The Metropolitan Transportation Authority on Wednesday outlined shutdown plans for later this year on the R and G trains, a result of repairs to tunnels damaged during Hurricane Sandy.

The Montague tube, which carries the R train between Brooklyn and Manhattan, will close for up to 14 months starting the first week of August, officials said, forcing as many as 65,000 daily riders to seek alternative routes.

The train will run in two sections on weekdays, from Forest Hills-71st Avenue in Queens to Whitehall Street in Manhattan, and from Court Street to Bay Ridge-95th Street in Brooklyn. On weekends, the R will be rerouted over the Manhattan Bridge, meaning it will not stop at Court Street or Jay Street-MetroTech in Brooklyn or City Hall, Cortlandt Street, Rector Street and Whitehall Street in Lower Manhattan. Overnight, the N train, which is typically rerouted through the tunnel to replace the R, will continue running over the Manhattan Bridge.