3.Containerisation

The most revolutionary development in freight transportation since the invention of the semi-trailer and since the appearance of the internal combustion engine is containerisation. Containerisation is not only the fact of transporting

by various means a big box called a container. It constitutes a complete system, throughout various means of transportation by sea, railroad and soon by air. Containerisation completely changes habits and traditions, the design of vehicles and snips. the methods of handling and strong. operating procedure, safety and insurance standards. road transport regulations, and so on. What is a container? A container is essentially a box of standard dimensions: 8 feet (2,44 metres) wide, 8 feet (2,44 metres) or 8 feet 6 inches (2,59 metres) high and of four standard lengths to choice. In practice the usual models are 20 feet (6.1 metres) long with a maximum gross weight of 20 tons (20,320 kg) or 40 feet long (12.192 metres) with a maximum gross weight of )0 tons ()0,480 kg). A container is usually handled from the top lifted by four of its specially shaped corner fittings attached to the top of the container end frames at each corner. Thanks to Giant-Gantry Cranes it can be lowered into the vertical cells of container ship in 3 minutes.

For overland transport the container is lowered into a container-carrying road semi-trailer or into a container-carrying railcar. In both cases tie down devices fitted

to the semi-trailer or rail car are located i~ four corner fittings attached to the container end frames at the corner to secure the container to the vehicle.

Дати письмову відповідь на запитання

1.What was the most revolutionary development in freight transportation?

2.What is a container?

3.How is container usually handled?

4.How are the containers lowered into the vertical cells of container ships?

5.Where are the tie down devices located?

4. Various types of sleepers

Sleepers originally consisted of slabs of stone or longitudinal bulks of timber laid under the rails. Both these types were discarded, as in the first case the running was rough and the noise was very great. Longitudinal sleepers were found to be expensive as they had to be of a large section to satisfactorily support the rail and the cost of timber increases rapidly with increase in section.

Cross sleepers, which were first introduced in 1835, are now employed universally. They are made of wood, steel, cast iron or concrete. A sleeper that fulfils all requirements most satisfactorily is the wooden sleeper. As the number of sleepers required is enormous and as timber is becoming scarce, sleepers of other materials are being used in increasing numbers in many countries. Metal sleepers have been used on a large scale in countries where deterioration of wooden sleepers due to the presence of vermin, e.g. white ants. and on account of climatic conditions is rapid. In Britain, treated wooden. sleepers last about 20 years in the main tracks and then give further service in siding, whereas the life of wooden sleepers in India is considered to be 15 years. Cast iron sleepers, although used extensively in India and South America, are little used elsewhere. Concrete sleepers both of the reinforced block type and the prestressed concrete type are being used increasingly in Europe. They have all the advantages of a material which is immune to corrosion and vermin attack.