Grand union

A grand union is a rail track junction where two double-track railway lines cross at grade, often in a street intersection or crossroads. A total of sixteen railroad switches (sets of points) allow streetcars (or in more rare installations, trains) coming from any direction to take any of the three other directions. The same effect may be achieved with two consequent wyes if the location allows for space.

Complexity

These types of complex junction are expensive to build and expensive to maintain. Special parts, sometimes made of manganese steel, are needed for each location where one rail crossed another (a "frog"); these parts often need to be custom-made and fitted for each single location, depending on the specific angle of crossing of the intersecting streets.

A full grand union junction consists of 88 frogs (where one rail crosses another rail), and 32 switchpoints (point blades) if single-point switches are not used. A tram or train crossing the junction will encounter four or twenty frogs within the space of crossing the junction.

Grand Union

Grand Union may refer to:

Transport

Entertainment

Other uses

See also

Union Canal

Union Canal may refer to:

Grand Union Canal

The Grand Union Canal in England is part of the British canal system. Its main line starts in London and ends in Birmingham, stretching for 137 miles (220 km) with 166 locks. It has arms to places including Leicester, Slough, Aylesbury, Wendover and Northampton.

The Grand Union Canal was also the original name for part of what is now part of the Leicester Line of the modern Grand Union: this latter is now generally referred to as the Old Grand Union Canal to avoid ambiguity.

History

With competition from the railways having taken a large share of traffic in the second half of the 19th century, improvements in roads and vehicle technology in the early part of the 20th century meant that the lorry was also becoming a threat to the canals. Tolls had been reduced to compete with the railways, but there was little scope for further reduction. The Regent's Canal and the Grand Junction Canal agreed that amalgamation and modernisation were the only way to remain competitive.

The Grand Union Canal in its current form came into being on 1 January 1929, and was further extended in 1932. It was formed from the amalgamation of several different canals, and at 286.3 miles (461 km) is by far the longest canal in the UK:

Union

Union is the state of being united or joined.

Union may also refer to:

Labor

Education

History and politics