The interns are cataloging away and have reached the “Lend Lease” section of the museum. The Lend Lease program was established in 1941 to allow the United States to provide material assistance to our allies in World War II. Ladd Field, here in Fairbanks, was the final transfer point for pilots, aircraft, and support personnel going to the Soviet Union beginning in 1942.
The wreckage at our museum is from two P-39s, a mid-flight crash that occurred just 60 miles east of Fairbanks in route to Ladd Field. Both pilots survived the crash, but the aircraft burned. Our wreckage is from aircraft number 43276. The vertical stabilizer, bottom half of the rudder, wing panels, and cockpit doors are on display in the Lend Lease exhibit.
A close up view of the plane wing with exposed self-sealing rubber material due to crash.
While cataloging, we discovered a rubber-like substance on the wing wreckage. After some research, information shared by our Curator, and a closer look, we discovered the substance was in fact part of the self-sealing technology used on the fuel tanks of the P-39. This technology was first patented in 1921 to George J. Murdock and used in military aircraft. It was revolutionary technology for the time. A conventional fuel tank would leak, ignite, or explode when hit by gunfire.
Many other chemists were working on developing this technology including Ernst Eger of Uniroyal and Goodyear chemist James Merrill. In 1941, Eger’s patent, published after the war in 1946, was for a “Puncture Sealing Gas Tank”. It utilized a two-layer system of rubber compounds that were encased in a metal outer shell over the wing of the aircraft. By 1942, the War Production Board implemented this technology in the Goodyear produced Corsair fighters and other aircraft of the time, including the P-39. The Fireproof Tanks were made of laminated self-sealing layers of rubber, reinforcing fabric, one of vulcanized rubber and one of untreated natural rubber which absorbed the fuel, causing it to swell and expand, sealing the puncture.
Not all aircraft were fitted with the self-sealing tanks because they were heavier than the non-sealed tanks, potentially limiting maneuverability and flight time. However, the craft with the self-sealing tanks were able to take more enemy fire than those without and sustained far more damage, allowing the pilots to safely return to base. This technology is still used today in modern jet fighters however, modifications and newer technologies have been created to accommodate the higher altitude flying.
Many other chemists were working on developing this technology including Ernst Eger of Uniroyal and Goodyear chemist James Merrill. In 1941, Eger’s patent, published after the war in 1946, was for a “Puncture Sealing Gas Tank”. It utilized a two-layer system of rubber compounds that were encased in a metal outer shell over the wing of the aircraft. By 1942, the War Production Board implemented this technology in the Goodyear produced Corsair fighters and other aircraft of the time, including the P-39. The Fireproof Tanks were made of laminated self-sealing layers of rubber, reinforcing fabric, one of vulcanized rubber and one of untreated natural rubber which absorbed the fuel, causing it to swell and expand, sealing the puncture.
Not all aircraft were fitted with the self-sealing tanks because they were heavier than the non-sealed tanks, potentially limiting maneuverability and flight time. However, the craft with the self-sealing tanks were able to take more enemy fire than those without and sustained far more damage, allowing the pilots to safely return to base. This technology is still used today in modern jet fighters however, modifications and newer technologies have been created to accommodate the higher altitude flying.
Sources:
Popular Science, 1942.
E. Eger Patent “Puncture Sealing Gas Tank”. 1946.
Dunn, Richard. “Exploding Fuel Tanks”. 2011.
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