Watch Bluegrass in National Geographic: World's Toughest Fixes (WTF) on Thursday June 25, 8pm on the National Geographic channel. Bluegrass diamond wire cut a 20" carbon steel shaft on a 50-ton rudder. Bluegrass was called on Friday and arrived on site Monday, and the cut took 7 hours.

• http://channel.nationalgeographic.com/series/worlds-toughest-fixes/4219/Overview