The Â£8m work on the Selby bridge and its hydraulics should end in November.
Network Rail said it was the "most significant" work done since the bridge was built in 1889 and should see it be maintenance-free for 25 years.
A landslip at Hatfield, South Yorkshire in 2013 meant the bridge work was delayed to keep a route to Hull open.
About one million cubic metres of mining spoil at Hatfield Colliery caused railway lines to buckle after it slipped in February 2013.
The repairs to the bridge will see train services through Selby affected from Saturday 26 July to Monday 8 September.
Passengers will face diversions, cancelled trains and some bus replacement services during that period.
Train operators which use the bridge said they were working with Network Rail to "minimise the disruption" caused by the work, adding that new timetables were yet to be issued.
Repairs to an ageing North Yorkshire railway swing bridge, which were postponed in June due to a landslip on another line, have begun.