Operation of the Krammer-sluices.
The Krammer-sluices, which are intended for
push-tow traffic through the Philips dam, will be
provided with a fresh/salt water separation
system. The output of this system can be
increased by adequate equipment and a correct
handling of the operating machinery. The right
moment to close the gates for the exchange
of fresh water for salt water and conversely salt
water for fresh water during the locking cycle,
plays a very important role here. The equipment
can be adjusted to follow the movement of the
borderline between salt and fresh water or to
indicate when it has reached the right level. It
can also determine the discharge of the
sewerage or signal when it has reached the
required height or depth. In view of the
uncertainties about the impact of the salt water
load or the loss of fresh water, it has been
decided to postpone, for a number of years, the
selection of the operational machinery and the
instrumentation.
The yachting-sluices in the Philips dam
In addition to the locks in the Philips dam
intended for shipping, two sluices will be built
for yachts, each with a lock-chamber 75 metres
long and 9 metres wide. In view of the high
costs, the concrete structure will be built in
conjunction with those intended for shipping.
For the time being, however, only one
yachting-sluice will be operational. The
requirement has been based on the number of
pleasure boats passing through the Volkerak
sluices. The usage rate of the locks increases
more rapidly than the rate in boat ownership.
Around the year 2000, between sixty and eighty
thousands yachts are expected to pass through
the Philips dam sluices.
The yachting-sluices will also be equipped with
a fresh water/salt water separation system, of
the same type as has been installed in the
'Kreekrak'. The yachting-sluices will have
waiting harbours and fixed overhead passings.
Computation of the dimensions of the
discharge canal Bath and of the scouring-sluice
near Bath.
These engineering structures must provide a
discharge from the Zoom Lake into the
Westerschelde. In particular with regard to
quality control, the discharge will provisionally
amount to 100 m3/sec. and eventually be
extended tot 150 m3/sec. The concrete
structures of the canal and the sluice will be
built in such a way that future extension will be
possible.
The discharge canal will look like a
slow-flowing stream with wide reed-banks and
open spaces for recreation purposes. In case of
future increase of the currents, due to an
increase in the discharge capacity, the shores
may have to be protected against scouring. The
discharge canal wille be of the syphon-type with
a free water level through which water can be
discharged into the Westerschelde under
gravity (i.e. without pumping). The sluice will be
built in the Westerschelde water defences and
be provided with ten outlets with doubles gates
and a sill at 5 m. below M.S.L. An outflow duct
and aprons will be built, to prevent scouring of
the bed behind the sluice.
The work-island for the Oester dam
The work-island should mainly be regarded as a
site where a lock can be constructed in the dry.
The working-harbour on the western side will
afterwards serve as a waiting-harbour for the
lock.
At the suggestion of the contractor the
work-island was constructed in an alternative
manner, as a result of which the costs were less
than calculated by any of the other contractors.
The alternative manner meant in fact that, for
the initial phase of construction of the island, nc
auxiliary dikes were used andthatthe hydraulic
sand fill was pumped straight on to the
designated area.
The design of the embankment for the
Markiezaat-area
Due to the embankment on the western side of
the Markiezaat-area, the surface area of the
region to be closed off by the Oester dam has
been decreased by 50 per cent; at the same tim
the shipping on the Scheldt/Rhine connection
will be hampered to a lesser degree.
From the three alternatives under
consideration, the one with a permeable dam
has been chosen. Thus, the transition between
the actual and the new situation will progress
more gradually in the Markiezaat-lake. After
completion of the Oester dam, the embankmen
around the Markiezaat-area can be lowered anc
a large quantity of its material can be re-used.
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