London Bridge

Carries: 5 lanes of A3

Crosses: River Thames

Locale: Inner London

Maintained by: Bridge House Estates, City of London Corporation

Design: prestressed concrete box girder bridge

Total length: 269 m (882.5 ft)

Width: 32 m (105.0 ft)

Opened: 17 March 1973

London Bridge is a bridge over the River Thames, connecting the City of London and Southwark, in central London.

Situated between Cannon Street Railway Bridge and Tower Bridge, it forms the western end of the Pool of London.

On the south side of the bridge are Southwark Cathedral and London Bridge station; on the north side are the Monument to the Great Fire of London and Monument tube station.

It was the only bridge over the Thames downstream from Kingston until Putney Bridge opened in 1729. The current bridge opened on 17 March 1973 and is the latest in a succession of bridges to occupy the spot and claim the name.

The bridge carries part of the A3 road, which is maintained by the Greater London Authority; the bridge itself is owned and maintained by the Bridge House Estates, an independent charity overseen by the City of London Corporation.

The area between London Bridge and Tower Bridge on the south side of the Thames is a business improvement district (BID) and is managed by Team London Bridge.

LPG

Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles.

It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer.

When specifically used as a vehicle fuel it is often referred to as autogas.   Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.

In the United States, primarily only two grades of LPG are sold, commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA) and the American Society of Testing and Materials (ASTM).

Propane/butane blends are also listed in these specifications. Propylene, butylenes and various other hydrocarbons are usually also present in small concentrations. HD-5 limits the amount of propylene that can be placed in LPG, and is utilized as an autogas specification.

A powerful odorant, ethanethiol, is added so that leaks can be detected easily. The international standard is EN 589. In the United States, tetrahydrothiophene (thiophane) or amyl mercaptan are also approved odorants, although neither is currently being utilized.

LPG is synthesised by refining petroleum or “wet” natural gas, and is almost entirely derived from fossil fuel sources, being manufactured during the refining of petroleum (crude oil), or extracted from petroleum or natural gas streams as they emerge from the ground.

It was first produced in 1910 by Dr. Walter Snelling, and the first commercial products appeared in 1912. It currently provides about 3% of all energy consumed, and burns relatively cleanly with no soot and very few sulfur emissions. As it is a gas, it does not pose ground or water pollution hazards, but it can cause air pollution.

LPG has a typical specific calorific value of 46.1 MJ/kg compared with 42.5 MJ/kg for fuel oil and 43.5 MJ/kg for premium grade petrol (gasoline). However, its energy density per volume unit of 26 MJ/l is lower than either that of petrol or fuel oil.

LPG evaporates quickly at normal temperatures and pressures and is usually supplied in pressurised steel gas cylinders. They are typically filled to between 80% and 85% of their capacity to allow for thermal expansion of the contained liquid.

The ratio between the volumes of the vaporized gas and the liquefied gas varies depending on composition, pressure, and temperature, but is typically around 250:1.

ENGLISH

English is a West Germanic language spoken originally in England, and is now the most widely used language in the world. It is spoken as a first language by a majority of the inhabitants of several nations, including the United Kingdom, the United States, Canada, Australia, Ireland and New Zealand.

It is the third most common native language in the world, after Mandarin Chinese and Spanish. It is widely learned as a second language and is an official language of the European Union, many Commonwealth countries and the United Nations, as well as in many world organisations.

English arose in the Anglo-Saxon kingdoms of England and what is now south-east Scotland, but was then under the control of the kingdom of Northumbria.

Following the extensive influence of Great Britain and the United Kingdom from the 18th century, via the British Empire, and of the United States since the mid-20th century, it has been widely propagated around the world, becoming the leading language of international discourse and the lingua franca in many regions.

Historically, English originated from the fusion of closely related dialects, now collectively termed Old English, which were brought to the eastern coast of Great Britain by Germanic (Anglo-Saxon) settlers by the 5th century – with the word English being derived from the name of the Angles, and ultimately from their ancestral region of Angeln.

A significant number of English words are constructed based on roots from Latin, because Latin in some form was the lingua franca of the Christian Church and of European intellectual life. The language was further influenced by the Old Norse language due to Viking invasions in the 8th and 9th centuries.

The Norman conquest of England in the 11th century gave rise to heavy borrowings from Norman-French, and vocabulary and spelling conventions began to give the appearance of a close relationship with Romance languages to what had then become Middle English.

The Great Vowel Shift that began in the south of England in the 15th century is one of the historical events that mark the emergence of Modern English from Middle English.

Owing to the assimilation of words from many other languages throughout history, modern English contains a very large vocabulary, with complex and irregular spelling, particularly of vowels.

Modern English has not only assimilated words from other European languages but also from all over the world, including words of Hindi and African origin.

The Oxford English Dictionary lists over 250,000 distinct words, not including many technical, scientific, and slang terms.