Warplanes of the USA: Martin P5M Marlin

Martin P5M Marlin

(Bill Larkins Photo)

U.S. Navy Martin SP-5B Marlin (BuNo. 135539) of Patrol Squadron 48 (VP-48) at Naval Air Station North Island, California, on 27 January 1967.

The Martin P5M Marlin (P-5 Marlin after 1962), built by the Glenn L. Martin Company of Middle River, Maryland, was a twin piston-engined flying boat that entered service in 1951, and served into the late 1960s with the United States Navy performing naval patrols. It also served with the United States Coast Guard and the French Navy. 285 were produced. Built as a successor to the PBM Mariner, it had better engines, an improved hull, and a single vertical fin tail. The XP5M Marlin prototypes were based on the last PBM-5 Mariners, the company designation being Model 237. The type was heavily improved, again leading to the P5M-2 (Model 237B), which was redesignated SP-5B. A number of P5M-1 models were also used for training, designated TP-5A (after 1962).

The Marlin was designed as a gull-winged aircraft to place the engines and propellers high above the spray. Power was provided by two Wright R-3350 radial engines. The rear hull did not lift sharply from the water at the tail, instead rising up steadily, a Martin innovation; this gave the aircraft a longer base of flotation and reduced "porpoising" over waves. The prototype had nose and tail turrets with twin 20 mm (0.79 in) cannon in each, as well as a dorsal turret with two 0.5 in (12.7 mm) M2 Browning machine guns. The cockpit area was the same as the Mariner's. It first flew on 30 May 1948.

The first of 167 production P5M-1 aircraft was produced in 1951, flying on 22 June 1951. Changes from the prototype included a raised flight deck for improved visibility, the replacement of the nose turret with a large radome for the AN/APS-44 search radar, the deletion of the dorsal turret, and new, streamlined wing floats. The engine nacelles were lengthened to provide room for weapons bays in the rear.The P5M-1 was followed by 116 P5M-2 planes. These had a T-tail to put the tail surfaces out of the spray, an AN/ASQ-8 MAD boom at the rear of the tail-tip, no tail guns (the gun position replaced by the antenna for the AN/APN-122 Doppler Navigation Set), better crew accommodation, and an improved bow to reduce spray during takeoff and landing.

The last flying boat operations of the United States Navy were Market Time patrols of VP-40. Maritime surveillance patrols began in February 1965 to locate small craft transporting supplies from North Vietnam to Viet Cong units in South Vietnam. VP-40 operated from seaplane tenders and patrolled off the Mekong delta between Phú Quốc and Vung Tau. The last U.S. Navy P5M, redesignated as SP-5B, was flown to NAS Patuxent River, Maryland on 12 July 1968 for interim storage pending construction of display area at the Smithsonian Institution in Washington, D.C. As a display area at Smithsonian did not materialize, the aircraft was later relocated to the National Naval Aviation Museum at NAS Pensacola, Florida where it is currently on display. The final Marlin flight was carried out by VP-40, to San Diego Bay on 6 November 1967. (Wikipedia)

(USN Photo)

Martin P5M-1 Marlin of patrol squadron VP-45 Pelicans, bein prepared for launch at the Naval Air Station Jacksonville, Florida, in 1954.

(USN Photo)

Martin P5M-1 Marlin (BuNo. 135464) of patrol squadron VP-45 Pelicans about to launch from Naval Air Station Jacksonville, Florida, in 1954.

(USN Photo)

U.S. Navy Martin SP-5B Marlin (BuNo. 135542) from Patrol Squadron VP-49 taking off from Guantanamo Bay, Cuba, on 15 March 1963.

(USN Photo)

A U.S. Navy Martin SP-5B Marlin patrol plane (BuNo 135517) uses JATO (jet assisted take-off) rockets to lift from the waters of Cam Ranh Bay, South Vietnam, to begin a patrol of the coast, in April 1967. The plane was attached to Patrol Squadron 40 (VP-40), the last seaplane squadron deployed in Southeast Asia.

(USN Photo)

U.S. Navy Martin P5M-2S Marlin (BuNo 135531) from Patrol Squadron VP-31 Genies in flight, June 1962.

(USN Photo)

U.S. Navy Martin P5M-2 Marlin from Patrol Squadron VP-47 Golden Swordsmen in flight near Naval Air Station Alameda, California.

