Yep it was. It was designed and originally used to drop bombs from 30,000ft in day time. They dutifully used it in that way. Now they couldn't accurately drop bombs from 20,000ft at that time so it was even less accurate than all the daylight B-17s, B-24s in the ETO.
And yet, due to
atmospheric conditions over the Japanese Isles,
any bomber was met with the same frustration with warload delivery at designed altitudes. Be it a B-17, B-24, Lancaster or any other heavy bomber.
The impact on Japan was similar to Germany, limited (mining, the submarine blockade and the later naval blockade had a far greater effect). Plus by the time the B-29 bombing got really going they were bombing Japan from aircraft carriers....
Keep in mind that the B-29 was also hammering targets in the CBI, from Asian bases, even though attacks against Japan were not as productive as hoped. So don't think that the B-29 was solely intended as a weapon against Japan.
Also, might want to double-check your timeline, the forward bases in the Pacific were secured in mid-1944, allowing for extreme long range bombing missions against the Japanese Islands as well as missions against Japanese held islands in the region. It wasn't until early in 1945 (February) that carrier based attacks were conducted against Japanese proper.
So they turned it into a low level (less than 5,000ft) night time incendiary bomber and stripped out a lot of stuff out of it (guns, etc). Now anything could do that. All that money spent on giving it all that high altitude performance was wasted. And what it ended up doing could have been done by a lot of other, far cheaper aircraft.
I need to disagree here. One B-29 was capable of carrying a standard bomb load of 20,000 pounds long distance. For a bomber like the B-17 or the B-24, distance decreases as bombload increases. Even at max load for either one of those types, one B-29 is still doing the job of two bombers.
As for the nukes. The Fat Boy weighed 10,300lbs, the Little boy 9,700lbs. A Lanc could carry that.... as for the range, my rough calculations make it that a Lanc with that load (and a late model with late model Merlins) needed a minimum of another 600 UK gals of fuel (4,500lbs) to make it from Tinian to Hiroshima and back. Say make it 700 UK gals and 5,200lbs for a reserve. Need a bit of tricking up and stripping out, but they did that with B-29 too.
Anyway they could have done it from Okinawa by that time, which B-24s bombed Japan from, round trip about 1,300 miles ..easily within a Lanc's range. Heck at that range you might have been able to trick up a B-24 to carry the nukes (maybe, Fat Man maybe yes, Little Boy maybe not because of the shape).
Now we're entering the shady area of "what-ifs".
You're not only carrying a max load aboard, but now you want to load it down even more with extra fuel?
Obviously, the heavier it gets, the shorter the range...throwing more fuel onboard isn't going to somehow fix that.
One other thing to keep in mind, the altitude for Atomic bomb deployment was 30,000 feet and if memory serves me right (I may be off, here) the Lancaster's ceiling with a full bombload was 25,000 feet?
The B-29 cost $640,000*. B-24 $300,000 and the Lanc (at a 4:1 exchange rate of the time) $200,000.
That must be just the manufacturing cost, adding the development costs I get $1.4 million per plane. But I don't have the equivalent B-24 and Lanc development costs, but you'd expect them to be a heck of a lot less....
Again, the B-29 was an advanced piece of hardware...Aerodynamic advancements, new innovations in defensive turrets, pressurized cabin/personnel compartments, extreme load carrying, extreme long distance.
It carried a crew of 11 men and standard designed bombload of 20,000 pounds.
For a B-24 to match that bombload by comparable range, it would require four B-24 bombers.
That's four times aircraft cost each $298,000 = $1,192,000
That's four times the crewmen at 11 men each = 44 crewmen
Then let's factor in fuel for the four B-24s and logistics, support, maintenance, forward airbase area consumed and so on and so on.
So back to the original point, what could a B-29 militarily do that another aircraft of the time couldn't also do at a fraction of the cost (albeit with a bit of tricking up)?
The economics have already been covered above and when the B-29 entered service, it reclassified "heavy bomber" and introduced the era of long-range strategic bomber.