Improvements in or appertaining to Steam Propelled Vessels.
Year: 1891

page_text: Date of Application, 20th Jan., 1891
Complete Specification Left, 15th Sept., 1891-Accepted, 2nd Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Steam Propelled Vessels.
A communication. from abroad by Charles G. LUNDBORG, of the City, County,
and State of New York, United States of America.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street
Manchester, both in the County of Lancaster, and 323 High Holborn in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this
invention to be as follows:-
The constantly growing demand for steam-propelled vessels of increased speed
requires a constant increase in the power and weight of the engines and their
connections, and is attended with greatly increased difficulties and risks in running
such ponderous masses at the high speeds required.
The adoption of twin propellors and the division of the propelling power between
two engines made it possible to develop and apply a greater aggregate engine power
than was before possible with lighter engines, ships and propellors. A point has,
however, been reached-beyond-which-it-is hazardous to attempt to increase-the-
power applied to two propellors. It has, therefore, been proposed to use in con-
nection with a hull of ordinary form three independently-driven screw propellors,
one in the middle line at the stern, as usual, and the others, one on each side at a
higher level forward of the stern. This arrangement is open to the objection that
the full and rapidly converging lines of the hull prevent the water from reaching
the forward propellors in an advantageous manner, and to the further objection
that the rolling of the vessel is liable to uncover the forward propellors.
Now it is the aim of this invention primarily to produce a hull of such form or
construction at the stern that any desired number of propellors may be used in
connection therewith, and that the water may be allowed a free, easy and advan-
tageous run to all of the propellors, to the end that they may act efficiently and
economically in the propulsion of the vessel.
It is also an aim of this invention to arrange multiple propellors in advantageous
relations to each other and to a hull constructed on this plan.
It is the further object of this invention to provide for the application of two or
more rudders in such positions that they will act efficiently in directing the
course of the vessel, and that in war vessels they may be beyond the reach of the
enemy's shot.
In constructing a hull in accordance with this invention its forward portion may
be built of any ordinary or approved form, but the stern instead of terminating in
a single stern post of great depth, as usual, is terminated below the water line by
two or more stern posts located in the centre line of the vessel, each at a con-
siderable distance forward of the next and at a lower level, the horizontal water
lines of the hull being correspondingly modified at the different levels to give a
ong and easy run of the water inward, past the respective posts.
This construction of the hull with two or more stern-posts at different levels and
at different points in its length, with the lines drawn inward on the respective levels
to meet the posts, is the essence of this invention.
The keel forming the deepest part of the hull is terminated some distance forward
of the extreme after end of the vessel, at which point is erected a stern post rising
alfway to the load water line or thereabouts. From the top of this post the keel
orming the deepest part of that portion of the hull, is extended rearward to a stern
post rising therefrom and forming the extreme after end of the hull as usual.

page_text: The portion of the hull between the two stern posts has therefore less depth or
draught of water than that portion of the hull forward of the front stern post.
The horizontal lines of the hull are given a long easy curvature but drawn inward
to the respective stern posts, in such manner that the water is given a free and easy
passage astern. In other words, the water is permitted to pass to each of the stern
posts in essentially the same manner that is, in essentially the same direction, as in
passing the stern of an ordinary hull. To propel the hull thus formed two pairs of
propellors are employed. The shafts carrying the rear propellors are projected
through the sides of the hull at the proper place and depth, supported in the
ordinary manner, and provided with the propellors slightly forward of the rear
stern post. These propellors are a considerable distance astern of the forward
stern post. The forward propellors are also carried by shafts projected through
the sides of the vessel and sustained in the ordinary manner, their propellors being
located slightly forward of the front stern post and at a considerably lower level
than the rear propellors. It will be perceived that the water is allowed a long and
easy run to each of the propellors and that the latter are located in such relation
to each other that they may all act efficiently and without interference.
It will be understood that the draught of water of the after part of the bull
abaft the forward stern post is about one half of the draught forward of said post,
and that, on account of the shafts on the same side of the vessel being in the same
longitudinal vertical plane, the diameter of the forward propellors (in order that
the blades may not project below the keel) is limited by the vertical distance
between the two shafts. The part of the hull aft of the forward stern post may
vary considerably in depth and draught of water.
