
Originally Posted by
jackie schmidt
Mort, I have build boring bars that cut the taper in those large rudder frames.
Back in the ‘80’s we had a contract with Halter Marine in Mobile to do the machine shop work on five 20,000 HP sea going tugs. The rudders were built on a frame that had a 40 inch long taper fit at the top, the top was 14 inches diameter and tapered at 1 inch to the foot. It had a 3 inch wide key way.
That contract is the reason we bought that big LeBlond Lathe we are now getting rid of. The main prop shafts were 20 inch diameter, about 18 feet long, with a 36 inch diameter flange forged on one end.
I learned a lot doing that job. We even built a small taper cutting boring bar to do the tapered coupling bolt’s. They were a nominal 3 inch diameter on the big end.
It’s hard to believe that was over 30 years ago.