The Martin PBM Mariner was a patrol flying boat used by the US Navy and Royal Australian Navy during World War II. Made in seaplane and amphibian versions, it was the most important naval aircraft in its class during this armed conflict. It was a versatile, reliable and easy to fly aircraft. It was widely employed as a replacement for the Consolidated PBY Catalina, which was the only better known flying boat. The Mariner was used in every combat theater, from the Pacific to the Mediterranean as it was also employed as a bomber. Martin built a total of 1,366 PBM flying boats.
The prototype of the Mariner, the XPBM-1 (BuNo 0796), made its first flight on February 18, 1939. It was equipped with two Wright Cyclone R-2600-6 radial engines, each one of them providing 1,600 horsepower. The first flight tests were satisfactorily, with only some tail problems. Flight characteristics were also good. To solve the tail flaw, dihedral (upward angle) was added to the horizontal tail surfaces. The flight test phase would take more than a year as it was accepted by the US Navy into service on October 10, 1940, as the PBM-1 Mariner. It was first assigned to the VP-55 and VP-56 Squadron in Norfolk, Va.
The PBM-3 and PBM-3D were the most widely used versions, with the PBM-3R being a transport Mariner and the PBM-3S an anti-submarine variant. The PBM-5 was a postwar version, which flew sorties in the Korean War (1950-1953). In the bomber role, the Martin PBM Mariner fought everywhere in the Pacific Theater. It was particularly active at Saipan and during the liberation of the Philippines in 1944.
Technical Characteristics
The Martin PBM Mariner was a two-engine monoplane flying boat. It was fitted with cantilever gull-wing, which was mounted high on shoulder of fuselage. The tailplane had a 15-degree dihedral and two vertical fins, one at each end. The amphibian variant was equipped with retractable landing gear. The PBM-3D version was powered by two Wright Cyclone R-2600-22 radial engines, each one delivering 1,900 HP. All-in-all, this flying boat was reliable, sturdy, and tough, being able to take a lot of beating. Pilots and crew had great confidence when they flew sorties with the Mariner as it had been optimized to give them the strongest chance of survival.
Specifications (PBM-3D)
Type: patrol/bomber flying boat.
Length: 24.38 m (80 feet)
Wing Span: 35.97 m (118 feet)
Wing Area: 130.71 m2 (1,407 square feet)
Height: 8.23 m (27 feet)
Power Plant: two 1,900-HP, Wright Cyclone R-2600-22, 14-cylinder, radial engines.
Maximum Speed: 338 km/h (210 mph)
Range: 3,597 km (2,235 miles)
Service Ceiling: 6,095 m (20,000 feet)
Armament: eight 12.7-mm (.50-cal) machine guns set up in nose, dorsal turrets, waist, and tail; 800-kg (1,649-lb) of bombs.
Crew: seven.
Below, the prototype XPBM-1 in a flight test in March 1939. Notice it still had the straight horizontal tailplane. It would soon be replaced a new one with 15-degree dihedral angle.
The PBM-3D variant of the Mariner flying over a naval base in 1943. Notice the search radar on the forward dorsal side of fuselage, right above cockpit.
Below, the Mariner PBM-5A in 1948.
