Military Wiki
BRP Rajah Humabon (PF-11)
Philippine Navy PF-11 at Balikatan 2010.jpg
BRP Rajah Humabon (PF-11)
Career (United States)
Name: USS Atherton (DE-169)
Ordered: 1942
Builder: Federal Drydock & Shipbuilding Co.
Laid down: 14 January 1943
Launched: 27 May 1943
Commissioned: 29 August 1943
Decommissioned: 10 December 1945
Struck: 15 June 1975
Fate: Transferred to JMSDF in 1955, reverted back to US Navy in 1975. Transferred to Philippine Navy in 1976.[1]
Career (Japan)
Name: JDS Hatsuhi (DE-263)
Operator: Japan Maritime Self-Defense Force
Commissioned: 1955
Decommissioned: 1975
Fate: reverted back to US Navy in 1975.
Career (Philippines)
Name: RPS Rajah Humabon (PS-78)
Namesake: Rajah Humabon was the native chieftain of Cebu in the Philippines at the time of Ferdinand Magellan's arrival in the archipelago in 1521.
Operator: Philippine Navy
Acquired: 23 December 1978
Commissioned: 27 February 1980
Recommissioned: January 1996
Decommissioned: 1993

BRP Rajah Humabon (PF-6) - 28 June 1980[2]

BRP Rajah Humabon (PF-11) - January 1996
Homeport: Naval Base Cavite
Fate: in active service, as of 2022
General characteristics
Class & type: Datu Kalantiaw class (Cannon class)
Type: Destroyer Escort / Frigate
Displacement: 1,390 tons standard, 1,620 tons full load
Length: 306 ft (93 m)
Beam: 36.66 ft (11.17 m)
Draft: 8.75 ft (2.67 m)
Installed power: 6,140 hp (4,580 kW)
  • 2 × GM-EMD 16-645E7 (Turbo) Main Diesel Engines[3]
  • 2 × GM-EMD 8-268A Auxiliary Diesel Engines with 200 kW Generator
  • 1 × GM-EMD 3-268A Auxiliary Diesel Engine with 100 kW Generator
  • 2 × shafts
Speed: 18 knots (33 km/h) maximum
Range: 6,000 nmi (11,000 km) at 14 knots (26 km/h)
Complement: 165
Sensors and
processing systems:
  • Raytheon AN/SPS-64(V)11 Surface Search and Navigational Radar[4]
  • Furuno navigation radar
  • AN/SQS-17B Hull mounted Sonar[3]
  • Mk.52 GFCS with Mk.41 Rangefinder for 3-inch (76 mm) guns[3]
  • 3 Mk.51 GFCS for 40 mm guns[3]
  • 3 × 3"/50 caliber gun Mk.22 dual purpose guns[3]
  • 3 × Mk.1 Mod.2 Twin L/60 caliber Bofors 40 mm gun[3]
  • 6 × Mk.10 70 caliber Oerlikon 20 mm cannon
  • 4 × M2 Browning 50 caliber 12.7 mm heavy machine guns
  • The BRP Rajah Humabon (PF-11) is a frigate of the Philippine Navy, and is the last World War II-era destroyer escort/frigate active in its fleet and is one of the oldest active warships in the world. She is one of three ex-USN Cannon-class destroyer escorts that served the Philippine Navy, the others being BRP Datu Sikatuna (PF-5/PS-77) and BRP Datu Kalantiaw (PS-76).


    United States Navy

    as USS Atherton c. 1945

    Commissioned in the US Navy as the USS Atherton (DE-169) in 1943, she was mostly assigned at the Atlantic theatre doing patrols and anti-submarine missions. She was credited of having destroyed a German U-boat, the U-853 off the coast of Rhode Island, on 9 May 1945. She served in the Pacific theatre in the middle of 1945 until she was decommissioned and placed in reserve on 10 December 1945. For her service during World War II, she was awarded with one battle star.[5]

    Japan Maritime Self-Defense Force

    as JMSDF Hatsuhi c. 1967

    She was transferred to the Japanese government as JDS Hatsuhi (DE-263) on 14 June 1955. Together with her sistership JDS Asahi (DE-262), they became one of the first warships of the newly organized Japan Maritime Self-Defense Force. As newer ships became available to the JMSDF, both ships were decommissioned and returned to the US Navy on June 1975.[4][5][6]

