Classification of Diesel Engines
Diesel engines are divided according to operating cycle, method of charging
the cylinder and general design. So diesel engines may operate on a constant
pressure cycle (large slow-speed air injection engines) and on a combination cycle
when part of the fuel burns at constant volume and part of the fuel burns at
constant pressure.
There are four-stroke and two-stroke engines. In four-stroke engines the
piston and the cylinder act as a pump which removes products of combustion and
fills the cylinder with fresh air charge. In two-stroke engines the cylinder is
scavenged and filled with fresh compressed air charge by an external pump. By
general design all engines may be divided into single-acting and double-acting.
The main working parts of a diesel engine are the cylinder, the cylinder
head, the piston, the connecting rod, the crankshaft, the fuel pump and fuel nozzle.
The auxiliary parts are the cylinder liner, the crank pin, the piston rings, the valve
springs, the crankcase and others.
2) 180100.62 «Кораблестроение, океанотехника и системотехника
объектов морской инфраструктуры» (только для профиля
кораблестроение)
A Ship
The main parts of a ship are a hull, some decks and deck superstructure. The
hull is the body of the ship. It is painted grey, white and black. There are two lines
on the sides of each ship. One line shows the draught with a full cargo. The other
line shows the draught without cargo in her holds. These lines help to control the
degree of submergence and to avoid overloading.
Inside the hull there are frames and beams that make the ship stronger and
help to withstand pressure from outside and from inside. The forward part of a ship
is called her bow, the after part – the stern or aft. The lowest part is called a
bottom. The space under the bottom is a double bottom for carrying fuel, oil, fresh
water and water ballast.
The part of the hull below water is ship’s quickwork. The part above the
water is ship’s freeboard. Many ships have three decks: the main deck, the upper
deck and the lower deck. There are some openings in the deck: ventilators, scuttles
and skylights. They are used for free passage of air and light.
Cargoes are loaded into holds through hatchways which are closed with
hatch covers. There are cargo-handling appliances and machinery on deck, such as
winches, derricks, windlasses, capstans.
Deck superstructures are accommodation for the crew.
Types of Cargo Ships
Modern ships deliver cargoes all over the world. They carry general cargo,
bulk and liquid cargoes. Dry cargo ships transport packed cargo in boxes, bags,
barrels, bales, container; they can carry heavy weights, timber logs. Containers are
loaded and discharged by ship’s own derricks or by shore-based cranes.
Bulkers carry unpacked cargo, such as grain, ore, coal, fertilizers, wheat etc.
The holds of bulkers are self-trimming. Tankers are specially designed to transport
liquids: crude oil, liquefied gas, petroleum. Tankers are equipped with pipes,
valves and pumps to handle cargo.
There are special vessels that do auxiliary service. Tugs assist ships when
entering or leaving the ports and take part in salvage operations. Salvage vessels
rescue ships, their cargoes and passengers, if any. Icebreakers sail in northern icy
areas. Dredgers deepen port fairways, anchorages, roadsteads.
Ro-Ro ships load and unload cargo via a ramp placed on the berth. Liners
carry cargo between fixed ports. Tramps have no fixed schedule, fixed ports of
destination and fixed ports of call.
3) 270800.62 «Строительство»
A Port
A port is a protected place where ships can load, unload and ride at anchor.
There are commercial ports, military, industrial, fishing and ports of refuge. By
their geographical situation ports can be ocean and inland waterway ports.
Ocean ports are usually located in natural harbours, in bays, tidal estuaries
and river mouths. They also may be formed on an unprotected shore line by the
construction of breakwaters. Inland waterway ports are constructed on navigable
rivers, canals and lakes. River ports have no wave-protecting structures.
Every port should be readily accessible, provide good shelter and
accommodation. The accessibility of a port depends on the depth of water in the
approach channel. This channel is deepened by dredging. The configuration of the
coast line influences the amount of shelter.
A modern port should be provided with terminal facilities, such as piers,
wharves, quays, docks or berthing places for ships. Their main function is to
handle passengers and cargo.
Every port has hoisting facilities, storage areas, such as warehouses, transit
sheds, port cold stores, and ship repair facilities. There are special complexes
which specialize in handling specific types of cargoes (general cargo, timber, oil,
ore, coal, containers).
Port communications increase the efficiency of cargo-handling operations
and delivery of cargo. Goods must be turned around a port as rapidly as possible.