 The SER was granted permission to build a line from Ashford in Kent to St Leonards , East Sussex in 1845 . The LBSC reached St Leonards from Lewes the following year . This gave the LBSC a shorter route to Hastings than the SERs route , then still under construction . The SER sought permission to extend their branch from Tunbridge Wells across the High Weald to reach Hastings . Authorisation for the construction of a 25 @-@ mile @-@ 60 @-@ chain ( 41 @.@ 44 km ) line to Hastings was obtained on 18 June 1846 , Parliament deemed the line between Ashford and St Leonards to be of military strategic importance . Therefore , they stipulated that this line was to be completed before any extension was built from Tunbridge Wells . The extension into Tunbridge Wells opened on 25 November 1846 without any public ceremony . In 1847 , the SER unsuccessfully challenged the condition that the line between Ashford and St Leonards be completed first . That line was opened in 1851 , passing through Hastings and making an end @-@ on junction with the LBSC line from Lewes . 