With the hull constructed and the propellors arranged as above described, the
propellor shafts may be independently driven by engines arranged in any suitable
manner but it is preferred to employ four independent engines located in four
distinct and independent compartments in the hull. The forward engines are
coupled directly to the forward ends of the lower shafts for driving the lower and
forward propellors.
As the shafts of the rear propellors are at a higher level than the others they
are driven directly by overhead engines, and in order that these engines may be
properly sustained without interference with the lower shafts, their frames are
constructed to straddle both the upper and the lower shafts and rest in the bottom
of the hull.
The steering of the hull constructed as above is effected by two rudders attached to
the two stern posts, one rudder being forward of and at a lower level than the other.
The rudders thus located may be operated by any suitable steering gear, but it is
preferred to provide the rudder posts at their upper ends with the ordinary sector
heads and to connect these heads through intermediate lines or chains passing
around suitable guides to the single operating lines whereby the two rudders are
caused to move simultaneously and equally.
Another arrangement will now be described. The hull of the vessel will be
found practically identical with that already described. It terminates like the first
in two stern posts, the former located forward of and at a lower level than the
latter. As in the first example, there are two rudders attached to the respective
stern posts the forward rudder has its top located at some distance below the load
water line that it may be the better concealed and protected in the case of a war
vessel from the projectiles of the enemy. The stern post is carried in suitable form
rearward over the top of this rudder so as to bring the rudder within the longi-
tudinal limits of the hull. As in the first example the vessel is propelled by two
pairs of propellors on horizontal shafts projected outward through the quarters of
the hull, two on each side of its central line. The forward and lower propellors
are, however, arranged at a somewhat greater distance apart than the upper
propellors. This arrangement gives an increased distance between the shafts on
the same side of the vessel and permits the forward propellors to be made of
greater diameter than under the arrangement as first described.

page_text: Another arrangement of four propellors is as follows:-
The hull is formed with the forward and lower stern post as in the preceding
examples, but the rear post is extended somewhat below the level of the top of the
forward post and given a curved form at its lower end to admit of the propellor
being located immediately in front thereof on the rear end of a shaft located in
the middle line of the hull as in single propellor ships. A second propellor is located
in the centre line of the vessel forward of the front stern post, and below the level
of the rear propellor. Two additional propellors are also located, one on each
side of the vessel, in the same or substantially the same transverse plane as the
propellor located in the centre line of the vessel forward of the front stern post.
The shafts of these three forward propellors are preferably in the same horizontal
plane, but the height of the side propellors may be varied at will. Two rudders
are hung upon the respective stern posts as in the preceding examples.
In a vessel provided with three propellor screws, the stern is formed with two
posts and provided with two rudders hung upon said posts. One propellor screw is
located in the centre line of the vessel, immediately in front of the rearmost stern
post. The remaining propellors are located in a plane slightly forward of the front
stern post and on opposite sides of the centre line of the vessel..
In another arrangement, the stern is constructed with three stern posts at
different longitudinal points and in the centre line of the vessel but at different
depths below the load water line. The foremost post rises from the keel or lower-
most portion of the hull. The second post located some distance aft of the foremost
post rises about half the distance to the load water line, while the third post at the
extreme stern of the vessel rises from the level of the top of the intermediate post
to the top of the hull. The lines of the vessel converge to the respective stern
posts on their different levels. It will be observed that this hull involves the same
principles of construction as those previously described: that is to say, a plurality
of stern posts located at different depths and at different points in the length of
the vessel with the hull shaped to give a free run of the water past each of the
posts. This hull with its three posts is propelled by three pairs of twin propellors
located just forward of the respective stern posts, and at corresponding depths, the
two propellors of each pair being located on opposite sides of the middle line of
the vessel. It is preferred to arrange the foremost propellors at a greater distance
from the middle line of the vessel than the others and to place the two upper shafts
on each side of the vessel in the same longitudinal vertical plane, but their relative
positions may be modified as the size of the propellors to be employed may demand.
Each of the three stern posts has a rudder hung upon it.
In another arrangement, a hull is formed, having three stern posts, as in the
preceding example, but the middle post instead of being straight is curved forward
in order to permit the use of a balanced rudder, which is thus hung at a considerable
depth below the surface and in a position of safety. This hull is provided with
four propelling screws arranged in pairs, the after propellors being hung at a higher
level and forward of the rearmost stern post, while the forward propellors, which
are more widely separated are located forward of the foremost post.
