IMPROVEMENTS IN AND RELATING TO THE ADAPTED TO THE CON- CONSTRUCTION OF NAVIGABLE VESSELS ESPECIALLY A com- STRUCTION OF CRUISING CANOES AND LIGHT DRAUGHT VESSELS
Year: 1882

page_text: LETTERS PATENT to John Troughton Grindrod of Liverpool in the County
of Lancaster for an invention of "IMPROVEMENTS IN AND RELATING TO THE
ADAPTED TO THE CON-
CONSTRUCTION OF NAVIGABLE VESSELS ESPECIALLY
A com-
STRUCTION OF CRUISING CANOES AND LIGHT DRAUGHT VESSELS
munication to him from Abroad by Edward Jackson of Manilla one of the
Philinine Islands
PROVISIONAL SPECIFICATION left by the said John Troughton Grindrod
at the Office of the Commissioners of Patents on the 18th May 1882.
JOHN TROUGHTON GRINDROD, of Liverpool, in the County of Lancaster
IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION OF NAVIGABLE VESSELS
ESPECIALLY ADAPTED TO THE CONSTRUCTION OF CRUISING CANOES AND LIGHT
DRAUGHT VESSELS [A communication to him from Abroad by Edward Jackson
of Manilla one of the Philipine Islands]
"
This Invention has for its object certain improvements in the construction of
navigable vessels and especially adapted to the construction of cruising canoes,
beach boats, launches and light draught cargo steamers.
In The usual system of ship designing, the resistance of the parallelogram
forming the base of the shape of the hull, is fined, or diminished by cutting away
from the sides and bilges.
In the Invention of which this forms the subject matter, this fineness is partly,
or principally obtained by hollowing out, or concaving the bottom much, or little
throughout the whole, or part of the vessels length according to the purpose to
which the vessel is to be applied.
The accompanying Drawings show examples of this construction, namely
Figure 1 illustrates a cruising canoe
Figure 2 a beach boat.
Figure 3 a steam launch

page_text: The advantages of this construction as compared with hulls on the usual system
on a given displacement, length, breadth and depth are
1 with large cubic contents an unusually clean run of dense, or solid water to
the rudder and screw propeller is obtained.
2 greater stability and sea worthiness.
3 an exceedingly straight course with quickness to helm.
4 freedom from lateral and longitudinal motion.
5. relative equality of seagoing qualities whether with cargo, heavy, or light
stowed high, or low.
6. relative freedom from ballast.
7. speed accruing from the above advantages.
8., taking the ground upright with bearing on two outside keels, which may be
broad and strong, thereby insuring proportionately lessened danger in bars and
shallow waters
9. in vessels of extremely light draught in which the concavity of the bottom of
the midship section would be indefinitely small, or even a dead flat, yet a far
greater volume of water would be admitted to a screw, or stern paddle wheel than
by hulls of the usual form.
REFERENCE TO THE DRAWINGS.
In the cruising canoe shown at Figure 1, the crown of the arch in the bottom is
about at the water line, fining up aft between two keels. Forward the boat
developes into a single bow, the boat in fact partaking under water much of the
form of the double hull with the advantage of the single bow. In the example
shown at Figures 2. 3 and 4 the same elements of design are maintained as in the
canoe, but the crown of the arch in these cases is deeper immersed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Troughton Grindrod in the Great Seal Patent Office on the
18th November 1882.
JOHN TROUGHTON GRINDROD, of Liverpool, in the County of Lancaster
IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION OF NAVIGABLE VESSELS
ESPECIALLY ADAPTED TO THE CONSTRUCTION OF CRUISING CANOES AND LIGHT
DRAUGHT VESSELS." A Communication to him from abroad by Edward Jackson,
of Manilla, one of the Philippine Islands
This Invention has for its object certain improvements in the construction of
navigable vessels and boats and is especially applicable to the construction of
cruising canoes, beach boats, launches, vessels, or ships boats and light draught
cargo steamers,

