Midterm 1st Topic

Question 1

when a refined metal is naturally converted to a more stable form such as its oxide, hydroxide or sulphide state this leads to deterioration of the material

Answer 1

Corrosion

Question 2

the process resulting from random motion of molecules by which there is a net flow of matter from a region of high concentration to a region of low concentration

Answer 2

Diffusion

Question 3

– the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius
– indicates the direction in which heat energy will spontaneously flow—i.e., from a hotter body (one at a higher temperature) to a colder body (one at a lower temperature)

Answer 3

Temperature

Question 4

– a measure of the ability of water to pass an electrical current
– the measure of the ease at which an electric charge or heat can pass through a material

Answer 4

Conductivity

Question 5

a material which gives very little resistance to the flow of an electric current or thermal energy

Answer 5

Conductor

Question 6

a chemical substance, usually a liquid, which contains hydrogen and can react with other substances to form salts

Answer 6

Acid

Question 7

occurs when two dissimilar metals are present in an electrolytic medium

Answer 7

Electrochemical Corrosion

Question 8

– a chemical compound that dissociates into ions and hence is capable of transporting electric charge - i.e.
– an electric conductor; unlike metals the flow of charge is not a flow of electrons, but is a movement

Answer 8

Electrolyte

Question 9

Main Factors influencing the Rate of Corrosion

Answer 9

● Diffusion
● Temperature
● Conductivity
● ph (Acid)
● Electrochemical Corrosion/Corrosion Potential
● Types of Ions/Ions

Question 10

electrically charged atoms

Answer 10

Ions

Question 11

Two types of ions

Answer 11

Cations & Anions

Question 12

positively charged ions

Answer 12

Cations

Question 13

negatively charged ions

Answer 13

Anions

Question 14

when metals collect this, an electrochemical reaction causes the steel to corrode

Answer 14

Moisture

Question 15

– also known as metal oxides
– forms when oxygen reacts with metal atoms

Answer 15

Rust

Question 16

– a coating which is the major line of defense against corrosion in ballast tanks and void spaces
– in ballast tanks, they are commonly used and there is some interest in using inert gas atmospheres

Answer 16

Hard Epoxy Coating

Question 17

– a means of preventing electrochemical wastage is required
– a system of preventing corrosion by forcing all surfaces of a structure (e.g. hull) to be cathodes by providing external anodes

Answer 17

Cathodic Protection

Question 18

Types of Cathodic Protection

Answer 18

Sacrificial Anode System/Sacrificial Anodes
Impressed Current System/Impressed Current Cathodic Protection (ICCP)

Question 19

Type of Cathodic Protection that can be accomplished by fitting aluminium, magnesium or zinc anodes in tanks or underwater portion of a ship, which waste away by galvanic action

Answer 19

Sacrificial Anode Cathodic Protection

Question 20

Type of Cathodic Protection that can be achieved by superimposing on the hull an impressed current provided by a remote power source through a small number of inert anodes

Answer 20

Impressed Current Cathodic Protection

Question 21

– metals or alloys attached to the hull that have a more anodic, i.e. less noble, potential than steel when immersed in sea water
– supply the cathodic protection current, but will be consumed in doing so and therefore require replacement for the protection to be maintained

Answer 21

Sacrificial Anodes

Question 22

– may be safely employed
– sacrificial anodes made of zinc that are attached to a ship’s hull
– a critical component of a cathodic protection system, which is used to protect the ship’s metal structure from corrosion
– they work by corroding instead of the hull, providing protection against corrosion

Answer 22

Zinc Anodes

Question 23

– consists of a number of anodes (lead or platinised titanium) fitted to the hull at
selected places below the waterline, and control equipment which automatically
regulates the anode current to the required value
– consists of anodes connected to a DC power source

Answer 23

Impressed Current Cathodic Protection (ICCP)

Question 24

an electrical device used to convert alternating current (AC) into direct current (DC) by allowing a current to flow through the device in one direction only

Answer 24

Rectifier

Question 25

Process of converting alternating current (AC) into direct current (DC)

Answer 25

Rectification

Question 26

the negative or reducing electrode that releases electrons to the external circuit and oxidizes (corrode) during and electrochemical reaction

Answer 26

Anode

Question 27

the positive or oxidizing electrode that acquires electrons from the external circuit and is reduced during the electrochemical reaction

Answer 27

Cathode

Question 28

combined with inappropriate manipulations may lead to damage of a vessel, threatening the cargo, the environment or, even worst, human life

Answer 28

Heavy Weather

Question 29

Preventive Actions to be taken for Heavy Weather

Answer 29

1. Always the cargo to be loaded as per Cargo Security Manual 2. Speed of the vessel need to be adjusted with the course and slow down if needed 3. Consideration of the actual stability conditions 4. Maintaining of the lashing equipment to be in a good condition (container ships or Ro-Ro vessels) 5. Hatch covers and seals must be in good water-tight condition (bulk carriers) 6. Officers to be aware and well trained to handle the mentioned risks 7. Alternate route through a less risky course

Question 30

– the manual required on all types of ships engaged in the carriage of all cargoes other than solid and liquid bulk cargoes – cargo units, including containers, shall be loaded, stowed and secured throughout the voyage in accordance with it approved by the Administration

Answer 30

Cargo Securing Manual

Question 31

Preventing Structural Damage of the Ship

Answer 31

1. The selection of high-quality materials and effective coating systems is pivotal in preventing hull damage 2. Investing in robust and corrosion-resistant materials during construction or repair can enhance the vessel's longevity and reduce the likelihood of structural weaknesses

Question 32

Precautions while cargo loading operations

Answer 32

Pre-arrival checks Ship-Shore Safety Checklist

Question 33

must be carried out before reaching the loading port on the cargo/bunkering systems and equipment

Answer 33

Pre-arrival checks

Question 34

must be agreed with the terminal and understood by all personnel involved in the cargo operations

Answer 34

Ship-Shore Safety Checklist

Question 35

– everywhere, incur a measure of liability for the safety of the goods – in common-law countries, liable for any damage or for the loss of the goods that are in their possession as carriers, unless they prove that the damage or loss is attributable to certain excepted causes

Answer 35

Carriers