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Like the Martin 167 Maryland, the Douglas DB-7 Boston used Pratt and Whitney R-1830 engines. The Martin 187 Baltimore and the Douglas A-20 upgraded to Wright R-2600 engines. So, as I understand it, the US didn't buy either plane with R-1830 engines, but bought the Douglas plane once it had R-2600s. By appearances, the Martin plane changed more with the engine swap. It also seems that the A-20 went into production with R-2600s slightly ahead of the Martin Baltimore. We are talking a few months. But in 1940-1941, a few months make a big difference.At the risk of being shot to pieces for diverting a bit from the opening theme, I don't see the Baltimore offering any significant improvement over the earlier and under-appreciated Maryland.
The Maryland (Martin Model 167) was in direct competition with the Douglas DB-7 (A-20), but came in second in the 1938-1939 USAAC competition. Trying to juggle specs between what Wiki and Joe Baugher's site offer, the Maryland had several attributes where it may have bested the A-20, but a lot depends on which model A-20 you're trying to make the comparison with. It appears the Maryland had better range (1300 mi vs. about 1000 mi), better rate of climb (2400 fpm vs. 2000 ft/min), and may have been a bit more nimble with a lower wing loading, with 1100 less total HP.
Assuming the slight advantages are true, would this justify U.S. adoption? It didn't historically, and the speed advantage in the earlier/lighter A-20s was significant. I'd guess there would need to be a problem in the USAAC getting the numbers of aircraft it needed within the required timeframe. If more light attack bombers were needed, the Maryland would have made a decent substitute standard.
Timing for one thing.
A-20s were coming off the production line in late 1940, First flight by Baltimore prototype was June of 1941.
A-20 was almost 40mph faster.
A-20 had less range (at least early versions)
You may have to bring the B-25 into it (at least early ones) as the Baltimore was sort of in-between the A-20 and B-25 as far as weight and wing area go and the Baltimore was designed for a 4 man crew from the start. A-20s used 3-4 men depending on if they carried a 4th man for the lower fuselage gun.
All three planes used R-2600 engines.
Boston was quite fast (up to 310 mph in some configurations, more in the later war versions but those were too late for action in the med). I think (only based on anecdotal comments by pilots) it was the fastest of the three down near sea-level, but not by much.
Boston / A-20 was used quite effectively in the anti-shipping role in the Med with mast-height bombing techniques and sunk some ships close to shore.
Well, I mean they were 'quite fast' compared to other contemporaneous bombers active in the Theatre, and notably so at the (fairly low) altitudes they were flying.
They were faster than SM. 79, SM. 84, CANT Z.1007, He 111, Blenheim, Beaufort, Ju-88A, B-26, or B-25 for example.
~300 is decent speed for a bomber, it's not just about battling it out with fighters, it's also a matter of how quickly they can exit the battle area after dropping their bombs, how easily they are to intercept etc. 340 mph is very good speed I'd say. I'd love to know if any of the DB-7/ A-20 aircraft operational in the MTO could make that speed.
I agree, you have to start with comparing the Maryland and the DB-7/early A-20.At the risk of being shot to pieces for diverting a bit from the opening theme, I don't see the Baltimore offering any significant improvement over the earlier and under-appreciated Maryland.
The Maryland (Martin Model 167) was in direct competition with the Douglas DB-7 (A-20), but came in second in the 1938-1939 USAAC competition. Trying to juggle specs between what Wiki and Joe Baugher's site offer, the Maryland had several attributes where it may have bested the A-20, but a lot depends on which model A-20 you're trying to make the comparison with. It appears the Maryland had better range (1300 mi vs. about 1000 mi), better rate of climb (2400 fpm vs. 2000 ft/min), and may have been a bit more nimble with a lower wing loading, with 1100 less total HP.
Assuming the slight advantages are true, would this justify U.S. adoption? It didn't historically, and the speed advantage in the earlier/lighter A-20s was significant. I'd guess there would need to be a problem in the USAAC getting the numbers of aircraft it needed within the required timeframe. If more light attack bombers were needed, the Maryland would have made a decent substitute standard.
The Russians got some mileage out of the DB-7 as well, but I think the British did the most damage with them.
I think you need to research the A-20 a bit more.
We at least need to figure out where the DB-7 stops and the A-20 begins
as for
By the end of the war, 3,414 A-20s had been delivered to the USSR, 2,771 of which were used by the Soviet Air Force.
This is out of 7,478 built in total. At some points during the war the USSR had more A-20s than the US did.
The US ordered 186 A-20s in June of 1939, these were all powered by Wright R-2600s of several different models. Deliver took a while but the US order was not influenced by user reports by either the French or British.
The US ordered 999 A-20Bs in Oct of 1940, again showing US interest without benefit of much in the way of user reports from either France or Britain. This was a bit of a panic buy as the planes were not equipped with armor or self sealing tanks and thus, only a percentage saw service with the US forces. 665 of them were sent to the USSR.
The US never got any production DB-7s/A-20s with P&W R-1830s.
US interest in the Martin Baltimore has to take into account the B-25 Program.
The US issued an order for 184 B-25s on Aug 10th 1939 although final approval took until Sept 10th 1939 (same date the US placed initial order for Martin B-26 bombers).
The first French Martin 167 (Maryland) flew in Aug 1939. The British wound up with about 125 Maryland Is (50 ?) ex-French and 75 British ordered and a further 150 Maryland IIs.
The Martin 187 (Baltimore) was not ordered by a French/British purchasing commission until May of 1940. (400 planes) which is a bit late for the USAAC to decide to cancel the B-25.
Even though the B-17 had better survivability, the B-24 became prominent in the PTO after late 1943/early 1944.B-24 did seem like the better fit as far as the heavies.