(USN Photo)

U.S. Navy Martin P5M-2 Marlin (BuNo. 137847) from Patrol Squadron VP-40.

(USN Photo)

U.S. Navy Martin P5M-2 Marlin (BuNo. 137847) from Patrol Squadron 40 (VP-40) in flight.

(USN Photo)

U.S. Navy Martin P5M-1 Marlin.

(NMNA Photo)

Five U.S. Navy Martin P5M-1 Marlin of Patrol Squadron 56 (VP-56) "Dragons" in flight, circa in 1954.

(USN Photo)

U.S. Navy Martin P5M-2 Marlin in flight, showing the open bomb bays in the engine nancelles. This aircraft is still equipped with the tail guns which were later replaced by a MAD boom.

(USN Photo)

U.S. Navy Martin P5M-1 Marlin from Patrol Squadron VP-40 in the water linked to what appears to be a fuel point at Naval Air Station Whidbey Island, Washington, 1953.

(NMUSN Photos)

A Martin P5M Marlin being hoisted from the deck of USS Salisbury Sound (AV 13) by a huge crane, 8 July 1953. Salisbury Sound was serving with the Seventh Fleet during this time and the P5M flying boas patrolled thousands of square miles per day.

(USN Photo)

U.S. Navy Martin P5M-2 Marlin (BuNo. 135534) from Patrol Squadron VP-47 being hoisted aboard the seaplane tender USS Currituck (AV-7). VP-31 was deployed to Kodiak, Alaska, from 27 May to 30 September 1962.

(NMNA Photo)

U.S. Navy seaplane tender USS Pine Island (AV-12) with a Martin SP-5B Marlin (BuNo. 135542) of Patrol Squadron VP-48 on a crane in San Diego Bay, circa 1963.

(USN Photo)

U.S. Navy submarine USS Guavina (AGSS-362) fueling a Martin P5M-1 Marlin of Patrol Squadron 44 (VP-44) in the open sea off Norfolk, Virginia (USA), in 1955. Prior to the Second World War, several submarines were fitted to refuel seaplanes. During the war, Germany and Japan used this technique with some success. After the war this technique was experimented with within the U.S. Navy. It was planned to use submarines to refuel the new jet powered Martin P6M Seamaster flying boats. As part of this program, Guavina was converted to carry 160,000 gallons (605,700 l) for aviation fuel. To do this, blisters were added to her sides and two stern torpedo tubes were removed. When the P6M project was canceled, there was no further need for submarine tankers. This concept was never used operationally in the U.S. Navy.

(USN Photo)

U.S. Navy Martin SP-5B Marlin (BuNo. 135533) of patrol squadron VP-40 Fighting Marlins landing after its last operational flight in San Diego Bay on 6 November 1967. It is now on display at the National Museum of Naval Aviation at Pensacola, Florida.

(Bill Larkins Photo)

(Greg Goebel Photo)

(USN Photo)

The U.S. Navy's last Martin SP-5B Marlin (BuNo. 145533) in the markings of its last operator, Patrol Squadron VP-40 Fighting Marlins, at the U.S. National Museum of Naval Aviation at Pensacola, Florida. The aircraft had been retired and transferred to the Smithsonian Institution in 1968 and was turned over to the Museum in 1977.

(Rob Bixby Photo)

Martin SP-5B Marlin (BuNo 135533), is now displayed inside the new hangar (as of the spring of 2010) and much of the exterior has been restored. The restoration is being financed by the museum and the Mariner/Marlin Association.

(USCG Photo)

USCG Martin P5M-2G Marlin (BuNo. 1312), 1955.

Seven P5M-1Gs and four P5M-2Gs were built for the United States Coast Guard for air-sea rescue service, but they found the planes difficult to maintain and surplus to requirements. They were subsequently transferred to the U.S. Navy, which redesignated them as TP-5As and used them as training aircraft, since they had no provision for armament.

(Bill Larkins Photo)

Martin P5M-1G (BuNo. 1287) USCG, on beaching gear, assigned to CGAS San Francisco in 1955.

(NMAM Photo)

U.S. Coast Guard Martin P5M-2G Marlin (BuNo. 1318), assigned to Coast Guard Air Station San Diego in flight on 28 January 1958.

The French Navy took delivery of ten former U.S. Navy Marlins between 1957 and 1959 to replace Short Sunderlands in maritime patrol service, based in Dakar, Senegal in West Africa. They were returned in 1964.