Midterm SEAM 4 Flashcards by Ahron Gabriel

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

Corrosion

How well did you know this?

Not at all

Perfectly

Main Factors influencing the Rate of Corrosion

Diffusion
Temperature
Conductivity
Acid
Types of Ion
Electrochemical Corrosion

How well did you know this?

Not at all

Perfectly

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

Diffusion

How well did you know this?

Not at all

Perfectly

– 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)

Temperature

How well did you know this?

Not at all

Perfectly

a measure of the ability of water to pass an electrical current

Conductivity

How well did you know this?

Not at all

Perfectly

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

Acid

How well did you know this?

Not at all

Perfectly

occurs when two dissimilar metals are present in an electrolytic medium

Electrochemical Corrosion

How well did you know this?

Not at all

Perfectly

– 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

Electrolyte

How well did you know this?

Not at all

Perfectly

electrically charged atoms

Ions

How well did you know this?

Not at all

Perfectly

Two types of ions

Cations
Anions

How well did you know this?

Not at all

Perfectly

positively charged ions

Cations

How well did you know this?

Not at all

Perfectly

negatively charged ions

Anions

How well did you know this?

Not at all

Perfectly

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

Moisture

How well did you know this?

Not at all

Perfectly

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

Rust

How well did you know this?

Not at all

Perfectly

– 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

Hard Epoxy Coating

How well did you know this?

Not at all

Perfectly

– 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

Cathodic Protection

How well did you know this?

Not at all

Perfectly

A 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

Sacrificial Anode Cathodic Protection

How well did you know this?

Not at all

Perfectly

A 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

Impressed Current Cathodic Protection

How well did you know this?

Not at all

Perfectly

Two Types of Cathodic Protection Method

Sacrificial Anode System
Impressed Current System (ICCP)

How well did you know this?

Not at all

Perfectly

– 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

Sacrificial Anodes

How well did you know this?

Not at all

Perfectly

– 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

Zinc Anodes

How well did you know this?

Not at all

Perfectly

– 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

Impressed Current Cathodic Protection (ICCP)

How well did you know this?

Not at all

Perfectly

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

Rectifier

How well did you know this?

Not at all

Perfectly

The process where diodes work like one-way valves within the rectifier to maintain the flow of current

rectification

How well did you know this?

Not at all

Perfectly

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

Anode

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

Cathode

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

Heavy Weather

– 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

Cargo Securing Manual

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

Pre-arrival checks

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

Ship-Shore Safety Checklist

– 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

Carriers

Exceeding the maximum permissible cargo load in any of the holds of a ship will lead to

overstressing of the local structure

– also considered as ‘material wastage’ – the lead cause for structural deformations and fracturing – by far the most ‘common’ of all other defects directly related to steel and its components – if left unattended, is a disaster waiting to happen; either by cargo or fuel oil contamination, structural losses, pollution and finally, possible loss of the ship itself

Corrosion

primarily affects iron and its alloys, such as steel

Rust

can affect various materials including metals (like aluminum, copper, and brass)

Corrosion

– a sub-component defect caused due to damage to steel platings or material failure – could be a change in shape or physical disfigurement of steel that is caused either by implosion (caused due to vacuum build up in tanks) or explosion, excessive dynamic (wave bending/loading) as well as static stress (ship’s hogging & sagging conditions) and strains onto the steel structures, and likewise – should be noted that deformations observed on the ship’s hull are more likely to affect structures on the interior too

Deformation

– due to the propagation of cracks through the steel plating, which has been left unattended – most of it occurs due to excessive stress concentrated on weakened steel plates throughout the tanks’ dimensions – along with fatigue, they are important design criteria for ships to ensure a sufficiently high safety level

Fractures

the stress a ship's hull or keel experiences that causes the center or the keel to bend upward

Hogging

the stress a ship's hull or keel is placed under when a wave is the same length as the ship and the ship is in the trough of two waves

