Now we unfortunatley all know that the twin towers as the World Trade Center was often called is no more. Due to the horrific events of September 11 2001 both towers were destroyed and thousands of poor souls lost their lives.
We will never forget.
The World Trade Center (WTC) was a complex of seven buildings best known by the 110 story twin towers.
The North Tower which had a large antenna on the top stood 1,368 feet (417 m) high with Tower Two the South tower at 1,362 feet (415 m) and this tower also contained the massive observation deck. Tower One was completed in 1972 with Tower two being completed a year later, they became the tallest buildings in the world and stood a full 100 feet (30m) taller than the Empire State Building.
As with most tallest world records this one was short lived, as in 1973 building work had already begun on the Sears Tower in Chicago which finished at a height of 1,450 feet (442m).
With the events of September 11 2001, the tallest building in New York went once again to the Empire State Building,
The idea of a world trade center grew as New York was one of the world's busiest ports and the construction of a world trade building had been under consideration since the end of the second World War. The original idea was to bring together steamship companies, importers, exporters, freight forwarders, and customs brokers all under a single roof.
The buildings height of 100 feet higher than any other buildings gave designers some additional things to consider, to solve the problem of wind sway or vibration in the construction of the towers. The engineers took at what was at the time a unusual approach, instead of bracing the buildings corner-to-corner or using internal walls, the towers were essentially hollow steel tubes surrounding a strong central core.
The 208 feet (63.4 m) wide facade is, in effect, a prefabricated steel lattice, with columns on 39 inch (100 cm ) centers acting as wind bracing to resist all overturning forces; the central core takes the majority of the gravity loads of the building.
The core supported the weight of the entire building and the outer shell containing 240 vertical steel columns called Vierendeel trusses around the outside of the building, which were bound to each other using ordinary steel trusses. In addition, 10,000 dampers were included in the structure. With a strong shell and core such as this, the exterior walls could be simply light steel and concrete.
Rebuilding on the World Trade Center site is gonig to take place over the coming years and at present the plans are to include a large Freedom Tower with a height of 1,776 feet (541 m) serveral new buildings including 7 world Trade Center, the number scheme as with other incidents it is common not to replace the numbers 1-6 out of respect.
The World Trade Center name will remain but the site will be very different with memorials and places for people to come and pay their respects. Plans may include to have a total of five new office towers built on the new site to replace but not forget the previous monuments.