7. Traditional cargo ships

Today, cargo ship has powerful, electrically driven cranes and derricks. She can be loaded at the side and stern as well as at the hatches. She has automatic engine room controls and automatic navigation equipment. A typical ship may carry automobiles, sacks of flour, cases of whiskey, television sets, airplane engines, crates of chinaware, and a variety of other items. Loading and unloading such a mixture of items of varying shapes and sizes requires much time and labor and is, therefore, expensive. As a result, the number of ships designed to carry only one type of cargo - tankers and dry bulk carriers, for example - has increased.

12. Answer the questions.

1. What are the main types of cargo ships?

2. What are general cargo ships?

3. What are multipurpose ships used for?

4. What are tramp ships?

5. What is the difference between cargo liners and tramps?

6. What types of tramps do you know?

8. Classification of cargo ships (Part II)

Reefer - they transport perishable foods such as fruit, vegetables, meat, fish and dairy. They sail at a speed of 18-22 knots which is higher than that of the common general-cargo ships because these perishable goods require faster delivery. Foodstuffs are kept in holds with good heat and freezing insulation. Reefers are equipped to carry not only frozen stuff but also goods which first have to be refrigerated to a specific temperature for transportation. Timber carriers - one-decked ships designed to carry logs and beams.

Container ships eliminate the individual hatches, holds, and derricks of the traditional general cargo vessel. The hull of a container ship is simply an enormous warehouse divided into cells by vertical guide rails. The cells are designed to hold cargo in prepackaged units called containers. These ships are classified as unit-load ships because freight is carried in huge boxes of standard size (units), usually from 10 to 40 t.

The ship does not need a large gang of workers spending hours to fit various items into different holds. Giant cranes pick up the containers, swing them over the ship, and then lower them one upon the other into the cells. After the hold has been loaded, additional containers are stacked on the deck.

Barge-carrying ships (lighter ships) -This type of ships pertains to the category of containerships but the principle is slightly different. Cargo is carried in floating containers, also referred to as barges or lighters. Difference between a container and barge: much bigger and can float. As these barges cannot sail on their own, they need to be tugged or towed to the ship. There, they can be loaded aboard in different ways depending on the type of lighter ship.

For example, LASH (Lighter Aboard Ship) type that carry preloaded seagoing lighters (barges) has a high-capacity crane at the stern which lifts the barge, moves it horizontally over the deck and arranges it. SEA BEE type has a platform at the stern which is just like an elevator - it takes the lighter on and lifts it up to the deck. From then on, another device carries the barge to its place. Unloading is done in the same way on the following principle - lighters are unloaded from the ship, let in the water and tugged to the pier. Advantages: 1) Rapid loading/discharging 2) Can anchor and discharging don’t using berth 3) Long life in 2,5 times more than container 4) Simpler organization . Disadvantages:

1) distribution is limited by draught 2) ice on waterways can restrict barge transport 3) LASH type is more expensive than the equivalent container ship.

Barges are somewhat like small bulk carriers. These boxlike vessels haul such cargoes as cement, coal, grain, gravel, and sand across harbours, on canals and rivers, and along coasts. Modern barges have diesel motors or are pushed or towed by tugs. The size of a canal or river barge is limited by the waterway on which it operates. The barge must be short enough to make the curves in the waterway and narrow enough to pass through canals. Barges that operate in coastal waters can be practically any size.

Roll-on/roll-off ships, also known as ro-ro ships, take containers mounted on a framework of wheels like a truck trailer. These ships have a stern opening and side openings. Ro-ro ships also haul cars, buses, house trailers, trucks, and any other cargo that can be rolled aboard. Ro-ro ships usually have 2-6 decks and look like huge parking lots with stern openings and lifting platforms to sort out trailers. Advantages: 1) independence of port facilities 2) quick door - to door service; 3)faster cargo handling rate; 4) the risk of damage or pilferage is reduced. Disadvantage of Ro-Ro ships: 1) considerable amount of cargo volume is occupied by vehicles or trailers; 2) considerable space below the lower deck cannot be used for trailers.

Bulk-carriers (bulkers) - designed to carry loose goods which constitute about 70% of all the shipments carried by sea. Bulkers are single-decked ships with no tweendecks in their holds but fitted out with various types of special cargo handling equipment. They transport fertilizer, grain, ore, salt, sugar, or any other cargo that can be piled loose into a hold. The cargo is often shot straight in to the holds and discharged by grabs pneumatic suction plants and other bulk handling methods. A modern seagoing bulker has the bridge and engine room near the stern. The rest of the ship is a level area of deck with a line of hatches. Motor-driven equipment on board quickly removes the enormous hatch covers.

Heavy-cargo ships - designed to carry cranes, oil drills, machinery for factories and power stations, equipment for heavy industry and other cargo weighing 700-1000 t.

Cattleships - as the name implies, these ships transport cattle.

13. Check your understanding. Answer the following questions.

1. How is containerised cargo loaded and unloaded?

2. What are some advantages of containerisation?

3. What ships do we call Ro-Ro ships?

4. What does the word LASH stand for?

5. What are LASH ships used for?

6. How are SEE BEE vessels unloaded?

7. What do bulkers transport?

8. What are heavy-cargo ships designed for?

9. What are the advantages of LASH ships?

10. What are barges?

11. What is the main requirement for barges?