Gateshead Millennium Bridge

Gateshead Millennium Bridge Gateshead Millennium Bridge is the world's first and only tilting bridge, and was designed by the structural engineering group Gifford and the architectural firm Wilkinson Eyre, the bridge takes its place at the end of a line of distinguished bridges across the River Tyne, England, including the Tyne Bridge and Robert Stephenson's High Level Bridge.Gateshead Millennium Bridge first tilted in June 2001 and was first opened to the public in September that year.The very top of the arch stands 50 metres above the River Tyne when in its normal state. This bridge is also known as “The Blinking Eye Bridge” and “The Winking Eye Bridge”. This nickname is provided because of its appearance when it tilts over, for allowing water transport. During maximum tilt, the angle between the two arches of the bridge will be 40°. This is the first tilt bridge in the world that uses hydraulics for operation and it cost £22m for its construction. The largest floating crane, the Asian Hercules II was used to place the offsite constructed bridge into place. It has a total length of 126 m (413 ft) and a width of 8 m (26 ft). The top arch of the bridge stands about 50m (164 ft) above the river level. The bridge takes four and a half minutes for each opening and closing. Other than allowing river traffic, it opens periodically for sightseers and for major events. In 1996, Gateshead Council launched a competition to find a bridge that would link developments on both sides of the River Tyne and also complement the existing six bridges crossing the river.There were over 150 entries. Gateshead residents voted for their favourite design from a shortlist of leading architectural companies.The brief was to create a bridge for pedestrians and cyclists that: ● Allowed ships to pass underneath; ● Did not overshadow the world famous view of the existing bridges; ● Didn't obstruct the Quayside Gateshead Millennium Bridge Design and Working: The bridge is made up of a pair of steel arches connected with a series of suspension cables. The deck consists of a pedestrian and cycle path(one foot below the pedestrian path) and the other arch will support this deck by forming an ark.The bridge is designed in such a way that it can clean up its own litter during each time it opens. Gateshead Millennium Bridge working is based on hydraulics. It contains eight hydraulic motors, a hydraulic pump and six hydraulic rams. Ends of the deck and the arch will meet at a trunnion(a horizontal cylinder). The trunnion is connected to a steel paddle that connects with hydraulic rams. Hydraulic Ram for Gateshead Millennium Bridge makes the tilting operation safer and smoother by pushing water against them. Whilst small river craft can sail beneath the bridge, for larger craft the cable-stayed double arched structure pivots at the abutments through an angle of 40 degrees to give the 25m navigational clearance as specified by the client, Gateshead Borough Council. Powered by eight electric motors, it takes approximately four minutes to rotate the 850 tonne dead weight of the structure to its fully open position.

When raised the suspension cables lay horizontal holding the pair of arches together. Huge 14 tonne castings on either side support bearings which withstand the outward and radial thrusts imposed. The 130m long bridge deck is parabolic in elevation. It carries a pedestrian footway that varies from 3m to 5m in width as well as a 2.5m cantilevered cycleway. The main arch is also parabolic in shape and tapers both in plan and elevation. source:https://www.lusas.com “Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry(1900-1944),french writer,aviator