JRM Mars
Encyclopedia
The Martin JRM Mars is a large, four-engined cargo transport
Cargo aircraft
A cargo aircraft is a fixed-wing aircraft designed or converted for the carriage of goods, rather than passengers. They are usually devoid of passenger amenities, and generally feature one or more large doors for the loading and unloading of cargo...

 seaplane
Seaplane
A seaplane is a fixed-wing aircraft capable of taking off and landing on water. Seaplanes that can also take off and land on airfields are a subclass called amphibian aircraft...

 originally designed and built in limited numbers for the U.S. Navy during the World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 era. The surviving aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 were later converted for civilian use, after the war and their Navy service, as firefighting water bomber
Aerial firefighting
Aerial firefighting is the use of aircraft and other aerial resources to combat wildfires. The types of aircraft used include fixed-wing aircraft and helicopters. Smokejumpers and rappellers are also classified as aerial firefighters, delivered to the fire by parachute from a variety of fixed-wing...

s.

The Mars was the largest Allied
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

 flying boat
Flying boat
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...

 to enter production, although only seven were built. The United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 contracted the development of the XPB2M-1 Mars in 1938 as a long range ocean patrol flying boat, which later entered production as the JRM Mars long range transport.

Design and development

The Glenn L. Martin Company
Glenn L. Martin Company
The Glenn L. Martin Company was an American aircraft and aerospace manufacturing company that was founded by the aviation pioneer Glenn L. Martin. The Martin Company produced many important aircraft for the defense of the United States and its allies, especially during World War II and the Cold War...

 effectively scaled up their successful PBM Mariner patrol bomber design to produce the prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...

 XPB2M-1 Mars. The XPB2M-1 was launched on 8 November 1941, after a delay caused by an engine fire during ground runs the aircraft first flew on 23 June 1942. After flight tests with the XPB2M between 1942 and 1943, she was passed on to the Navy. The original patrol bomber concept was considered obsolete by this time, and the Mars was converted into a transport aircraft
Cargo aircraft
A cargo aircraft is a fixed-wing aircraft designed or converted for the carriage of goods, rather than passengers. They are usually devoid of passenger amenities, and generally feature one or more large doors for the loading and unloading of cargo...

 designated the XPB2M-1R. The Navy was satisfied with the performance, and ordered 20 of the modified JRM-1 Mars. The first, named Hawaii Mars, was delivered in June 1945, but with the end of World War II the Navy scaled back their order, buying only the five aircraft which were then on the production line. Though the original Hawaii Mars was lost in an accident on Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

 a few weeks after it first flew, the other 5 Mars were completed, and the last delivered in 1947.

U.S. Navy service

Named the Marianas Mars, Philippine Mars, Marshall Mars, Caroline Mars, and a second Hawaii Mars, the 5 production Mars aircraft entered service ferrying cargo to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 and the Pacific Islands. The last production airplane (the Caroline Mars) was designated JRM-2, powered by 3000 hp Pratt & Whitney R-4360 engines, and featured a higher maximum weight and other improvements. On 4 March 1949, the Caroline Mars, set a new world passenger load record by carrying 269 people from San Diego to Alameda, CA. On 5 April 1950, the Marshall Mars was lost near Hawaii when an engine fire consumed the airplane after her crew had evacuated. The remaining "Big Four" flew record amounts of Naval cargo on the San Francisco
San Francisco, California
San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...

-Honolulu
Honolulu, Hawaii
Honolulu is the capital and the most populous city of the U.S. state of Hawaii. Honolulu is the southernmost major U.S. city. Although the name "Honolulu" refers to the urban area on the southeastern shore of the island of Oahu, the city and county government are consolidated as the City and...

 route efficiently until 1956, when they were beached at NAS Alameda
Naval Air Station Alameda
Naval Air Station Alameda was a United States Navy Naval Air Station in Alameda, California, on San Francisco Bay.NAS Alameda had two runways: 07-25 and 13-31...

