I'm not sure what you mean. There are two bridges at Saltash in
Cornwall, which cross the River Tamar. Neither is called the
Saltash bridge though.
The oldest is the Royal Albert Bridge - desigend by Isambard
Kingdom Brunel and completed in 1859. It is a railway bridge.
The other is the Tamar Bridge - a suspension road bridge built
in 1961.
If you're referring to any other bridge actually called the
Saltash bridge then I'm not sure what that is.