In Episode 11 of The Machine Shop, renovations hit a snag when the plumber Tay hired to dig a trench for new piping hits the 100-year-old line shaft in the ceiling with his mini excavator. Now the damaged section has to be trimmed away to keep the rest in operating condition.
(A line shaft is what old machine and wood shops used to use to power all their machinery. A central motor would spin a giant overhead shaft and big canvas belts would transfer power through pulleys to the machines on the floor.)
