The B-24D was the first truly combat-capable version of the Liberator to be delivered to the USAAF. Under the provisions of the Liberator Production Pool program, B-24D was the designation assigned to those production Liberators built by Consolidated/San Diego as primary contractor. As part of its participation in the Liberator Production Pool, the Consolidated/San Diego plant supplied components and sub-assemblies of B-24Ds to Consolidated/Fort Worth and to Douglas/Tulsa for final assembly.
The B-24D was essentially similar to the B-24C which immediately preceded it. Since B-24D was the designation assigned to the production pool version of the Liberator that was built by the Consolidated/San Diego parent company, B-24Ds were the first to roll off the production line. The first B-24Ds produced by Consolidated/San Diego were delivered to the Army in late January or early February of 1942. A total of 2425 B-24Ds were built by Consolidated/San Diego.
As part of its participation in the Liberator Production Pool, the Consolidated/San Diego plant began to supply components of B-24Ds to Consolidated/Fort Worth and to Douglas/Tulsa for final assembly. The first B-24Ds rolled off the line at the Consolidated plant in Fort Worth in May of 1942. Fort Worth eventually built 303 B-24Ds. In July of 1942, the first Douglas-assembled B-24Ds were delivered. However, only ten B-24Ds were assembled by Douglas/Tulsa before production switched over to later versions.
A total of 2738 B-24Ds were built by the three contractors in the pool before production switched over to later versions.
During the production run of the B-24D, it was found necessary to introduce the production block designation system, in which a number was added behind the series letter in the aircraft designation in order to keep track of the myriads of different innovations that were introduced on the production line. This production block designation system began with San Diego-built serial number 41-23640, which was assigned the designation B-24D-1-CO. Since the Liberator was now being built by more than one manufacturer, the manufacturer identification had to be included as well, with CO standing for Consolidated/San Diego, CF for Consolidated/Fort Worth and DT for Douglas/Tulsa. To make things even more confusing, there was usually no correlation between the various production block numbers used by the three different plants which built the B-24D.
The Martin upper fuselage power turret (400 rpg) and the Consolidated A-6A tail turret (600 rpg) introduced on the B-24C were retained on the B-24D. However, the ventral tunnel gun initially installed on the B-24C was not fitted, and no waist guns were provided. The maximum bomb load was 8000 pounds, and the maximum fuel tankage was 2364 US gallons. The first 94 B-24Ds built by Consolidated (up to B-24D-15-CO) had a single flexible 0.50-inch machine gun installed on a ball-and-socket mount in the lower part of the nose.
A retractable tailskid was first added with B-24D-1-CO 41-23640 and subsequently added to airplanes 41-11582 and later. On airplanes without the tailskid installed, a tail bumper was provided.
Beginning with the 77th production B-24D (41-11587), a Bendix-designed remotely-controlled power turret was installed in the ventral position. It housed a pair of 0.50-inch machine guns. The power turret was retractable and was aimed by a gunner who sighted the target through an optical periscope. A similar sort of design had been fitted to the early B-17E. On both aircraft, gunners found the system to be completely unworkable in combat. It was almost impossible to see anything through the rather complicated optical system during realistic operational conditions, the gunners often suffering from disorientation, vertigo, and nausea when sighting a target through the periscope. When viewed to the front, the target showed up in the sight in its normal upright position, but the image tilted left or right on the sides, and was inverted in the sight when viewed to the rear. After 287 B-24Ds had been built with this turret, the USAAF finally admitted that the sighting system was unworkable, and the ventral tunnel gun was re-introduced on the B-24D-15-CO 41-23970 production block of airplanes.
Based on combat experience, it soon became clear that additional armament would be needed on the B-24D. Beginning with B-24D-25-CO serial number 41-24220 and B-24D-10-CF 42-63837, single waist guns in full swivel mounts were installed, with a total of 350 rounds per gun. When not in use, the waist guns could be stowed and a hatch cover could be placed over the window cutouts. A deflector shield was installed in the forward side of the waist window to keep some of the wind from blowing in when the cover was opened. This brought the total armament of the B-24D to eight guns (one in the nose, two in the top turret, two in the tail turret, one in the ventral tunnel, and one in each of the left and right waist positions).
