The Fan Bay plotting room — a concrete-walled bunker buried four metres deep within the White Cliffs of Dover — has been opened to the public through guided tours administered by the National Trust.
Origins and Design
Buried beneath a field near the Kent coast, the bunker controlled an artillery battery that defended British shores and targeted enemy ships navigating the English Channel. It was ordered directly by Winston Churchill following his July 1940 speech in which he declared: 'We have to fight for command of the straits by artillery, to destroy the enemy batteries and fortify our own.'
The plotting room housed a 1.8-metre-long electromechanical fire direction table — considered Britain’s first land-based computer-aided targeting system. This device calculated trajectories based on shell impact data and transmitted firing instructions to gun crews.
Construction and Urgency
Constructed within just over two months after Churchill's directive, the bunker was completed 64 days after the guns were ready. The speed of construction reflects an unprecedented level of urgency: physical traces such as rough wall openings for cabling remain visible at site, indicating that equipment installation occurred before official architectural plans existed.
The guns themselves became known locally as 'Churchill’s pets,' a nickname reflecting both their strategic importance and the high priority given to their deployment during wartime operations.
Declassification and Discovery
The bunker had been secretly mothballed in 1957 due to its military significance and remained classified until declassified in 1981. It was rediscovered in 2017 when Jon Stewart, who led the excavation project for the National Trust, first entered it through a hatch in an adjacent field.
"It was a Tutankhamun moment for a conflict archaeologist," said Stewart. "We had done all this research on the people who served there, and then suddenly you’re standing in their office. It was an exciting moment."
The discovery reminded him of the 1990s rescue of Bletchley Park — a codebreaking site whose existence remained unknown until later revealed as part of national heritage.
Operational History and Personnel
Up to ten individuals could work at the plotting room simultaneously. The identities of only a few operators are known: Wallas Eaton, an actor best remembered for his role as Senator Ludicrus Sextus in the TV series Up Pompeii, and WP Bryant, a lance bombardier who was also a tailor reportedly skilled with numbers.
The records of personnel remain sparse. Stewart has expressed interest in contacting descendants or relatives of those who served there, noting that 'what we know about it is based on a manual and ghost markings on the floor.' He hopes personal accounts will help reconstruct how the machine functioned during operations.
Preservation and Site Features
The bunker has been preserved exactly as found — without reconstruction or modernization. Remnants include old newspapers, discarded shoes, official notices, and chalk graffiti on one service tunnel reading: "heroes fan hole Dodds and Petitt".
"They were probably self-appointed heroes responsible for marshalling horrible thick cable through particularly uncomfortable tunnels," Stewart said.
This preservation allows visitors to experience a tangible connection with wartime technology and personnel. The site stands as an example of how military infrastructure was both advanced and human at its core.
All information presented is derived from the National Trust’s excavation report and public statements by Jon Stewart. No independent verification or third-party confirmation has been conducted beyond these sources, though the physical evidence remains consistent with historical records of WWII coastal defences in southern England.