Interesting article, took me back a long way to the start of it all. On the firms slipways as a boy with a fitter, stripping out all stern gear and one bolt out of every skin fitting for electrolysis checking. All to be inspected by a surveyor and renewed as necessary. How to remove props on yachts and gunboats/ torpedo boats without the use of extractors and oxy/Acet. Dolly the boss and many , many careful hammer blows to the opposite boss and ensure the back nut was on a few threads to ensure when it did let go it didn't launch itself down the slipway and into the water when it let go. Some of the more difficult ones would sometimes go off with a bang like a shotgun being fired in your ears. Oh, and don't lose the key. Being told why the shafts were allways offset to the rudders? Ping the blades, if a dull dead sound job scrap. Catholic protection failure example here. I well remember straight ing the blades and grinding out damaged areas and using mini flux A rods attempting to braze the damaged areas, impossible on non pinging/ dead equipoise blades no matter how long you tried. A nice resilient ping was a good prop. Still got some at work now. Making up special extractors to change a damaged cutlass bearing without drawing the shaft. Recutting damaged prop key ways on the shaper machine, milling out the shaft and making up an oversize interference key to fit. Making up new castellated locknuts from octagonal brass metal, learning to recut tapers on new shafts etc and making sure contra rotating shafts had to have a correct rotation thread cut on it is L/H thread cut for anti-clockwise shafts and R/H threads for clockwise shafting to ensure both shafts were self tightening in normal use age. Some installations were both clockwise and some were handed. Ahead of the balanced rudders to counter the torque effect generated by same way rotation shafting sometimes would be on the top of the rudder a small trim tab bolted onto the rudder to counter the Starboard pull encountered on the wheel. Sometimes this would have to be " tuned " so the wheel stayed straight ahead, hands off at max speed. Measuring electronic leakages and slip ring performances etc on prop shafts concerning Cathodes and Anodes protection. No Anzipods here yet, not a lot of thrusters, no surface props, submarine props removed using PE ( plastic explosive ) but I never had a chance to get involved in any of that. So why were rudders always offset to shafts?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.