How much torque does it take to rotate the HET once the air bearings have lifted it off the pier ring?
(Jim Fowler): I don’t have an exact figure. However, recall that the air bearing creates an essentially frictionless surface (recall your air hockey tables) so the only friction in the system comes from the central bearing and the occasional drag on the air bearings. It takes some force to get things started, the moving weight is 80 tons after all, however, it is possible for one person to get it going and to push it around by hand.
