Trains are to begin running along the new Loughor Viaduct next week, as the £48 million replacement project nears completion.
As well as replacing the existing bridge, engineers are redoubling a 5.25 mile stretch of railway through Gowerton.
The new bridge is now in place and work is on schedule to be completed by Monday, April 8.
Mark Langman, route managing director, Wales, said: “The difficult and exciting task of replacing the Loughor Viaduct is now complete and progress with the redoubling of the five-mile stretch of line is going to plan.
“This new viaduct and redoubling of the railway through Gowerton will remove the current bottleneck created by the stretch of single line and provide capacity to run more trains in the future.
“This project joins a number of other rail improvement projects in South and West Wales that will help deliver better journeys and boost economic growth in the area.
“The new viaduct at Loughor and the redoubling, as well as the new station platform and footbridge at Gowerton are part of a package of station and infrastructure improvements to make rail travel more comfortable and attractive to the public.”
