Damage/Defect Inspection of Cargo Spaces, Hatch Covers and Ballast Tanks Flashcards
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
Flag State
Duty of Flag State
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
the country visited by a ship other than the flag state that is port of registry
Port State
– 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
Types of Port State Control Inspection
● Initial Inspection
● Expanded Inspection
● More Detailed Inspection
● Concentrated Inspection Campaign
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
How to conduct a Ballast Tank Inspection
Check for corrosion
Inspection of coating
Resolution on Regional co-operation in the control of ships and discharges promoting the conclusion of regional agreements
A.682(17)
What percentage of the allowable margin might indicate the need for repairs if the tank surface faces it?
Over 75%
Three General Defects that affect the steel structures due to direct wear and tear
● Corrosion
● Deformation
● Fracture
– 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
– 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 and 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
9 Pointers one should specifically identify while inspecting the steel tanks
- Assessing the Overall Condition
- Condition of Corrosion Levels
- Condition of ‘Sacrificial’ Anodes fitted inside the tank
- Checking for Damages/Cracks/Deformations
- Pitting Corrosion & Blister Formation
- Condition of the tank gauging systems
- Condition of the Safety Devices
- Condition of Mud or Sludge Build Up
- 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 should be maintained for future examination. One must also inspect whether the anodes are well secured to the brackets provided.
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
Pitting Corrosion
– 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.
Pitting Corrosion & Blister Information
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
Safety devices 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
Condition of the Safety Devices
Accumulation of mud and oily sludge in the tanks
– could be detrimental in terms of hiding away serious defects and also to promote the development of structural deterioration underneath the horizontal/parallel surfaces
Condition of Mud or Sludge Build Up
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
