2: Seawater & Ballast

Question 1

What does it cool?

Answer 1

Engine
* 300+ degree celcius
* cause component to overheat and expand
* reduce material failure by cooling

Steam

Question 2

Freshwater

Answer 2

• pumped into space surrounding of engine cylinders, known as jacket cooling water
• cools cylinder liner, cylinder cover, exhaust valve
• Outlet temp:80-95 degree celcius

Question 3

Seawater

Answer 3

• cool down jacket water that exits the engineS
• contains impurity and is corrosive
• only used for cooling water that comes out of engine

Question 4

Steam

Answer 4

• steam cooled can be returned to boiler by condensing back to water
• seawater used

Question 5

Valve

Answer 5

Regulates flow of seawater by opening, closing
Partially obstructed the passage through the pipeline

Question 6

Sea Chest

Answer 6

Low sea chest: used in deep sea to prevent air from entering system when ship is rolling
High sea chest: used when ship is port or shallow waters to avoid taking in debris from seabed

Question 7

Strainer

Answer 7

removes impurity from seawater to prevent blockages
cooler, system, pump
checked and cleaned regularly to prevent starving of water from blockages

Question 8

Seawater pumps

Answer 8

centrifugal
number of pump used depends on engine load and seawater temperature

Question 9

Recirculation valve

Answer 9

3 way valve used to control the temperature of cooling Seawater entering the cooler

Question 10

Cooler and condenser

Answer 10

Cooler: hot jacket water outlet from engines cooled by seawater
condenser: steam condensed back to water by seawater

Question 11

Emergency Bilge Suction

Answer 11

pump water out of engine room during flooding
allows large quantity of water to be pumped out of the engine room straight overboard

Question 12

Ballast System

Answer 12

pump in/ out sea water to/from shipboard tanks in large quantity and faster rate

to alter draft, list, trim

vessel trim to be leveled for steering and propulsion

Question 13

list and trim can change during

Answer 13

cargo loading and discharging as the vessel centre of gravity will shift

ship fuel used in sailing will cause ship to be lighter, float higher and unstable

Question 14

Clinometer

Answer 14

Instrument to tell if ship is upright

Question 15

When to ballast
Discharging cargo:
Loading:
Control list:
Control Trim:

Answer 15

Discharging cargo: ballast to make ship bottom heavy
Loading: deballast the ship to carry maximum cargo
Control list: Transfer the ballast water from port to starboard or vice versa
Control Trim: Transfer ballast from forward to aft tanks or vice versa