In connection with a hull having three stern posts of essentially the same form
and arrangement as those described above and with a balanced rudder hung upon
the middle post, are arranged two pairs of propellor screws, one pair forward of the
middle stern post, the other forward of the forward post. The two propellors of
each pair are in opposite sides of the middle line of the vessel and the lower
propellors are more widely separated than the upper.
In a vessel provided with five propellors the hull is formed with three stern posts
having the aftermost post curved downward in order to permit the use of a large
propellor at the extreme stern. The propellors are arranged as follows:-A centre
propellor at the middle line at the extreme stern, a pair of propellors forward of
the middle post and below the level of the rear propellor, and a second pair of
propellors forward of the front post at a lower level than the first pair and more
widely separated.

page_text: It is to be noted that in each example of this vessel the lines are adapted to
permit the free run of the water to and past each of the stern posts, and that the
propellor shafts are in each case projected through and sustained outside of the
vessel, either in the ordinary manner, or by supports of any other construction
adapted to maintain them in position.
From the foregoing description it will be seen that this invention embraces and
admits of a great variety of combinations and varied positions of any desirable
number of propellors, either in the middle line or in the sides of the vessel, or in
one or more of the stern posts, the number of which may also vary as desired, as
well as the number and positions of the rudders. An immense aggregate engine
power and weight may be consequently divided between several comparatively
light engines, propellors and shafts which may be easily and adequately supported,
and safely operated at high speed.
The invention as regards the shape of the hull also affords means of giving to
each and all of the propellors such positions that the lines of the vessel will permit
a free and direct run of the water to the discs of the propellors.
The invention also admits of the rudders and propellors being placed at such
great depth below the surface of the water that in the case of war vessels they are
free from liability of injury by the enemy.
It will be obvious that any one of the rudders may be made large enough to
alone steer and manoeuvre the vessel.
The
The upper propellors, owing to their position near the middle line of the vessel,
are not exposed to the liability of racing when the ship rolls in a heavy sea.
lower propellors owing to their depth are never uncovered and they must therefore
act steadily in all weathers while their greater distance from the vessel's middle line
gives them a greatly increased nanoeuvring power.
The propellors on each vessel may be made of the same or of different diameters
as preferred, and they may be placed either forward of the adjacent stern post,
(which if preferred is placed further aft) or even astern of the stern posts, if
desired.
The height or depth of the several stern posts and their distance from each other
may be modified at will within reasonable limits.
The form of the hull both in longitudinal and transverse section' may be modified
at will, provided only it is constructed with the series of stern posts at different
depths or, in other words, reduced in draught step by step toward the stern, the
lines in the different horizontal planes being modified accordingly.
When the shaft of the propellor in the middle line of the vessel lies directly over
the forward rudder, it will be necessary to construct the rudder head in the form of
a yoke as is commonly practised, in order that it may straddle the shaft.
Dated this 19th day of January 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or appertaining to Steam Propelled Vessels.
A communication from abroad by CHARLES GEORGE LUNDBORG, of the City,
County, and State of New York, United States of America.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street,
Manchester both in the County of Lancaster and 323 High Holborn, in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The constantly growing demand for steam-propelled vessels of increased speed
requires a constant increase in the power and weight of the engines and their

page_text: connections, and is attended with greatly increased difficulties and risks in running
such ponderous inasses at the high speeds required.
The adoption of twin propellers and the division of the propelling power
between two engines made it possible to develop and apply a greater aggregate
engine power than was before possible with lighter engines, ships and propellers.
A point has, however, been reached beyond which it is hazardous to attempt to
increase the power applied to two propellers. It has, therefore, been proposed to
use, in connection with a hull of ordinary form, three independently-driven
screw-propellers; one in the middle line at the stern, as usual, and the others, one
on each side at a higher level forward of the stern. This arrangement is open to
the objection that the full and rapidly converging lines of the hull prevent the
water from reaching the forward propellers in an advantageous manner, and to the
further objection that the rolling of the vessel is liable to uncover the forward
propellers.
Now, it is the aim of this invention primarily to produce a hull of such form or
construction at the stern that any desired number of propellers may be used
in connection therewith, and that the water may be allowed a free, easy and
advantageous run to all of these propellers to the end that they may act
efficiently and economically in the propulsion of the vessel.
