Cargo-Related Orals Questions for Officer of the Watch
Preparing for your Officer of the Watch (OOW) exams? Mastering cargo-related topics is crucial for your success. Our comprehensive guide to cargo-related orals questions will equip you with the knowledge and confidence needed to excel. Dive into essential questions covering cargo handling, stowage, safety protocols, and international regulations. Gain insights into best practices, common challenges, and effective solutions to ensure you're fully prepared for your exams. Start your journey towards becoming a proficient Officer of the Watch with our expert resources today!
What guidance publications are required when carrying timber?
Timber deck cargo (required by SOLAS)
Cargo securing manual
Shippers’ instructions
What can cause a list during a voyage?
Cargo shift
Water ingress
Loll (-ve GM)
Water absorbtion
Weather (ice / strong winds)
Unequal consumption
What are the key requirements of the Timber Deck Cargo Code (TDC Code) for securing timber deck cargoes?
The TDC Code requires proper stowage and securing arrangements, the use of adequate lashing materials, maintenance of vessel stability, and regular inspections to ensure safety.
What are the main hazards associated with timber deck cargoes, and how can they be mitigated?
Hazards include shifting cargo, reduced stability, and fire risk. Mitigation involves proper securing, regular inspections, and compliance with safety regulations.
Describe the process of preparing a timber deck cargo for loading, including any necessary inspections.
Preparation includes inspecting the cargo for damage, ensuring the deck is clean and free of obstructions, and verifying that securing equipment is in good condition. Proper stowage plans should also be prepared.
What are the best practices for documenting the securing and stowage of timber deck cargoes?
Best practices include detailed records of the stowage plan, securing methods, inspection reports, and any adjustments made during the voyage to ensure compliance and safety.
What does the CSM & TDC provide?
stowing instructions for stowing and securing timber on deck and;
Practises for safe transportation
Methodologies for safe stowage
Designs for securing
Specifications & inspections of equipment.
Checklists
During sailing with timber deck cargo what checks and actions may be required by the OOW?
Monitor lashings regularly
Condition of uprights and lashings
Monitor weather forecasts regular.
Inform Master or Chief mate of any concerns
Describe the Upright Fixed Loop Lashing method and its advantages for securing timber deck cargoes.
This method involves securing timber with a loop lashing around uprights fixed to the deck, providing stability and preventing shifting. It is effective in maintaining cargo integrity during rough seas.
What are the differences between hog lashing and top-over lashing in securing timber deck cargoes?
Hog lashing involves securing timber with lashings passed over the top and around the cargo, while top-over lashing secures cargo with lashings running horizontally over the top. Each method provides different levels of stability and security.
What are the common mistakes made during the securing of timber deck cargoes, and how can they be avoided?
Common mistakes include inadequate lashing, improper stowage, and failure to maintain stability. Avoidance involves thorough training, adherence to the CSM, and regular inspections.
How should the ship's stability be calculated when carrying timber deck cargoes?
Stability should be calculated considering the weight and distribution of timber cargo, ensuring compliance with stability criteria and the Timber Deck Cargo Code requirements.
What are the OOW duties during loading timber?
Monitor loading activities according to plan
Monitor safe work practises by stevedores
Ensure equipment and cargo is treated with care
Keep a record of cargo inboard
Prevent any damaged or suspect cargo from being loaded
Rectify any defaults.
Call Chief Officer or Master as required.
Ensure that safe access is always available
Ventilators & Air pipes
Lifesaving appliances kept clear and free
Fire Fighting equipment kept clear and free
Ensuring block stow
Lashings and securing’s are completed
Maintain log of events
How should timber deck cargoes be stowed to prevent shifting during the voyage?
Timber should be stowed tightly and securely, with appropriate dunnage and lashings to prevent movement. Regular checks during the voyage are also essential.
How should the condition of timber deck cargoes be monitored throughout the voyage?
Regular inspections should be conducted to check for shifting, damage, and lashing integrity. Any issues should be addressed immediately to maintain safety.
Bulk Carrier Cargo
What is Angle of repose?
Angle between horizontal plane and cone of slope of non-cohesive free flowing material
High angle = stable cargo
Low angle = unstable / liable to shift
What is Flow state?
When cargo / granular mass is saturated as liquid
What is Transportable moisture limit?
Limit of ac cargo which may liquefy
Represents the maximum moisture content which is considered safe for transport
TML = 90% of flow moisture point
How to prevent shift with solid bulk cargo?
Trim level
Secure
Moisture content within transportable moisture limit
What hold preparation procedures are required for cargo?
