NVSC semester 5 test 3

Question 1

Reduction Gear Classification

Answer 1

• Double-Helical
  
  • Double- Reduction
  • Locked Train
  • Articulated (draw and describe)-greater power transmission capability in a short quill shaft, shortens the size of reduction gears and allows for equal load distribution

Question 2

Ratio of Reduction for the US Navy

Answer 2

30:1

Question 3

Classes of fires

Answer 3

A - Wood,paper,etc
B - Flammable liquids - oil, etc
C - Electrical
D -Metal

Question 4

What agents are used to extinguish each type of fire (and how each agent affects the tetrahedron)

Answer 4

A - Water - Removes heat
B - AFFF, PKP, HALON 1301 - Smothers fire
C - CO2 - Displaces Oxygen (Most important thing to do is turn off the electronics)
D - Flood, Jettison - Solid Steam, fog

Question 5

Positions of fire fighting Nozzels

Answer 5

• Wide Angle Fog
  
  • -Heat Shield
• Narrow Angle Fog
  
  • -Used for firefighting
• Flush
  
  • -Used to clear line or just dispense as much water as possible
• Stream
  
  • -Used to penetrate and clear burnt material

Question 6

Who is responsible for damage control?

Answer 6

The DCA and Engineer

Question 7

What is the role of DC Central?

Answer 7

Directs Manpower

-Take in MAIDS report and relay the appropriate information

Question 8

What does MAIDS stand for?

Answer 8

Man in Charge
Assistance Needed
Injured Personnel
Damaged Equipment
Status of the Casualty

Question 9

Stress vs. Strain

Answer 9

Stress= Force/cross-sectional area
Strain= change in length/ original length

Question 10

Constant pitch vs. Variable pitch

Answer 10

Pitch - Axial distance advanced during one complete revolution of screw

Variable pitch - Twisted look
curved, not the same throughout the axis of a screw
More efficient over wide range of speeds

Constant - keeps a constant speed based on the pitch
Automatically changes pitch; regulated by governor

Question 11

Fixed pitch vs. Controllable pitch

Answer 11

Fixed - set at a constant angle or pitch, not very maneuverable

Controllable - Blades can rotate on hub to change pitch (change direction), better maneuverability

Question 12

What is Freeboard?

Answer 12

The distance between the main deck and the waterline

Question 13

Chemical makeup of Batteries

Answer 13

• Lead oxide

- Sulfuric Acid