00:00Roman soldiers brace against the wooden frame as the massive tension arm snaps forward with bone-crushing force.
00:07The terrifying onager packs enough violent recoil to shatter its own oak base during heavy bombardment.
00:14Rigid iron braces might seem like a fix for the kick, but wrought iron deforms under such violent stress.
00:21Engineers solve the lethal shock by wrapping thousands of strands of braided animal tendon that stretch and absorb recoil.
00:28This living muscle spring handles the brutal impact, proving why Roman soldiers brace against the wooden frame.