In order to protect against frontal attacks, the single nose gun was supplemented by additional cheek-mounted guns firing from ball-and-socket slots cut into each side of the nose. An additional window had to be cut into the nose to provide a view for the operators of these guns. The cheek guns could be aimed by the bombardier when he was standing. With all three guns fitted, the space inside the nose was extremely crowded. This brought the total armament to ten guns (3 in the nose, two in dorsal turret, two in waist positions, two in the tail, and one in the tunnel position). Later, an additional socket was cut into the apex of the nose, and the flexible nose gun was often carried at this position rather than in the lower nose position. However, I don't think that B-24Ds ever flew with four nose guns fitted.
Beginning with B-24D-140-CO serial number 42-41164, the tunnel gun mount in the rear ventral fuselage was replaced by a manned Sperry ball turret similar to that mounted on the late B-17E. It carried a pair of 0.50-inch machine guns, with all the ammunition being carried inside the turret. Like the ball turret in the B-17, the gunner sat entirely inside the turret to operate the guns. Unlike the ball turret in the B-17, was fully-retractable into the fuselage, which made landings much easier and less hair-raising. The turret could rotate a full 360 degrees and the guns could depress between 0 and 90 degrees. The armament was now eleven guns (three in the nose, two in upper dorsal turret, two in tail turret, two in belly turret, and two in the waist positions).
Late production B-24Ds beginning with B-24D-135-CO 42-41115 on the San Diego line and with the B-24D-20-CF block on the Fort Worth line introduced the R-1830-65 engine. This engine differed from the R-1830-43 previously used in having a Stromberg PB12 carburetor in place of the Chandler Evans CE-1099-CPB-3 carburetor. This engine still developed an output of 1200 hp at an altitude as high as 26,500 feet, greatly enhancing altitude performance. The R-1830-65 was also used on the few B-24D-1-DT to -5-DTs built by Douglas.
German and Japanese fighters quickly found that the Liberator (like the B-17) was vulnerable to frontal attack. The addition of the two 0.50-inch machine guns in the cheeks of late-model B-24Ds did not help very much in warding off these attacks. The cheek guns were awkward to operate and there were significant blind spots. Various field modifications were tried out in an attempt to correct this problem. Modifications such as the fitting of two 0.50-inch machine guns firing through the forward nose glass or the adding of more forward-firing guns underneath the bombardier's floor were tried, but did not help that much.
One modification that did work fairly well was the field installation by the 90th Bombardment Group of a Consolidated A-6 tail turret from a wrecked Liberator in the NOSE of another B-24D. The idea was supposedly the brainchild of Art Rogers, who first thought of it in April of 1942. A mockup was tried out at Ford/Willow Run in August of 1942. It took a while, however, before a working turret was actually installed in the nose of a Liberator. The first nose turrent was installed in 41-23759 while the plane was being repaired in Australia. So successful was this modification was that the Army authorized the installation of nose turrets in all Pacific-bound Liberators. The first such modifications were performed by the Hawaii Air Depot, with the Oklahoma City Army Air Corps Modification Center later joining the program. The Oklahoma City modified Liberators had a redesigned bombardier station which gave the aircraft nose a pronounced drooped chin and a distinct "tacked-on" appearance. These modified B-24Ds were given the designation B-24D1.
