The ultimate version of the A-20 was a different plane, the A-26, also pretty fast. That gives you the bomb load, extra range, a second pilot, armor and ss fuel tanks, and heavy defensive armament.
But prior to that they did develop A-20 variants which were only a little slower than the A-20A, had reasonable fuel and range, and still handled really well. Bomb load was never huge especially internally, but I'm always an advocate of precision over simple weight of ordinance. Fast and agile seemed to translate to fairly accurate in the case of this one. It wasn't a dive bomber but it could do low-level attacks, and also worked pretty well as a strafer.
The 1940 version was apparently flying just barely in time for the last few days of the Battle of France, got 70 of them to North Africa which then flew across the Med to France, and seem to have flown about one sortie each. But that variant (DB-7 B-3) had smaller engines (R-1830s) and a lot less fuel. Probably still pretty useful, I think it would be hard for German fighters to shoot down.
The early A-20/DB-7 story is rather confusing. The Prototype, which crashed with a French observer aboard, was powered with P&W R-1830s and that is what the French ordered (different nose and canopy). Without cracking a book I can't remember if the French placed a 2nd order before anybody else got involved. I believe the British placed an order in the fall of 1939 (?) with R-1830 engines. The US took a 2nd look, they had not ordered any in the first months after the attack plane trials. Then they ordered the A-20 with the R-2600s and a beefed up wing, not larger, just stronger to handle the extra weight. At some point the Dutch got involved (Just before Holland failed) and sorting out the different models gets hard as a lot of them didn't go to the countries that ordered them.
The R-1830 versions were good for around 310mph give or take. There were several different versions of R-1830s used and the first ones the French got had single speed superchargers. Later ones (and British ) got 2 speed but since the British got some of the French left overs the British engine situation was a bit confused. The smaller engines didn't require as much fuel and the area of operations (France or cross channel) short range was not a big problem.
The US with the bigger, thirsty engines faced a problem.
The Douglas airplane was designed to use integral fuel tanks. The wing skin top and bottom was part of the fuel tank with other wing parts like ribs forming some of the other surfaces.
This style of fuel tank construction was all the rage in US design circles. Right up until somebody pointed out it wasn't a good idea for planes that got shot at.
The Original French aircraft held about 325-327 US gallons in two tanks. As did the early British planes. The American A-20s started with 4 tanks by adding an 87 gal tank to each wing for a total of 500 US gallons. BUT, only 16(?) were delivered that way. The rest got self sealing fuel cells placed in the area of the original fuel tanks but that dropped the fuel capacity to 400 US gallons. And that pretty much started the path to put more fuel in the upper bomb bay. Which was helped, in large part, by the size of the bomb bay because the US, in the 1930s was a big advocate for it's
attack planes of not using precision bombing attacks. They were advocates of dropping large amounts (huge at times) of small 30lb bombs over a wide area while spraying with machine guns. One the French, British and finally the Americans decided they needed around four large bombs (250-500lb each) there was all this empty space in the top of the bomb bay they could fill with fuel tanks.
Keep note of this for "What Ifs" By the time the A-20 gets to the "G" series it is carrying 725 US gallons of fuel in internal tanks. It might have been a little faster with a skinner fuselage, less depth, if designed to hold four medium bombs at the start but then fitting the larger fuel tanks gets very hard. An A-20 bomb bay was only 28in wide at the top and 32in wide at the bottom but it was 62.5 in high. The bomb bay had been designed to load the small fragmentation bombs in tubes from the top of the aircraft.
The panel to the rear of the raised hatch/cover also hinges to the right. As time went on they filled the space with radio gear.
The US planes were also designed to hold two 600lb bombs or one 1100lb or in overload sixteen 100lb bombs.
Another case of the plane not being used as designed
