Tide mill
A tide mill ( less commonly Tide ( s) or mill called tide mill) is periodically driven by tides in coastal areas with sufficient tidal range. It is related to traditional water mills and can be used all year round.
Operation
Tidal mills were usually in the mouths of tidal rivers, far enough from the sea to avoid negative influences of the wave passage, and close enough to take advantage of the tidal range. Flooded area, or part of an estuary was made into a reservoir by a dam with a sluice. The tide flows through the lock which closes automatically when the tide goes back into the mill pond. At low tide you can leave the pent-up water flow back through the mill wheel.
Dissemination
Tide mills are found on the coasts of the Atlantic between the British Isles and Portugal ( Alhos Vedros, Corroios, Mourisca, Olhão ) in Europe. The previous earliest archaeologically documented tide mill was discovered on the grounds of Nendrum monastery on an island in Strangford Lough in Northern Ireland. It was dendrochronologically dated to the year 787. Your millstones have a diameter of 830 mm, and the horizontal wheel was able to develop a peak power of about 0.65 kW. An even older mill ( built in 619) is mentioned in the " Domesday Book" ( 1086 ) and stood at the port of Dover. Perhaps the power of the tides in England (4 mills ) and France (about 70 Moulin à marée ). They were already used by the Romans is unlikely because the Mediterranean cultures vorfanden no tidal situation. In the early Middle Ages they were used to grind grain or spices, and later as a drive for hammer and saw mills in the paper and pulp industry.
In the United Kingdom there are four tide mills obtained:
- The Carew Tidal Mill in Wales, now a museum
- In Eling or Lymington in Southampton
- On the River Lea in east London
The Tide Mill Woodbridge in the estuary of the Deben goes back to the period around 1170 and was rebuilt in 1792. It is a museum owned by the city and the public. Only the " Eling Tide Mill " still works. This mill was first mentioned in 1086; the present building dates from the 18th century. The tide mill inland on Lea River is located in London's industrial area " Bromley -by -Bow ".
In London there were many tidal mills, including two at London Bridge. In the U.S., worked for a time on the Atlantic Ocean about 750 tide mills.
In France there were once about 70 " Moulins à marée ". They are widespread in Brittany ( Ile d' Arz, Ile- de -Bréhat, La Vicomté -sur -Rance, Ploumanac, Trégastel ).
The last and long time the only tide mill in Germany the Sierkesche mill was (also Au mill called ), a water mill on the march dam at Horne castle in Lower Saxony (53 ° 30 ' 37 "N, 9 ° 35' 20" O53.5103959.588752 ). She used the power of the flood, which pushes on the lower Elbe by the Liihe to the Alte Aue. Built in 1877 the mill was rebuilt after the closure of the operation to a residential building.
Tidal power plants
In more recent times Tideenergie is used in tidal power plants. Since the end of 1966, the Rance tidal power plant works at St. Malo on the Rance river. The total of 24 turbines generate around 500 GWh of electricity, representing about 0.2 % of France's electricity needs. For the construction of tidal power plant around € 200 million was spent.