11. Present a monologue.

Speak about recent modifications of ro-ro-vessels. What are advantages and disadvantages of these modifications?

Unit IV. The hull of the bulk carrier

1. Answer the following questions.

1) What are cargo ships used for?

2) What cargo handling facilities are used on cargo ships?

3) What are special requirements for dry cargo handling?

2. Read the new words.

single-hull – однокорпусный;

bulbous bow – бульбообразный нос;

block coefficient – коэффициент полноты водоизмещения;

carrying capacity – грузовместимость;

deadweight tonnage – полная грузоподъемность;

ballast tank – балластовая цистерна;

ship's trim – положение судна;

corner tank – бортовая подпалубная цистерна;

angle of repose – угол предельного равновесия;

side-to-side movement – поперечное перемещение;

mild steel – низкоуглеродистая сталь;

high-tensile steel – сталь повышенной прочности;

tare weight – конструкционный вес;

transverse reinforcement – поперечная арматура;

longitudinal reinforcement – продольная арматура.

3. Read the text.

Bulkers are designed to be easy to build and to store cargo efficiently. To facilitate construction, bulkers are built with a single-hull. Also, while a bulbous bow allows a ship to move more efficiently through the water, designers lean towards simple vertical bows on larger ships. Full hulls, with large block coefficients, are almost universal, and as a result, bulkers are inherently slow.

Bulkers have a cross-section typical of most merchant ships. The upper and lower corners of the hold are used as ballast tanks, as is the double bottom area. The corner tanks are reinforced and serve another purpose besides controlling the ship's trim. Designers choose the angle of the corner tanks to be less than that of the angle of repose of the anticipated cargoes. This greatly reduces side-to-side movement, or "shifting," of cargo which can endanger the ship.

The double bottoms are also subject to design constraints. The primary concern is that they be high enough to allow the passage of pipes and cables. These areas must also be roomy enough to allow people safe access to perform surveys and maintenance. On the other hand, concerns of excess weight and wasted volume keep the double bottoms very tight spaces.

Bulker hulls are made of steel, usually mild steel. Some manufacturers have preferred high-tensile steel recently in order to reduce the tare weight. However, the use of high-tensile steel for longitudinal and transverse reinforcements can reduce the hull's resistance to corrosion.

4. Suggest the English equivalents or find them in the text.

Облегчать конструкцию, быть медленным по определению, быть типичным для большинства судов, склоняться к чему-л., служить цели, подвергаться расчетным ограничениям, первоочередная задача, обеспечить безопасный доступ к чему-л., избыточная масса, коррозийная стойкость, ожидаемый груз, производить исследования и ремонт.

5. Answer the questions.

1) In what way are bulk carriers designed?

2) Why are bulkers slow?

3) How are upper and lower corners of the hold used?

4) What for were corner tanks reinforced?

5) How do designers achieve the reduction of side-to-side movement?

6) What are the main requirements for the double bottom design?

7) What kinds of steel are bulker hulls made of? What is the difference between them?