The PBM Mariner never achieved the popularity of the PBY Catalina. Martin's PBM Mariner
offered considerably greater military capability at the expense of increased complexity. Unlike the PBY, which had relatively
few problems in service, the PBM suffered from a number of problems, many of them related to the engine. These were finally
overcome when the more powerful P&W R-2800s replaced the Wright R2600s in 1944.
The Navy contracted for the XPBM-1 in June 1937. Prior to this time, Martin had flown
a quarter scale, piloted "flying model," the Martin 162A, to explore hydrodynamic and aerodynamic characteristics. The XPBM-1
first flew early in 1939 but, in spite of the testing with the 162A, experienced problems both on the water and in flight.
Gull wings, twin tails and retractable tip floats were its most distinguishing features. Hull redesign in 1940 and addition
of dihedral to the horizontal tail, resulting in the vertical surfaces being canted inward, were major changes introduced
to correct the problems in the XPBM-1. They were incorporated in the 20 PBM-1s, which followed. The first of the 1s to enter
the fleet was assigned to VP-55 in September 1940.
Along with the PBM-1s, one XPBM-2 was ordered-modified to be a catapultlaunched long-range patrol seaplane.
While tests were satisfactory, the concept was not pursued. The next service aircraft were the 3 series, delivered from 1942
through mid-1944. Initially delivered as PBM-3s, they featured improved armament and engines, and could be easily recognized
by the fixed wing-tip floats replacing the retractable floats of the 1s. Many of the early 3 series were converted to unarmed
3R transports. 3C patrol planes went to fleet squadrons, followed by stripped 3S ASW versions and, finally, 3Ds with improved
R-2600 engines. Radar had been added in a large radome behind the cabin, starting with the 3Cs. Improved versions of radar
were used as they became available. With the R-2800 engine, the subsequent PBM-5 series was destined for service long after
WW II. Initial 5s were followed by 5Es with improved radar, and in the postwar period a limited number of 5Gs were delivered
with a new radar in a teardrop radome. A prototype amphibian version of the 5 was proposed in April 1944, but was not flown
until December 1945. Thirty-six were produced before production stopped in 1949. Up to that time, 1,366 Mariners had been
Improvements in the 5 series led to ASW PBM-5S conversions starting late in 1949, while the 5As were converted
to unarmed transports. Both models served worldwide wellinto the Fifties, the 5Ss being supplanted by 5S2s with updated equipment,
before the last fleet squadron, VP-50, relinquished them for P5M Marlins in June 1956. Individual Mariners continued in Navy
service to meet special needs for a few more years, the last one flying being a hydro-ski test aircraft. Mariners were also
transferred and served with the Coast Guard and several foreign countries.
The Martin PBM-3
/ PBM-5 Mariner was a World War 2 era flying boat used in the maritime. The Mariner first appeared in 1937 and it first flew
in 1939 as the Martin Model 162 project, giving birth to the prototype XPBM-1 as a twin engine flying boat with a high-mounted
monoplane gull wing. Martin designed a ‘splash’ with their PBY Catalina flying boat series in operation with the
United States Navy.
It had twin
tail rudders, retractable stabilizing floats and a deep hull-like fuselage. Its earlier versions featured 2 x Wright Cyclone
R-2600-6 radial engines which produced a total output of 1,600 horsepower. Just a year after it came into the WW2 scene, it
became a mainstay of the Naval Air Transport Service as it was the first aircraft to provide a vital link between Hawaii and
the South Pacific. The PBM-3 was the first in the series to feature fixed floats; a lengthened engine nacelle also added to
this model series allowed for a greater external ordnance load to be carried.
A crew of 7
to 9 men could be accommodated in the Martin PBM-3 / PBM-5 Mariner. Armament consisted of a twin 12.7 mm gun mounting at the
bow, tail and dorsal positions with an additional 2 x 12.7 mm machine guns at the beam (waist) positions firing through hatches.
The bomb load was a pretty respectable 8,000 pounds (PBM 3D). The PBM-3 eventually became the first widely-produced and modified
model in the series with unarmed transport and passenger transport derivatives joining the base production model. It had an
appropriate and consistent surface detail which was engraved and raised. This was a product of thoughtful engineering to join
wing to fuselage and horizontal tail surfaces. It also featured fixed under wing floats. About 1,700 aircraft were produced
which included various variants. They were used by both the American and the British forces.Despite being of a more modern
design and an equally capable performer, the Mariner was never able to gather the top spot which was always with the Catalina
||Two R-2800-34 Pratt & Whitney engines |
||178 kn |
||20,800 ft |
||750 n.mi/kn |
Power Off - No Fuel
||178 kn/9,500 ft |
||55.6 sec |
|Rate of climb -- sea level:
||590 ft/min |
|Time-to-climb 10,000 ft:
||18.6 min |
|Time-to-climb 20,000 ft:
||56.4 min |
|Combat Range/V av 1,500 ft. n.mi/kn:
60,300 (smooth), 48,000 (rough)
1,408 sq ft
79 ft 10 in
24 ft 10 in
13 ft 1 in
Two .50 Cal. (Nose Turret) with 800 rds.
Two .50 Cal. (Tail Turret) with 2000 rds.
18-4 Gunsights in Turrets
12 x 100 lbs
8 x 1,000 lbs
8 x 1,600 lbs
8 x 325 lbs
8 x Mk 26-1
4 x Mk 13 or 13-5
4 x Mk 24
Mark 23-7 Bombsight
AN/APA-11, -38, AN/APR-4