Behaviour and Handling of Ships - Hooyer
The position of the __________ plays a crucial role in explaining ship behavior.
Pivot point
Behaviour and Handling of Ships - Hooyer
True / False
We can not move a ship sideways without rotational motion.
True
pg 8
Behaviour and Handling of Ships - Hooyer
The moment of a force about a point is the product of that force and ____________________.
The perpendicular on its line of action.
Behaviour and Handling of Ships - Hooyer
Momentum is the quantity of motion measured by the product of mass and __________.
Velocity
Pg 8
Behaviour and Handling of Ships - Hooyer
True / False
Frictional drag has relatively less retarding effect on bigger ships.
True
Big ships sustain speed because of the relatively small wetted area and lower frictional drag.
Pg 9
Behaviour and Handling of Ships - Hooyer
When ship’s momentum acts as a force the ___________ is the pt of impact of that force.
Center of gravity
Behaviour and Handling of Ships - Hooyer
The magnitude of longitudinal and lateral resistance depends on what?
(Two things)
Ships speed and shape
Pg. 11
They are directly proportionate to ship’s prop force at a constant speed.
Behaviour and Handling of Ships - Hooyer
Force exerted a ship will result in motion only after _______ has been overcome.
Inertia
Pg 11
Behaviour and Handling of Ships - Hooyer
True / False
A beam wind meets lateral resistance where a beam current does not.
True
Pg. 11
Behaviour and Handling of Ships - Hooyer
When birthing big tankers the sim is to obtain a singular ___________ motion and prevent __________ motion the moment of making contact on the dock.
Lateral motion
Rotational motion
Pg. 12
Easier to check lateral motion.
Behaviour and Handling of Ships - Hooyer
Rudder and propeller produces a combination of ______ motions. A. 1 B.2
C.3 D. 4
C. 3
Pg.12
Behaviour and Handling of Ships - Hooyer
What are the three motions a propeller and rudder produce?
Lateral, longitudinal and rotational
Pg. 12
Behaviour and Handling of Ships - Hooyer
The direction of ________ motion of the ship determines to a very large extent the position of the pivot pt.
Longitudinal
Pg. 13
Behaviour and Handling of Ships - Hooyer
1 ton of bollard pull = ________ HP
100 HP
Behaviour and Handling of Ships - Hooyer
Longitudinal resistance = _____ % of propulsion force under constant speed.
25 %
Behaviour and Handling of Ships - Hooyer
Transverse force of propeller working astern = _____ % of applied stern power.
5 - 10 % applied stern power.
Behaviour and Handling of Ships - Hooyer
Rotational motion is about a ____________ axis and is influenced by ship’s shape, motion, magnitude and point of impact of various forces.
Vertical the top of the vertical axis can be considered the pivot pt spot.
Behaviour and Handling of Ships - Hooyer
True / False
Frictional drag has no effect on the position of the pivot point.
True
Pg. 17
Behaviour and Handling of Ships - Hooyer
The position of G is indicated by _____________ .
Trim. Only when on even draft is the G at the center.
Pg. 17
Behaviour and Handling of Ships - Hooyer
When a ship makes a turn what happens to the pivot point?
The pressure pushes the pivot point closer to amidships.
Behaviour and Handling of Ships - Hooyer
What does the pressure aft of the pivot point do to the drift angle?
Limits the drift angle.
Behaviour and Handling of Ships - Hooyer
On a directionally stable ship what happens to the turn when the rudder is placed amidships?
The turn will stop or slow down.
Behaviour and Handling of Ships - Hooyer
Two tugs push on a ship under headway (fwd motion) which tug has more leverage?
The aft tug and creates rotational motion.
Behaviour and Handling of Ships - Hooyer
True / False
As long as the center of wind pressure (P) is not above the Center of Underwater Resistance the wind will turn the ship.
True