2. In the smaller width of the semi-vessel as compared with
the duplex vessel.
3. In the fact that the combination and separation of the
vessels can be effected, without the least disturbance of the
cargo, in a minimum of time.
It facilitates the utilization, to the highest possible extent, of the
varying conditions and dimensions of canal locks and rivers.
The transition from rivers to canals, and from larger canals to
smaller ones, is expedited by the possibility afforded of, on the
arrival at the locks, dividing the vessel in a space of a few minutes;
of passing with the semi-vessel, singly, the various smaller locks or
the shallow canal, after which the two sections may be re-combined and
navigated again as one vessel. The process of "folding up" the two
vessels will of course take longer than that of separation.
On rivers, the channels of which are interrupted by sand banks and
rapids, the same operation may be carried out, thus avoiding the
expense and delay necessitated by, perhaps, repeated "lightering,"
i.e., reduction of the cargo.
Thus, the through traffic on large rivers like the Danube, with its
repeated obstacles to navigation, such as the "iron gate," and several
sand-banks known and dreaded by bargemen, would be materially
facilitated, any necessity for unloading part of the cargo being
obviated; moreover, such a duplex vessel composed of two semi-vessels
affords the advantage of utilizing to a fuller degree the power of
traction, and one large vessel will be more convenient for traffic
than two smaller ones.
Further, the mode of construction of the semi-vessels--both ends of
which are of a similar pattern--allows of their being navigated up and
down a water channel without the necessity of turning them round;
provision having also been made for the fixing of the rudder at either
end, which would therefore merely require exchanging. This is of some
advantage in narrow river beds and canals, and applies equally to the
duplex vessel as to the single semi-vessels.
[Illustration: FIG. 1.]
[Illustration: FIG. 2.]
[Illustration: FIG. 3.]
[Illustration: FIG. 4.]
[Illustration: FIG. 5.]
Each semi-barge on its part is also constructed of two equal
halves--which are, however, inseparable--and as there is no distinct
stem or stern, any one of these semi-vessels will fit any other
semi-vessels of the same dimensions, and can be attached to the same
by means of the coupling apparatus, and the two "folded up" into one
duplex vessel. This process does not present any material
difficulties. The two single boats on being coupled together can be
made to lean over toward each other, by filling their lateral water
compartments, to such an extent that the further closing up can be
easily effected by means of specially constructed windlasses. In the
case of petroleum vessels the "folding up" operation is facilitated by
the circumstance that the petroleum may be made to serve the purposes
of water ballast.
As regards the size and tonnage of the new vessels, this will of
course depend on the local condition of the rivers and canals to be
navigated. Thus a vessel destined for traffic on canals with locks of
varying dimensions will have to be adapted to the dimensions of the
smallest existing lock.
Supposing the size of the latter to be such as found in the case of
the Rhine-Marne or the Rhine-Rhone Canal, or on the Neckar down to
Cannstadt, or in the Danube-Main Canal and some smaller canals in the
Weser district, etc., viz.:
Length of lock 34.5 meters.
Width 5.2 "
Depth 1.6 to 2.0 meters.
The semi-barge may be made 32 meters in length, 4 meters in breadth
and 2.5 meters total depth, and with a draught of 1.5 meters will be
capable of carrying a load of 100 tons (of 1,000 kilos each).
Correspondingly the duplex vessel will be able to carry 200 tons, with
a minimum draught of 2.4 meters and a width of 5.4 meters, but, with a
favorable height of the water level, the draught of the semi-barge may
be increased to 1.65 and that of duplex vessels to 2.7 meters.
Where not limited to certain proportions by the dimensions of the
locks to be passed, the vessel may in the first place be made longer;
the width and height may also be increased accordingly (provided that
the proportion of breadth to width is kept within the ratio 4:2.5), so
that the semi-barges may be constructed for a single burden up to 300
tons, or 600 for the duplex vessel.
As regards the nature of the cargo, parcels would not be admissible in
this instance, but any kind of homogeneous cargo would be suitable
which would bear laying over on one side.
Thus this style of vessel would be well adapted for petroleum tank
vessels, for the transport of all kinds of cereals, flour, coffee, and
sugar in sacks--these latter being held in position by an arrangement
of planking and boards so as to prevent any overturning of the goods
on the vessels being folded up or taken apart. Similarly in the case
of a cargo of loose grain or other loose produce, the same must be
prevented from being upset by a kind of wooden casing.
Two semi-vessels loaded with different cargoes may be coupled
together, provided that there is not too much difference between their
respective draughts. Slight differences may be balanced by the water
compartments being filled to a greater or smaller extent.
The peculiar position of the hatches allows of loading the
semi-vessels separately as well as when coupled together.
If there is for the time being no necessity for using the vessels in
their capacity of separate and duplex barges, any kind of cargo might
be loaded that does not require large hatches.
The vessels, on account of their more complicated construction, will
be somewhat more expensive, but wherever the advantage offered by them
outweighs the extra expenditure, they can be used with success.
The innovation might be of particular importance where a new canal
system is being constructed, since the latter might be subdivided into
main canals and branch canals--similarly as in the case of ordinary
and narrow gauge railways--the main canal being built of a larger
section and with larger locks to suit the duplex barges, while the
branch canals could be planned of smaller dimensions calculated to
suit the semi-barge. Thus the first cost of such a canal system would
be materially reduced as compared with a canal installation of one
uniform section throughout.
Likewise in mountainous districts with rock soil it would be an
important consideration whether a canal had to be blasted out of the
solid rock or a tunnel cut, in dimensions suitable for a vessel of 6
or of 14 square meters section below the water line.
In this case, even in certain portions of a main canal--where rendered
desirable by the rocky nature of the ground--a smaller section might
be adopted, which would only be large enough for single semi-barges,
so that the duplex vessel would in these instances have to be taken
apart in the same way as in a branch canal.
The saving to be effected by constructing a canal on this principle,
as compared with a canal of one uniform section throughout, must be
considerable, and the advantages of the arrangement are apparent.
The appended figures will further illustrate the arrangement. Fig. 1
shows two separate semi-barges ready to pursue their journey
independently. Fig. 2 shows two semi-barges coupled together ready to
be "folded up" by means of ropes and specially constructed
windlasses--their lateral water compartments having previously been
filled. Fig. 3 shows the duplex vessel after the "folding up"
operation just described; and Figs. 4 and 5 show the cross section of
two loaded semi-barges as outlined in Figs. 2 and 3.
These Figs. 4 and 5 will also serve to illustrate the manner in which
sacks and loose produce should be loaded. Fig. 4 also shows the filled
water compartments, and the effect of their weight in making the boats
lean toward each other.
The materials most suited for this new style of vessel will be iron
and steel such as generally used in the construction of canal and
river vessels.
The new ship can be moved by any motor or driving implement, nor could
there technically a great difficulty be found for making the boilers
move on a quadrant-like rail base in the shape of a circle segment's
quarter, or for building a double screw steamer by combining two
single screw propellers.
May be a ship owner is willing to submit the innovations to an
attempt, so much the more as there is running no great risk by doing
so; for in case the ships should not answer the expectations, both
separable as well as joinable, they can be used like single ships,
without any further alteration being made, except as to the loading
gaps.
The above invention is covered by United States patent No. 435,107.
Any further information may be had by addressing M. v. Szabel, ix
Bezirk, Beethovengasse 10, Wien, Austria.
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