|THAT'S SOMETHING TO GNAW ON.|
Abby again. I didn't think any butt could be bigger or wider than Shiloh's butt, but this butt seems to be even bigger than her butt. The Titanic had three propellers but only the two bigger outboard props could be reversed. When the engines were reversed the center prop would simply be stopped. The back wash and turbulence of the two outboard propellers would have disrupted the water flow past the rudder and the stopped center prop just forward of the rudder would have further impeded the water flow past the rudder. The force of the water against the facing side of the deflected rudder is what causes the stern to turn and thus steer the ship. Next time you go for a drive in the front passenger seat of your car, lower the window and hold your hand out in the moving airflow in a vertical and straight fore and aft position. Then turn your hand slightly left or right and feel the force against your hand. That's the force that turns the direction of the ship. Now do it a second time with your hand directly behind the rear view mirror. Notice that the force isn't as great because of the disturbed airflow over the rear view mirror. Your rudder (hand) won't turn the ship as fast as it did in the undisturbed airflow. How do I know this. Dad has a BS (appropriate) in Naval Science (not like Navel Science which is the study of belly buttons and oranges.) and he often reads me bedtime stories from his old text books.ABBY (TBH+K)
|NOTICE A MAN STANDING BENEATH THE CENTER PROPELLER|
|With her rudder cleaving the sand and two propeller blades peeking from the murk, Titanic’s mangled stern rests on the abyssal plain, 1,970 feet south of the more photographed bow. This optical mosaic combines 300 high-resolution images taken on a 2010 expedition. (Photo: COPYRIGHT 2012 RMS TITANIC, INC; Produced by AIVL, Woods Hole Oceanographic Institute) / SF|
Achilles heel?Building ships this large led to inevitable compromises. Titanic, identical in almost every respect to her sister, adopted tried and trusted methods for her design and construction. No risks were taken with the choice of engines which were enlarged versions of the propulsion system first used experimentally in Laurentic, another White Star liner, in 1909. The triple screw vessel had proved that two expansion engines feeding exhaust steam into a low pressure turbine were more economical than vessels using expansion engines or turbines alone.
...little thought was given to how a ship, 852 feet in length, might...avoid collision with an iceberg.