Martin PBM Mariner

Country of Origin: United States | Type: Seven-eight crew patrol and transport flying boat

Introduction

Designed in 1937, the PBM Mariner served the US Navy mainly in the Pacific during the Second World War in a variety of roles including maritme patrol, anti submarine warfare (ASW), air-sea rescue and transport. It augmented the Consolidated PBY Catalina and remained in production until 1949.

Development

A quarter scale single seat 'proof of concept' aircraft preceded the XPBM-1 prototype which first flew on 18th February 1939 powered by 1,600hp (1,193kW) R-2600-6 engines. Retractable outrigger floats and 'flat' horizontal tail surfaces were features, the latter disappearing with the first production model and replaced with the distinctive dihedral tailplane and inwards canted twin fins which were a Mariner trademark.

Into Service

The first deliveries of the initial model, the PBM-1, began in 1941 and numerous variants followed, those from the PBM-3 models onwards featuring fixed outrigger floats and lengthened engine nacelles. The PBM-3B introduced more powerful R-2600-12 engines and 25 were delivered to RAF Coastal Command in August 1943 under Lend-Lease as the Mariner GR.I. Their British service lasted just six weeks before they were returned to the USA. Other PBM-3 subvariants were the -3C, with armour protection, -3D with more powerful R-2600-22 engines, increased armament, radar and self sealing tank, the -3R was an unarmed transport version for up to 20 passengers, and the -3S ASW version.

Major Production

The major production version was the radar equipped and R-2600-34 powered PBM-5 of 1944, while the PBM-5A amphibian model, fitted with retractable tricycle undercarriage was used mainly by the US Coast Guard for air-sea rescue duties and was a postwar development. PBM-5 conversions were the -5E with different radar, -5G for the Coast Guard and -5S for use in ASW. The RAAF received 12 PBM-3R transports in 1943, these operating from Australia to New Guinea and from mid 1944 supporting the 'island hopping' campaign throughout the Pacific.

Specification

Dimensions

Wingspan: 35.97 metres (118 feet 0 inches)
Length: 24.38 metres (80 feet 0 inches)
Height: 8.38 metres (27 feet 6 inches)

Powerplants

PBM-3B/C - two 1,700hp (1,268kW) Wright R-2600-12 Cyclone 14-cylinder radials with four bladed propellers
PBM-3D - two 1,900hp (1,417kW) Wright R-2600-22 Cyclone 14-cylinder radials with four bladed propellers
PBM-5 - two 2,100hp (1,566kW) Wright R-2600-34 Cyclone 14-cylinder radials with four bladed propellers

Weights

PBM-3C - Empty: 14,687kg (32,378lb)
Loaded: 26,309kg (58,000lb)

Armament

PBM-3C - two 0.50 inch machine guns in each of nose and dorsal turrets, waist and tail positions
Maximum Bomb Load: 907kg (2,000lb) bombs or depth charges
PBM-3D - guns, plus provision for up to 3,628kg (8,000lb) of ordnance including two underwing torpedoes