Martin MB

The Martin MB is an American twin-engine biplane of the Entre-deux wars. Drawn by Douglas Donald, it was the subject of many versions of bombardment, torpedoing and even transport. It is also the first heavy bomber of American design to enter in service the United States Army Air Service.

Design

At the end of 1917 Glenn L. Martin withdrew off Wright-Martin Corp California to form the Glenn L. Martin Aircraft Company with Cleveland, Ohio. One of the first programs on which the new company worked consisted in trying to produce at the request of the US Army a bomber able to compete with the Caproni Ca-5 and Handley-Page O/400 whose one was on the point of launching the production at Standard Aircraft in Elizabeth, New Jersey. The apparatus drawn by Donald Douglas was a biplane with timber structure and cloth-lined coating driven by two engines Liberty 12A of 400 ch suspended in the wing gap. The landing gear included/understood 4 wheels assembled on a single axle and the empennage was bidérive. Three-seater, the apparatus is defended by 5 machine-guns of 7,62 mm, that is to say two for the bomber in front of the fuselage, two in dorsal open station just behind the aerofoil and a ventral weapon. The load of bombs out of ventral compartment could reach 470 kg.

Martin MB-1

6 apparatuses were ordered on January 17th, 1918 under designation GMB ( Glenn Martin Bomber ). While launching the construction of the prototypes, Martin made build an assembly hall of 5600 m ² to ensure the future series production. The first specimen took the air, according to the sources, the 15 or on August 17th, 1918 and showed good performances immediately. The order thus was carried to 50 specimens the next on October 22nd, then brought back to 10 in January 1919, the war being finished in Europe. The last specimen was delivered in February 1920. These ten twin-engines and 62948/62951, become without utility, were affected in McCook Field for operational tests in various roles, taking into account their performances and of their relatively low size:

Martin GMB

4 apparatuses completed like twin-engines of observation and three like bombers.

Martin GMT

Intended for flights of very long distance ( Glenn Martin Transcontinental ), with an autonomy of 2.400 km.

Martin GMC

Modified in hunter of escort with a gun of 37 mm with before ( Glenn Martin Canon ).

Martin GMP

Transformed into transport aircraft: the armament was removed, the upper part of the raised fuselage, the seats for 12 passengers and the port-holes making their appearance, as well as a glazing entirely closing the cockpit. Designation GMP ( Glenn Martin Passenger ) was modified thereafter in Martin T-1 ( Transport-One).

It should be noted that 6 MB-1 were modified in the mail planes and used by the US Postal Service when the US government decided to deal with postal transport at the beginning of 1920. In addition a third engine accepted it on an experimental basis, of type Hispano-Suiza. The last MB-1 were reformed only in 1931.

Martin MBT

At the beginning of 1920 the US Navy ordered two MB-1 modified to be able to carry a torpedo of 750 kg, which supposed to modify the principal train by removing the central axle. The second was lost on accident with broad Hampton Roads, Virginia, on April 15th, 1922, the versed first with USMC.

Martin MT

At the end of 1920 US Navy orders 8 new twin-engine destroyers. Only it was preserved by the Navy, the 7 other apparatuses being yielded to USMC. To test at the same time these apparatuses and the techniques of flight to long distance, three of these apparatuses carried out a transcontinental crossing between San Diego and Quantico in 11 days.

Martin MB-2

In June 1920 USAAS ordered a modified version of MB-1 , the cell being increased to increase the load of bombs. Intended for the bombardment of night, one sacrificed speed and handiness to the profit of the payload. The apparatus underwent in the passing some modifications: the engines were lowered to the level of the lower plan, the landing gear was simplified with a wheel of large diameter under each spindle-engine. Finally the part of the aerofoil located outside the engines folded up towards the back on the level it member back to facilitate the housing of the plane in a hangar. The defensive armament was identical, but the new bomber carried up to 900 kg of bombs with a crew of 4 men. These apparatuses were renamed NBS-1 ( Night Bend-Shorts arranges ) with the coming into effect of the new designation of the aircraft of USAAS in 1921.

Martin NBS-1

10 apparatuses produced by Glenn L. Martin with Cleveland. Martin proposed to produce 50 additional apparatuses, but in the immediate future post-war period the Army Air Service bought the rights on the apparatuses which it ordered, reserving the possibility of placing from the orders near industrialists lowest bidder or of breaking down its thin orders between several suppliers to support national industry. Martin will thus produce only 10 of 130 NBS-1 built and delivered to USAAS.

Curtiss NBS-1

50 built apparatuses, the 20 last being equipped with compressors General Electric theoretically enabling them to reach 7.724 Mr. In practice these compressors appeared particularly not very reliable, and it will be necessary to await the Boeing B-17B to have a using bomber of the turbocompressés engines.

LWF NBS-1

The firm Lowe, Willard & Fowler Engineering Company of College Not, New York profited from an order of 35 specimens.

Aeromarine NBS-1

Last order, last with Aeromarine Planes and Motor Company for 25 apparatuses.

In service

130 NBS-1 will be distributed between the 2nd Bomber Group (11th, 20th, 49th and 96th Bomber Squadrons) based with Langley, Virginia, 4th Composite Group (28th Bomber Squadron) stationed with the Filipino and 5th Composite Group (23rd and 72nd Bomber Squadrons) with Hawaii. They remained in service until replacement by Keystone LB-5/LB-6 at the end of the Twenties.

June 21st, 1921 began off the coasts from Virginia a series from tests aiming at studying the capacity of the planes to destroy combat ships and measurements to be brought in the field of naval construction to protect itself from the planes. In front of the insistence of the General Sergeant Billy Mitchell, which especially wished to prove the superiority of the air weapon on the fleets of war, USAAC was invited by the US Navy to take part in these demonstrations, the targets used being warships captured in Germany. July 13rd NBS-1 ran the G-102 destroyer and on July 18th the light cruiser Frankfurt was sent by the bottom thanks to 74 bombs released by planes of the Army and operative Navy of coordination. July 20th the target was the battleship Ostfriesland , which remained with flood in spite of 52 bombs released by the Navy and the Marine Body. The following day NBS-1 of the US Army passed to the attack with 11 bombs of 450 and 900 kg, completing the ship.

External bonds

Martin MB-1
Martin MB-2

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