4. With the coming of the railway i

4. With the coming of the railway in the 19th century there was a great demand for bridges, and the railways had capital for building them. The first railway were built of stone or brick. In many places long lines of viaducts were built to carry railways; for instance, there are miles of brick viaducts supporting railways to London.

The next important development in bridge-building was the use of iron and, lather, steel. The first iron bridge crossed the river Severn in Great Britain.

The idea of a drawbridge, a bridge hinged so that it can be lifted by chains from inside to prevent passage, is an old one. Some St. Petersburg bridges were built on this principle.

A modern bridge probably demands greater skill from designer and builder than any other civil engineering project. Many things should be taken into consideration, and these may vary widely according to local conditions. In deciding what type of bridge is most suitable the designer has to consider the type and weight of the traffic, and width and depth of the gap to be bridged, the nature of the foundations and the method of erecting the bridge. The designer has to calculate carefully how the various loads would be distributed and to decide which building materials are more suitable for carrying these loads.

Tunnels

5. Tunnelling is difficult, expensive and dangerous engineering work. Tunnels are built to provide direct automobile or railway routes through mountain ranges, under or over rivers. They can also provide underground channels for water, sewage or oil. Before the 19th century men had not acquired enough skill in engineering to carry out extensive tunneling. Tunnels, however, were known in ancient times. They were, for instance, driven into the rock under the Pyramids of Egypt, and the Romans built one in Rome for their chief drain, parts of which still remain. One of the earliest tunnels known was made in Babylon. It passed under the Euphrates river, and was of arched brickwork being 12 feet high and 15 feet wide.

Other ancient tunnels were built for water supply and for drainage.

6. Modern tunnels are often very long and deep. The Simplon Tunnel on the France-to-Italy railway, for example, is 12 miles long and in one place the peaks of the Alps rise over 6,000 feet above it. Some tunnels are over 50 feet in diameter. Many are circular in cross-section. Other are horseshoe-shaped, with a level floor on which it is easy to lay permanent roads and railways.

Tunnel Under Channel

7. Connecting the Isles of Great Britain to mainland Europe is a fantasy that can be dated back nearly 200 years.

We can name very few projects against which there existed a deeper and more powerful prejudice than the construction of a railway tunnel between Dover and Calais.

The objections have been cultural, political and, of course, military. The British government objected to the scheme mainly because they thought that the enemy could easily invade England through such a tunnel.

The first suggestion to construct a tunnel came from Napoleon in 1800. His engineers even drafted a tunnel plan, but Britain and France were at war at that time.

In 1988 the question of a Channel Tunnel was studied afresh by a group of French and British engineers and work actually began. They agreed to start boring for the Eurotunnel on both English and French Coasts.

The Tunnel runs under the sea through a layer of dense chalk which is know to be free of cracks and allows water to penetrate it slowly.

The work proceeded very quickly and was successfully completed in about six years. The Tunnel was opened to traffic on May 7, 1944.

Two main tunnels, with service tunnel between, carry one-way rail traffic.

8. Original estimate was 7.2 billion dollars at current exchange rates, but cost to date is 13.1 billion dollars shared between Britain, France and other investors. So far project is not quite profitable and still needs more investments.

Cars and trucks carried by rail make crossing in 35 minutes, about an hour less than by ferry. Passengers remain in their vehicles.

The Tunnel personnel does its best to make passengers feel comfortable and safe during the crossing. But as it was mentioned by the commercial director of the Tunnel, they still have many serious problems and one of them is security. Nevertheless, the authorities are sure to be able to solve all the problems successfully.

Результаты (русский) 1:

4. с приходом железной дороги в XIX веке был большой спрос на мосты и железные дороги были капитал для их строительство. Первая железная дорога были построены из камня или кирпича. Во многих местах длинные линии виадуки были построены для железных дорог; Например есть мили кирпича виадуки, поддерживая железные дороги в Лондон.Следующим важным событием в строительстве моста было использование железа и мыльная пена, сталь. Первый Железный мост через реку Северн в Великобритании.Идея подъемный мост, мост, шарнирно так, чтобы его можно поднять цепочки из внутри для предотвращения прохода, является старый. Некоторые Мосты Санкт-Петербурга были построены на этом принципе.Современный мост, вероятно, требует большего мастерства от дизайнера и строитель чем любой другой проект гражданского строительства. Многие вещи должны быть приняты во внимание, и они могут широко варьироваться в зависимости от местных условий. При принятии решения, какой тип моста наиболее подходящий дизайнер должен учитывать тип и вес трафика и ширину и глубину преодолеть разрыв, характер основ и метод возведения моста. Дизайнер должен тщательно рассчитать, каким образом будут распространяться различные грузы и решить, какие строительные материалы являются более подходящими для перевозки этих грузов.Туннели5. Tunnelling is difficult, expensive and dangerous engineering work. Tunnels are built to provide direct automobile or railway routes through mountain ranges, under or over rivers. They can also provide underground channels for water, sewage or oil. Before the 19th century men had not acquired enough skill in engineering to carry out extensive tunneling. Tunnels, however, were known in ancient times. They were, for instance, driven into the rock under the Pyramids of Egypt, and the Romans built one in Rome for their chief drain, parts of which still remain. One of the earliest tunnels known was made in Babylon. It passed under the Euphrates river, and was of arched brickwork being 12 feet high and 15 feet wide.Other ancient tunnels were built for water supply and for drainage.6. Modern tunnels are often very long and deep. The Simplon Tunnel on the France-to-Italy railway, for example, is 12 miles long and in one place the peaks of the Alps rise over 6,000 feet above it. Some tunnels are over 50 feet in diameter. Many are circular in cross-section. Other are horseshoe-shaped, with a level floor on which it is easy to lay permanent roads and railways.Tunnel Under Channel7. Connecting the Isles of Great Britain to mainland Europe is a fantasy that can be dated back nearly 200 years.We can name very few projects against which there existed a deeper and more powerful prejudice than the construction of a railway tunnel between Dover and Calais.The objections have been cultural, political and, of course, military. The British government objected to the scheme mainly because they thought that the enemy could easily invade England through such a tunnel.The first suggestion to construct a tunnel came from Napoleon in 1800. His engineers even drafted a tunnel plan, but Britain and France were at war at that time.In 1988 the question of a Channel Tunnel was studied afresh by a group of French and British engineers and work actually began. They agreed to start boring for the Eurotunnel on both English and French Coasts.The Tunnel runs under the sea through a layer of dense chalk which is know to be free of cracks and allows water to penetrate it slowly.The work proceeded very quickly and was successfully completed in about six years. The Tunnel was opened to traffic on May 7, 1944.Two main tunnels, with service tunnel between, carry one-way rail traffic.8. Original estimate was 7.2 billion dollars at current exchange rates, but cost to date is 13.1 billion dollars shared between Britain, France and other investors. So far project is not quite profitable and still needs more investments.Cars and trucks carried by rail make crossing in 35 minutes, about an hour less than by ferry. Passengers remain in their vehicles.The Tunnel personnel does its best to make passengers feel comfortable and safe during the crossing. But as it was mentioned by the commercial director of the Tunnel, they still have many serious problems and one of them is security. Nevertheless, the authorities are sure to be able to solve all the problems successfully.