Part of a landmark railway bridge is to be demolished this month.
The Vicars Bridge, which connects East Cliff with the Lancashire County Council offices in the former Park Hotel, Preston, is the last surviving remnant of the former Butler Street station.
The girder and lattice bridge, which dates back to 1848 and is in a Conservation Area, has corroded badly in recent decades.
It is now set to be pulled down, three years after plans were first submitted by Network Rail to Preston Council.
A separate Bailey bridge, which sits within the old structure and was erected in the 1950s to carry cars and pedestrians, will remain.
Trains on the East Lancashire Railway once passed under the bridge when travelling between Bamber Bridge and the Butler Street Station.
Today it remains at the far end of what is now Fishergate car park, but it is almost 40 years since a train has passed under it, has rusted and buckled to the point that it must be removed for safety reasons.
Network Rail sent out a letter to businesses explaining it needed to undertake “essential improvement works” to provide a “safe, reliable and efficient railway fit for the 21st Century”.
Preparatory works have begun, with the majority of works being carried out from Monday to Friday, between 7.30am and 6pm, until April 5.
However, the letter said: “Safety is our priority and for this reason some stages of the demolition work must be carried out while the road is closed. Unfortunately this means carrying out some of the improvements during the night and over the weekend.”
Network Rail said that from midnight on Saturday, March 16 to 5am on Monday, March 18, there would be work involving “lighting, generators and hand-held power tools” with “two large cranes and large steel cutting shears” during some periods.
The letter added: “The equipment we use means some disturbance is unavoidable, but we will make every effort to minimise any unnecessary noise. Furthermore, those working on site are briefed on working responsibly in the local community.”
Lancashire County Council expects ‘minimal’ disruption for those using its remaining children’s and adults social care services within its offices at the former hotel.