It won't be strong enough for people to drive cars over. Experts are still looking at way to solve that problem.
The bridge in Cumbria will look like this one in Huddersfield
Some drivers could be in trouble after cameras spotted them removing road safety signs and barriers on the Calva Bridge so they can drive across. There are worries the bridge could collapse, so it has been closed.
Some 200 soldiers will be involved in the operation to create the new footbridge, including the Royal Engineers, Royal Logistic Corps, Royal Signals and Royal Military Police.
On Friday, the funeral of Pc Bill Barker, who died helping motorists off a bridge in Cumbria, took place.
More than 500 people attended the public service in his home town of Egremont.