Sagging

Wave Parts

Crest Trough Wave Height Wavelength

highest part of a wave

Crest

lowest part of a wave

Trough

the overall vertical change in height between crest and trough

Wave Height

distance between two successive crests or troughs

Wavelength

includes incorrect, improper, and insufficient lashing (not using enough dunnage, chocking, lashing materials), incorrect weight distribution, improper loading affecting the stability of the cargo

Bad Stowage

If the tank surface faces over how much percent of the allowable margin, repairs can be needed

75%

must be inspected on a twelve-monthly basis and a report on the condition of the tank sent to the Management Office

Ballast Tanks

How often are Ballast Tanks inspected

twelve-monthly basis

9 Pointers one should specifically identify while inspecting the steel tanks

1. Assessing the Overall Condition 2. Condition of Corrosion Levels 3. Condition of ‘Sacrificial’ Anodes fitted inside the tank 4. Checking for Damages/Cracks/Deformations 5. Pitting Corrosion & Blister Formation 6. Condition of the tank gauging systems 7. Condition of the Safety Devices 8. Condition of Mud or Sludge Build Up 9. Condition of Cargo Equipment

Immediately on entering the enclosed space, one can figure out the tank’s well being by considering the state of the accessways and the ladders, paint coatings, and closely observing areas susceptible to corrosion, such as near the weld joints.

Assessing the Overall Condition

For example, corrosion on the inner surfaces of the liquid cargo tanks (for example, Crude Oil Tankers) is mainly due to the mixture of corrosive gases, crude oil acids, as well as seawater (Crude oil washing).

Condition of Corrosion Levels

To maintain their integrity, anodes have to be checked and inspected closely for excessive wear and tear. A record of material wastage (deterioration) should be maintained for future examination.

Condition of ‘Sacrificial’ Anodes fitted inside the tank

Deformations may generally not be readily evident when viewed over a larger area. To identify this, it is good to highlight the area using a high beam torch by projecting it parallel to the surface.

Checking for Damages/Cracks/Deformations

– often known to be observed in the bottom plating of ballast tanks, especially near the ‘bell- mouth’, near the ‘bell-mouth’ in a liquid cargo tank, or next to suction wells associated with the submerged pumps fitted within the tanks – a localized form of corrosion by which cavities or "holes" are produced in the material – considered to be more dangerous than uniform corrosion damage because it is more difficult to detect, predict and design against

Pitting Corrosion

occurs when oxide scale is swollen during oxidation

Blistering

Gauging systems that include gas measuring gauges, pressure gauges, temperature gauges, remote level sensing meters, sounding pipes, as well as striker plates, should be checked for functional abnormalities.

Condition of the tank gauging systems

ensures accurate level, temperature, and pressure measurements for inventory control, oil movement and overfill prevention, securing efficient operations

Tank Gauging System

fitted in the tanks critical for providing the operators a remote indication of an unwanted threat such as water ingress in the bilges of cargo holds due to sweating or any other reason for that matter

Safety devices

could be detrimental in terms of hiding away serious defects and also to promote the development of structural deterioration underneath the horizontal/parallel surfaces

Accumulation of mud and oily sludge in the tanks

Cargo equipment within the tanks includes heating coils, cargo pumps, crude oil washing machines, remote gauging systems, temperature/heat sensors, etc.

Condition of Cargo Equipment

necessary to confirm hatch covers are weathertight and will remain weathertight throughout the voyage

test and a visual inspection

generally sufficient to prove that the hatch covers are in order

satisfactory ultrasonic or hose test

provide evidence that the condition of the hatch covers does not pose a threat to the cargo

SGS Hatch Inspections

– visually inspect hatch covers at departure and arrival for water tightness and proper operation – look for obvious damage, holes and leak points that may jeopardize the quality of the cargo

SGS Inspectors

a multinational company headquartered in Geneva, Switzerland, that provides inspection, verification, testing, and certification services