It is also an aim of this invention to arrange multiple propellers in advantageous
relations to each other and to a hull constructed on this plan.
It is the further object of this invention to provide for the application of two or
more rudders in such position that they will act efficiently in directing the course
of the vessel, and that,_in_war_vessels, they may be beyond--the reach of the
enemy's shot.
In order that the nature and scope of this invention may be more fully and
clearly understood, a number of hulls, constructed in accordance with the inven-
tion, but modified according to the number and position of the propellers employed,
has been represented in the accompanying drawings, constituting a part of this
Specification

page_text: Figures 22 and 23 are respectively a side elevation and a top plan view of a
vessel having two rudders and three propellers.
Figures 24 and 25 are cross sections of the correspondingly-numbered lines of
Figures 22 and 23.
Figure 26 is a stern view showing the position and arrangement of the propellers
represented in Figures 22 and 23.
top plan view of a hull
Figures 27 and 28 are respectively a side elevation and
having three rudders and six propellers arranged in pairs.
Figures 29, 30 and 31 are cross sections on the correspondingly-numbered lines
of Figures 27 and 28.
Figure 32 is a stern view illustrating the relative position of the propellers
shown in Figures 27 to 31.
Figures 33 and 34 are respectively a side view and a plan view of a hull having
two pairs of propellers and a single balanced rudder.
Figures 35 and 36 are cross sections on the correspondingly-numbered lines of
Figures 33 and 34.
Figure 37 is a stern view illustrating the relative position of the propellers
shown in the four preceding figures.
Figures 38 and 39 are respectively a side elevation and a plan view of a hull
provided with two pairs of propellers and single balanced rudder.
Figures 40 and 41 are cross sections on the correspondingly-numbered lines of
Figures 38 and 39.
Figure 42 is a stern view showing the relative positions of the propellers.
Figures 43 and 44 are respectively a side elevation and a top plan view of a hull
having a single rudder and five propellers.
Figures 45, 46 and 47 are cross sections on the correspondingly-numbered lines
of Figures 43 and 44.
Figure 48 is a stern view showing the relative positions of the propellers shown
in Figures 43 to 47.
Figures 49 and 50 are a side elevation and a cross section respectively, showing
a vessel with two stern posts and two pairs of propeller's screws, the forward pair
aft of the forward stern post.
Figures 51 and 52 are respectively a side elevation and a top plan view of the
after part of a hull below the load water line, having full lines and large
displacement.
Figure 53 is a stern view of the same.
Figures 54, 55 and 56 are cross sections on the lines therein indicated.
In each of the drawings, W represents the load water line.
In constructing a hull in accordance with this invention, its forward portion
may be built of any ordinary or approved form, but the stern, instead of
terminating in a single stern post of great depth, as usual, is terminated below the
water line by two or more stern posts located in the centre line of the vessel, each
at a considerable distance forward of the next and at a lower level, the horizontal
water line of the hull being correspondingly modified at the different levels to give
a long and easy run of the water inward past the respective posts.
This construction of the hull with two or more stern posts at different levels
and at different points in its length, with the lines drawn inward on the respective
levels to meet the posts, is the essence of this invention, and is to be found in
slightly modified forms in each of the constructions represented in the drawings.
Referring to Figures 1 and 2, in which A represents the hull, it will be observed
that the keel B, forming the deepest part of the hull, is terminated at a point B¹,
some distance forward of the extreme after end of the vessel, at which point a
stern post C is erected rising half way to the load water line or thereabout.
From the top of this post C, the keel B, forming the deepest part of that portion
of the hull, is extended rearward to a stern post C¹, rising therefrom and forming
the extreme after end of the hull, as usual.
The portion of the hull between the two stern posts has therefore less depth or

page_text: draught of water than that portion of the hull forward of the front stern post C.
As shown in cross section in Figures, 6 and 7, the horizontal lines of the hull are
given a long, easy curvature but drawn inward to the respective stern posts, as
shown by dotted lines, in such manner that the water is given a free and easy
passage astern.
