The Martin PBM Mariner was an American patrol bomber flying boat of World War II and the early Cold War era. It was designed to complement the Consolidated PBY Catalina and PB2Y Coronado in service. A total of 1,366 were built, with the first example flying on 18 February 1939 and the type entering service in September 1940. In 1937 the Glenn L. Martin Company designed a new twin-engined flying boat, the Model 162, to succeed its earlier Martin P3M and complement the PBY Catalina and PB2Y Coronado. It received an order for a single prototype XPBM-1 on 30 June 1937. This was followed by an initial production order for 21 PBM-1 aircraft on 28 December 1937. To test the PBM's layout, Martin built a ⅜ scale flying model, the Martin 162A Tadpole Clipper with a crew of one and powered by a single 120 hp (89 kW) Chevrolet engine driving two airscrews via v-belts; this was flown in December 1937. The first genuine PBM, the XPBM-1, flew on 18 February 1939. The aircraft had multiple gun positions including single mounts at each midship beam and stern above the tail cone. Additional guns were positioned in the nose and dorsal turrets, each fitted with two-gun turrets. The bomb bays were in the engine nacelles. The gull wing was of cantilever design, and featured clean aerodynamics with an unbraced twin tail. The PBM-1 was equipped with retractable wing landing floats that were hinged outboard, with single-strut supported floats that retracted inwards to rest beneath the wing, with the floats' keels just outboard of each of the engine nacelles. The PBM-3 had fixed floats, and the fuselage was three feet longer than that of the PBM-1. Martin PBM Mariners were operated by RAAF Squadrons 40 and 41. For details of the operational history, and the 17 variants, click here.
