The Dortmund-Ems Canal, destined to connect the heart of German
industry with the sea, was formally dedicated on April 1, and
partially opened to commerce. After its completion, German coal will
be transported to the harbors of the Ems at the same cost as the
English coal which has hitherto forced back the treasures of our soil;
our black diamonds will then be sold in the markets of the world, and
the Kaiser Wilhelm Canal will enable the western part of the empire to
exchange its coal and iron for the grain and wood of the East.
Many difficulties were encountered in cutting the canal, owing partly
to the vast network of railroads in the coal region of Westphalia, but
chiefly due to the insufficiency of moisture in the highlands, the
latter not containing enough water to supply the many necessary
sluices, at which it could be easily foreseen considerable traffic
would occur.
[Illustration: THE LOCK OF THE DORTMUND-EMS CANAL AT HENRICHENBURG.]
For the modern engineer there are, however, no insurmountable
obstacles. Instead of a line of ordinary locks, a single structure was
erected sufficient for the needs of the entire region. This lock is
situated at Henrichenburg, near Dortmund, and our illustration
pictures it with its lock-chamber half raised.
The lock, which serves to overcome a difference in level of fifty-nine
feet, raises vessels of 1,000 tons capacity with a velocity of 0.3 to
0.7 foot per second, and has been constructed after a new and
astonishingly simple system.
The lock chamber, designed for the reception of the various vessels,
is 229.60 feet in length and 28.864 feet in breadth and normally
contains 8.2 feet of water. Under the sluice in a line with the long
axis are five wells filled with water in which cylindrical floats are
placed, connected to the bottom of the chamber by means of iron
trellis-work. The floats are placed so deeply that, in their highest
position, their upper edges are always submerged; they are, moreover,
of such size that by means of their upward impulsion the chamber is
held in equilibrium. Irrespective of the small differences of pressure
which arise from the varying immersion of the framework, the lock will
in all positions be in equilibrium. Since a vessel which enters the
lock displaces a volume of water whose weight is equal to the weight
of the vessel, a constant equilibrium will always be maintained and
only a minimum force required to raise or lower the chamber. In order
to move the lock-chamber up and down and to sustain it constantly in a
horizontal position, nuts have been fixed to strong crossbeams,
through which powerful screw-rods work.
These rods are held in place by a massive framework of iron and are
turned to the left or to the right by means of a small steam engine,
placed at one side of the lock, which engine, by means of a
longitudinal shaft, drives two cross shafts to which bevel wheels are
attached. By this means the chamber is lowered and raised. The screw
rods are so powerful that they sustain the entire weight of the lock
chamber, and the pitch of the thread is such that spontaneous sliding
or slipping is impossible, the chamber being, therefore, kept
constantly in the desired position.
It is interesting to note that the hollow space in the screw rods is
heated by steam during winter, thus preventing the formation of ice in
the machinery.
During the eighties, locks for ships of 400 tons capacity were
erected in England and France, at Anderton, Les Fontinettes and La
Louvière. The lock at Henrichenburg, however, exceeds all its
predecessors, not only in size, but also in security. At all events,
the structure is a worthy memorial of the energy and genius of
German engineers.--Illustrirte Zeitung.
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Paper hanging by machine is the latest achievement, according to a
German contemporary, says The Engineer. The arrangement used for this
purpose is provided with a rod upon which the roll of paper is placed.
A paste receptacle with a brushing arrangement is attached in such a
manner that the paste is applied automatically on the back of the
paper. The end of the wall paper is fixed at the bottom of the wall
and the implement rises on the wall and only needs to be set by one
workman. While the wall paper unrolls and, provided with paste, is
held against the wall, an elastic roller follows on the outside, which
presses it firmly to the wall. When the wall paper has reached the
top, the workman pulls a cord, whereby it is cut off from the
remainder on the roll.
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