Martin_Baltimore

Martin Baltimore

The Martin 187 Baltimore was a light two-engined attack-bomber built by the Glenn L. Martin Company in the United States. To enable the aircraft to be supplied to the British under the Lend-Lease Act the United States Army Air Forces designation A-30 was allocated. It was not used in combat by the United States forces, but saw service with the British, Canadian, Australian, South African, Hellenic and the Italian air forces.

Design and development

The Model 187 was developed from the Martin 167 Maryland, it had a deeper fuselage and more powerful engines.

It was originally designed for French as a joint project in May 1940 by the Anglo-French Purchasing Commission to replace the Maryland. With the fall of France the RAF took over the order for 400 aircraft in May 1940. The RAF named the aircraft the Baltimore.

With the passing of the Lend-Lease Act two further batches of 575 and then 600 were provided to the British.

Operational history

The first British aircraft were delivered in late 1941 to equip Operational Training Units. The RAF only used the Baltimores operationally in the Mediterranean area and North Africa.

Many users were impressed by the step up that the Baltimore represented from older aircraft like the Blenheim. The users of the Baltimore, and Martin pilot Benjamin R. Wallace, praised the aircraft for its heavy armament, structural strength, maneuverability, bombing accuracy and relatively high performance but crews complained of cramped conditions like the earlier Maryland. Due to the narrow fuselage it was nearly impossible for crew members to change positions during flight if wounded(the structure of the interior meant that the pilot and observer were separated from the wireless operator and rear gunner). This was common for most light bombers of the era like the Hampden, Boston and Blenheim. In combat service the Baltimore had a very low loss rate. The majority of losses came from operational accidents.

The Baltimore saw limited Fleet Air Arm service with aircraft transferred from the RAF in the Mediterranean to equip a squadron in 1944. The RAF also transferred aircraft to other allies in the Mediterranean area. After the capitulation of Italy in 1943 an Italian-manned squadron was equipped with ex-RAF Baltimores, becoming the co-belligerent Stormo Baltimore. The Italians suffered considerable attrition during their training phase on the Baltimore. The majority of accidents were during takeoffs and landings due to the aircraft's fairly high wing loading, high approach speed and a directional stability problems during take-offs. The Italians only operated the Baltimore for roughly six months. Many of those operations were in Yugoslavia and Greece providing air support for partisan forces or dropping supplies.

Used in the anti-U-boat role during the war, the plane achieved moderate success, sinking up to eight submarines.

All Baltimores were withdrawn from service by the end of 1949, the last one being withdrawn on December 23. The Baltimore was used to test instruments and control surfaces for the efforts to break the sound barrier.

Variants

Baltimore I

Fitted with 1,600 hp Wright GR-2600-A5B radial piston engines, armed with ten 0.303-inch (7.7-mm)machine guns eight fixed Brownings and two flexible Vickers guns, all marks had two 0.303 Brownings in the leading-edge of each wing and four similar fixed guns, two on each side of the lower fuselage firing aft, 50 aircraft built.Baltimore II

As with the Mk I;defensive armament was increased to twelve 0.303 machine guns including twin 0.30-inch (7.7-mm) Vickers K machine guns in both the dorsal and ventral positions, 100 aircraft built.Baltimore III

Modified Mk II design defensive armament was increased to fourteen 0.303 guns and impoved with a hydraulically-powered dorsal turret supplied by Boulton Paul in the UK with 4 Browning machine guns, 250 aircraft built.Baltimore IIIA

Ordered by USAAF and supplied under Lend-lease to the RAF, two 0.50-inch (12.7-mm) machine guns in a Martin-built electrically-powered dorsal turret. Designated A-30 by the USAAF, 281 aircraft built.Baltimore IV

USAAF order, lend-lease to RAF. Four 0.303-inch (7.7-mm) Brownings machine guns in the wings. Designated A-30A by the USAAF, 294 aircraft built.Baltimore V

USAAF order, Upgraded with two 1,700 hp Wright R-2600-29 radial piston engines. Wings fitted with 0.50-inch (12.7-mm) machine guns, 600 aircraft built.

All 1,575 built were for the RAF. A number were lost on delivery across the Atlantic Ocean when two ships carrying Baltimores were sunk.

Operators

Survivors

Although the Baltimore was produced in greater numbers than any other Martin plane except the B-26, with over 1500 produced,not one aircraft has survived.