Engineer Thomas Dwyer stands with the new Bionic Exoskeleton next to Amanda Boxtel during its launch at the Excel centre on October 21, 2011 in London, England. The bionic device developed by Ekso Bionics is a wearable, battery-powered, robotic exoskeleton, designed to aid wheelchair users and those who have suffered from spinal chord injuries to stand and walk. (Photo by Dan Kitwood/Getty Images)

Passengers ride an articulated bus known as a “bendy bus” on December 9, 2011 in London, England. The last remaining bendy bus will go out of service at midnight. London Mayor Boris Johnson called them cumbersome and pledged to remove them. 500 new buses are being introduced as replacements. (Photo by Peter Macdiarmid/Getty Images)

Men dressed as Vikings lead the torchlight procession as it makes its way along Princess Street for the start of the New Year celebrations December 30, 2011 in Edinburgh, Scotland. Thousands of people joined in the torchlight procession, which is followed by the burning of a Viking long ship, to mark the start of Edinburgh's Hogmanay celebrations. (Photo by Jeff J. Mitchell/Getty Images)

Police take part in a role play exercise as they clear a protest on top of a train during training on March 6, 2012 in Oxenhope, England. A new team of specialist officers set up to deal with searches and policing at a height, such as on top of a train, undergo training exercise in Oxenhope, West Yorkshire. (Photo by Bethany Clarke/Getty Images)

These Filipino icons of ingenuity were originally re-crafted from abandoned US army jeeps after the second world war, and helped to establish a new system of urban transportation. Jeepneys are being phased to help ease city congestion, but the move will also cause unemployment for experienced drivers – and higher fares for commuters. (Photo by Claudio Sieber/Barcroft Media)

Men dressed as soldiers pose with models before the opening of the Gamescom 2013 fair in Cologne,Germany, on August 23, 2013. The Gamescom convention is Europe's largest video games trade fair. (Photo by Ina Fassbender/Reuters)

Actress Liv Tyler, 40, stripped in shots for the Triumph Essence's Autumn/Winter 2017 campaign in November, 2017. The Essence line is Triumph’s premium offering, with this season taking on the theme of “opulent Art Nouveau”, featuring designs in velvet embellished mesh, Leavers lace and silk satin. (Photo by Rankin/The Mega Agency)

Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)