Answer the questions

1. What equipment is used for loading/discharging liquid cargo?
2. What precautions should be taken during these procedures?

Tank Cleaning Practice

1 Study the pictures. What method is used and what tools for tank cleaning up do you see in pictures?

a)   ____________________________________ ____________________________________ ____________________________________ ____________________________________

b)

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c)

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2 Watch the video and say if the statements are true or false. Correct the false ones.

1. It is preferable to clean the tanks in port.

2. Drain and purge is enough for cleaning if previous and next cargo is the same.

3. Portable washing machine is used in restricted areas.

4. The dirty water from the tank is discharged into the sea.

5. The inert-gas system is used to control the atmosphere in a tank.

6. After a tank is gas-free, "mucking" is generally done by able seamen and deck officers using tools such as mops, buckets, rags and sponges.

3 Discuss the questions

1 Why is cleaning one of the most dangerous procedures?

2 What factors influence the amount of cleaning required?

3 What cleaning equipment is used?

4 Why is it important to monitor the tank atmosphere?

4 Read the text.

a) Choose the word or word combinations from the box.

crude oil, seawater, load on top

__________________________________

1.________________________

_________________ washing (COW) is washing out the residue from the tanks of an oil tanker using the _________________cargo itself, after the cargo tanks have been emptied. ________________ is pumped back and preheated in the slop tanks, then sprayed back via high pressure nozzles in the cargo tanks on to the walls of the tank. Due to the sticky nature of the __________________, the oil clings to the tank walls, and such oil adds to the cargo 'remaining on board' (the ROB). By COWing the tanks, the amount of ROB is significantly reduced, and with the current high cost of oil, the financial savings are significant. MARPOL 73/78 made this mandatory equipment for oil tankers of 20,000 tons or greater deadweight.

2. Originally oil tankers used one set of tanks for cargo and about one third of the same tanks were for water ballast on their empty trips. High pressure, hot, __________________ jets were used to clean the tanks and the mixture of ___________________ and residue called slops discharged into the sea. The 1954 OILPOL Convention attempted to reduce the harm by prohibiting such discharges within 50 miles (80 km) of most land and 100 miles (160 km) of certain particularly sensitive areas. Nowadays discharging of any amount of contaminated water is strictly prohibited.

3. The discharges from __________________ washing were still considered a problem and during the 1960s the __________________ approach began to be adopted. The mixture of cleaning water and residue was pumped into a slop tank and allowed to separate into oil and water during the journey. The water portion was then discharged, leaving only ____________________in the slop tank. This was pumped into the main tanks and the new cargo ____________________ of it.

5 Answer the questions.

1 What types of tank cleaning operations do you know? What are their advantages / disadvantages?

2 What equipment is used to clean tanks?

3 What types of tank cleaning up do you know? What are their advantages/disadvantages?

4 What is the procedure of cleaning tanks?

5 What international regulations about liquid cargo transportation do you know?

Дата добавления: 2015-11-14