(All photos © Josh Gibbens)
In 1845 the South Eastern Railway was granted Royal Assent for the construction of a line from Tonbridge to Hastings via Tunbridge Wells. The steeply-graded 5¾-mile northern section opened in September 1845 to a temporary terminus at Jackwood's Spring. This was extended into the centre of Tunbridge Wells on 25th November 1846.
The southwards expansion of the SER's network caused alarm bells to ring in the headquarters of the London Brighton & South Coast Railway. So the company drew up plans for its own line into Tunbridge Wells from the west, authorised by a Parliamentary Act on 7th August 1862. Only after three inspections did the Board of Trade approve its opening, welcoming traffic for the first time on Monday 1st October 1866.
The SER's intention of building its own line to Eastbourne - which would rival that of the LB&SCR - prompted the establishment of a single-track connection between the two networks. Just over half-a-mile in length, this opened to goods traffic in 1867; a through passenger service was not inaugurated until January 1876.
A sandstone spur was penetrated by a 183-yard tunnel which follows a straight course except for a slight curve to the north at its eastern end. Horseshoe in profile, it features a red brick lining of five rings - 15'7" high and 13'9" wide at track level. There is 65 feet of cover above the tunnel. Refuges are provided on alternating sides at 22-yard centres. These are generous in size, measuring 6' wide, 5'7" high and 4'3" deep.
When Grove Junction was removed as part of British Rail's 1983 upgrade to the Tonbridge-Hastings line, the decision was taken to close the route. The last train ran through Grove Tunnel on 6th July 1985.
Despite the withdrawal of its maintenance regime, the structure remains in reasonable condition. Severe spalling affects the northern wing wall at the west portal. The sections within 25 yards of each entrance are wet and numerous patch repairs have taken place in these areas.
An investigation into the tunnel's condition was carried out by Mott MacDonald in 1997 as part of a feasibility study into the possible reopening of the Tunbridge Wells-Lewes route. This found that around £81k worth of repairs were needed to bring the structure back into operational use.