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About St. Mary's Island, Chatham

St Mary's Island, is part of the Chatham Maritime development area in Medway, Kent. It is located at the northern end of Chatham, adjacent to Brompton and Gillingham. Once part of the Royal Dockyard, Chatham, St. Mary's Island is divided from mainland Chatham by three basins, one used by Chatham Docks.

In the late 1990s, the South East England Development Agency (SEEDA) and housing developer Countryside, came together to build homes on the island, under the development name Countryside Maritime Limited. In due course, some parcels of land were allowed to be developed by Redrow and Barratt Homes. Until 2011, the island remained separated from the mainland by two lifting bridges. The main road and pedestrian bridge is now fixed in place.

As well as several hundred new homes, there is a primary school and community church, a community centre, a doctor's surgery and a late-night pharmacy. There is extensive open space between housing parcels, as well as sports fields and play areas.

There are riverside walks and cycle paths on the island, and many of the paths in the middle of the island give views of the surrounding area.

South of the island (on the mainland), a number of restaurants and other amenities have opened. Nando's, Pizza Hut, Subway and the Dockside Outlet Centre shopping precinct are all within a five-minute walk. This also includes a local grocery shop and The Ship and Trades public house (a Shepherd Neame outlet). The western lock basin (Basin 1) now houses a 300-boat marina.

Since 2008, with the growth of the island community, the youth club "The Island's Castaways" has been established, providing many activities for children. Also, for retired members of the community, there is St Mary's Island Active Retirement Association (SAINTARA) that has been successfully running since 2008. From January 2012 the Maritime WI (Women's Institute) is also based in the Community Centre.

Sector Map

St. Mary's Island was developed out in a series of Sectors.

This map shows the various sectors.


Development history of the area

The three dockyard basins are sited on St Mary's Creek, which passed from the River Medway, near Gillingham to the River Medway (again) near Chatham. In 1575, the creek was blocked with stakes, as a defensive method against the Spanish forces. In 1585, a chain was placed across the River Medway, secured on the island and linked with a wheelhouse at Upnor Castle. It would have been raised in times of danger. In the 1600's, a fort was built at the mouth of the creek, since the creek was now a passageway to the thriving dockyard. The fort had 54 guns of various calibres, but it has since been demolished. It was called Gillingham Fort. In 1663, Samuel Pepys mentions St.Mary's Creek, twice in his famous diaries, while travelling towards the Dockyard.

A map of the dockyard in 1746 shows the marshland of the island, but it also shows a small mast pond, a reed house and timber storage land had been constructed on the north banks of the stream.

During the Napoleonic Wars, St. Mary's Island was used as a burial ground for the French POW's who died on the prison hulks moored in the Medway. The bodies of the prisoners were exhumed, and then re-interred in the grounds of St George's Church, now the St George's Centre (within the grounds of the Universities at Medway).

In 1847, 19 Acres was purchased by the Crown to enlarge the dockyard. Then in 1854, another 185 acres were purchased. This meant the whole of the island was now in the hands of the Crown and the dockyard.

Between 1854 and 1856, St Mary's Prison was built on the island. It had approximately 1,700 prisoners and staff of 232 (including 117 armed wardens). The prison was demolished in 1898.

In 1862, the dockyard was again re-modernised by engineer John Rennie the Younger. Most of the new work concentrated on St Mary's Island. Which had been recently purchased by the admiralty for the new works. This included the three huge basins along the creek, linked by passageways. This shortened the time taken to reach the dockyard from Sheerness. A plan was also drawn-up for the bend of the river to be converted into a 50-boat basin. This was estimated to cost too much and was rejected. The spoil from the basins was spread across the island, filling the marshes. Also machine shops and 4 graving docks (a form of drydock) were built. A sea wall was built around the island, using convict labour. At one-time there were over one thousand prisoners working on the site.

A timber landing jetty was constructed beside the seawall, so that materials could be off loaded from ships. Blue Gault clay came from Burham and yellow sand from Aylesford. A 21 acre brickfield was also built on the northern end of the island for the docks. The brick earth came from the digging out of the basins. This was mixed with imported material. More than 23,000 bricks were made each week, and about 110 million bricks were manufactured overall.

Sixty-foot timber piles were driven into the marsh ground, to form the stable foundations of the basins. The excavated earth was then transported by tramways and spread over the island marshes. This subsequently raised the ground level, to approx. 6 ft above the high water mark at spring tide of the river Medway. Portland Stone was shipped in and used to face the sides of the drydock.

In 1871, the 1st phase of work was completed, but it took until 1885 for all the work to be completed. An official opening took place on 26 September 1885.

In 1940, during the Second World War, the island was used as a training ground for mock battles, which were staged against the dockyards. More than 2,000 incendiary devices were dropped on the dockyard during the war. In December 1940, a bomb hit a factory and caused the death of 8 workers and injured 63 others.

In 1984, the dockyard was closed after mainly being used to maintain the Royal Navy's fleet of nuclear submarines. The huge site was then broken up into three large zones. The largest zone was for the historic section of the dockyard, now the Chatham Historic Dockyard. The next zone (including St Mary's Island, and No 1 and No 2 Basins) was to be re-developed as residential and commercial accommodation. The final zone, of No.3 Basin and the lock gates, was taken over by the Medway Ports authority and is now a commercial port.

The Urban Regeneration Agency was responsible for land acquisition and major development projects, particularly difficult ones, in the case of St Mary’s Island in joint partnership with private sector developers. St. Mary’s Island was a particularly difficult project (overseen by the South East England Development Agency – SEEDA) because at ground level the Island was made up from waste materials from the Royal Naval dockyard and brickworks. SEEDA set about determining the nature and level of such wastes as an absolute priority. A detailed research plan to test the ground across the whole of the Island was therefore put into effect, extensively testing and retesting soil and water samples.

Once the testing process was completed, a programme of work was begun to bring the Island up to the most stringent levels recommended by Government safety guidelines. Over a three-year period 1.2 million cubic metres of soil was taken away from the site and replaced. The extent of the clean-up operation and the attention to detail with which it was carried out can best be illustrated by the fact that for virtually three years, every four hours, twenty-four hours a day, a train left the site carrying away soil and unwanted deposits in covered containers. Because the dockyard was the site of nuclear submarine maintenance, radiological testing was carried out by the Ministry of Defence and English Partnerships and checked annually thereafter by an independent assessor.

All these works were a considerable expense to the Government, so the regeneration of St Mary’s Island became more than just a building project. It was going to be a grand scheme to create a new way of life for people who valued tranquillity, harmony and community. St. Mary’s Island has the unique distinction of being Britain’s first and only strategically planned island community.

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