUR NINE ONE EIGHT TWO CMA PAREN FROM MARSHALL TO MACARTHUR CMA INFO NIMITZ DEANE AND WEDEMYRE PAREN YOU ARE HEREBY OFFICIALLY NOTIFIED OF JAPANESE CAPITULATION PD YOUR DIRECTIVE AS SUPREME COMMANDER FOR THE ALLIED POWERS IS EFFECTIVE WITH RECEIPT OF THIS MESSAGE."
SO. WEST PACIFIC, U.S.A. Sig. Corps. 1941 - WWII
- 1945 "As I Recall" - Book 1.
by George J. Sullivan
Can anyone help me with more information?
"Australia @ War" Research Products
© Peter Dunn 2015
This page first produced 10 February 2017
This page last updated 10 February 2017