The first B-24Ds to go abroad were the Liberators of the Halverson Detachment, which consisted of 23 planes commanded by Col. Harry A. Halverson. The purpose of this group of picked aircrew was to begin bombing operations against Japan from bases in China in June of 1942. They were to fly to their Chinese bases by way of Africa, the Middle East, Iraq, and India. However, this force was held, initially only temporarily, in the Middle East to help defend against Rommel's advancing Afrika Korps. While there, the decision was made for the force to carry out a single raid against the Ploesti oilfields in Rumania. Thirteen planes of the Halverson Detachment carried out the first Ploesti raid on June 11-12, 1942, which was also the first strategic attack of any significance of the war to be carried out by land-based aircraft of the USAAF. The Liberators took off from the RAF base at Fayid in Egypt and flew across the Mediterranean, Greece, and Bulgaria to reach Ploesti. Complete surprise was achieved, and the planes dropped their 4000-pound bombloads through cloud at 10,000 feet. Seven of the planes reached their intended base in Iraq, two landed in Syria, and four landed in Turkey, where they were interned. Unfortunately, the damage to Ploesti was minimal and only succeeded in alerting the German High Command to the vulnerability of one of its primary fuel sources. This was to cost American bomber forces dearly during the epic low-level mission of August 1, 1943, when out of 178 bombers dispached to Ploesti only 33 were still fit to fly after the mission was over.
The Halversen Detachment never did reach China. After the first Ploesti raid, it remained in the Middle East to fight against Rommel, eventually being absorbed by the 1st Bomb Group in October of 1942.
B-24D-160-CO 42-72843 *Strawberry Bitch* is on display at the US Air Force Museum at Wright-Patterson AFB in Dayton, Ohio. This is the only B-24D that still survives. However, there are reports that B-24D 40-2367 which was wrecked in Alaska during the war will be recovered by the Alaska Aviation Heritage Museum for display in a museum in Denver, Colorado.
Serials of Consolidated B-24D Liberator:
40-2349/2368 Consolidated B-24D-CO Liberator 41-1087/1142 Consolidated B-24D-CO Liberator 41-11587 Consolidated B-24D-CO Liberator 41-11588/11589 Consolidated B-24D-CF Liberator 41-11590/11603 Consolidated B-24D-CO Liberator 41-11604/11605 Consolidated B-24D-CF Liberator 41-11606 Consolidated B-24D-CO Liberator 41-11607 Consolidated B-24D-CF Liberator 41-11609/11626 Consolidated B-24D-CO Liberator 41-11627/11628 Consolidated B-24D-CF Liberator 41-11629/11638 Consolidated B-24D-CO Liberator 41-11643/11654 Consolidated B-24D-CO Liberator 41-11658/11673 Consolidated B-24D-CO Liberator 41-11677/11703 Consolidated B-24D-CO Liberator 41-11705 Consolidated B-24D-CF Liberator 41-11710/11727 Consolidated B-24D-CO Liberator 41-11734/11741 Consolidated B-24D-CO Liberator 41-11748/11753 Consolidated B-24D-CO Liberator 41-11754/11756 Douglas-Tulsa B-24D-DT Liberator 41-11757/11787 Consolidated B-24D-CO Liberator 41-11790/11799 Consolidated B-24D-CO Liberator 41-11801/11836 Consolidated B-24D-CO Liberator 41-11839/11863 Consolidated B-24D-CO Liberator 41-11864 Douglas-Tulsa B-24D-DT Liberator 41-11865/11906 Consolidated B-24D-CO Liberator 41-11909/11938 Consolidated B-24D-CO Liberator 41-23640/23668 Consolidated B-24D-1-CO Liberator 41-23671/23693 Consolidated B-24D-1-CO Liberator 41-23697/23724 Consolidated B-24D-1-CO Liberator 41-23725/23727 Douglas-Tulsa B-24D-1-DT Liberator 41-23728/23750 Consolidated B-24D-1-CO Liberator 41-23751/23755 Consolidated B-24D-5-CO Liberator 41-23756/23758 Douglas-Tulsa B-24D-5-DT