31. The US Navy secured a licence to copy the main shaft flexible coupling arrangement in US-built submarines. 32. The swashplate moves up and down, along the main shaft , to change the pitch of both blades. 33. Later this system was modified with the main shafts on the three upper floors being driven by belts. 34. The main shaft was re-timbered, a new headframe and brace constructed, and a 2, 000 gallon tank installed. 35. The air winch was repositioned and a winch house almost directly west of the main shaft was made. 36. Nobles Nob became an open-cut mine in 1967, after the main shaft collapsed on 11 August at 5am. 37. The mines have since filled with water; the main shaft extended in excess of 1100 feet straight down. 38. The remains of mullock dumps extend east from the early main shaft site and adjacent open cut workings. 39. The main shaft is rectangular, measuring high; by at the bottom . tapering to by at the top. 40. Used in this way, the other fingers are kept on the main shaft , with the thumb supporting the handle.
