A TWO-YEAR, £21million programme of repairs and improvements to Sevenoaks Tunnel in Kent is almost complete.
The 150-year-old tunnel is one of the longest in southern England and has long been a source of delays because of its poor condition and flooding, caused by inadequate drainage.
However, Network Rail has installed new drainage systems since 2017, and replaced several thousand sleepers and several miles of track to improve conditions in the tunnel.
Engineers have also partially lined 13 ventilation shafts, some of which are more than 120m deep, to prevent water below the Sevenoaks Weald flooding tracks deep below.
Completion of the main works over the Christmas and New Year period has allowed NR to eliminate a long-standing speed restriction and raise line speeds from 50mph to 90mph, cutting journey times through the tunnel by more than a minute.
Read more in the February 2019 issue of The RM – on sale now!