Hampshire landslip
Line in a deep cutting closed to traffic after landslip following a period of intense rainfall.
A landslip in a deep cutting closed the South Western Main Line between Winchester and Basingstoke from August 27-29.
As at Carmont in Scotland earlier in the month, a sudden debris flow followed a brief period of unseasonal and intense rainfall. A volume equivalent to the average rain for the whole of August fell in less than four hours.
The landslip occurred at the southern portal of the
0.5km Wallers Ash Tunnel near Micheldever.
A large volume of mud, water and debris collected high above the tunnel and spilled suddenly down the steep slope. A Cross Country service struck the debris at around 1730, with the front of the train sustaining minor damage. It took more than
three hours to disembark the 50 passengers on board. There were no injuries.
Although only five miles north of Winchester, the tunnel is in a rural location with no road access. Contractors were only able to reach the site after cutting through thick vegetation and abseiling down the slope on ropes. They found a large volume of unstable material requiring removal.
There was no previous record of landslips at this location and the slopes were previously regarded as stable. However, there were many other flooding incidents in the surrounding area of Hampshire on the same day, including blocked roads and shops under water in Winchester city centre.
Network Rail’s Wessex Route Director Mark Killick said: “We appreciate this has caused a lot of disruption on one of the busiest sections of railway in southern England for both passengers and freight. This is a challenging location, with inspection carried out by engineers reaching the slip by descending on ropes.
“It certainly appears to have been caused by a very large amount of water flowing after torrential rain and washing a lot of mud and debris across both tracks. But it is too early to say exactly how it happened. We have been working around the clock to make the site safe.”
Some South Western Railway services were diverted via Havant and Cross Country trains were diverted via Andover and Laverstock, each adding an hour to journey times. Replacement buses ran between Basingstoke and Winchester, with some passengers complaining about a limited service.