IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-PROPELLING SHIPS
Year: 1878

page_text: LETTERS PATENT to Friedrich Hermann Felix Engel, Civil Engineer and
Patent Agent, in the City of Hamburg, Germany, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-PROPELLING SHIPS."
A communication from August Herrmann Reichelt, of Hamburg, in the
German Empire.
Sealed the 28th March 1879, in pursuance of an Order of the Lord Chancellor, anḍ
10L1
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Sealed the 28th March 1879, in pursuance of an Order of the Lord Chancellor, and
dated the 19th September 1878.
PROVISIONAL SPECIFICATION left by the said Friedrich Hermann Felix Engel
at the Office of the Commissioners of Patents on the 19th September 1878.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hainburg, Germany. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-
PROPELLING SHIPS." (A communication from August Herrmann Reichelt, of
Hamburg, in the German Empire.)
This new construction of screw ships of all kinds consists in an altered form of
the hull or body, and in placing the screw propeller or propellers below the hull
instead of at the end as heretofore usual.
According to this Invention a part of the middle of the hull is constructed in
such a manner that the ribs or frames are prolonged sharply downward, and when
provided with the iron skin or outer wooden planking a kind of keel is formed for
this part of the length of the ship.
At each end of this downward prolonged part of the ship, or at the aft part of
same only, are placed two screw propellers or a single screw propeller fastened to a
longitudinal propeller shaft or shafts as the case may be. The rudder is placed aft
of the aft propeller. To lift the propellers and the rudder when required wells may
be provided leading to the deck; these may at the same time serve as ventilating
shafts for the engine room and stoke-hole.
The advantages of this system of naval construction are chiefly that the screws
act more efficiently under the ship than at the stern, and may be of materially.

page_text: smaller diameter than heretofore usual; also the immersed or wetted surface of the
hull is by this construction reduced, because the ship itself has not to be made so
deep as heretofore necessary for the purpose of employing a screw propeller of
sufficiently large diameter. The surface of the downward prolonged part of the
hull, required in this construction for the propeller shaft or shafts and screw or
screws and rudder, is comparatively small, as it only extends to part of the vessel's
length. The vibrations caused by the working of the screw are also less than by
screws placed at the stern.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Hermann Felix Engel in the Great Seal Patent Office on the
28th March 1879.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW-
PROPELLING SHIPS." A communication from Auguste Hermann Reichelt, of
Hamburg, in the German Empire.
This construction is applicable to screw-propelling vessels of all systems, and
consists of an original form of the ship's body, and of an arrangement according to
which one or two screw propellers are placed underneath the ship's body instead of
on the end as formerly. The middle part of the ship's body is constructed in such
manner that the corresponding frames are prolonged below in sharp lines to form a
keel of the ship after planking.
At each end of this prolongated part of the ship's body or at the stern end only,
screws or one screw are placed and secured to the end or ends of a cranked driving
shaft placed in the hollow part of the said prolongation of the ship's body. The
rudder is arranged behind the stern screw.
The advantages of this system of ship's construction are mainly a better action
and smaller dimensions of the screw propellers, further a reduction of the immersed
surface of the ship's body, less friction, and a steadier motion of the vessel.
In the accompanying Drawing this construction, as illustrated, Fig. 1, is a ground
plan; Fig. 2, a longitudinal section; and Fig. 3 represents the lines of the middle
frame. a, a, is the water line of the ship; b, are the prolongated frames; S, S', are
the screws; K, K', crank shafts; and R, the rudder of the ship; C, C1, C2 are vertical
openings arranged for the lifting and lowering of screws and rudder. These
openings may at same time be used as ventilating channels.
Having now described the nature of the said Invention and shown how the same
is carried into practical effect, I claim,-
The prolongated frames and planking of the middle part of the ship's body aud
the arrangement of placing one or two screws and the rudder underneath the
bottom of the ship instead of on the ends, in the manner and for the purpose
substantially as herein set forth and shown by the Drawings.
In witness whereof, I, the said Friedrich Hermann Felix Engel, have hereunto
set my hand and seal, this Twenty-fourth day of March, the year of
our Lord One thousand eight hundred and seventy-nine.
FRIEDRICH HERMANN FELIX ENGEL. (L.S.)