More on KentOnline
Trains have been delayed through Kent today after damage was discovered under the tracks between Gravesend and Higham.
Southeastern said trains could not run between the stations when a drainage channel at Denton partially collapsed this morning.
It led to severe delays on trains between Charing Cross and Gillingham for several hours.
Network rail said trains were stopped from running at 11am when the damage was spotted by a member of staff.
Workers were able to shore-up the partial collapse, which Southeastern originally said was a landslip, and the track was reopened in about an hour.
The line was reopened shortly before midday, but disruption was expected throughout the afternoon - with some services cancelled, delayed or revised at short notice.
Delays of about 15 minutes were still being experienced by passengers at 2pm.
Southeastern said an emergency speed restriction has been put in place.
This will be in force until a full repair is completed over the weekend.
Replacement buses were running between Gravesend and Rochester in both directions for about an hour from midday.