This week a £1m scheme to save the 1876 River Tyne swing bridge ended in failure.
The machine room, showing one of Armstrong’s original three-cylinder oscillating hydraulic motors
First used for road traffic on 15 June 1876 and opened for river traffic on 17 July 1876 the bridge, connecting Newcastle upon Tyne and Gateshead, and lying between the Tyne Bridge and the High Level Bridge, was both a marvel of hydraulic engineering and a world record holder.
The bridge, designed by William Armstrong, allowed boats to the upper reaches of the River Tyne while letting traffic across the river. Since then it is thought to have swung open more than three hundred thousand times, letting over a 500,000 boats pass.
However, an ‘unforeseeable’ fault led to the anti-climatic culmination of the rescue scheme as crowds gathered to watch it open after 18-months of in-operation as engineers renovated its’ inner workings. The Port of Tyne authority – responsible for its upkeep – has promised a speedy repair but has left supporters worrying that the authority has allowed the bridge to fall into a state of disrepair.
The fault seems to lie with a jam in the bridges hydraulics which, today, are driven by electrical pumps. The system works around a hydraulic accumulator which is sunk into a 60 ft shaft below the bridge; the water is then released under pressure which runs the machinery to turn the bridge. The mechanism used for this is still the same machinery originally installed by William Armstrong in 1876.
It is hoped the bridge will be repaired in the coming weeks.
