¶ Ruddering Sequence (2)
← Ruddering Sequence (1) | Ruddering Sequence (3) →
Index Entry
Ruddering Sequence:
“bow when the ship is in motion. In order to change course, the stern is deliberately swung to one side or the other. This is done by the rudder at the stern which is so small as to be easily manipulated. The rudder, by making a small drag angle, creates a partial vacuum on the side of the rudder opposite to that of the direction in which the rudder is moved. This partial vacuum starts to pull the stern of the boat, which causes a much larger partial vacuum to build up on the stern quarter of the ship on the side toward which the stern swings as the ship moves through the water in this askew attitude. This vacuum is built up for the same reason that the horizontal askew attitude of a wing foil in motion through the air creates the lifting vacuum on its cambered or top surface. The reason is that it is a longer distance around the cambered askew side for the parted water to reach, as suddenly displaced by the ship’s motion, which makes the longer-way-reach tense the air-interspersed water molecules creating a partial vacuum. So powerful is this partial vacuum, or negative pressure, chain reaction buildup that it can, for instance, suck-pull the 30-knot speeding hull of the 85,000 ton, Empire State Building-sized Queen Mary into a new angle in respect to the directionally fixed”
