Malky, in your 2nd link it refers to the bridge as being a General Wade bridge, as is the bridge at Newton.
General Wade was Commander in Chief of the army in northern Britain. He went to Scotland in 1724 and was in charge of the building of 240 miles of roads and 30 - 40 bridges to try andcontrol the Jacobite rebellion. These are known as Wades roads. It is said he used the same wooden former for many of his bridges, so they have the same arch span etc. There could be a possibility it is one of his bridges, or on the other hand, maybe not.

Pat
edit. I've just seen your 3rd link is a Wades bridge too !!