SAGGING overhead wires which cancelled scores of rush-hour trains last summer are to be replaced as part of a £40billion railway shake-up.

Network Rail’s “orange army” will be replacing 1,200 metres of wire at Brentwood over the bank holiday weekend to prevent a repeat of last year’s mass delays and cancellations.

On June 30, as the mercury hit 28C, speed restrictions were imposed by Greater Anglia due to the sagging 1950s wires.

This led to double-digit cancellations.

Network Rail’s Anglia route manager Richard Schofield said: “Our work to build a bigger, better railway takes place round-the-clock, each and every day of the year.

"We’ve been careful to plan our work this bank holiday weekend to keep disruption to a minimum.”

Additionally, 550 metres of track will be replaced at Brentwood to improve reliability for passengers travelling between Southend Victoria and Liverpool Street, as well as reducing maintenance time.

Crossrail construction will also continue from Brentwood to Liverpool Street, with the old footbridge being removed from Harold Wood station and a new roof installed on the footbridge at Gidea Park station.