Liberator 41-23759/23790 Consolidated B-24D-5-CO Liberator 41-23794/23824 Consolidated B-24D-5-CO Liberator 41-23825/23849 Consolidated B-24D-7-CO Liberator 41-23853/23858 Consolidated B-24D-7-CO Liberator 41-23864/23902 Consolidated B-24D-10-CO Liberator 41-23906/23919 Consolidated B-24D-10-CO Liberator 41-23920/23958 Consolidated B-24D-13-CO Liberator 41-23960/23969 Consolidated B-24D-13-CO Liberator 41-23970/24003 Consolidated B-24D-15-CO Liberator 41-24007/24026 Consolidated B-24D-15-CO Liberator 41-24030/24099 Consolidated B-24D-15-CO Liberator 41-24100/24138 Consolidated B-24D-20-CO Liberator 41-24142/24157 Consolidated B-24D-20-CO Liberator 41-24164/24171 Consolidated B-24D-10-CO Liberator 41-24175/24219 Consolidated B-24D-20-CO Liberator 41-24220/24311 Consolidated B-24D-25-CO Liberator 41-24339 Consolidated B-24D-25-CO Liberator 42-40058/40137 Consolidated B-24D-30-CO Liberator 42-40138/40217 Consolidated B-24D-35-CO Liberator 42-40218/40257 Consolidated B-24D-40-CO Liberator 42-40258/40322 Consolidated B-24D-45-CO Liberator 42-40323/40344 Consolidated B-24D-50-CO Liberator 42-40345/40392 Consolidated B-24D-53-CO Liberator 42-40393/40432 Consolidated B-24D-55-CO Liberator 42-40433/40482 Consolidated B-24D-60-CO Liberator 42-40483/40527 Consolidated B-24D-65-CO Liberator 42-40528/40567 Consolidated B-24D-70-CO Liberator 42-40568/40612 Consolidated B-24D-75-CO Liberator 42-40613/40652 Consolidated B-24D-80-CO Liberator 42-40653/40697 Consolidated B-24D-85-CO Liberator 42-40698/40742 Consolidated B-24D-90-CO Liberator 42-40743/40787 Consolidated B-24D-95-CO Liberator 42-40788/40822 Consolidated B-24D-100-CO Liberator 42-40823/40867 Consolidated B-24D-105-CO Liberator 42-40868/40917 Consolidated B-24D-110-CO Liberator 42-40918/40962 Consolidated B-24D-115-CO Liberator 42-40963/41002 Consolidated B-24D-120-CO Liberator 42-41003/41047 Consolidated B-24D-125-CO Liberator 42-41048/41092 Consolidated B-24D-130-CO Liberator 42-41093/41137 Consolidated B-24D-135-CO Liberator 42-41138/41172 Consolidated B-24D-140-CO Liberator 42-41173/41217 Consolidated B-24D-145-CO Liberator 42-41218/41257 Consolidated B-24D-150-CO Liberator 42-63752/63796 Consolidated B-24D-1-CF Liberator 42-63797/63836 Consolidated B-24D-5-CF Liberator 42-63837/63896 Consolidated B-24D-10-CF Liberator 42-63897/63971 Consolidated B-24D-15-CF Liberator 42-63972/64046 Consolidated B-24D-20-CF Liberator 42-72765/72814 Consolidated B-24D-155-CO Liberator 42-72815/72864 Consolidated B-24D-160-CO Liberator 42-72865/72914 Consolidated B-24D-165-CO Liberator 42-72915/72963 Consolidated B-24D-170-CO Liberator
Specification of Consolidated B-24D Liberator:
Four Pratt & Whitney R-1830-43 fourteen-cylinder turbosupercharged air-cooled radial engines, each rated at 1200 hp at 23,400 feet. Performance: Maximum speed 303 mph at 25,000 feet. Cruising speed 200 mph. Landing speed 95 mph. Service ceiling 32,00 feet. An altitude of 20,000 feet could be reached in 22 minutes. Range was 2300 miles with 5000 pounds of bombs. Range 1800 miles at maximum cruising power. Maximum range 3500 miles. Initial production blocks had a fuel capacity of 2364 US gallons, but later production blocks increased this to 3614 US gallons. Dimensions: Wingspan 110 feet 0 inches, length 66 feet 4 inches, height 17 feet 11 inches, wing area 1048 square feet. Weights: 32,605 pounds empty, 55,000 pounds gross, Maximum takeoff weight 64,000 pounds. Armament: Bomb bay could accommodate up to eight 1100-pound bombs. Underwing racks for two 4000-pound bombs were available, but were seldom used. Later models could carry eight 1600-pound bombs. Defensive armanent varied signficantly according to model, as described above.