.

Civilian use

In 1959, the remaining Mars were to be sold for scrap but a Canadian company Forest Industries Flying Tankers (FIFT) was formed and bid for the four aircraft and a large spares holding. The company represented a consortium of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 forest companies and the bid was accepted and the sale was completed in December 1959. The four aircraft were flown to Fairey Aviation at Victoria, British Columbia for conversion as water bombers. The conversion involved the installation of a tank in in the cargo bay and retractable pick-up scoops to allow uploading of water while the aircraft was taxying. The scoops allowed 30 tons of water to be taken onboard in 22 seconds. Later some of the hull fuel tanks were replaced with water tanks.

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 Hawaii Mars and Philippine Mars had their conversions to water bombers accelerated and entered service in 1963. They appeared at local airshows, demonstrating their water-dropping ability. Flying Tankers Inc. also flew the water bombers to other hot spots around the province when a need developed, such as in August 2003, when a large forest fire
2003 Okanagan Mountain Park Fire
On August 16, 2003 a wildfire was started by a lightning strike near Rattlesnake Island in Okanagan Mountain Provincial Park in British Columbia, Canada. The wildfire was fuelled by a constant wind and one of the driest summers in the past decade...

 threatened the city of Kelowna, British Columbia
Kelowna, British Columbia
Kelowna is a city on Okanagan Lake in the Okanagan Valley, in the southern interior of British Columbia, Canada. Its name derives from a Okanagan language term for "grizzly bear"...

.
On 10 November 2006, TimberWest Forest Ltd. announced that they are looking for buyers of the Mars. A condition of this sale was that the purchasers would have to donate one back to Port Alberni when they are retired, as a historical attraction. 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. On 13 April 2007, TimberWest announced the sale of both aircraft to Coulson Forest Products, a local forestry company in Port Alberni, British Columbia
Port Alberni, British Columbia
Port Alberni is a city located in the province of British Columbia in Canada. It is the location of the head offices of the Alberni-Clayoquot Regional District. The city has a total population of 17,743, and the census agglomeration area a total of 25,396....

. The two surviving tankers are operated by Coulson Flying Tankers and are based and maintained at Sproat Lake
Sproat Lake
Sproat Lake, named after Gilbert Malcolm Sproat, is a lake in central Vancouver Island. Home of the last Martin Mars type Waterbombers, and near Port Alberni, Sproat Lake is a summer hangout for the Alberni Valley. Highway 4 runs along its scenic north shore....

 near Port Alberni. On 25 October 2007, the Hawaii Mars ("Redtail") arrived at Lake Elsinore
Lake Elsinore
Lake Elsinore, originally named Laguna Grande by the Spanish explorers, renamed for the town Lake Elsinore, California established on its northeastern shore April 9, 1888.-Limnology:...

 in Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...

, on a private contract, to assist with the firefighting efforts containing the California wildfires of October 2007
October 2007 California wildfires
The October 2007 California wildfires were a series of wildfires that began burning across Southern California on October 20. At least 1,500 homes were destroyed and over 500,000 acres of land burned from Santa Barbara County to the U.S.–Mexico border...

. The Philippine Mars is undergoing "extensive maintenance and renovation" and will not be ready to fly again until 2010. , the Hawaii Mars was in service fighting the La Brea fire east of Santa Maria in Southern California.

Based on historical data, each plane can make a drop every fifteen minutes. Working in tandem, this equates to 7,200 US gallons (27,276 litres) every seven minutes and each drop can cover an area of up to 4 acres (1.6 hectares). The aircraft can also carry up to 600 US gallons (2,270 litres) of foam concentrate for gelling the load drop. They are used to fight fires along the coast of British Columbia and sometimes in the interior. As of July 29, 2010, the Martin Mars was being used to fight the Mason Lake/Bonaparte Lake fire north of Kamloops.

