It was designed by Francis Webb, and built at the Crewe Works in June 1884, it was withdrawn from service in January 1905. I estimate that this photograph was taken around 1903.
1904 London & North Western Railway Tourist Guide North Wales United Kingdom 62p
POSTCARD - LONDON & NORTH WESTERN RAILWAY - PONT ABERGLASLYN - NORTH WALES
Pont Aberglaslyn North Wales bridge London & North Western Railway Co Postcard
1906 Windermere Looking north London & North Western Railway Co card
Aberglaslyn North Wales London & North Western Railway Co card v3