sentences:  Later, the government announced plans to electrify the line, with the intention that TfL would procure a new fleet of 4-car EMUs (Class 710) for use on both this route and the inner-suburban routes from Liverpool Street, taken over by London Overground from 2015.Electrification was completed in February 2018 (later than the original target of June 2017) and as of June 2018 the Class 172 units were set to be replaced by Class 710 EMUs from November 2018 although this did not happen as planned.They were temporarily replaced by Class 378s redeployed from other parts of the London Overground network and moved to West Midlands Trains in March 2019.