England's Historic Seascapes: Southwold to Clacton
Oxford Archaeology (South), 2007. https://doi.org/10.5284/1000277. How to cite using this DOI
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Resource identifiers
- ADS Collection: 746
- ALSF Project Number: 4729
- DOI:https://doi.org/10.5284/1000277
- How to cite using this DOI
England's Historic Seascapes:
Southwold to Clacton
ALSF Project Number 4729
Oxford Archaeology, 2007
Kentish Knock and Knock Deep
Primary Subcharacter Type:
Caution area
Main Character / current form and use
This area is one of several pairings of sandbank and channel off the North Essex coast which form a series of treacherous navigational features and hazards in one of the major approaches to the Thames. The pairings are considered together due to the dynamic nature of sandbanks. The area is currently predominantly characterised as a dredging area, generally avoided by shipping, though traversed by a limited number of commercial vessels, mainly dredgers. The dredging area known as Long Sand is licensed to Britannia Aggregates, Cemex UK Marine, and United Marine Dredging. Recent studies indicate the area is no longer heavily used (London Array 2005).
The area is used by recreational traffic and has limited fishing activity. The latter is likely to be related to the presence of aggregates dredging, as dredged areas are temporarily closed to fishing. This restriction usually covers a small proportion of the licensed area depending on demand for aggregates (Rogers 1997). The very northern part of the area contains a junction of Royal Yacht Association (RYA) routes, heading out to sea and into coastal waters. The area is also a potential recreational dive site.
Kentish Knock is a recognised shipping hazard and the area contains 18 dangerous wrecks, most clustered around the sandbank. The area is subject to restrictions based on draught, changing depth and high speed craft and is covered by Vessel Traffic Services (VTS). Depth in the area reaches up to 30 m but decreases to 0 m at Kentish Knock. Around the sandbank sediment is mainly gravelly muddy sand with gravel in the deeper areas of Knock Deep. The tidal range in the character area is mainly within the range of 4-5 m at Mean Spring Tide (DTI 2004).
The character of the area is soon to be significantly changed by the construction of the London Array wind farm which will cover the southern part of the character area, continuing to the south. The land was leased to London Array Ltd in December 2003, the company comprises Shell Wind Energy Ltd, E.ON UK Renewables and CORE Ltd. The development is expected to be the world's largest offshore wind farm (London Array 2006), containing up to 271 turbines over an area of c 245 km�. This will include the areas known as Long Sand, Kentish Knock and Kentish Deep. The wind farm is expected to have a capacity of 1000 MW, enough to supply all the homes of Kent and Sussex or one quarter of Greater London (London Array 2005), with an onshore substation out of the study area. The development is expected to be completed in 2010 and London Array Ltd. has a 50 year lease (ibid).
The area was chosen due to its excellent wind regime and lack of heavy traffic requiring minimal re-routing. The turbines will be up to 100 m above sea level but are not expected to significantly impact upon the landscape from shore due to their distance from it (20km). At sea safe zones will be set up for recreational traffic, though fishing will be restricted. Physical impacts will include seabed disturbance by erection of turbines, and placement of cables 0.5-3 m below the seabed.
Historic Character and archaeological potential
Kentish Knock and Knock Deep are marked on the Admiralty chart of 1855 and the former is a recognised shipping hazard. Known wrecks include HMS Leandros, mined while on Admiralty service and Birgit, on passage from London to Stockholm, also mined. Records suggest that The Colchester, a 4th rate fighting ship was lost on Kentish Knock in 1744. One of the most famous wrecks lost in the area was that of the Deutschland (see link).
Kentish Knock is also known as the site of the battle of the same name which took place in October 1652 during the First Anglo-Dutch War. A total of 68 English ships led by Robert Blake met the 62 ships of the Dutch led by Witte de With. The English ships were larger and better equipped than the Dutch who were fighting amongst themselves and finally withdrew.
The Albert Close fishing chart of 1953 records that this area was good sole ground in the summer.
Kentish Knock was the original home of pirate station Radio Caroline (see link). begun in 1964. The station moved in 1967 after the territorial waters boundary was shifted from 3 to 12 miles.
As a result of its rich maritime heritage the area has high potential for shipwrecks and lost artefacts. In addition the area has potential to contain submerged prehistoric landscapes, features or artefacts, having been dry land prior to 8000 BP. However, no investigation work is known to have been done in this area.
Character perceptions
The character area of Kentish Knock and Knock Deep is well-known due to the hazardous nature of the sandbank and is generally avoided by shipping as a consequence. It is of historic and cultural significance as the location of the Battle of Kentish Knock, the first home of Radio Caroline and the location of the tragedy of the Deutschland.
The perception of the area is likely to change significantly with the construction of the London Array windfarm, which will dominate a large area of the sea. The impact on sailing and shipping is likely to be minimal though commercial fishing will be adversely affected. The construction of the London Array wind farm may impact upon the archaeology of the character area and has the potential to inform. The project could have far-reaching socio-economic consequences for the local population. Many local residents and businesses have made their support for the project known.
Bibliography
DTI, 2004, Mean Spring Tidal Range: Atlas of UK Marine Renewable Energy Resources. Department of Trade and Industry, 2004
Jarvis, S., 1990, East Anglia Shipwrecks. Countryside Books
London Array. Non-Technical Summary, London Array Ltd. June 2005
London Array Newsletter, December 2006
Rogers, S. I., 1997, A review of closed areas in the United Kingdom Exclusive Economic Zone. CEFAS Science Series Technical Report No. 106
Hopkins, G. M., 1918, The Wreck of the Deutschland http://www.bartleby.com/122/4.html (07/03/2007)
