The Martin T3M was an improved version of the Curtiss CS-2, using a geared Wright engine. It was the most numerous member of its family, with 124 produced.
The T3M was developed from a Navy design that had originally been produced by Curtiss as the Curtiss CS-1 and CS-2, before Martin won the main production contract, building it as the Martin SC-1 and SS-2. All four of these aircraft were basically identical three man biplanes, with open cockpits for the pilot and gunner and an internal position for the bomber/ torpedo man, an unusual configuration with a longer lower wing and powered by Wright T-2 or Wright T-3 engines. The aircraft was designed to operate on wheels or as a float plane, and for it to be possible to change between the two quickly.
In November 1924 one of the Curtiss CS-2s was given a geared Wright T-3 engine, replacing its normal un-geared T-3, becoming the Curtiss CS-3. Martin then carried out further development work on this model, moving the pilot and torpedo-man further forward, into a position in front of the wing.
The Martin produced version of the Curtiss CS-2 was known as the Martin SC-2 or T2M. When Martin was given a production order for the CS-3 on 12 October 1925, the new aircraft was given the designation of T3M.
The T3M was produced in two main versions. The first was the T3M-1, which was powered by a 575hp Wright T-3B engine. Twenty four were produced, with deliveries beginning in late 1926.
The second was the T3M-2, which introduced equal span wings and was powered by a 710hp Packard 3A-2500 engine. 100 of these were built. A third cockpit was added, between the wings, for the bomber/ torpedo man.
Two prototypes were produced from the T3M. The XT3M-3 was the designation given to the first T3M-2 after it was given a Pratt & Whitney R-1690 Hornet engine by Martin.
The XT3M-4 was the designation given to the XT3M-3 after it was given a Wright R-1750 Cyclone engine by the Naval Aircraft Factory.
The T3M was followed into production by the T4M-1, which was powered by the Pratt & Whitney R-1690 Hornet. 100 were built by Martin, but just to add to the confusion, Martin then sold their Cleveland factory to the Great Lakes Aircraft Corporation, which continued to produce the aircraft, as the Great Lakes TG-1 and Great Lakes TG-2.
The wheeled version of the T3M-2 served on the USS Lexington (with VT-1S) and USS Saratoga (with VT-2B), alongside the T4M-1. It was also used by a number of other Naval torpedo squadrons, both ship and shore based.
Engine: Packard 3A-2500
Crew: 3 - pilot, bombardier, gunner
Span: 56ft 7in
Length: 41ft 4in
Height: 15ft 1in
Empty Weight: 5,814lb
Gross Weight: 9,503lb
Maximum Speed: 109mph at sea leve
Climb rate: 16.8min to 5,000ft
Range: 634 miles
Guns: One 0.30in gun in rear cockpit
Bomb load: One torpedo