JRM Mars

The Martin JRM Mars was the largest flying boat ever to enter production although only 6 were built. The U.S. Navy contracted the development of the XPB2M-1 Mars in 1938 as a flying dreadnought for ocean patrol.

In 1959, the remaining Mars were sold for scrap. Dan McIvor, who represented a consortium of British Columbia lumber companies, recognized their potential value as water bombers and had them converted. A company called Flying Tankers Inc. was formed, and purchased the "Big Four" for aerial firefighting. The Marianas Mars crashed near Northwest Bay, British Columbia on 23 June, 1961 during firefighting operations; all four crewmembers were lost. Just over a year later, on 12 October, 1962, the Caroline Mars was destroyed by Typhoon Freda while parked onshore. The remaining Hawaii Mars and Philippine Mars had their conversions to water bombers accelerated and entered service in 1963.

The two surviving tankers are now operated by the Coulson Group, based at Sproat Lake near Port Alberni, British Columbia. When converted, the original powerplants were replaced with four Wright R-3350-24WA Cyclone engines of 2,500 hp (1,860 kW) each. The aircraft can carry up to 7,200 US gal (27,250 litres) of water, enough to cover an area of 4 acres (16,000 m²).[3] They are used to fight fires along the coast of British Columbia, and even sometimes in the interior. They also make appearances at local airshows, demonstrating their water-dropping ability. Flying Tankers Inc. also flies the water bombers to other hotspots around the world if a need develops, such as in August 2003 when a large forest fire threatened the city of Kelowna, British Columbia. On 10 November 2006, TimberWest Forest Ltd. announced that they are looking for buyers of the Mars. A condition of this sale is that the purchasers will donate one back to Port Alberni when they are retired as a historical attraction.[4] The Maryland Aviation Museum and British Columbia Aviation Council have initiated a joint effort to preserve the aircraft, one in Maryland and the other at their current location in Canada. [5] On 13 April 2007, TimberWest has announced the sale of both Martin Mars aircraft to Coulson Forest Products, a local forestry company in Port Alberni. The Mars will remain in the Alberni Valley operating from their base at Sproat Lake. On 25 October 2007, Hawaii Mars ("Redtail") arrived at Lake Elsinore in Southern California, negotiated through a private contract, to assist with the firefighting efforts containing the California wildfires of October 2007.


Specifications (JRM-3 Mars)

Philippine Mars taking off from Alameda in 1946
Caroline Mars at NAS Jacksonville in 1949Data from Jane’s Fighting Aircraft of World War II[2]

General characteristics

Crew: four (with accommodations for a second relief crew)
Capacity: 133 troops, or 84 litter patients and 25 attendants
Payload: 32,000 lb (15,000 kg) of cargo, including up to seven jeeps
Length: 117 ft 3 in (35.74 m)
Wingspan: 200 ft 0 in (60.96 m)
Height: 38 ft 5 in (11.71 m)
Wing area: 3,686 ft² (342.4 m²)
Empty weight: 75,573 lb (34,279 kg)
Loaded weight: 90,000 lb (40,820 kg)
Max takeoff weight: 165,000 lb (74,800 kg)
Powerplant: 4× Wright R-3350-24WA Duplex Cyclone (JRM-1 aircraft were originally powered with this engine, but modified by the Navy with more powerful Pratt & Whitney R-4360 Wasp Major "corncob" radial engines and designated JRM-3; civilian operators converted them back to Wright R-3350s) 18-cylinder radial engines, 2,500 hp (1,865 kW) each
Performance

Maximum speed: 192 knots (221 mph, 356 km/h)
Range: 4,300 nautical miles (5,000 mi, 8,000 km)
Service ceiling: 14,600 ft (4,450 m)