Sunday 11 September is the tenth anniversary of that horrendous and highly symbolic event, the ramming of two aircraft into skyscrapers in New York City and one into the Pentagon in Washington DC. This portion of a girder cut from one of the World Trade Center buildings, distorted and blackened by fire, serves as a poignant, physical reminder of the event.
The relic was brought to Australia by a group of New York fire fighters and police officers who took part in the rescue and clean-up. They visited Sydney in February 2002 as guests of the NSW government and donated this object to the Premier in honour of the ten Australians who died alongside 3000 others that day. Its value as a museum object is symbolic, commemorating not just those ten but all who died, including those on board a fourth plane that did not reach its target, and all who took part in the rescue and recovery operation.
The hijackers aimed to create carnage, havoc and fear. Symbolism determined their choice of targets: the centre of world capitalism and the nerve centre of US defence. Symbolism also determined their choice of weapon: three airliners carrying large quantities of jet fuel, perhaps sourced from the Middle East’s massive oilfields.
The two skyscrapers were symbols of American technological leadership and economic success, soaring above the land and casting shadows on the water. They were made of steel, concrete and glass, all materials known and used since ancient times. They were clad with aluminium, a material that only became widely available in the twentieth century – thanks to Charles Martin Hall, the American who devised a process to separate it cheaply from its ores.
Skyscrapers embody a good deal of engineering know-how. A key technology is the elevator with safety brake, invented in 1853 by another American, Elisha Otis. The Otis style governor above spent its working life in a shed perched on top of a Sydney retail building, ready to activate a brake if the lift it was connected to started falling too fast. Buildings could not be built more than a few storeys tall before the advent of the safety lift.
The electric lift motor is another key enabling technology for multi-storey buildings. This lift motor with integrated winch spent its working life in a shed at the top of another Sydney retail building, reliably starting at full load whenever someone pushed a button and unerringly stopping the lift level with the required floor. It was made in England around 1915, but the firm that made it was eventually taken over by Otis Elevator, the world’s largest lift company.
The first successful powered flight was achieved by two Americans, brothers Wilbur and Orville Wright, in 1903. Many other researchers had been trying to develop flying machines, including Australia’s own Lawrence Hargrave, whose box kite (below) probably contributed to the design of the Wright flyer’s wings. Hargrave also investigated animal movement and experimented with model ornithopters, making several different engines and a turbine to power them. Having put so much of his time and energy into pursuing the dream of flight, he expressed the hope that aircraft would not be used as war machines.
Of course, it was not long before planes were used in warfare. They grew bigger, stronger and faster, but there was a limit to how fast reciprocating engines could spin propellers. In the 1930s and 40s in England, Frank Whittle was the first to develop gas turbine engines, which could move planes much faster than piston engines. Engineers in Germany and America also developed turbine engines. The engine below was made by Whittle’s company, Power Jets Ltd, in 1943.
The American-made turbo-engine aeroplanes hijacked on 9/11 were not sinister war machines bristling with gun turrets and bombs, but sleek civilian craft similar to the Boeing 767 depicted by the model below. Their fuselage and wings were clad, like the twin towers of the World Trade Center, with that modern, lightweight, corrosion-resistant product of American ingenuity, aluminium.
Just as we rarely think about the technology that enables skyscrapers to exist, we rarely worry about the civilian planes whizzing around our skies. Bringing the two together on that day in 2001 was a shocking act that changed the world, opening new fault lines and accentuating old enmities. Ten years later, the fault lines have stretched around the world and destroyed or disrupted thousands more lives. And while technology has made our lives more interesting, healthy and comfortable, it is certainly a two-edged sword in the hands of those with enmity in their hearts.