UNITED24 - Make a charitable donation in support of Ukraine!

Weapons of Mass Destruction (WMD)

B-29 - Variants

  • Silver Plate In early 1944 the Army Air Forces started its program to develop an atomic bomb delivery capability using the B-29 aircraft. The B-29 was the logical choice in view of its long range, superior high-altitude performance, and ability to carry an atomic bomb that was expected to weigh 9000 to 10,000 pounds. In March and again in June dummy atomic bombs were dropped by B-29s at Muroc Army Air Force Base in California to test the release mechanism. In August seventeen B-29s entered a modification program at the Glenn L. Martin plant in Omaha, Nebraska, to apply the lessons learned at Muroc. The "Silver Plate" project was the code name of the pilot and crew training program for the coming World War II atomic missions.

  • B-29 MR [MR standing for Modified Receiver] could refuel in mid-air. The KB-29M was the tanker, using what was called the British 'looped hose' method, a 400 foot length of hose that tethered the two airplanes together. In order to extend the range of the new generation of jet aircraft, a B-29 was also fitted with a flying boom for experiments in air-to-air refueling.

  • B-29D Washington A stop-gap measure to fill the long-range bomber requirement in the Cold War, the Boeing B-29D Washington began entering service with UK Bomber Command Squadrons during August 1950. The type began to be retired in 1953 with the advent of the V-bombers, but the last did not leave the RAF until 1958.

  • KB-29M: In 1948, 92 B-29s were sent to the newly reopened Boeing Wichita Plant for conversion to hose type tankers, subsequently known as KB-29Ms. This project was urgent, being directly associated with the build up of the atomic forces. The bomber's serious range limitations had called for special arrangements. There was an extensive forward base network, encompassing airfields in Alaska, Canada, England, West Germany, Spain, North Africa, Okinawa, and Guam. But the use of overseas staging bases was a troublesome expedient. A better solution was to develop inflight refueling systems that would give to the SAC bombers the intercontinental striking range they still lacked.
    The first such system was featured by the K 29M, which was fitted with British developed hose refueling equipment. The British system involved trailing a hose from the tanker to the receiver and transferring fuel practically by means of gravity. The receiver aircraft (listed as B-29MR, in the B-29's case) also required modifications, but they were relatively minor. In contrast, the tanker modifications were extensive. Each bomb bay was fitted with a separate jettisonable tank holding approximately 2,300 gallons of fuel. These tanks were connected to the aircraft's normal fuel system so that fuel from it could also be transferred to the receiver bomber. The KB-29M's inflight refueling system required that the tanker and receiver fly in formation, with the tanker above and ahead trailing a cable referred to as the hauling line. The receiver trailed a line of its own from its refueling receptacle. Called the contact line, this line was so equipped that it could hook the tanker's trailing line and lock the two lines together. The receiver operator then caught the lines, separated them, secured them, pulled the tanker's refueling hose and put it into the receptacle of his bomber. The whole procedure, obviously, was perilous from the start, and the KB-29Ms, after reaching the inventory in late 1948, were replaced within a few years.

  • KB-29P: The hose refueling system had many disadvantages, especially in the lengthy time required to make contact, the slow rate of fuel transfer, and the very limited airspeed imposed by the hoses. Boeing therefore soon developed on its own an aerodynamically controlled swiveling and telescoping arm, known as the "Flying Boom." Essentially, this system consisted of a telescopic pipe, which was lowered from the tanker, and connected to a socket in the receiver aircraft. The system was entirely controlled by an operator in the tanker, and the fuel transfer was made with the aid of a pump. B-29s so equipped were designated KB-29Ps. The first of 116 KB-29Ps reached SAC's 97th Air Refueling Squadron on 1 September 1950, the total contingent being delivered by the end of 1951. In spite of the increasing availability of the much faster KC 97, 25 SAC retained many of its KB-29Ps until 1957. The Tactical Air Command gave up its last KB-29s in the middle of that year.

  • RB-29: Nearly 120 B-29s were converted to the reconnaissance configuration and redesignated as RB-29s. Some of these aircraft, known as F 13s during World War II, were first fitted with fairly primitive photographic equipment: 3 K 1713s, 2 K 22s, and 1 K 18 camera. After 1948, when the RB-29 designation came into being, the converted bombers began acquiring more sophisticated components. The RB-29s were assigned to the 91st Strategic Reconnaissance Squadron, which like other SAC units played a crucial role during the Korean conflict. The RB-29s followed the phaseout pattern of the bombers from which they derived. The same reasons prompted their retirement.

  • TB-29: Some B-29s, fitted with additional trainee or instructor stations, recording equipment, and related types of apparatus, were used for training and identified as TB-29s.

  • VB-29: A few B-29s, after being internally refurbished, were used for the transportation of key personnel.

  • WB-29: Some B-29s were modified to carry meteorological equipment and used on weather reconnaissance flights. Designated as WB-29s in 1948, these aircraft were the last B-29s to phase out of the regular Air Force.

Join the GlobalSecurity.org mailing list

Page last modified: 23-07-2018 13:44:51 ZULU