Train services between Horsham and Dorking have been cancelled this morning (April 13) after a landslip blocked all lines.
Network Rail said around 100 tonnes of mud, grass and trees slid onto the tracks at Holmwood, in Surrey, yesterday.
Nearly 20 tonnes has been removed as engineers worked throughout the night and this morning but the embankment remains unstable with more slippages occurring.
Network Rail said all lines have been affected and they are expected to remain closed until the end of today.
Southern Rail has put on replacement bus services between the two stations, departing every 30 minutes.
Shaun King, Network Rail interim chief operating officer, said: “Our team has worked hard through the night to remove more than 20 tonnes of debris from the tracks, but there’s still a huge amount more to do. It’s a challenging location but we’re absolutely focused on getting the railway back open for Southern passengers as quickly and safely as possible.”
A Southern spokeswoman added: “We apologise to those impacted by this incident. To help passengers keep moving, a replacement bus service has been in place since 05:00 this morning - in both directions - and continues to depart every 30 minutes, calling at all stations. We also have ticket acceptance in place with South Western Railway between Dorking and Clapham Junction. We encourage passengers to allow extra time for their journeys today.”
An emergency response team was sent to the site after the landslip was spotted by a train driver. One line was kept open initially but further slips led to both lines being closed.
Engineers are using a range of equipment including a crane and road-rail vehicles to remove the debris. Once removed the embankment will be stabilised to allow the tracks to reopen.