Monday, December 11, 2017
Text Size

Consolidated B-24D Liberator

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.

comments