Train lines from East Anglia to London are back in operation today following a 10-day closure to replace track and install new overhead lines between Shenfield and Chadwell Heath.

However there were delays and cancellations for rush-hour travellers because Network Rail had problems running electric power through the new overhead lines.

Installation work on the overhead lines was actually completed ahead of schedule on Monday night, but when the engineers handed them back to Network Rail’s operational team there were difficulties running power through the new wires.

These problems were eventually solved just before 5am – but by that time the first trains were due to be running and empty trains were due to be travelling from their depots to stations to pick up the first passengers of the day.

That meant there was serious disruption to services until about 7am – with knock-on problems until mid-morning with many trains running up to 10 minutes late.

A spokesman from Greater Anglia said services from Ipswich, Braintree, Clacton-on-sea and Norwich are returning to normal but there was a further problem after a passenger was taken ill on a train – causing it to be delayed and blocking routes into London for several minutes.

The problems came on the day that passengers saw fares for season tickets and some other tickets go up by an average of 1.8% on the Greater Anglia network.