SGS

SGS Meaning

Société Générale de Surveillance

a Non-Destructive Testing (N.D.T.) whereby, with the use of the appropriate equipment, tightness of Hatch Covers can be tested against leakages which can cause charterers claims and affect seaworthiness of vessels

Ultrasonic Hatch Leak Inspection

8 Most Commonly used NDT in Hatch Cover Techniques

1. Visual NDT (VT) 2. Ultrasonic NDT (UT) 3. Radiography NDT (RT) 4. Eddy Current NDT (ET) 5. Magnetic Particle NDT (MT) 6. Acoustic Emission NDT (AE) 7. Dye Penetrant NDT (PT) 8. Leak Testing (LT)

makes the voyage uncomfortable and dangerous by causing the ship to roll, pitch, or yaw, potentially causing cargo shift, equipment damage, or injuries to the crew

High Swells & Rough Seas

6 Types of Ship Motion during Rough Seas

1. Heaving 2. Surging 3. Swaying 4. Rolling 5. Pitching 6. Yawing

Moving up and down along the vertical axis

Heave (Heaving)

Moving left and right along the lateral horizontal axis

Sway (Swaying)

Moving forwards and backwards along the longitudinal horizontal axis

Surge (Surging)

Rotating about the longitudinal horizontal axis

Rolling (Roll)

Rotating about the lateral horizontal axis

Pitch (Pitching)

Rotating about the vertical axis

Yaw (Yawing)

– the inspection of foreign ships in national ports to verify that the condition of the ship and its equipment comply with the requirements of international regulations and that the ship is manned and operated in compliance with these rules – a ship inspection program whereby foreign vessels entering a sovereign state’s waters are boarded and inspected to ensure compliance with various

Port State Control

– the country in which the ship is registered – it is its duty to ensure that the ship entitled to fly its flag is safely constructed, equipped and subsequently properly maintained and manned as per regulation based on the International Convention developed by IMO for this purpose – carries out survey and inspection on the vessel for issuance of various statutory certificates

Flag State

– when a country exercises control over a ship that is registered in that country – limited to ensure that valid certificates are onboard (Statutory Certificates)

Flag State Control

A Port State Control visit on board a ship will normally start with, as a minimum and to the extent applicable, with an examination of the documents in accordance with Annex

Annex 10 of the Paris MOU Memorandum

Ship Particulars

Form A

details about the vessel, including its length, breadth, depth, gross tonnage and where the ship was built

Ship Particulars

details about the ship's engine, including the make and model and a description of the engine

Ship Engine Particulars

Deficiencies

Form B

These ships are designed with multiple layers of safety features and redundancies to minimize the risk of accidents or incidents

Low Risk Ships

How often are low risk ships inspected

every third year

a vessel that is designed and built to meet the requirements of a specific classification society, such as the American Bureau of Shipping (ABS), Lloyd's Register (LR), or Det Norske Veritas (DNV)

Standard Risk Ships

How often are Standard Risk Ships inspected

every year

ships of a risk type (chemical tanker, gas carrier, oil tanker, NLS tanker, bulk carrier and passenger ship) and more than 12 years old are eligible for an expanded inspection

High Risk Ships

How often are High Risk Ships inspected

every six months

shall include a check of the overall condition, including the human element where relevant

Expanded Inspection

– involves checking of several aspects of the ship in both deck and engine departments of the ship – involves important checking of documents, technical details, and structural elements of the ship

Port State Control Inspection

General Inspection of the Ship

Initial Inspection

Initial Inspection of Certain Type of Ships of Certain Age

Expanded Inspection

Detailed Inspection based upon the findings (clear grounds) of non compliance

More Detailed Inspection

Any of the three inspections that focus on specific areas where high levels of deficiencies have been encountered by PSCOs, or where new convention requirements have recently entered into force

Concentrated Inspection Campaign

Resolution the Organization adopted on Regional co-operation in the control of ships and discharges promoting the conclusion of regional agreements

A.682(17)

Midterm SEAM 4 Flashcards

(97 cards)