Summary

Phoenix caisson. Built in 1943-4 as part of the 'Mulberry' floating harbour.

Source: Historic England

Details

The monument comprises a single Phoenix caisson, resting on the sea bed and exposed at low tide. It is approximately 200 ft (61m) in length, 32 ft (10m) wide. The height is unclear from current information but, depending on the type of caisson, will be between 24 and 60ft high (7-18m). It is constructed of a steel framework with concrete base and walls around 0.3m thick. The interior is divided into nine sections, open to the sky. These are further divided by a spine wall creating 18 square cells. Some of these retain their diagonal steel tension bars. Later navigation lights are mounted at the four corners on steel posts.

EXTENT OF SCHEDULING
The scheduled area is restricted to the structure of the caisson itself. A protective margin is not considered necessary as it is thought unlikely that any archaeology relating to the positioning and attempted re-floating of the caisson in June 1944 exists on the sea bed.

EXCLUSIONS
The four navigation lights and their mountings are excluded from the scheduling.

Source: Historic England

Reasons for Scheduling

The Phoenix caisson off Littlestone-on-Sea, built in 1943-4 as a breakwater component of the pre-fabricated Mulberry Harbours which were a key element of the Normandy landings, is scheduled for the following principal reasons:
* Historic interest: as a tangible reminder of Operation Overlord and its significance to national and world history. Its location off Littlestone-on-Sea is illustrative of the logistical preparations and problems involved in the invasion as it remains where it was ‘parked’ prior to D-Day after it proved impossible to refloat and tow it across the Channel;
* Innovation: as a component of the innovative feat of engineering which enabled the transport and construction of a vital pre-fabricated port facility, the Mulberry Harbour, off the coast of Normandy;
* Rarity: it is one of only six known examples of Phoenix caissons in British Waters;
* Survival: it survives remarkably intact, having lost only its anti-aircraft gun mounting and other metalwork, and retains its structural integrity.

Source: Historic England

Sources

Books and journals
Hartcup, G, Codename Mulberry: The Planning Building and Operation of the Normandy Ha, (2006)
White, B, The Artificial invasion harbours called Mulberry, (1980)
Websites
“The difficulties will argue for themselves”: Mulberry Harbours and the D-Day Landings, accessed from http://pw20c.mcmaster.ca/case-study/difficulties-will-argue-themselves-mulberry-harbours-and-d-day-landings
The Mulberry Harbours, accessed from http://www.ukho.gov.uk/Media/News/Pages/Mulberry-Harbour-survey.aspx

Source: Historic England