As per SMS procedure and risk assessment
Permit to work in force – dangerous space
Remove all remaining residues and sweep clean
Shipper will provide information about hold cleanliness levels
Bilges – clean out and check function
Seal with burlap cloth over bilge cover plate
Hatches – condition of coamings, gasket, clamps and other sealing devices.
Check hold condition, access, lighting and sensors after discharge and prior to loading.
Any Planned Maintenance items should be addressed at this point.
The vessel may also have an inspection regime for holds and cargo tanks
What is defined as a non-cohesive cargo?
When angle of repose is less than 30°
Examples include grain
What is Flow moisture point?
% of moisture content when flow state develops
What is Max tonnage per hold?
= 0.9 x Length x breadth x depth
Maybe increased by 20% in lower hold if cargo is trimmed level
Refer cargo loading manual for maximum load
How to test the moisture content?
Half fill 1.0 litre cylinder
Strike sharply from m at 2 second intervals
If moisture appears or flow state develops -> get lab to check, don’t load.
What information does the cargo loading manual contain?
Stability information
Maximum permissible forces
(de) ballasting rates
Max tank top loading
General (un)loading
What is Moisture migration?
Movement of moisture in materials by settling and consolidation of materials
Due to vibration may cause flow state to develop at surface
What is Moisture content?
Amount of moisture present in sample expressed as % of weight of sample
What are cargoes which may liquify?
Cargos which may shift as per appendix A
Occurs when moisture content above transportable moisture limit
What are the potential hazards associated with Solid Bulk Cargoes?
Self-heating
Corrosive
Dust -> inhalation, fire
Reactivity of cargoes
O2 depletion -> rusting steel cargoes or grain
Production of gases -> coal = CO & methane
Fumigated cargoes
High density -> limit on loading
Shifting -> low angle of repose, non-cohesive cargo
Liquefaction -> may become liquid on surface due to vibration
Coal
What are the main hazards of coal?
Flammable
Liquefaction
Toxic
Corrosive
Self-heating
Asphyxiation
What gases can coal produce?
Methane
Carbon Monoxide
(Results in depleted oxygen levels)
What happens if self-heating is evident?
Master has information from Shipper
Monitor atmosphere conditions – log
Close after loading and sealed
Minimum surface ventilation
Monitor CO and record
If hold temperature >55° seek advice
Make log book entry
What happens if the temperature of the coal exceeds 55°?
Stop loading
Self-heating occurring
What happens if methane gas greater than 20 LEL?
maintain surface ventilation
Don’t open hatches until 0 gas
Open slowly
Check adjacent spaces
Inform Chief / master
What groups of Cargo categories are there in the IMSBC code?
Group A – liquefiable cargoes
Group B – chemical properties
Group C
What are the considerations when dealing with Group B cargoes?
Cargo is dangerous goods in bulk
Comes from IMDG code
Check entry in IMDG code, MFAG and Ems and be prepared!
Info is in cargo schedule
Hazards include
Combustible solids, self-heating, solids that evolve into flammable gas when wet, solids that emit toxic gas when wet, toxic solids, corrosive solids
Must have DG DOC
Stowage plan and manifest
Thorough cleaning after carriage
Cargoes with strong PH values may corrode
What does MGN 60 say about the carriage of coal?
Always check documents – listed as category A / B
Monitor weather conditions
Ensure atmosphere monitoring devices functional
No smoking, hot work or naked flames.
Shipper must declare if cargo liable to self-heat
Shipper must provide ventilation instructions – usually for first 24 hours then monitor regulate
Vent coal before discharge
Avoids sparks
Monitor methane and temperature for signs of self-heating
Monitor temperature in centre of cargo and from sides
What are the considerations when dealing with Group A cargoes?
Danger of shifting
May have high moisture content
Shipper must provide signed statement of transportable moisture content and transportable moisture limit
If in doubt stop, and perform own test or get independent surveyor involved
Need for visual monitoring during cargo operations
Monitoring weather conditions
Cargo needs trimming
Check shipper’s instructions for specifics
Inert Gas
Explain how an inert gas system works?
Flue gas goes to scrubber
Cooled, dried and cleaned
Blown by rotors
Passes through regulator for pressure
Passes through Deck Non-Return Valve
What alarms are required on an inert gas system?
>5°
>8°
Low lube oil pressure
Deck seals
What is a deck seal?
Water mix with anti-freeze elements
Stops cargo gas going back into inert gas system
Who is required to carry an Inert Gas system?
As per SOLAS
Required on vessels >8000gt
When carrying flammable cargo with flashpoint >60°c
What happens if the inert gas plant fails?
As per company procedure
Check if back up available
Stop operations
-Inform shore side
-Inform Master
-Log it
-Close and seal tanks
-Close down deck isolating valves
Resume operations when system operational or suitable alternative
What is an inert gas system required to do?
