EDITIONS ATLAS #4646107 1/144 Boeing B-29 Bockscar, Dropped A-Bomb on Nagasaki

Although Boeing is the aircraft company normally associated with the B-29, both as its designer and builder, USAAF demands for the bomber resulted in it being built not only by Boeing at two plants - in Wichita, Kansas, where production began, and in Renton, Washington - but also at a Bell Aircraft Company plant in Marietta, Georgia outside Atlanta and and a Glenn L. Martin Company plant in Bellevue, Nebraska outside of Omaha.

The variants of the B-29 are as follows - quantities are in parenthesis with the manufacturing location(s) indicated:

     XB-29 - Prototype (3) - Boeing's Plant 2, King County, Washington. This plant did not build any additional B-29s beyond the prototype because of its major role in B-17 production However, it did manufacture sub-assemblies for the B-29A variant which were transported to the nearby Boeing-Renton plant where the B-29A was built.

     YB-29 - Pre-production aircraft (14) - Boeing-Wichita.

     B-29 - Original Production Version (2,537) - production distributed as follows: Boeing-Wichita - 1,644, Bell-Atlanta - 357, and Martin-Omaha - 536.

     At war's end incomplete airframes on Wichita's assembly line were scrapped. Under these circumstances they apparently were not included in Boeing-Wichita's total.

     Silverplate B-29 - Variant of original B-29 (46) - Aircraft were modified to specifications enabling them to drop an atomic weapon - the most visible change being the removal of all defensive armament except for that in the tail turret. All 46 were Martin-Omaha B-29s and are included in that plant's 536 total.

     B-29A - Improved version of original production aircraft (1,122) - Boeing-Renton. The definitive wartime variant. Enhancements included an improved wing and increased defensive armament. Production continued until May 1946 when the last of the type was completed.

     B-29B - Modification of the B-29 for low-level firebombing raids (311) - Bell-Atlanta. With little fighter opposition over Japan by late 1944, it was felt that a (lighter) faster bomber would better evade Japanese flak. As with the Silverplate B-29, the B-29B had all defensive armament removed except for the guns in the tail turret. The reduced weight increased the top speed from 357 mph to 364 mph.

     B-29C - Modification of the B-29A re-engined with improved Wright R-3350 Duplex-Cyclone engines. The USAAF originally ordered 5,000, but the end of WWII led to the order being canceled in September 1945 and none were built.

     B-29D - Improved version of the original B-29 design, featuring 28-cylinder Pratt & Whitney Wasp Major engines which were nearly 60% more powerful than the usual Duplex Cyclone. It also had a taller vertical stabilizer and a strengthened wing. A B-29A was modified as the testbed which was designated the XB-44. An order for 200 B-29Ds was placed in July 1945 but that December the order was cut to 60 and the designation was changed to B-50 Superfortress.

     Officially, the B-29D's new designation of B-50 was justified by the changes incorporated into the revised aircraft but a well-known authority on Boeing aircraft claimed the re-designation was an outright ruse to win appropriations for the procurement of an airplane that by its B-29D designation appeared to be merely a later version of an existing model that was being canceled wholesale. The 370 B-50s which were eventually produced were built by Boeing's Plant 2.

Including the XB-29s and YB-29s, the total number of B29s of all types manufactured came to 3,987. The 370 B-50s are not included in this figure.

Production totals by plant were: Boeing's Plant 2 - 3, Boeing-Wichita - 1,658, Boeing-Renton - 1,122, Bell-Atlanta - 668, and Martin-Omaha - 536.

Boeing-Wichita also built the equivalent of another 125 B-29s in spare parts and this plant's peak production was 4.2 B-29s per day!

Only two aircraft in the Allies inventory were capable of carrying the atomic bombs: the British Avro Lancaster and the American B-29, both of which were 4-engine land-based heavy bombers. The Lancaster had a cavernous 33-foot bomb bay served by a pair of 22-foot long bomb bay doors compared to the B-29's two 16-foot bomb bays served by pairs of 12-foot long bomb bay doors and consequently far less effort would have been needed to modify the Lancaster for the role.

Although the Lancaster was British, one of the 11 factories producing the type was the Victory Aircraft, Ltd. plant at Malton, Ontario on the outskirts of Toronto. The argument has been made that since the Lancaster was a foreign design, it would have required more training to make American aircrews proficient in flying it - particularly with regard to its instrumentation. However, the change over probably would have been no greater an effort than that to modify the B-29's bomb bay configuration and quite likely less. 

The "Silverplate" in the B-29 atomic bomber's designation was derived from the original directive from June 1943 establishing the USAAF's participation in the Manhattan Project, which was entitled "The Silver Plated Project". Having determined that the B-29 was the only aircraft in the US inventory having the power and lifting capacity to carry either of the two atomic bombs under development - the "Thin Man" (later changed to "Little Boy" after essentially being redesigned) and the "Fat Man", this authorized the USAAF to quickly proceed with the necessary modifications.

There had been growing support among some factions for using the British Avro Lancaster for the role because the type arguably required limited modifications to carry either type of bomb as mentioned above and the USAAF directive was aimed at preventing this from happening. Although the Malton plant's proximity to the US would have facilitated coordinating the modifications.

However, for nationalistic reasons Army Lieutenant General Leslie Groves, head of the Manhattan Project for producing the Atomic Bomb, and possibly with the urging of senior officers within the Army Air Corps, felt the atomic bomber had to be an American type and effectively controlled the decision in favor of the B-29. By the time the prototype B-29 atomic bomber was ordered, "Silver Plated" had been shortened to "Silverplate"

That prototype Silverplate B-29 was code named "Pullman" to imply to anyone not involved in its conversion that it was special VIP passenger aircraft. "Thin Man", "Fat Man", Silverplate B-29 and "Pullman" were purposely deceptive code words used in message traffic about a purported visit by Roosevelt accompanying by Churchill in a specially upgraded aircraft for an inspection of the B-29 production line at Boeing-Wichita.

While "Pullman" was still in the works, orders were received for the 45 production versions of the type which were completed by the end of the war. As yet unnamed, Bockscar as B-29-36-MO Serial #44-27297 was one of the first group of 15 Silverplate B-29s delivered which formed the 393d Bombardment  Squadron of the 509th Composite Group. Built at Martin-Omaha as a Block 35 aircraft, it was one of 10 from that production block modified as Silverplate B-29s and re-designated "Block 36".

Delivered to the USAAF on March 19, 1945, the aircraft was assigned to Captain Frederick C. Bock and Silverplate crew C-13, and flown to Wendover Army Air Field, Utah in April. Bock himself wasn't new to the B-29, having flown early Superfortress missions against Japan from bases in China. The name of "Bockscar", punning on Bock's name was chosen for the aircraft (but was only painted on it after the Nagasaki mission. It left Wendover on June 11, 1945 for Tinian, arriving on June 16.

Bockscar was originally given the Victor (unit-assigned identification) number 7 but in July and August aircraft of the 509th used other groups' markings as a security measure to help conceal their special purpose. In keeping with this practice Bockscar was given the Triangle N tail markings of the 444th Bombardment Group and its Victor "7" changed to "77" to avoid mis-identification with an actual 444th aircraft.