Experts from the University of Leicester immersed the 11th century bridges – whose ruins were so heavy they had to be carried in sections by eight-man teams – in tanks of sugar solution.
Leicestershire County Council persuaded British Sugar to provide the sticky haul in three huge delivery batches after a retired local GP found the fragile 11th century timbers in Hemington Quarry in 1993.
“Securing the viability of the bridge is testament to the natural preservative qualities of sugar,” said Dr Julian Cooper, head of food science at British Sugar.
“Our long association with the River Trent at Newark made it a privilege to be involved in the restoration of the Hemington Bridge, which once spanned the same river.
“Now we have reached the final stages of this 15 year conservation process, we congratulate the determination of those involved in safeguarding the bridge for generations to come.”