page_text: The following is a description of this Invention sufficient to enable anyone
skilled in the art of boat building to put the Invention into practice, reference
being had to the annexed sheet of Drawings making a part of this Specification
and to the letters and figures of reference marked thereon, such letters and figures
correspond with those used in the following explanation and the same letters and
figures are used to denote the same, or corresponding parts throughout the various
views.
In the usual system of ship and boat designing, the resistance of of the parallel-
ogram forming the base of the shape of the hull is fined, or diminished by cutting
away from the sides and bilges. In the Invention of which this forms the subject
matter this fineness is partly, or principally obtained by hollowing out, or
concaving (much, or little) the bottom throughout the whole, or part of the vessel
or boats length according to the purpose to which the vessel, or boat is to be
applied.
The accompanying Drawings show examples of this construction, namely
Figure 1 illustrates an elevation and plan of a cruising canoe
Figure 2 illustrates an elevation and plan of another arrangement of cruising
canoe.
Figure 3 illustrates and [sic] elevation and plan of a paddle canoe.
Figure 4 illustrates an elevation and plan of a yachts small boat, or dingey and
Figure 4 illustrates an elevation and plan of a ships life boat
Figure 5 illustrates an elevation and plan of a sailing beach boat.
Figure 6 illustrates an elevation and plan of a steam launch.
Figure 7 illustrates an elevation and plan of a light draught screw steamer. for
cargo
Figure 8 shows a type of rig and sail suitable to be used for canoes and boats
constructed according to this Invention.
Upon reference it will be seen that in the various types of craft illustrated in
the Drawings, the bottom of each boat, or vessel is more, or less hollowed out, or
concaved at A. The crown of the concave, or arch being water bourn and the
springing of the concave forming the arch, forms two outer keels B. B. The
advantages of this construction as compared with hulls constructed on the usual
system on a given displacement length, breadth and depth are.
First with large cubic contents an unusually clean run of dense, or solid water
to the rudder and screw propeller is obtained.
Second a greater stability and seaworthiness and strength of construction.
Third an exceedingly straight course with quickness to helm.
Fourth freedom from lateral and longitudinal motion.
Fifth relative equality of seagoing properties whether with passengers, cargo,
heavy, or light, stowed high, or low.
Sixth relative freedom from requiring ballast.
Seventh speed accruing from the above advantages.
Eighth ability to take the ground upright bearing on two outside keels which
may be broad and strong thereby ensuring proportionately lessened danger in bars
and shallow waters.
Ninth vessels of extremely light draught in which the concavity of the bottom
of the midship section would be indefinitely small or even a dead flat, yet a far
greater volume of water would be admitted to a screw, or stern paddle wheel than
by hulls of the usual form.
In the cruising canoe shown at Figure 1, the crown of the arch A in the bottom
is about at the water line, fining up aft between the two outer keels B. B. Forward
the boat developes into a single bow, the boat in fact partaking under water much
of the form of a double hull with the advantage of a single bow.
In the example of cruising canoe shown at Figure 2, the concave of the bottom
dies away before the after end is reached and the after end is fined into a central
keel, or dead wood in like manner to the forward end.
The dotted line in the cross section Figures 1 and 2 shows the section of an

page_text: ordinary canoe as compared with the section of a canoe according to this
Invention.
In the example shown at Figure 3 a paddle canoe is illustrated (on a larger scale
than Figures 1 and 2). In this case the crown of the arch A is lowered below the
water line, so as to fine the ends and keep them below water and the bilge of the
boat is slightly rounder than the other example shown.
In the example shown at Figures 4 44 5. 6 and 7 the same elements of design,
as in the previous examples are retained. The crown of the arch A in these cases
is more deeply immersed. In Figure 7 the dotted cross sections illustrate a vessel
on ordinary lines.
In conclusion, it may be mentioned that prior to this Invention, it has been
proposed to construct navigable vessels with a channel, or channels at the bottom
of the vessel. The channel however in the forms previously proposed terminated
in a double bow, or the bow converging into a single stem, in a different manner
to that of this Invention. Another prior method being the use of two channels.
It has also been proposed to construct boats with double hulls, the hulls being
joined together by a central arch but it cannot be ascertained that it has ever
been proposed to build what are known as canoes on the concave bottom principle.
What is claimed as this Invention is:
First The particular form and construction of concave bottomed canoe, or boat
herein described and shown at Figure 1 of the Drawings hereto annexed
Second The particular form and construction of concave bottomed canoe, or boat
herein described and shown at Figure 2 of the Drawings hereto annexed.
Third The particular form and construction of concave bottomed canoe, or boat
herein described and shown at Figure 3 of the Drawings hereto annexed.
Fourth The particular form and construction of concave bottomed boat herein
described and shown at Figures 4 and 44 of the Drawings hereto annexed.
Fifth The particular form and construction of concave bottomed boat herein
described and shown at Figure 5 of the Drawings hereto annexed
Sixth The particular form and construction of concave bottomed launch herein
described and shown at Figure 6 of the Drawings hereto annexed
Seventh The particular form and construction of concave bottomed light
draught cargo steamer herein described and shown at Figure 7 of the Drawings
hereto annexed.
In Witness whereof, I, the said John Troughton Grindrod have hereunto set
my hand and seal this fifteenth day of November, in the year of our Lord,
one thousand eight hundred and eighty two.
JOHN TROUGHTON GRINDROD. (L.S.)