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MythBusters Episode 248: Duct Tape: The Return

Premier Date: March 6, 2016

This was the last new episode of MythBusters to ever air. It premiered one day after the Grande Finale to promote the Science Channel as the future home of MythBusters reruns.

It is possible to build a fully-functional trebuchet held together only by duct tape.

confirmed

Adam built a small-scale model trebuchet using wooden beams and duct tape and fine-tuned its design. Jamie developed construction methods designed to withstand the significant forces involved and incorporated them into his own model.

At a large field, they began assembly; the full-scale trebuchet used 78 rolls of tape, 2,600 pounds (1,200 kg) of construction lumber, and a 750-pound (340-kg) automobile engine block as the counterweight. A test shot with a watermelon as the projectile achieved a range of 171 feet (52 m) and the structure remained intact. To simulate using their trebuchet in combat, they launched a Molotov cocktail to a distance of over 100 feet (30 m), and then launched another to ignite a giant inflatable shark set up at that same distance.

A seat belt made from duct tape can save a driver from injury in an accident.

busted

On an inactive runway, Adam and Jamie set up a crash target consisting of two side-by-side shipping containers reinforced with steel plates. They broke the windows out of a car and cut an opening in the roof to give clear views of the interior, then put two dummies equipped with accelerometers in the front seats. Buster, the driver, was restrained with a seat belt made of the greatest thickness of duct tape that would pass through the standard buckles (9 layers at the lap, 6 at the shoulder). The passenger dummy was secured with a standard belt for comparison.

Adam watched from overhead in a boom lift while Jamie towed the car into the target at a speed of 25 miles per hour (40 km/h). The passenger experienced forces of 30 g to the head and 51 g to the body, indicating survival with some injuries. Buster’s belt snapped at the shoulder, causing him to hit the steering wheel with forces of 136 g to the head and 133 g to the body, high enough to be fatal.

Next, Adam taped Buster directly to the seat, frame, and body of the car with multiple wrappings and they repeated the test. Buster’s acceleromter readings decreased to survivable levels of 41 g to the head and 55 g to the chest, and he remained in his seat even though most of the wrappings broke in different places.

For the third and final test, Adam used 40 layers of tape to hold Buster in place, and the crash speed was increased to the industry standard of 40 miles per hour (64 km/h). The tape did not break, but Buster sustained lethal forces of 85 g (head) and 311 g (body). Adam and Jamie noted that the tape around Buster held him so firmly in place that he experienced the same deceleration as the car, leading to the fatal results.