Variants

XPB2M-1
Model 170 prototype long-range patrol flying boat powered by four Wright R-3350-8 piston engines, one built, converted to XPB2M-1R.

XPB2M-1R
Prototype converted in December 1943 as a prototype transport version, armament removed, installation of additional cargo hatches and cargo loading equipment, existing hatches were enlarged and the decking was reinforced.

JRM-1
Model 170A, production long range transport variant, originally 20 aircraft ordered later reduced to six. Single-tail design, and having a longer hull with fewer bulkheads and a larger maximum take-off weight. It had also been fitted with equipment for overhead cargo handling and was powered by four Wright R-3350-24WA Cyclone engines with 4-bladed propellers, five built, surviving four converted to JRM-3.

JRM-2
The last JRM-1 on order was completed as the JRM-2 with the engines changed to 3,000 hp Pratt & Whitney R4360-4T engines with 4-blade, 16 ft, 8 in diameter Curtiss Electric propellers. Gross weight increased by 20,000 lbs.

JRM-3
Model 170B, conversion of the remaining four JRM-1s re-engined with 2,400 hp Wright R3350-24WA engines turning 16 ft, 8 in Curtiss-Electric props, of which the inboard two engines were fitted with reversible-pitch devices.

Aircraft

  • The Old Lady - serial Bu 1520. Ordered on 23 August 1938 and completed as the prototype long-range patrol XPB2M-1, it was first flown on 3 July 1942 and converted in December 1943 to transport variant and designated XPB2M-1R. Assigned initially to VR-8 (NAS Patuxent River) for crew training, it was later transferred to VR-2 (NAS Alameda) and scrapped in 1945.
  • Hawaii Mars I - JRM-1 Bu. 76819 first flown on 21 July 1945 and delivered to the United States Navy. It sank on 5 August 1945 in Chesapeake Bay and was disposed as scrap.
  • Philippine Mars - JRM-1 Bu. 76820, delivered to the USN on 26 June 1946 and assigned to VR-2 (NAS Alameda). Converted and re-designated JRM-3. Withdawn from service on 22 August 1956 and sold in 1959, it was converted to forest fire fighting aircraft and registered
    Aircraft registration
    An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...

     CF-LYK (later C-FLYK). The aircraft is still flying with Coulson Group at Sproat Lake, British Columbia, Canada.
  • Marianas Mars - JRM-1 Bu. 76821, delivered to the USN on 26 February 1946 and assigned to VR-2 (NAS Alameda). Converted and re-designated JRM-3, it was withdrawn from service on 22 August 1956 and sold in 1959. Converted to forest fire fighting aircraft and registered CF-LYJ, the aircraft crashed into Mount Moriarty near Nanaimo, Vancouver Island, on 23 June 1961, when the water drop mechanism failed, leaving the aircraft unable to climb quickly enough to clear a mountain. In the ensuing crash, the crew of four were killed.
  • Marshall Mars - JRM-1 Bu. 76822, delivered to the USN, converted and re-designated JRM-3. It was destroyed by an engine fire and sank on 5 April 1950 off Diamond Head, Oahu.
  • Hawaii Mars II - JRM-1 Bu. 76823, delivered to the USN on 23 April 1946 and assigned to VR-2 (NAS Alameda). Converted and redesignated JRM-3, it was withdrawn from service on 22 August 1956 and sold in 1959. Converted to forest fire fighting aircraft and registered CF-LYL (later C-FLYL), it is still flying with Coulson Group at Sproat Lake, British Columbia, Canada.
  • Caroline Mars - * JRM-2 Bu. 76824, delivered to the USN on 10 May 1948 and assigned to VR-2 (NAS Alameda). It was sold in 1959 and converted to forest fire fighting aircraft by Forest Industry Flying Tankers. Registered CF-LYM. the aircraft was destroyed during Typhoon Freda at Victoria, Canada on 12 October 1962.

Specifications (JRM-3 Mars)


See also

External links

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