By David Grundy
BBC Wales news
Barmouth Bridge will close for 12 weeks as the last part of its £30 million refurbishment gets underway.
The bridge carries trains on the Cambrian Coast line over the Mawddach Estuary and is important for the tourism industry in the area.
It will be closed from 2 September until 24 November.
Bus services will be used to carry people while the 150-year-old structure is repaired.
The bridge has a Grade II listed status, but the timber elements had decayed significantly over the years. A large proportion of the metallic elements had also corroded.
Eleri Evans, the senior quantity surveyor for the three-year refurbishment project, said: “We’ve had to approach the design throughout to construction with a sympathetic feel.
“This has come down to the small details involved in the bridge.”
Gareth Yates, project manager for Network Rail, said: “It’s a challenging environment, definitely our main obstacle is wind.
“We know the importance of the structure to the local economy so we undertake the works outside of the main holiday season.
“But then we have to couple that with making sure that we are not doing it in the worse of the weather at the same time.”