Decided it was time to look stuff up. The Porthmadog Britannia Bridge is older by about 35 years than the Anglesey version. Admittedly less impressive, but it did carry rails for most of its life. Both Britannia bridges have been rebuilt.
Don't forget the Britannia Bridge at Lower Ince, Wigan, that carries the A573 over the Leeds and Liverpool Canal. No railway angle though.
