Paul Dunn, a member of the Industrial History Group of U3A, described
at our meeting on 11 November how local rail travel changed beyond
all measure in the 1860s.
Until 1862 residents of Sevenoaks had to go by road to Tonbridge
to catch a train to London (by way of Redhill).
Then the London, Chatham, and Dover Railway was extended from
Swanley to Bat and Ball, and the following year the South Eastern
Railway gained royal assent to a line from Lewisham to Sevenoaks
This required two long tunnels. The Polhill tunnel (1 mile 849
yards) was cut through the chalk of the North Downs, which was
easy to work.
The Sevenoaks tunnel, from Tubs Hill to near Weald (1 mile 1691
yards) had to be driven through the harder greensand ridge.
A fine drawing of work in the cutting at the north portal appears
in the Sevenoaks Historical Dictionary.
The thick woodland of Sevenoaks Common meant that the line of
the tunnel was not easy to survey, and work of preparation took
The thirteen access/ventilation shafts had a maximum depth of
394 feet, nearly double the depth at Polhill. Some shafts survive
in private gardens, others almost unnoticed in odd byways along
Skips on cable winders powered by horses provided access for the
navvies and for hauling up the material that had been excavated.
Excess water was brought up in tubs.
Underground flooding, where the overlying clay and soil joined
the greensand, led to the resignation of the first contractor,
but also to a new source of water for the town.
The contractor built huts for the navvies, and a tin chapel that
also served as a school. Living conditions were very bad, the
huts overcrowded, poorly ventilated, and with inadequate sanitation.
Infectious diseases, including smallpox, were rife, a serious
concern to the Nuisance Removal Committee of Sevenoaks.
The chairman wrote a letter to the Home Secretary about the disgrace,
a letter that came to the attention of Karl Marx (Das Capital,
chapter 25, an unexpected source for local history).
It took five years, but the tunnel was finally opened in 1868,
the most expensive railway project of the day.