Tanker Operations Flashcards
What certificates are required on tankers?
IOPP to carry oil based products - MARPOL 1
Certificate of fitness for carriage of noxious substances or liquified gasses - MARPOL 2
What is included in a tanker loading plan?
- Cargo grade
- Cargo quantity
- Cargo density
- Cargo temperature
- Ullage
- Tank and line setup - which valves should be operated
- Voyage details - Load and discharge ports
- Inert gas requirements
- Ballasting requirements
- Sequence of loading
What does a tankers loading rate depend on?
- Pipeline diameter
- How many tanks are open
- Backpressure from the tank. How full is the tank?
- Venting capacity
- Ballasting/de-ballasting rate
How can you check the GM of the vessel at any point of loading during tanker operations?
By checking the loading computer which can be compared with visual drafts
Who is responsible for maintenance of the inert gas system?
The Chief Officer as head of the deck department would liase with the Chief Engineer as head of the technical department.
When discharging on a tanker, the inert gas system fails, what are your actions?
Stop operations and fix the IG plant or source IG from shore.
How does inert gas make tanker operations safer?
Inert gas reduces the oxygen level in the atmosphere to below 8% where the atmosphere is no longer flammable
How are flammable vapours prevented from flowing back through the IG lines on tankers?
IMO guidelines require two non return valves to be fitted. One of which is a deck seal.
How does a tanker deck seal work?
The high pressure Inert gas is forced through a pipe into tank of water where it bubbles up to the surface and enters the cargo tanks via pipework. If vapour returns into the same water tank, it can enter the tank atmosphere which is inerted but can not enter the IG line through the water.
Which liquid levels must be checked in the IG system line?
- The deck seal water tank
- The pressure/vacuum breaker
How is boil off from LNG on passage managed?
Either
- Diverted to the engine room for use in propulsion
- Reliquefied in a deck compressor and returned to the tanks
- Vented to atmosphere
How is a tankers vapour return line identified?
It is painted red and yellow. It has a small bolt on the manifold so the cargo hose cant fit on it by mistake.
You identify oil is leaking into a ballast tank. What are your actions?
- Use a flexible hose from the IG line into the ballast tank to inert the atmosphere.
- Pump out the ballast water using the cargo pump so that it passes through the oily water filter, leaving the contaminated oily water at the top.
- Pump the oily water to the slop tank using the emergency connection to the cargo pump and the cargo system.
What precautions must be taken when tank cleaning on a tanker?
Tank cleaning should be carried out in an inert condition due to static electricity.
Tank washings should be discharged to a reception facility or pumped through the tank monitoring system as per MARPOL restrictions
