This cache is not at the given co-ordinates.
The co-ordinates take you to one of the bridges over the River Tees that didn't make the cut when we finalised the bridges for the lab caches.
This is the bonus cache for our lab caches: A bridge over the River Tees Part I & A bridge over the River Tees Part II
You need to have completed these in order to aquire the final co-ordinates.