- Deliver oxygen content <5°
- Never more than 8% oxygen content
- Alarm and switch to back up
- Maintain positive pressure – 125%
What is the dilution method?
Inert gas blown into tank rapidly
Mixes with existing
Uses more gas
What is the displacement method?
Uses difference in air vapour densities
Heavy gas sinks to bottom, lighter gas out
Chemical Tankers
What MARPOL annex applies?
MARPOL Annex II applies due to Noxious Liquid substances.
What documents are required for a chemical tanker?
All chemical tankers must be certified and provided with a list of what cargoes they can carry and in which tanks
Cargo record book (NLS)
Procedures and arrangement manual.
SMPEP (maybe combined with SOPEP)
International Pollution Prevention Certificate
What documents are required for a vessel carrying Annex II Noxious liquids when over 150gt?
For vessels >150gt
-Procedure and Arrangement manual
-Cargo record book
-SMPEP
-IBC code
Certificate of Fitness
Or, International Pollution Prevention certificate
What are the general procedures for tank emptying and stripping?
In accordance with procedures and arrangement manual
Vessel trimmed and listed
Continue to pump until loss of suction
Slow pump down to maintain
Use stripping pump
When empty close main cargo valve
Keep pump running until pipe is empty
What are the 4 different categories?
X = Major hazard, no discharge
Y = Severe hazard, no discharge
Z = Minor hazard, less stringent requirements
OS= Very little impact on environment.
Where can cargo information be found?
Cargo information is found in the IBC code chapter 17
Shippers instructions
What general precautions are there for Tank cleaning chemical tanks?
Tank cleaning is conducted as per Procedures and arrangement manual.
The vessel is trimmed and listed to assist with cargo stripping.
Maintain a high cargo temperature to keep in fluid state when stripping
Tank and pipes cooled prior entry
Check with MSDS / shippers info
Company procedures
Risk Assessment including recent contents
Permit to work
Appropriate PPE worn
How can you avoid a stripping pump losing suction?
The pump may lose suction during stripping. To continue stripping reduce the speed of the pump.
When empty close the main cargo valve and purge by IG, keep the pump running until the pipe is empty.
What are the main types of cargoes carried?
Petrochemical
Alcohols
Vegetable oils
Acids
Inorganics
What Entries are required in the Noxious Liquid Substances Cargo record book.
All entries must be timely and signed by the officer in charge.
Loading
Discharging
Transferring
Tank cleaning
Surveys / inspections
Breakdowns of equipment
Accidental discharges
What are the contents of a Procedures and Arrangement Manual?
Main features of MARPOL
Description of vessel and equipment & arrangements
Tank diagrams and capacity
Cargo handling procedures -> load, discharge and cleaning
Cleaning of tanks
Discharge of residues
General arrangement plan
What information is contained in Chapter 17 of the IBC code?
Product name, UN number, pollution category (X,Y,Z)
Hazards: S = Safety, P = Pollution, SP = safety and pollution
Ship type required: 1,2,3
Tank type required: 1 = independent, 2 = integral, G = gravity, P = pressure
Vents: Open or controlled
Fire protection
Eye and respiratory protection
Gas Carriers
What are the safety features of gas carriers?
Have double hull therefore cargo tanks away from hull
Gas detectors and safety alarms in hulls
Auto shut down of cargo systems if error
What monitoring equipment is required?
Temperature sensors of cargo and structure
-If too high or low could induce stresses
Liquid level
-High level (97%) and High High level alarm (98.5%)
Gas detectors in void spaces, duct keels, double hulls etc.
Why and how is tank inserting done?
Prevents flammable mixture
Use nitrogen
Why do we spray tanks slowly when conducting cool down operations?
Spray allows more heat absorption
What hazard categories exist for gas carriers?
1G - most hazardous
2G/2PG
3G -least hazardous
What are the initial checks prior loading?
Initial check of tanks, linings, pumps and gaskets
Pressure test of flanges and hatches
Tank suitable
Clean condition
Why can’t we use ships own IG system?
Ships IG contains carbon
If carbon freezes it can contaminate cargoes
What are extra precautions to take when tank cleaning?
As per company SMS
Tank warmed through with hot air
Inerted
Gas freed
Atmosphere checked thoroughly
What specific certificate is required for a Gas Carrier?
Certificate of Fitness
What is meant by drying a tank?
Remove all moisture from tank
Mau cause icing during cooldown
Done by air driers
Why are the tanks subject to a cool down?
Cargo systems cooled down slowly
Many cargoes have sub zero boiling point therefore immediately boil off if temperature too high in tanks
Boil off causes a rise in pressure.
Cool down introduced slowly via spray lines