Question: What is the official name of the tower, previously known as Clock Tower, next to which a proposed Thames Airport was to be built in the 1930s?

full_context: Document 1: Upper Thames River Conservation Authority: The Upper Thames River Conservation Authority is a body based in London, Ontario, Canada. It was created in 1947. It was responsible for the construction of the Fanshawe Dam, completed in the 1950s, to control flooding from the Thames River, which runs through London. During the last ice age, the site of London was the terminus of a large glacier. When the region warmed at the end of the ice age, the glacier melted and receded North, leaving behind a drainage ditch and features such as Sifton Bog. As such, the Thames is a watershed for most of Western Ontario, and is therefore highly susceptible to seasonal flooding. In 1937, such flooding had devastating consequences, destroying over 1,000 homes, and causing millions of dollars in damage.
Document 2: Victoria Tower: The Victoria Tower is the square tower at the south-west end of the Palace of Westminster in London, facing south and west onto Black Rod's Garden and Old Palace Yard. At 98.5 m , it is slightly taller than the more famous Elizabeth Tower (formerly known as the Clock Tower and popularly known as 'Big Ben') at the north end of the Palace (96.3 m ). It houses the Parliamentary Archives in archive conditions meeting the BS 5454 standard, on 12 floors. All 14 floors of the building were originally linked via a single wrought-iron Victorian staircase of 553 steps, of which five floors survive.
Document 3: Big Joe (bell): Joseph (commonly known as Big Joe) is a bronze bell that hangs 125 ft into the bell tower of Neo-Gothic Saint Francis De Sales Catholic Church in Cincinnati, Ohio, United States. The endearing moniker Big Joe is a combination of the names of Joseph T. Buddeke, the largest donor of the project, and Big Ben, the great bell in the iconic Palace of Westminster clock tower in London.
Document 4: Expansion of Heathrow Airport: The expansion of Heathrow Airport has involved several proposals by Heathrow Airport Holdings and an independent proposal by Heathrow Hub, to increase capacity at Heathrow Airport.
Document 5: Little Ben: Little Ben is a cast iron miniature clock tower, situated at the intersection of Vauxhall Bridge Road and Victoria Street, in Westminster, central London, close to the approach to Victoria station. In design it mimics the famous clock tower colloquially known as Big Ben at the Palace of Westminster, found at the other end of Victoria Street.
Document 6: Plot 3a Princes Dock: Plot 3a Princes Dock is a 33-storey mixed use building that has been approved for construction alongside Prince's Dock at the waterfront of Liverpool, England. If and when built, it will stand alongside the likes of 1 Princes Dock and Alexandra Tower. Besides West Tower, Radio City Tower and Liverpool Cathedral, Plot 3a Princes Dock is the only structure over 100 m that has been approved for construction in the city's history. Planning permission has been granted for the building on two occasions (2007 and 2011), despite this construction is still yet to commence.
Document 7: Clock Tower, Brighton: The Clock Tower (sometimes called the Jubilee Clock Tower) is a free-standing clock tower in the centre of Brighton, part of the English city of Brighton and Hove. Built in 1888 in commemoration of Queen Victoria's Golden Jubilee, the distinctive structure included innovative structural features and became a landmark in the popular and fashionable seaside resort. The city's residents "retain a nostalgic affection" for it, even though opinion is sharply divided as to the tower's architectural merit. English Heritage has listed the clock tower at Grade II for its architectural and historical importance.
Document 8: Proposed Chicago south suburban airport: A major airport has been proposed to be built in Peotone, Illinois, a suburb of Chicago. There is no official name and two separate plans exist, one known as the "South Suburban Airport" and another known as "Abraham Lincoln National Airport". The FAA refers to the two proposals as South Suburban Airport. The airport would serve as an additional airport in the Chicago metropolitan area. Supporters of the airport say it will bring new jobs to the southern suburbs and the entire Chicago region, while relieving critical runway and terminal congestion at O'Hare International Airport and Chicago Midway International Airport. A new airport would accommodate large jet service similar to that of O'Hare, but that Midway International Airport does not offer.
Document 9: Big Ben: Big Ben is the nickname for the Great Bell of the clock at the north end of the Palace of Westminster in London and is usually extended to refer to both the clock and the clock tower as well. The tower is officially known as Elizabeth Tower, renamed to celebrate the Diamond Jubilee of Elizabeth II in 2012; previously, it was known simply as the Clock Tower.
Document 10: Big Ben (solitaire): Big Ben (or known in other solitaire brands as Clock) is a solitaire card game which uses two decks of playing cards mixed together. It is basically a large-scale, two-deck version of Grandfather's Clock and is probably named after Big Ben, the colloquially used nickname for the bell at the tower of the Palace of Westminster in London.
Document 11: Thames Gateway Bridge: The Thames Gateway Bridge was a proposed crossing over the River Thames in east London, England. It was first mooted in the 1970s but never came to fruition. In November 2008, Boris Johnson, the then Mayor of London, formally cancelled the entire £500 million scheme.
Document 12: Tower Bridge: Tower Bridge is a combined bascule and suspension bridge in London built between 1886 and 1894. The bridge crosses the River Thames close to the Tower of London and has become an iconic symbol of London, resulting in it sometimes being confused with London Bridge, situated some 0.5 mi upstream. Tower Bridge is one of five London bridges now owned and maintained by the Bridge House Estates, a charitable trust overseen by the City of London Corporation. It is the only one of the Trust's bridges not to connect the City of London directly to the Southwark bank, as its northern landfall is in Tower Hamlets.
Document 13: Big Ben Aden: Big Ben Aden (Arabic: بيج بن عدن‎ ‎ ) is a clock tower built by British engineers, along with locals, beside Aden Harbour in Yemen during the period that Aden Province (later called Aden Colony) was a territory within the British Empire. It is superficially similar to the Elizabeth Tower (popularly known as Big Ben), the famous clock tower attached to the Palace of Westminster in London. The clock was shut down for renovation about a quarter of a century ago, and returned to service in February 2012. The tower was built during the 19th century as part of the British colonisation of Aden Province, which began in 1839 and came to an end in 1967.
Document 14: Proposed Thames Airport: Thames Airport was a proposed elevated airport during the 1930s that would have been constructed over the River Thames between Westminster Bridge and Lambeth Bridge. Not much is known about the proposed airport, except that it would have had an elevator to bring people to the flight deck, as well as room underneath for a hangar. It would have also been next to the nearby Big Ben and Palace of Westminster.
Document 15: More London: More London, also named London Bridge City, is a privately owned development on the south bank of the River Thames, immediately south-west of Tower Bridge in London. The southern exit is on Tooley Street.
ground_truth: Elizabeth Tower