The railway line through Caldicot was built as the
broad gauge South Wales Railway in 1850, although the nearest station was at
Portskewett, two miles to the east. In 1861 a private
siding was opened to serve the Caldicot Iron & Wire Works, from 1880 the Severn Tinplate Works, on what is now the industrial estate on the Sudbrook road, south of the
castle. In typical broad gauge fashion, these works lines used two short hand-worked
turntables to move wagons between the lines, rather than
points. In 1872, the
South Wales Railway was re-gauged from
broad gauge to
standard gauge. This underpass was originally provided to give farm access to the land of the
Caldicot Levels south of the railway and it is a mark of the passenger station's minor importance that such a restricted access continues to this day. In 1939, construction began on the
Royal Navy Propellant Factory, Caerwent. A second branch was laid from Caldicot, this time to the north east. The private siding agreements are first made in the name of the builders
McAlpine, then the
United States Army Air Forces from 1943, and only transferred to the
Ministry of Defence as the
Royal Navy in 1944. To support the increased traffic, a second crossover was constructed, together with a loop siding on the Down line. Although production at the propellant factory ceased in the 1960s, it remained an important storage depot for munitions until 1993. The branch remains in service to this day, although little used and mostly just as a storage area for railway vehicles awaiting scrapping. Most military use of the site, now as a training area, is handled by road, not rail. The original tinplate works sidings and the sidings serving the town were also taken out of use in the 1960s. Owing to later building work, no trace remains. The Sudbrook branch remains, although it is overgrown and no longer immediately usable. ==Facilities==