Phoenix Caisson in Kent Designated - Part of the Mulberry Floating Harbour Used in the D-Day Landings
It is a large concrete structure that survives remarkably intact and is visible at low tide off Littlestone-on-Sea in Kent. It is one of only six known examples of Phoenix caissons in British waters. The others can be found in Portland Harbour, Dorset, (two caissons listed Grade II) Shoebury Ness, Essex, (scheduled) Langstone Harbour, Portsmouth and off Pagham, West Sussex.
The Phoenix caisson was built in 1943-4 as a floatable breakwater component of the Mulberry Harbour which was considered to be a major technological and engineering achievement. It was effectively a mobile port facility, designed to sink or float as necessary, and was used by the Allies to land troops and arms at Normandy as part of Operation Overlord.
Its location, stuck in sand and silt on the sea floor off Littlestone-on-Sea illustrates the logistical problems involved in the invasion, as it remains where it was 'parked' prior to D-Day after it proved impossible to re-float and tow it across the English Channel.
Veronica Fiorato, Designation Team Leader for English Heritage in the South said: "The Phoenix caisson is a tangible reminder of Operation Overlord and its vital contribution to British and world history. It has stayed exactly where it was parked during the Second World War and survives in very good condition, having lost only its anti-aircraft gun mounting."