BRABANT FIGHTS AGAINST WATER
Oosterschelde
Oosterschelde barrier (Eastern Scheldt barrier)
The
largest, most expensive and difficult part of the Delta works was the
construction of the flood barrier Oosterschelde. This partly open barrier
in the Oosterschelde is considered
to be "the eight's world wonder".
First
of all the plans were different. It was the intention to close the Oosterschelde
with a "conventional " barrier
The
works started in April 1967. The workdock Schelphoek (Schouwen-Duivelland) en
Sophia (North Beveland) and the work island Roggenplaat (1969), Neeltje Jans (
1970) and Noordland (1971)were completed. After the construction of the
connection barriers between the work dock and work islands at the end of 1973 a
total 5 out of the 9 km wide Oosterschelde
was closed. What remained were three openings, Hammen,
Schaar van Roggenplaat en Roompot. The
intention was to closed them by using concrete blocs dumped by
cable car. The required twelve support towers for this cable car were
positioned during 1972.
But
why did they change the plans???. They changed under the influence and pressure
of a large part of the population who protested against the complete closure of
the Oosterschelde. The results of the protest activity under the name of
" Oosterschelde Open"
was that all final activities were postponed in July 1974, awaiting the
final decision by the government.
A
turbulent period started the Oosterschelde problem as priority on the
political agenda. The final decision toke a long time.
Finally
the government decided not to build the conventional dam but a storm
barrier with movable gates. As a direct consequence during the winterperiod
1976-1977 the support towers for the cable car were taken down.
The
new plan to construct storm barrier existed of huge concrete pillars resting on
the seabed of the Oosterschelde . Between the pillars the steel movable gates
were positioned which can close the Oosterschelde completely during a storm
surge. On the weir a road is constructed of various different concrete elements.
The
construction started in 1978 from the work island
Neeltje Jans which could be reached
from Schouwen-duivelland by a temporary road bridge with a length of 2780
m . Next was the construction of
the building dock where the concrete pillars could be fabricated.
In
July 1981 orders were placed to constructed the steel gates..
Also
here they faced problems. The gates were very heavy and so a strong foundation
was required.. To improve the resistance of the sand the sandy bottom was
prepared for this resistance up to a depth of 15 meters. The special constructed
vessel Mytilus was able to put long needles in the bottom. By vibration
the sand closed in and formed a prpoer foundation to withstand the
weights of the steel barriers. The treatment of the sand lasted from the
beginning of 1980 until the end of 1982.
After
the sandy bottom was prepared it had to be reinforced and levelled. A specially
for this purpose plant was constructed on the Neeltje Jans.
The plant produced artificial filled with a variety of shingles.
The
mats were put in position by two specialized vessels the "Cardium" and
the "Dos. 1". In addition the stone and the asphalt dump barge "
Jan Heijmans" filled the gaps in between the mats with different type of
stones. The mats are positioned between
November . '82 and June '84.
When
the total carpet of mats are ready the pillar can be positioned. For the
construction of the pillars a total number of three large
15 meters deep construction docks are available.. In April 1979 they
started with the construction of the first pillars in the building dock.
After having constructed all required pillars in 1983 the docks were flooded
allowing the special constructed lift vessel "Ostrea" to start with
the positioning of the pillars.
In
Augustus 1983 the first of the 65 pillars are put into position. Finally a total
of 16 in the North shutter hole, 17 in the middle shutter hole Schaar and 32 in
the South Shutter hole Roompot. The 66th pillar was just a spare one and wasn't
used..
Oosterschelde barrier
(Eastern Scheldt barrier)
Finally
the day is there: On October 4 1986
the Queen
of the Netherlands Beatrix the
storm barrier was officially put in service. Together with the Minister of
Transport and Public Works Miss Nelie
Kroes and the Director- General of Rijkswaterstaat Mr.
J. v. Dixhoorn she speaks
the historic words: "the
storm barrier is closed . The delta works are ready. Zeeland is safe."
On
1 January 1987 the Delta Service hand over the storm barrier to Rijkswaterstaat
of Zeeland. The road on the weir
was constructed later. On the fifth of November 1987 Princes Juliana opens
the road passage by normal traffic. In July 1988 the last activities at the
storm barrier are completed.
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