We illustrate a floating elevator and spoil distributor constructed by
Mr. A.F. Smulders, Utrecht, Holland, for removing dredged material out
of barges at the Baltic Sea Canal Works. We give a perspective view
showing the apparatus at work, and on a page plate are given plans,
longitudinal and cross sections, with details which are from
_Engineering_. The dredged material is raised out of the launches or
barges by means of a double ranged bucket chain to a height of 10.5
meters (34 ft. 5 in.) above the water line, from whence it is pushed
to the place of deposition by a heavy stream of water supplied by
centrifugal pumps.
[Illustration: FLOATING ELEVATOR AND SPOIL DISTRIBUTOR FOR THE BALTIC
SEA CANAL.]
The necessary machinery and superstructure are supported on two
vessels connected, as shown in Figs. 4 and 5, with cross girders, a
sufficient width being left between each vessel to form a well large
enough for a barge to float into, and for the working of the bucket
ladder utilized in raising the material from the barges. The girders
are braced together and carry the framing for the bucket chains,
gears, etc.
The port vessel is provided with a compound engine of 150 indicated
horse power, with injection condenser actuating two powerful
centrifugal pumps, raising water which enters by a series of holes
into the bottom of the shoots underneath the dredged material,
carrying the material to the conduit (as indicated on Fig. 4 and in
detail on Figs. 6 and 7).
A steel boiler of 80 square meters (860 square feet) heating surface,
and 6 atmospheres (90 lb.) working pressure, supplies steam to the
engine. Forward on the deck of the same vessel there is a vertical
two-cylinder high pressure engine of 30 indicated horse power, which
helps to bring the barge to the desired position between the parallel
vessels. A horizontal two-cylinder engine of the same power, fitted
with reversing gear, placed in the middle of the foremost iron girder,
raises and lowers the bucket ladder by the interposition of a strongly
framed capstan, as shown on Fig. 5. The gearing throughout is of
friction pulleys and worm and wormwheel. It is driven by belts.
In the starboard vessel there is a compound engine of 100 indicated
horse power, with injection condenser, working the bucket chain by
means of belts and wheel gearing, as shown on Fig. 2. A marine boiler
of 46 square meters (495 square feet) heating surface and 6
atmospheres (90 lb.) working pressure, supplies steam. In this vessel,
it may be added, there is a cabin for the crew.
The dimensions of the vessels are as follows; Extreme length, 25
meters (82 ft.); breadth, 4.5 meters (14 ft. 9 in.); depth (moulded),
2.7 meters (6 ft. 6¾ in.); average draught of water, 1.4 meters (4 ft.
7 in.); space between the ships, 6.55 meters (21 ft. 6 in.) The iron
structure connecting the ships is composed of four upright box-form
stanchions on both ships, connected at the top by two strong box
girders with tie pieces supporting the main framing. This main
framing, also of the "box girder" form, is strengthened with angle
irons and braced together at the tops by a platform supporting the
gearing of the bucket chains, as shown on Fig. 5. The buckets have a
capacity of 160 liters (5.65 cubic feet) and the speed in travel is at
the rate of 25 to 30 buckets per minute, so that with both ladders
working, 50 to 60 buckets are discharged per minute. The top tumbler
shaft is placed at a height of 13 meters (42 ft. 8 in.) above the
water line (Fig. 4), and the dredge conduit has a length of 50 meters
(164 ft.), Fig. 1. The shooting is done at a height of 8.5 meters (27
ft. 10 in.) above the water line, and the shoot catches the dredged
products at a height of 10.5 meters (34 ft. 5 in.) above the water
line, the sliding gradient being 4 to 100. The dredge conduit is
carried by timberwork resting on two of the upright box form
stanchions.
[Illustration: IMPROVED FLOATING ELEVATOR AND SPOIL DISTRIBUTOR.]
All cables are of galvanized steel and provided with open twin
buckles. The main parts of the apparatus are of steel, and all pieces
subject to wear and tear are fitted with bushes so formed that they
can be easily replaced.
The quantity of suitable soil removed by these apparatus amounts to
350 cubic meters (12,360 square feet) per hour. Four plants of similar
construction have been built for the new Baltic Sea Canal, besides a
fixed elevator of the same power and disposition, with the exception
that the top tumbler shaft was suspended at a height of 16.1 meters
(51 ft. 10 in.) above the water line, and the dredge conduit placed at
a distance of 13 meters (43 ft.) from it.
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