Subject: Bomber Series--Martin MB-1

From: [email-masked] (joseph.f.baugher)
Date: 20 May 94 01:11:45 GMT

In 1916, Glenn L. Martin withdrew from the Wright-Martin combine that 
he had been involved with and struck out on his own.  The Glenn L.  
Martin aircraft company was established in Cleveland, Ohio in late 
1917.  

One of the first Army contracts landed by the new company was the 
design a new bomber that would hopefully outperform the 
British-designed Handley-Page, which was at that time scheduled to be 
built in the USA by Standard Aircraft of Elizabeth, New Jersey.  

The aircraft that emerged was designated MB-1 by the Martin company.  
It was a wooden, fabric-covered biplane powered by a pair of 
liquid-cooled 400 hp Liberty 12A engines suspended between the wings.  
The engines were cooled by a set of radiators situated in the front of 
the engine mounts just above the propeller shaft.  Two bays of struts 
were outboard of the engines.  The fixed mainwheels were aligned on a 
single axle.  The tail consisted of twin rudders, mounted on top of a 
single horizontal stabilizer.  A crew of 3 could be carried, a 
bombardier in a nose position, a pilot, and a gunner in a position in 
the upper fuselage just aft of the top wing..  The armament consisted 
of five 0.30-inch machine guns, two in the nose position, two in the 
aft fuselage position, plus one firing downward and to the rear 
through a trapdoor.  Maximum bombload was 1040 pounds.  

The original contract for six examples was issued on January 17, 1918.  
It was increased to 50 on October 22, 1918, but then was cut back to 
ten in January 1919.  

The first MB-1 flew on August 17, 1918.  A total of ten examples were 
built, the last being delivered to the US Army Air Service in February 
of 1920.  They were designated GMB by the USAAS, where the letters 
stood for "Glenn Martin Bomber".  Their serials were 39055/39060 and 
62948/62951.  They were the first American-designed bombers to enter 
service with the USAAS.  

The Martin MB-1 had a good performance for its day.  However, the 
Martin bombers were too late to see any action during World War 1.  
They formed the nucleus of the first Army bomber squadrons during the 
immediate postwar years.  High power and a relatively small size made 
the GMB also capable of carrying out the long range observation and 
the escort fighter roles.  The first four were built as observation 
aircraft, and the next three were built as bombers.  The eighth 
(designated GMT for "Glenn Martin Transcontinental") was a special 
long-range version capable of 1500-mile range, and the ninth 
(designated GMC for "Glenn Martin Cannon") was fitted with a 37-mm 
cannon in the nose.  

The last example was completed as a transport by removing all the 
military equipment, raising the top of the fuselage, and adding cabin 
windows and seats.  The pilot's cockpit was enclosed in a glazed 
enclosure.  It was originally given the designation GMP (for "Glenn 
Martin Passenger"), but was later designated T-1, where the T was in 
the T-for-Transport series.  

Six modified MB-1s were turned over to the US Postal Service and flew 
air mail delivery runs for a short time during the period when the US 
government took over the delivery of air mail.  

So far as I am aware, no MB-1 aircraft survive today.  

Serials of the Martin MB-1: 

39055/39060 	Martin GMB 
62948 		Martin GMB 
62949 		Martin GMT 
62950 		Martin GMC 
62951 		Martin GMP (T-1) 

Specification of the Martin MB-1: 

Two 400 hp Liberty 12A liquid-cooled Vee engines.  Maximum speed 105 
mph at sea level, 100 mph at 6500 feet.  92 mph cruising speed at sea 
level.  Landing speed 53 mph.  Service ceiling 10,300 feet.  Absolute 
ceiling 12,250 feet.  Initial climb rate 630 feet per minute.  An 
altitude of 6500 feet could be attained in 14 minutes.  Range 390 
miles with 1040 pound bombload.  Empty weight 6702 pounds, gross 
weight 10,225 pounds.  Wingspan 71 feet 5 inches, length 44 feet 10 
inches, height 14 feet 7 inches, wing area 1070 square feet.  
Defensive armament was five 0.30-inch Lewis machine guns.  Bombload 
was normally 1040 pounds.  

Sources:

  United States Military Aircraft Since 1909, Gordon Swanborough
  and Peter M. Bowers, Smithsonian, 1989.

  American Combat Planes, 3rd edition, Ray Wagner, Doubleday, 1982.	

Joe Baugher			**************************************
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