Martin PBM Mariner

Martin PBM Mariner
Name	Martin PBM Mariner
Caption	A Martin PBM-5 Mariner in flight.
Type	Patrol flying boat
National origin	United States
Manufacturer	Glenn L. Martin Company
First flight	18 February 1939
Introduction	September 1940
Retired	1964 (United States Coast Guard)
Primary users	United States Navy; United States Coast Guard; Royal Air Force; Royal Australian Air Force
Number built	1,366
Developed from	Martin P3M

Martin PBM Mariner. The Martin PBM Mariner was a twin-engine American patrol bomber flying boat developed and manufactured by the Glenn L. Martin Company. It served extensively during World War II and the Korean War, primarily performing long-range anti-submarine patrols, search and rescue, and maritime reconnaissance duties for the United States Navy and United States Coast Guard. Renowned for its long range and substantial payload, it was a mainstay of Allied naval aviation in the Pacific and Atlantic theaters.

Design and development

The Mariner's development began in 1937 in response to a United States Navy requirement for a new patrol flying boat to complement the Consolidated PBY Catalina. The design, led by engineers at the Glenn L. Martin Company in Baltimore, featured a distinctive gull wing and a deep hull, with its two Pratt & Whitney R-2800 Double Wasp radial engines mounted on the wing's shoulder. A key innovation was its use of a Fowler flap system on the wings to improve low-speed handling, while its hull incorporated a planing surface optimized for open-water operations. The prototype, designated XPBM-1, first flew on 18 February 1939 from the waters of the Chesapeake Bay, demonstrating promising performance that led to an initial production order.

Operational history

Entering service with VP-55 in September 1940, the PBM Mariner saw its first combat during the Battle of the Atlantic, hunting German submarines. Its most significant service was in the vast expanses of the Pacific War, where squadrons like VP-16 and VP-21 conducted long-range patrols from bases such as Pearl Harbor, Midway Atoll, and the Philippines. Mariners were instrumental in the Battle of the Coral Sea and the Battle of Leyte Gulf, providing critical reconnaissance and participating in anti-shipping strikes. Notably, a Mariner from VP-74 depth-charged and sank the German submarine U-158 off Bermuda in June 1942. After World War II, it continued in service during the Korean War, performing patrols and air-sea rescue missions, and remained with the United States Coast Guard until the mid-1960s.

Variants

The primary production variants evolved significantly. The initial **PBM-1** featured Pratt & Whitney R-1830 Twin Wasp engines, while the definitive **PBM-3** series introduced more powerful Pratt & Whitney R-2600 engines and numerous sub-variants for specific roles, including the armed **PBM-3C** and the unarmed **PBM-3R** transport. The **PBM-5**, the most produced version, was powered by Pratt & Whitney R-2800 Double Wasp engines and featured enhanced armament and radar. The **PBM-5A** was a unique amphibious version with retractable tricycle landing gear. Post-war conversions included the **PBM-5E** with improved AN/APS-15 radar and the **PBM-5S** optimized for Anti-submarine warfare.

Operators

The primary operator was the United States Navy, which equipped numerous patrol squadrons (VP) and training units. The United States Coast Guard operated several aircraft for Search and rescue and Maritime patrol. Allied operators included the Royal Air Force, which received 32 aircraft under Lend-Lease for service with No. 524 Squadron RAF; the Royal Australian Air Force's No. 40 Squadron RAAF; and the Royal Netherlands Navy's Marine Luchtvaartdienst. After the war, a small number were exported to Argentina, Uruguay, and the Republic of China Air Force.

Specifications (PBM-5A)

* **Crew:** 8 * **Length:** 80 ft 0 in (24.38 m) * **Wingspan:** 118 ft 0 in (35.97 m) * **Height:** 27 ft 6 in (8.38 m) * **Empty weight:** 33,175 lb (15,048 kg) * **Gross weight:** 58,000 lb (26,308 kg) * **Powerplant:** 2 × Pratt & Whitney R-2800-34 Double Wasp 18-cylinder radial engines, 2,100 hp (1,600 kW) each * **Maximum speed:** 211 mph (340 km/h, 183 kn) * **Range:** 2,240 mi (3,600 km, 1,950 nmi) * **Service ceiling:** 19,800 ft (6,000 m) * **Armament:** 8 × .50 caliber M2 Browning machine guns in nose, dorsal, waist, and tail turrets; up to 8,000 lb (3,600 kg) of bombs, depth charges, or torpedoes

Survivors

No complete Martin PBM Mariners remain airworthy, and only a few substantial wrecks and partial airframes exist. The most significant survivor is a PBM-5A (Bureau Number 122071) on display at the National Naval Aviation Museum in Pensacola, Florida. Other remains include a PBM-5 wreck in Lake Washington near Seattle, a fuselage section at the Pima Air & Space Museum in Tucson, and a recovered PBM-5A (Bureau Number 59032) being restored by the New England Air Museum in Windsor Locks, Connecticut.

Category:Martin aircraft Category:Patrol aircraft of the United States Category:Flying boats Category:World War II patrol aircraft of the United States