Martin PBM Mariner

History

PBM originated from private venture capital work undertaken by Glenn L. Martin & Company. Before World War II in 1937, engineers designed the Type 162 to replace the aging line of Martin P3M airships that had been in service since 1929 (78 built). The Type 162 features a high-wing (gull-wing, cantilever) monoplane design with raised twin rudder tails.

The nose section is stepped to accommodate the flight deck facing the nose, which itself contains a crew station. The hull uses a boat-like hull for water landings and takeoffs. Outboard pontoons (retractable) are installed under each wing to help stabilize the aircraft in rough water.

The crew of seven included the pilot, mission specialist and machine gunner.

On June 30 this year, the company received a contract for a prototype of the XPBM-1 aircraft. To justify the design, the company's engineers built a flyable model of the aircraft, on the scale of a single-seat Model 162A "Tadpole Clipper". This offer has only one engine, the 120 hp Chevrolet type.

A full-scale prototype was then flown in the air on February 18, 1939.

Although the United States Navy (USN) has committed to the excellent Consolidated PBY Catalina (detailed elsewhere on this site), XPBM was adopted as the PBM "sailor" to fight alongside her. Then in December, USN commissioned 21 aircraft to the XPBM-1 standard.

The production quality version of the aircraft (PBM-1) is powered by 2 Wright R2600-6 14-cylinder air-cooled radial piston engines, each rated at 1,600 hp. These drive three-bladed propeller units. Their position on the high wing allows the necessary clearance to the water, especially the salt spray that can occur during running movements.

Performance includes a top speed of 205 mph, a range of up to 3,000 miles and a service ceiling of 19,800 feet. The climb rate is 800 feet per minute.

Overall length reaches 79.9 feet, with a wingspan of 118 feet and a height of 27.5 feet. The curb weight is 33,175 pounds, while the fully loaded MTOW is 56,000 pounds.

The PBM is a military-sponsored design equipped with a defense network of machine gun weapons. This includes no less than 8 x .50 Browning M2 heavy machine guns, two in the nose, two in the inverted position, and two in the stern turret.

A separate machine gun is mounted on the jet bladder to provide all-round coverage against incoming air threats. Internally, the aircraft is certified to carry up to 4,000 pounds of ammunition. This could include 2 x Mark 13 series torpedoes or conventionally dropped bombs or depth charges.

The Mariner entered service with the United States Navy on September 1, 1940. Patrols were conducted in Atlantic waters, while the country remained neutral in World War II. After the attack on Pearl Harbor brought the United States into war, the aircraft played an active role in both the European and Pacific theatersespecially the latter, where its excellent patrols were badly needed.

The British and Australians also operated the airship during the conflict.

In the postwar period, sailors continued to operate with the Coast Guard until they were replaced by more modern types. The U.S. Navy continued to use the model during the Korean War (1950-1953), but the fleet was eventually replaced by the Martin P5M Marlin.

The last sailor flew in 1964 (Uruguay) until the route was finally taken out of service.

Produced from 1937 to 1949, a total of 1,366 Sailors were built for the United States and its allies not a lot by WWII standards, but still excellent.

Martin developed or produced a number of PBM-related aircraft after the first PBM-1. XPBM-2 is a conversion of PBM-1 used for catapult experiments. The PBM-3 produced fixed pontoon pontoons powered by R2600-12 series engines rated at 1,700 hp - 32 aircraft were built to this standard.

The PBM-3R is an unarmed transport aircraft, of which 31 are converted from PBM-3 stock and 18 are built to order. As an upgraded maritime patrol aircraft, the PBM-3C carries an AN/APS-5 radar in a radome aft of the flight deck. About 274 of the standards have been completed. PBM-3B is a former RAF Sailor GR.

1A ("Mariner One") returned from the United Kingdom and returned to service with the United States Navy.

The PBM-3S became a dedicated submarine hunter with increased range but reduced machine gun load. 94 cars of this type were produced, with an additional 62 added through the converted earlier brands.

The PBM-3D is another patrol aircraft, but with a 1,900 hp R2600-22 engine. Beam cannon positions now have dual cannon weapons. 259 of these scores have been delivered.

The PBM-4 was a proposed variant to carry 2 x Wright R3350 series 2,700hp engines for increased performance, but the brand never went any further.

Production of the PBM-5 reached 628 units with two Pratt & Whitney R3350 series engines, each producing 2,100 hp. This model has several children in the upgraded PBM-5E (with better radar), PBM-5S (upgraded submarine hunter) and PBM-5S2 (another upgraded submarine hunter, also with better radar) Variants.

The PBM-5A is the sailor's amphibious version with retractable landing gear. A total of 36 aircraft were produced, with another 4 converted by other brands.

While the United States is the clear operator of the Mariner route in absolute numbers, the aircraft is also associated with Argentina (9 units, Navy), Australia (Nos. 40, 41, RAAF), the Netherlands (15 units, NAS), United Kingdom (28 out of 33 ordered, used by 524 Squadron) and Uruguay (3, Navy).

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes