Thread by @NetworkRailSE

Please get comfortable as this is a long thread from our MD John Halsall to explain what’s happened at #EastGrinstead and what we’re doing to get it fixed. Here goes…
We've had a landslip near East Grinstead station, so it’s not safe to run trains @SouthernRailUK @TLRailUK

We already had a smaller landslip at the same site on December 28 last year, however we were able to run trains safely by introducing a 20mph speed restriction. Since then we’ve been monitoring the embankment closely and designing options for a long-term fix.

However, the recent severe weather as a result of Storm Ciara and heavy rain overnight yesterday has beaten us to it, because the ground has started moving again and the embankment has got worse.

I know this will be really frustrating for you, our passengers, but it’s a decision we’ve had to make for your safety. The landslip was detected by sensors in the ground which alert us, so we can close the railway quickly and keep you safe.

As soon as we found out, we sent geotechnical experts to assess the damage and see if it was possible to run trains using just one track, before a planned closure to fix the embankment. However, we decided against this as it wasn’t the best thing for passengers.

Instead trains are still travelling to Oxted and Hurst Green, but buses replace trains between Hurst Green and East Grinstead.
From tomorrow though, we will be able to run a two trains per hour service between Lingfield and London Victoria, all day.

During the peaks, we will be able to run up to 3
12-car Thameslink trains between Oxted and London Bridge. These travel arrangements are subject to change though, so please continue to check with @SouthernRailUK or @TLRailUK before you travel.

The railway does need to close for a longer period to fix it permanently. This means we can get in and do the repairs properly, rather than carrying out a temporary fix and risking even further deterioration to the embankment that might force a longer closure.

I’d love to be able to tell you when the railway will be open again so you can plan ahead, however it’s simply not possible at this stage. First, we need to assess the damage properly to see what kind of fix is required.

Then we need to adjust our plan because this latest slip means our response needs to change, including how we mobilise contractors, resources, plant and machinery. Once we have that plan, we can give you a more definitive timescale.

But it does look like it could be a while. That’s because it’s a complicated repair. Due to the remote location of the landslip, we need to build an 800-metre haulage road just to bring materials and machinery to the site.

To avoid destabilising the embankment even further, we’re not going to use the typical sheet pile wall – this is where steel beams are vibrated into the ground. Instead we hope to build a 2,000 tonne base at the bottom of the embankment, dug down 2.5 metres deep into the ground.

We will then build a series of benches, much like this solution at Edenbridge, ready for more stone to be added later to rebuild the embankment and prevent further slippage. The bench-like formation allows materials to be ‘keyed’ into the slope, much like Lego blocks connect.

As soon as we have more information, we will update you on the timescales. Once again, I’m really sorry but I want to reassure everyone that we’re doing everything we can to put things right.