Waterways and Water Transport in Different Countries by J. Stephen Jeans
6. That the invention, device, or improvement can
1048 words | Chapter 143
be readily adapted to the present canal boats; and,
“Lastly, that the commissioners shall be fully
satisfied that the invention or device will lessen
the cost of canal transportation, and increase the
capacity of canals by any means of propulsion or
towage, other than by a direct application of power
upon the boat, which does not interfere in any manner
with the present method of towage on the canals, and
complying in all other respects with the provisions of
this Act, may be entitled to the benefits thereof.”
The system known as the Belgian system, or any mode of
propulsion by steam engines or otherwise, upon either
bank of the canal, was, however, excluded. A number of
attempts have been made to meet these desiderata, of
which the system known as Baxter’s is, perhaps, the
most successful.
On the running canals of China, Sir George Stainton observed a boat
of light construction, with only 14 tons lading, of 8 feet width of
floor, about 10 feet width of water-line, and 50 feet of extreme
length, drawing 2 feet 3 inches of water, and sharp at the ends,
dragged against a stream whose velocity was 5½ English miles per hour;
and, although there were twenty-eight trackers, or men hauling at the
line, fastened to the boat, besides three men in the boat, poling
it on, it advanced only at the rate of a quarter of a mile an hour,
notwithstanding that the channel was not materially contracted, in
either width or depth of waterway, in proportion to the section of the
boat.
Many suggestions have been made, and not a few experiments carried out,
with a view to enabling canal boats to navigate waters covered with
ice—the use of canals in cold countries being usually limited, from
this cause, to about one-half of the year only. None of them appear,
however, to have been very successful.
About the year 1796, the Chevalier Bentancourt Molina presented to the
Society of Arts a model of a barge, having a windlass in its stern,
which gave a circular motion to a pair of knives or scythes, or a lever
giving an alternating motion to knives, for mowing off weeds close to
the bottom of a canal in which the barge is to float, or on the sloping
sides of the canal; for which purpose the knives could be made to
revolve at any depth below the surface of the water, and either
horizontally or inclined at any angle. In most winters it happens that
an ice not more than 1 or 1½ inches thick continues for a considerable
length of time on canals and other stagnant waters. This, or even a
less thickness of ice, is sufficient to stop the trade upon the canals
unless the ice is broken; and for this purpose it is advisable, every
morning of a frost, unless the ice should be found more than usually
thick, and the frost increasing and likely to continue, to break the
ice. This was in some cases done by a strong and square-headed barge,
whose sloping or projecting head was covered with strong iron plates.
One of these barges, being drawn along the canal and into each lock by
several horses, has a tendency to rise upon the ice, and thereby breaks
it down before the boat. About the lock-gates it was necessary to break
the ice by stamping with the end of a pole. Mr. Symington provided the
head of his steam-barge with stampers, to be worked by the engine, for
breaking the ice before it in frosty weather.
The tempting prospects of towing a train of ten 100-ton barges with
scarcely any more power than would be required to tow only one of them,
and the alluring advantages of speedily loading each separate barge,
and of detaching and attaching barges at intermediate wharves along
the canal’s course, were held out in a proposal recently discussed in
France for adopting single-width canals.
On the other hand, however, it has been argued that in this case a
regular time-table would have to be strictly enforced; all boats would
have to be made up into trains, involving loss of time at starting;
there would be delays at the turn-outs, where the canal was widened
for allowing the return trains to pass; and steamers could no longer
go where and when they pleased. Bridges and locks, being already of
single width, could be built no cheaper; while the proposed long locks,
of 150 metres = 490 feet length, to take a train of barges, would cost
much more than the present French locks of 126 feet length. Even with
very few locks, a single-width canal would not come more than one-ninth
cheaper than the ordinary canals of double width. At the outside,
therefore, it would not take off more than 1 millime per tonne-kilom.
= 0·016_d._ per ton per mile from the tolls. Under the head of towing,
the only possible saving would be in consumption of coal in the
steam-tugs, which on the Willebroeck Canal costs about ¼ millime per
tonne-kilom. = ·008_d._ per ton per mile; if half this were saved in
a single-width canal, ¼ millime = 0·004_d._, would be all the economy
thereby effected. As for dispensing with barges on all except the tug
and the rear barge of a train, it has been argued that it would be
practically impossible to work a train of rudderless barges round the
bends of a canal, and it would be a most tedious and difficult job to
handle the barges separately at the wharves and docks where the train
has to be made up or dispersed; moreover, the cargoes would not get
properly watched, with so few men to look after them. The total saving
possible on a single-width canal, 0·020_d._ per ton per mile, would be
likely to be swallowed up by the extra management expenses consequent
upon having to organise the canal service on a similar plan to that of
railways.
FOOTNOTES:
[303] Paper on the canals and shallow draught steam navigation of
Canada. ‘Journal of the Society of Arts,’ 1888.
[304] Select Committee on Canals, 1883, Report, p. 44.
[305] Report App. 2, p. 206.
[306] Report App., 2, 117-119.
[307] Ibid., 2, 1548-1550.
[308] Ibid., 2, 1281-1283.
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