The Convair B-36 Peacemaker was a massive flying machine that bridged the gap between the prop and jet ages for the Strategic Air Command. It was extremely complex but it could fly far while carrying a lot of payload. Apparently that was not enough for SAC as it wanted to see if the big bomber could operate from rough fields as well. With that the B-36's huge tires gave way to tracks for testing.
A wingspan of 230 feet, six piston engines and later four additional turbojet engines, a 278,000lb empty weight, a max bomb load of close to 80,000lbs and intercontinental range, the B-36 was truly a remarkable giant of the skies.
Very few airfields in the US during the late 1940s were long and fortified enough to handle the XB-36's takeoff run and original main gear that featured one massive tire and that exerted 156 pounds per square inch. This, and the fact that it would be useful to forward deploy and disperse B-36s during a nuclear exchange, meant that a new landing gear system needed to be devised.
A track-style landing gear, although complex, would result in the lowest possible pressure on the XB-36's operating surface. So Convair moved forward with testing of such a system. Although the tracked apparatus was quite heavy, it did work as advertised, dropping the bomber's standing surface pressure down by about two thirds to 57 pounds per square inch. As you can see in the video above, it worked actually quite well during tests.
Still, the track system was heavy and complicated, and flying massive Peacemakers off of grass fields seemed like a less than pressing priority as American airfields were rapidly expanding to accommodate heavier aircraft. Instead, the production B-36 stuck to prepared surfaces but ditched the sing massive tired main gear configuration for a four wheel bogie setup. This new configuration helped relieve the pressure on the tarmac greatly while also lessening the chances of a catastrophic event caused by a tire blowout at high-speed.
The XB-36's tracked gear tests were not the only time the tracked gear concept was tested in aviation, but it was the most ambitious considering the weight and dimensions involved. The C-82 Packet tested a similar system as well as the A-20 Havoc. The tracked concept has also been applied to a handful of small bush plane concepts and suggested for the C-130 Hercules for special operations missions where uneven and very soft terrain is the only operating surface available.
Tyler Rogoway is a defense journalist and photographer that maintains the website Foxtrot Alpha for Jalopnik.com You can reach Tyler with story ideas or direct comments regarding this or any other defense topic via the email address Tyler@Jalopnik.com