Unit 3
Liquid Cargo Handling
Topic 1
Tanker Work
Starter
Discuss.
What types of tare is used for liquid cargo transportation?
What liquid cargoes are usually carried by sea?
What types of cargo are regarded as dangerous cargo? Why?
Reading
1 Are the statements true or false?
Lubricants are usually loaded only in cask.
Tanks should be cleaned from previous cargo before loading oils.
A substantial water quantity is desirable in oil products.
Density, viscosity and flash point of oil may be neglected while carrying in tanks.
2 Read the text, translate it and check your answers.
The most important liquid cargoes are oil products.
During the transportation and storage of such cargoes some of their properties should be taking into consideration. They are density, temperature of thickness, flash point, viscosity and water quantity.
Liquid oil products comprise: fuel oils, petrol, kerosene and lubricants.
Lubricating oils are loaded into oil tankers, containers, thermoses and sometimes in casks and cans. Iron casks and cans must be tightly closed with screwed plugs. While transporting iron casks and cans must be placed in strong wooden crates.
Oil products are carried by oil tankers which have some oil tanks, pumps and oil-conducting pipe lines for loading and unloading liquid cargoes. Each tank has a hermetically sealed hatch cover of about 60 cm in diameter. Since some oil products give off explosive gases, oil tanks are fitted with special tubes for giving gases the way to escape.
Oil tanks and cisterns should be in good state, and before loading the personnel's duty is to clear them from the residue of previous cargoes or any dirt, water or sand.
3 Discuss.
Why?
Iron casks must be tightly closed.
Oil tanks are fitted with special tubes.
It is very important to clear oil tanks from previous cargo.
Topic 2 Safety on Tankers
Reading
1 Answer the questions.
1 What precautions should be taken by crewmembers when working with chemicals?
2 How to prevent product contamination?
3 What potential hazards to health can the chemicals present?
2 What do you know about
• tankers’ hull design?
• inert gas system?
• requirement to navigational equipment?
• size classes?
• the biggest tanker in the world?
3 Read the text and title the paragraphs.
According to the United Nations Conference on Trade and Development, more than 2 trillion metric tons of oil is transported every year using oil tankers.
1_________________________________
The implementation of double-hull construction offers "increased environmental protection" and "better protection in case of collisions and grounding," according to 1998 Marine Board research findings. The United Nations in 2005 voted to phase out single hull oil tankers by 2010.
2__________________________________
One
of the greatest dangers in unloading oil from a tanker is that
dangerous gas mixtures will be formed. To avoid this, workers employ
a "blanket gas" into the hold. According to a 2003 safety
report by an industry consulting firm Hayler and Keever, "An oil
tanker's inert gas system is one of the most important parts of its
design". This not only helps to make s
ure
pressure levels stay at a desirable level, but also to prohibit a
hazardous introduction of oxygen. 3_______________________
Federal safety standards for oil tankers require them to be manufactured with "twin screws," because the use of two propellers provides greater maneuverability. In addition, ships are to be equipped with "two radars in working order," one of which must be a "collision avoidance radar".
4_______________________
There are six different oil tanker size categories. According to the American Bureau of Shipping, the smallest-sized tanker is general purpose tankers, which range in sizes from 10,000 to 24,000 dead weight tons (DWT). The largest is an ultra large crude carrier, which range in sizes from 320,000 to 549,999 DWT and can cost up to $120 million to build and equip.
5_________________________
With a width of 69 meters and a length of 458 meters the Knock Nevis is able to bring about 14 million oil barrels that could support all motorized vehicles on earth for 2 weeks. When the load is full, the hull sinks 25 meters, which resulted in the ship to sail safely only through waters that have minimal depths of 30 m. That is, the Knock Nevis cannot pass through the Panama Canal and Suez Canal.
4 Are the statements true of false? Correct the false ones.
Viewing
6 In pairs exchange the information about personal protective equipment you had aboard during your practice.7 Watch the video and make a list of rules of personal safety on tankers.
____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
7 Mark the statements as true / false / doesn’t say according to the content. Prove your choices.
Ullages and temperatures of all tanks should be taken at regular intervals during a voyage to ensure that serious leakage will be detected.
Viscous oils (such as fuel oil and heavy lubricating oil) should be heated for several days before arrival at the port of discharge so that their viscosity is decreased and a high rate of discharge is possible.
Tanks are ventilated by large diameter pipes which exhaust above deck level on masts or samson posts.
The water around the ship should be inspected after commencing, to ensure that no oil is escaping.
The degree of cleaning necessary depends upon the cargo previously carried and that to be carried next.
Mechanical tank washing machinery is usually used. This consists of rotating water jets which are lowered into a tank through a specially fitted manhole.
The International Chamber of Shipping, in collaboration with the Oil Companies International Marine Forum, has produced the International Safety Guide for Oil Tankers and Terminals.
Crude oil washing is a common technique now used for tank cleaning.