Tower Bridge glass walkway shatters after visitor drops a beer bottle on it Chris Earlie, head of Tower Bridge, explained that the unique design of the glass layers meant the repair job was very straightforward. He said: "We are gutted it's happened in the first couple of weeks when it's been open to the public but it's completely safe. We should have said no glass on the glass section of the floor. It was a bit shortsighted of us. A sacrificial layer of glass on the new West Walkway at Tower Bridge Exhibition shattered on Friday evening, when an empty beer bottle fell from a tray being carried by a member of the catering team during an event. The floor was immediately inspected and covered to protect guests from glass splinters. Tower Bridge Exhibition's engineering team attended the site on Saturday morning and the sacrificial glass panel was replaced on Sunday morning. The exhibition space remained open to the public as normal and no visitors were at risk. The new glass floor has four layers of glass with the sacrificial layer on top of that - this is installed so that it can be replaced if it is scratched or damaged. The walkway is one of two that will open between the north and south towers of the famous London landmark. A parallel glass floor running across the other side of the bridge is due to open early next month. Not only does the viewer get an unusual view of the river below, but also of the bridge's unique engineering as the two sections of the road open to allow large ships to pass beneath. Each glass panel along the 36ft walkway is getting on for three inches thick and weighs nearly 1,200lb. Building work began on Tower Bridge in 1886 and it took eight years to complete. The two walkways that connect the towers are designed to withstand the horizontal forces exerted by the suspension sections which tie the bridge to the land on the north and south sides of the river. In the early years of the 20th Century they were open to pedestrians who could use them to cross the river and gaze out across the capital. But they were closed in 1910 after gaining a reputation as a hangout for prostitutes and pickpockets. Around 40,000 motorists, cyclists and pedestrians use the crossing each day and the bascules or road sections, are raised around 1,000 times a year.