IMPROVEMENTS IN PROPELLING SHIPS OR VESSELS
Year: 1877

page_text: LETTERS PATENT to George Fellows Harrington, of Ryde, in the Isle of
Wight, Dentist, for the Invention of "IMPROVEMENTS IN PROPELLING SHIPS
OR VESSELS."
Sealed the 22nd January 1878, and dated the 24th July 1877.
"
PROVISIONAL SPECIFICATION left by the said George Fellows Harrington
at the Office of the Commissioners of Patents on the 24th July 1877.
GEORGE FELLOWS HARRINGTON, of Ryde, in the Isle of Wight, Dentist. "IM-
PROVEMENTS IN PROPELLING SHIPS OR VESSELS."
My Invention consists in modifications of my former Invention which I term the
fish gill principle of screw propulsion," and for which former Invention I obtained
Letters Patent, dated October 15th, 1873, No. 3341, and relates to the form of the
vessel, to the position of the screws which I use for propelling it, and to the mode
of utilizing the displaced water for propelling and impelling it, and filling the wake
within the boundary of its hull. For the purpose of attaining these objects I form
the parts of the hull which are to be immersed into twin sections with parallel out-
sides and a bottomless longitudinal space or waterway between the divided parts.
The bow of each section is formed to incline from the outside inwards at an angle
of from 45 to 60 degrees or thereabouts, so as to cause the water which the vessel
meets in its line of passage to converge upon a screw or screws placed near the
bows between the divided parts of the bull to receive such water and force it
backwards.
In rear of the screws, the sides which bound the space between the divided
hull are formed to bend outwards until they terminate at the sides of the parallel
outside of the hull so as to allow the water, as the screws force it backwards, to
diverge, fall into the wake, and assume its mean level as the vessel leaves it.
The power may be conveyed from the engines to the screws by means of universal
joints.

page_text: By means of these improvements no bow wave is permitted to form, and I
cause the force which the screws communicate to the water to raise it above its
mean level in their rear to re-act upon the hull of the vessel and assist in impelling
it as such water descends to its mean level again.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed a
by the said George Fellows Harrington in the Great Seal Patent Office
on the 24th January 1878.
GEORGE FELLOWS HARRINGTON, of Ryde, in the Isle of Wight, Dentist.
PROVEMENTS IN PROPELLING SHIPS OR VESSELS."
"
IM-
My said Invention consists of modifications of my former Invention, which I term
the "fish gill principle of screw propulsion," and for which former Invention I
obtained Letters Patent, dated October 15th, 1873, No. 3341, and relates to the form
of the vessel, to the position of the screw propellers which I use for propelling it,
and to the mode of utilizing the displaced water for propelling and impelling it, and
filling the space within the boundary of its hull. For the purpose of attaining these
objects I form the parts of the hull which are to be immersed as twin sections with
parallel outsides and a bottomless longitudinal space or waterway between the divided
parts. The bow of each section is formed to incline from the outside inwards at an
angle which may vary from, say, about 45 to about 60 degrees, so as to cause the
the water which the vessel meets in its line of passage to converge upon a screw or
screws placed near the bows between the divided parts of the hull to receive such
water and force it backwards.
At the rear of the screws, the sides which bound the space been the sections of
the divided hull are formed to bend outwards until they terminate at the extremities
of the parallel outsides of the hull so as to allow the water, as the screws force it back-
wards, to diverge and assume its mean level as the vessel leaves it.
By means of these improvements I cause the force which the screws communicate
to the water to raise it above its mean level in their rear to re-act upon the
hull of the vessel and assist in impelling it as such water descends to its mean level
again.
And in order that my said Invention may be fully understood, I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the several
Figures on the annexed Sheet of Drawings, the same letters of reference indicating
corresponding parts in all the Figures.
Figure 1 of my Drawings represents a longitudinal section of a vessel arranged to be
propelled according to my said Invention; Figure 2 is a plan of the same, corresponding
to Figure 1.
Figure 3 is a plan with the upper part removed; and Figure 4 is a transverse
vertical section of the vessel.
The hull is composed of an upper part A, which is non-submerged, and of the
lower parts B, B, which are immersed in the water. These lower parts consist of
twin sections, shewn parallel or nearly so on their outer sides a, a, and leaving a
bottomless longitudinal space or waterway C between the said two divided parts
B, B. The bow D of each section B is made to an inclined shape from the outside

page_text: inwards, as shewn at b, b, whereby the water which meets the vessel in its line of
passage is caused to converge upon the screw propellers E, E, which are placed near
the bows D, D, between the sections B, B, of the hull, and which may be driven by
means of shafting c having universal joints d from the engines F of any suitable
construction.
At the rear of the screws E, E, the inner sides e, e', of the sections B, B, are made
of such a shape that the width of the longitudinal space or waterway gradually
increases from the point e to the point e', where it terminates at the parallel outer
side of its corresponding section B, so that the water which the screws E, E, receive
from the converging bows D, D, and which is forced backwards and elevated under
the action of the screws is allowed to diverge by reason of the shape of the
longitudinal space or waterway C, fall into the rear and assume its mean level at the
sterns G as the vessel leaves it; the vessel thus always meeting and leaving the
water at or about its mean level. By means of this arrangement, moreover, the
force which the screws impart to the water to raise it above its mean level in their rear,
within the longitudinal space or waterway C, is caused to react upon the hull of the
vessel and assist in propelling it; the water as it descends to its mean level again, as
the vessel leaves it, being caused to fall against the inclined or curved sides of the
twin section B, B, at the stern and exert an impelling force upon the vessel, so that
the force which the screws communicate is utilized or expended in overcoming the
frictional resistance to the passage of the vessel.
In the example shewn in my Drawings the screws are each carried in a frame f
fitted so as to be capable of sliding vertically in guides f¹ attached to a cross bar g,
in order to admit of the screws being raised and lowered as required, the adjustment.
being effected by means of a screw ; but any other suitable means of varying the
height of the screws may be adopted in substitution for those illustrated in my
Drawings, if found desirable.
It is preferred to employ two rudders H, H, at the stern G, one to each section B, as
shewn.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the employment of a hull in twin sections with a longitudinal
intermediate space or waterway, within which the screw propellor or propellors is or
are mounted or suspended, such twin sections being formed on their outer sides
parallel the one with the other, on their inner sides at the bows converging towards
the propeller or propellers, and at the stern diverging from the said propeller or
propellers, substantially as and for the purpose herein-before described
In witness whereof, I, the said George Fellows Harrington, have to this my
Specification set my hand and seal, the Twenty-third day of January,
One thousand eight hundred and seventy-eight.
G. F. HAKKINGTON. (LS.)