    Philippine Navy

    BRP Rajah Humabon c. 2009

    Remained laid-up in Japan, she was transferred to the Philippine government in 13 September 1976[7] and was sold as Excess Defense Article on 23 December 1978.[3][4] As a Philippine Navy ship, she was named RPS Rajah Humabon (PS-78), and was towed to South Korea for an extensive refit and modernization in 1979.[3] During this period South Korea also turned over 2 of their own ex-USN Cannon class ships to the US Navy in 1977, namely the Kyong Ki (DE-71) / USS Muir (DE-770) and Kang Won (DE-72) / USS Sutton (DE-771). These were also turned-over by the US to the Philippine government, which were later on cannibalized for use as parts hulk to upgrade and repair the Rajah Humabon and her sistership Datu Sikatuna, and provide both ships with additional guns and improved machinery.[8][9]

    With these upgrades, she was formally commissioned to the Philippine Navy on 27 February 1980,[3] and formed the backbone of the Philippine Fleet together with 2 of her sister ships and other ex-US Navy destroyer escorts. She was renamed and reclassified as BRP Rajah Humabon (PF-6) effective 23 June 1980,[2] now using the "BRP" ship prefix in lieu of "RPS" and following a new standard classifying it as a "Frigate", and served until 1993 when she was retired. But due to pressing needs, she was later called back into service in 1995 after being overhauled at the Cavite Naval Dockyard by Hatch & Kirk Inc., and was formally recommissioned in January 1996 as BRP Rajah Humabon (PF-11) with a new hull number.[4]

    Another minor refit between 1995 and 1996 saw changes in the ship's weapons, sensors and engine systems. Her anti-submarine weapons and equipment were removed due to lack of spare parts. This includes the EDO SQS-17B hull-mounted sonar, a Mk.9 depth charge rack, six Mk.6 depth charge projects aft and a Hedgehog Mk.10 anti-submarine projectors forward, as well as Mk.38 anti-submarine torpedoes in two triple tube amidships.[4][10] This totally removed her anti-submarine warfare capabilities, which was outdated on modern conditions. But it was reported in 2005 that her fore Hedgehog ASW is still operational, together with her 8 K-gun Mk6 depth charge projectors and SQS-17B sonar,[3] although recent photos does not show the depth charge projectors on its usual location.

    She had been experiencing hull problems but was repaired with the assistance of the US Navy crew of USS Salvor during CARAT 2002 dive training operations held in Manila Bay.[10][11]

    Additional electronic upgrades were made, including the installation of a Furuno Satellite Communication system and a mast-mounted FLIR package.[10][12]

    Present Status

    Her current classification is Patrol Frigate. As recent as May 2010 she was part of the Philippine Navy contingent for the RP-US Balikatan 2010 exercises,[13] and continue to operate from the Philippine Navy's main naval base in Cavite and visits the Navy Headquarters in Manila. She is currently assigned to the Patrol Force of the Philippine Fleet.[14]

    Technical details


    Although fairly well-armed, most of her weapon systems are manually operated and are of World War II origin.

    The three Mk.22 3"/50 caliber guns, the ship's primary weapons, have a range of up to 14,600 yards (13,400 m) and are also capable of being used as limited anti-aircraft weapon. The guns were directed by a Mk.52 gun fire control system with a Mk.41 rangefinder, but this appears to be non-operational.

    She also carries a total of three twin Mk.1 Bofors L/60 40 mm anti-aircraft guns directed individually by Mk.51 gun fire control system, six Mk.4 20 mm Oerlikon cannons, and four M2 Browning 50 caliber machine guns.[4][10]

    All anti-submarine weapons were removed as of 1996.[10]


    The ship is powered by two EMD 16-645E7 turbo-blown diesel engines with a combined power of around 6,140 bhp (4,580 kW) driving two propellers. The main engines can propel the 1,620 ton (full load) ship at a maximum speed of around 18 knots (33 km/h). It has a range of 6,000 nautical miles (11,110 km) at a speed of 14 knots (26 km/h).[3] It replaced the original four EMD 16-278A diesel engines during the ship's overhaul in 1996.[15]


    The ship is equipped with a Raytheon AN/SPS-64(V)11 short range surface search and navigation radar[4] and a Furuno navigation radar, replacing the SPS-5 surface search radar and the RCA/GE Mk.26 navigation radar.[3] Previously equipped with an EDO AN/SQS-17B hull-mounted sonar, it is said to be deleted in 1996 due to lack of spare parts and obsolescence[10][16] although it was reported to be still present in 2004.[3]

    Notable Operations


    On 17 June 2011 the Rajah Humabon was sent for patrols around the Scarborough Shoal after China announced that its biggest maritime patrol vessel, the Haixun 31, will be sent to the area on its way to Singapore.[17][18]


