 The construction of the line between Tunbridge Wells and Robertsbridge was contracted to Messrs. Hoof & Wyths , subcontracted to Messrs. H. Warden . By March 1851 , the trackbed had been constructed as far as Whatlington , East Sussex , a distance of 19 miles ( 30 @.@ 58 km ) . All tunnels had been completed and a single line of railway had been laid for a distance of 10 miles 40 chains ( 16 @.@ 90 km ) from Tunbridge Wells . When the 15 @-@ mile @-@ 40 @-@ chain ( 24 @.@ 94 km ) section from Tunbridge Wells to Robertsbridge opened on 1 September , a single line of track extended a further 4 miles ( 6 @.@ 44 km ) to Whatlington . On the 6 @-@ mile ( 9 @.@ 66 km ) section between Whatlington and St Leonards , 750 @,@ 000 cubic yards ( 570 @,@ 000 m3 ) out of 827 @,@ 000 cubic yards ( 632 @,@ 000 m3 ) had been excavated . Construction of the line between Tunbridge Wells and Bopeep Junction cost in excess of £ 500 @,@ 000 . 
