An “unusual” sinkhole around 4ft deep and 2ft wide has been discovered next to train tracks on the Cumbrian coast.
The hole was found in the village of Harrington and the ground around it appears to be “shifting”, disrupting train services between Whitehaven and Workington.
Network Rail, which manages Britain’s railway infrastructure, said the “mysterious void” appeared on Thursday in the wake of Storm Eleanor.
Engineers working to repair rare #sinkhole on Cumbrian coast railway at #Harrington https://t.co/2xz6wz4G3p @northernassist @nationalrailenq @newsandstar pic.twitter.com/BQL3E0hq20 — The GNRP (@TheGNRP) January 5, 2018
Phil James, head of operations for Network Rail’s London North Western route, said: “Sinkholes are very unusual on the railway.
“We are trying to work out whether this one been caused by a collapsed culvert or sea erosion or both. Either way, we’ve got a big hole right by the tracks that we need to fill in.
“We’re having to run trains on one rather than two lines along this stretch while we make our repairs.
“We aim to have things back to normal by Sunday. In theory, running the railway is simple.
“But in practice, when you throw storms, wind, waves and sinkholes into the mix, it gets more complicated.”
Network Rail has recorded 50 sinkholes on the railway in the past 12 years.
What is a sinkhole?
Generally speaking, a sinkhole occurs in one of two ways. Either when soluble bedrock dissolves leaving a crater into which the ground above falls in on itself, or when a cave or man-made mine collapses with the same result.
In the UK we’re more concerned with the former. These type of sinkhole – sand washout cavitations – are more likely to occur in areas with a certain type of soil.
Dr Timothy Farewell, a senior research fellow in Geospatial Informatics at Cranfield University told HuffPost UK: “These types of events occur most commonly in sandy soils, and are very frequently associated with a leaking water main.
“This is because sandy material can be easily washed away (e.g. into sewers), when there is highly pressurised water present.
“Over time large cavities in the ground can form leading to a sinkhole.”