    On 2 February 2000, the Rajah Humabon fired warning shots at two Chinese fishing boats near Scarborough Shoal. According to Navy chief Vice Admiral Luisito Fernandez, the Rajah Humabon was forced to fire warning shots to avert a collision with two Chinese fishing boats and only after the Chinese boats refused to respond to radio contact, loudspeaker, sirens, and flashing lights.[19]

    On 22 June 2002, Rajah Humabon together with BRP Rizal visited Shanghai, China for a goodwill visit.[20]


    The Rajah Humabon, together with BRP Leopoldo Regis (PG-847), BRP Dagupan City (LC-551), BRP Artemio Ricarte (PS-37), USS Essex (LHD-2), and USS Tortuga (LSD-46) were part of the naval component of the US-RP Balikatan 2009 bi-lateral exercises held on April 2009.[21]

    Again Rajah Humabon, together with BRP Dagupan City (LC-551), and BRP Apolinario Mabini (PS-36), USS Essex (LHD-2), and USS Denver (LPD-9) were part of the naval phase of the US-RP Balikatan 2010 (BK10) bi-lateral exercises held on March 2010.[22]

    On 14 to 16 August 2012, the Naval Forces Northern Luzon (NFNL) conducted a small-scale Naval Exercise code-named SAGEX 02-12 at the waters of South China Sea. BRP Rajah Humabon together with BRP Gregorio del Pilar and BRP Liberato Picar participated under Naval Task Force (NTF) 11. The exercise includes patrol, simulated tracking of targets and interdiction and capped by live firing exercises.[23]

    Rajah Humabon, together with BRP Gregorio del Pilar participated in the sea phase exercises with the US Navy during the Balikatan 2013 from April 5 to 17, 2013.[24]

    Notable Popular Culture

    • BRP Rajah Humabon was among the Philippine Navy ships who battled invading People's Liberation Army - Navy ships in Dale Brown's 1991 novel Sky Masters. In this novel, she was classified as a PF class frigate, and was equipped with a four-shot Mk141 Harpoon missile launcher.[25]




    1. NavSource Online: Destroyer Escort Photo Archive. USS Atherton (DE 169).
    2. 2.0 2.1 Philippine Navy Information Manual 1995 - Adoption of Pilipino Translation of "Bapor ng Republika ng Pilipinas"
    3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Saunders, Stephen: Jane's Fighting Ships 107th Edition 2004-2005. Jane's Information Group Ltd, 2004.
    4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Wertheim, Eric: The Naval Institute Guide to Combat Fleets of the World 15th Edition, page 550. Naval Institute Press, 2007.
    5. 5.0 5.1 Dictionary of American Naval Fighting Ships. "Atherton" page.
    6. Dictionary of American Naval Fighting Ships. "Amick" page.
    7. "USS Atherton (DE-169)". Retrieved 2011-11-06. 
    8. Dictionary of American Naval Fighting Ships. "Muir" page.
    9. Dictionary of American Naval Fighting Ships. "Sutton" page.
    10. 10.0 10.1 10.2 10.3 10.4 10.5 Manokski's ORBAT @ Hueybravo. BRP Rajah Humabon page.
    11. Faceplate Vol.7 No.1, April 2003 "USS Salvor (ARS 52)" page.
    12. Jane's Fighting Ships 105th Edition 2002-2003.
    13. Philippine Navy Gallery Send Off Ceremony of Sailors and Marines to Balikatan 2010.
    14. Philippine Fleet Official Website. Commissioned ships and crafts.
    15. Philippine Panorama - 26 November 1995 Repowering Old Ships To Make Them Good As New by Randy V. Urlanda
    16. Friedman, Norman: The Naval Institute Guide to World Naval Weapons Systems 1997-1998, page 628. US Naval Institute Press, 1997.
    17. "Largest warship ng Philippine Navy, magpapatrolya sa Scarborough Shoal". Bombo Radyo Philippines. 2011-06-16. Retrieved 2011-06-20. 
    18. "Biggest Phl warship on patrol in Spratlys". (The Philippine Star). 2011-06-17. Retrieved 2011-06-20. 
    19. South China Tensions Promote Discussions on a Code of Conduct.
    20. Seawaves Magazine, June 2002. Warships Port Visit.
    21. US Navy News Balikatan 2009.
    22. Commander US 7th Fleet Balikatan March Imagery.
    23. Naval Forces Northern Luzon. "NAVAL FORCES NORTHERN LUZON CONDUCTS NAVAL EXERCISE". Philippine Navy. Retrieved 2012-08-21. 
    24. Asianet (2013-04-09). "Balikatan to make PN, USN more 'interoperable'". GlobalPost International News. Retrieved 2013-04-18. 
    25. Brown, Dale: Sky Masters ISBN 978-1-55800-915-8

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