B-24J DAISY MAE Being Refueled
The fuel system of the Consolidated B-24 Liberator was an intricate and carefully engineered component of the aircraft, designed to meet the heavy operational demands of long-range bombing missions. Here’s an overview of its design and functionality:
Integral and Self-Sealing Fuel Tanks
Initial Configuration:
- Integral Tanks: The original design featured two integral fuel tanks extending 147 inches from the wing centerline.
- Sealing Method: Used 1/32-inch synthetic rubber gaskets, proven effective from use in PBY Catalinas.
Transition to Self-Sealing Tanks:
- Necessity: Military requirements mandated the transition to self-sealing cells for enhanced safety.
- Design Changes: Minimal changes were needed:
- Larger access doors on the underside.
- Removable members in two bulkheads adjacent to the tank region.
- Small access doors for reaching fuel cell manifolds.
Fuel Tank Arrangement:
Main Fuel System:
- Number of Cells: 12 inboard self-sealing cells.
- Capacity: 2343 gallons.
- Configuration:
- Cells interconnected by flexible self-sealing manifolds.
- Formed six units of three cells each.
- Accessible manifold connections through lower wing surface doors.
- Fuel booster pump located under the final cell of each unit.
- Included shut-off selector valves, fuel strainers, and engine-driven pumps.
- Normally, each main unit delivered fuel independently to one engine.
Auxiliary Fuel System:
- Number of Cells: 6 outboard self-sealing cells.
- Capacity: 450 gallons.
- Configuration:
- Provided additional range.
- Connections accessible from the inboard side of inboard nacelles.
- Auxiliary cells transferred fuel to the main cells via the fuel transfer system.
- Connection to engines facilitated through the cross-feed system.
Additional Fuel Storage:
- Forward Bomb-Bay: Two additional cells with a combined capacity of 790 gallons could be installed here.
Installation and Support:
Fuel Cell Placement:
- Fit: Main fuel cells in the wing center section were secured by their fit into the compartment.
- Spacers: Used where cells did not occupy the full depth, with canvas curtains snapped into place between cells and rib members.
Venting and Draining:
Drainage:
- Purpose: To discharge any leaked fuel overboard.
- Location: Drains located on each side of the centerline, immediately aft of the inboard booster pumps.
- Shut-Off Valves: Fitted with shut-off valves and overboard discharge lines.
- Booster Pump Gland Drains: Emptied into these lines, leading through bulkheads and extending below the wing skin.
Vent Lines:
- Location: On each side of the centerline of the inboard nacelles.
- Routing: Passed through the wing center and exited aft of the number 2 and 3 nacelles.
The fuel system of the B-24 Liberator was designed to maximize range, safety, and operational efficiency. It incorporated both integral and later self-sealing fuel tanks, with a sophisticated arrangement of main and auxiliary cells supported by robust venting and draining mechanisms. This design allowed the B-24 to meet the demanding requirements of long-range bombing missions effectively.