Ship Construction by Type of Vessel - Part 2

Bulk/Ore Carriers

 

1. Bulk carriers are single-deck vessels, which transport single-commodity cargoes such as grain, sugar and ores in bulk.
2. The general-purpose bulk carrier, in which usually the central hold section only is used for cargo.
3. The partitioned tanks which surround it are used for ballast purposes either on ballast voyages or; in the case of the saddle tanks, to raise the ship's center of gravity when a low density cargo is carried.
4. Some of the double-bottom tanks may be used for fuel oil and fresh water.
5. The saddle tanks also serve to shape the upper region of the cargo hold and trim the cargo. Large hatchways are a feature of bulk carriers, since they reduce cargo-handling time during loading and unloading.
6. An ore carrier has two longitudinal bulkheads, which divide the cargo section into wing tanks port and starboard, and the center hold, which is used for ore.
7. On loaded voyages the ore is carried in the central hold, and the high double bottom serves to raise the center of gravity of this very dense cargo.
8. Two longitudinal bulkheads are employed to divide the ship into center and wing tanks which are used for the carriage of oil cargoes.
9. When ore is carried, only the center tank section is used for cargo.
10. A double bottom is fitted beneath the center tank but is used only for water ballast.
11. The structure is significantly stronger, since the bulkheads must be oil tight and the double bottom must withstand the high-density ore load.
12. Large hatches are a feature of all bulk carriers, to facilitate rapid simple cargo handling.
13. A large proportion of bulk carriers do not carry cargo-handling equipment, because they trade between special terminals which have particular equipment for loading and unloading bulk commodities.

 

Container ships

 

1.  A container is a re-usable box of 2435 mm by 2435 mm section, with lengths of 6055, 9125 and 12 190 mm.
2. Containers are in use for most general cargoes, and liquid-carrying versions also exist. In addition, refrigerated models are in use.
3. The cargo-carrying section of the ship is divided into several holds which have hatch openings the full width and length of the hold.
4. Cargo handling consists only of vertical movement of the cargo in the hold.
5. Containers can also be stacked on the hatch covers where a low-density cargo is carried.
6. The various cargo holds are separated by a deep web-framed structure to provide the ship
   with transverse strength.
7. The ship section outboard of the containers on each side is a box-like arrangement of wing tanks, which provides longitudinal strength to the structure. These wing tanks may be utilized for water ballast.
8. A double bottom is also fitted which adds to the longitudinal strength and provides additional ballast spacer.

Passenger ships

1. The passenger traveling in such a ship pays for, and expects, a superior standard of accommodation and leisure facilities.
2. Large amounts of superstructure are therefore an essential feature of passenger ships.
3. Several tiers of decks are filled with large open lounges, ballrooms, swimming pools and promenade areas.
4. Stabilizers are fitted for reduce rolling and bow thrust devices are employed for improved maneuverability.