Welwyn North railway station

Construction of the station and viaduct began in 1848 and the line was opened in 1850 as part of the Great Northern Railway. It was called Welwyn Station until 1926, when it was renamed following the opening of a new station for . It was built by contractor Thomas Brassey out of red brick produced locally from the Welwyn Brick Fields at Ayot Green. The viaduct is built on floating foundations as the bed of the Mimram Valley was not stable enough for normal ones. These floats consisted of timber beams filled with burned chalk onto which the towers were built. The tunnels were hand-dug by the thousands of manual workers, mainly Irish, for whom a new tented village was built centred on the…