Engineers continue work to create a controlled land slip near Teignmouth where about 20,000 tonnes of cliff face sheared away above the track in early March.
With the help of Devon and Cornwall Fire and Rescue Service, engineers have been spraying thousands of litres of water every minute onto the slip to encourage it slip to complete its fall to the railway below.
A Network Rail spokesman said: "After consultations with Cornwall’s china clay industry, we've brought a high pressure water cannon onto site that is proving very effective at turning the red earth of the slip into slurry that’s running off into the sea at a tremendous rate.
"Specialist army equipment and excavators may also be brought in to assist once more of the unsafe slip has been washed away.
"Everyone is working flat-out and we've made good progress, but the coming week will be critical if we are to meet our planned reopening date of 4 April."