A major landslip at the weekend has left one of the tracks of the main line from London to Basingstoke hanging in mid-air and another track damaged, after the embankment supporting it collapsed.
Network Rail has warned of ‘huge disruption’ for services west of Basingstoke, affecting places like Salisbury and Exeter.
The slip, on an embankment near Hook station, left only the up two tracks of the four-track main line undamaged.
Services have been restricted through the area, and no trains are calling at Hook, Winchfield or Fleet.
Network Rail warned that the section past the landslip will be affected for a week, but is hoping to reopen all four lines on Monday 23 January.
Wessex route director Mark Killick said: ‘This is a huge landslip and will have a massive effect. The main line to Basingstoke is the spine of our railway and there will be knock-on impacts across the route.
‘I can only apologise for the scale of the disruption and please ask that customers check before they travel.’
‘We will need to stabilise the embankment, essentially stopping it moving, and then rebuild the railway where it has slid away. We’ll keep everyone informed of our progress.’
Network Rail said the embankment is made of a mixture of London clay and other local soils, which had become saturated after days of heavy rain during a very wet winter. The slip happened when the soil gave way along a 44 metre section of the embankment, which is 10 metres high, sliding out from underneath the tracks in what engineers call a ‘rotational failure’.