In other words, the water.is permitted to pass to each of the stern
posts in essentially the same manner, that is, in essentially the same direction, as
in passing the stern of an ordinary hull. To propel the hull thus formed, two
pairs of propellers D D¹ and EE are employed. The shafts cel carrying the
rear propellers EE' are projected through the sides of the hull at the proper
place and depth, supported in the ordinary manner and provided with the
ropellers slightly forward of the rear stern post C₁. These propellers, it will be
observed, are a considerable distance astern of the forward stern post C. The
forward propellers D D are also carried by shafts dd projected through the sides
of the vessel and sustained in the ordinary manner, their propellers being located
slightly forward of the front stern post C and at considerably lower level than
the rear propellers, as plainly shown in Figures 6, 7 and 8. It will be observed
that the water is allowed a long and easy run to each of the propellers and that
the latter are located in such relation to each other that they may all act efficiently
and without interference.
On referring to Figure 1, it will be understood that the draught of water of the
after part of the hull abaft the forward stern post C is about one half of the
draught forward of said post, and that on account of the shafts on the same side
of the vessel being in the same longitudinal vertical plane, the diameter of the
forward propellers. (in order that the blades may not-project-below-the keel) is
limited by the vertical distance between the two shafts. The part of the hull
aft of the forward stern post C may vary considerably in depth and draught of
water.
With the hull constructed and the propellers arranged as above described, the
propeller shafts may be independently driven by engines arranged in any suitable
manner, but, as shown in Figures 1, 2, and 10, the employment of four
independent engines F, F¹, F³, F³, located in four distinct and independent
compartments in the hull, is recommended. The forward engines F, Flare coupled
directly to the forward ends of the lower shafts dd for driving the lower and
forward propellers.
As the shafts of the rear propellers are at a higher level than the others, they
are driven directly by overhead engines, and in order that these engines may be
properly sustained, without interference with the lower shafts, their frames are
constructed as shown in Figure 9, to straddle both the upper and the lower shafts
and rest in the bottom of the hull.
The steering of the hull constructed as above is effected by two rudders G
and G attached respectively to the stern posts C and C, one rudder G being
forward of and at a lower level than the other. These rudders, thus located may
be operated by any suitable steering gear, but it is preferable to provide the rudder
posts at their upper ends, as shown in Figure 11, with the ordinary sector heads !,
and to connect these heads through intermediate lines or chains y, passing around
suitable guides to the single operating lines 2 whereby the two rudders are caused
to move simultaneously and equally...
Referring now to the hull shown in Figures 12 to 16, its construction will be
found practically identical with that already described. It terminates like the
first in two stern posts C and C', the former located forward of and at a lower
level than the latter. As in the first example, there are two rudders G and G¹
attached to the respective stern posts. The rear rudder has its top located at
some distance below the load water line so that it may be the better concealed
and protected in the case of a war vessel, from the projectiles of the enemy. The
stern post is carried in suitable form rearward over the top of this rudder, so as to
bring the rudder within the longitudinal limits of the hull. As in the first example,
the vessel is propelled by two pairs of propellers on horizontal shafts projected

page_text: outward through the quarters of the hull, two on each side of its central line.
The forward and lower propellers are, however, arranged at a somewhat greater
distance apart than the upper propellers, as plainly shown in Figure 16. This
arrangement gives an increased distance between the shafts on the same side of
the vessel and permits the forward propellers to be made of greater diameter than
under the arrangement shown in Figures 1 to 8.
Figures 17 to 21 illustrate still another arrangement of four propellers. The
hull is formed with the forward and lower stern post C as in the preceding
examples, but the rear post C' is extended somewhat below the level of the top of
the forward post and given a curved form at its lower end to admit of the
propeller E being located immediately in front thereof on the rear end of a shaft
located in the middle line of the hull, as in single propeller ships. A second
propeller E is located in the centre line of the vessel forward of the front stern
post C, and below the level of the rear propeller. Two additional propellers E
and Es are also located, one on each side of the vessel, in the same or substantially
the same transversed plane as the propeller Es³. The shafts of these three forward
propellers are preferably in the same horizontal plane, as shown, but the height of
the side propellers E' and E' may be varied at will. Two rudders are hung upon
the respective stern posts, as in the preceding examples. Referring to Figures 22
to 26, the stern of the vessel is formed of two posts in essentially the same manner
as in Figure 17, and provided with two rudders hung upon said posts. It is
propelled, however, by three propeller screws, one propeller screw located in the
centre line of the vessel, immediately in front of the rearmost stern post C, as in
Figure 17. The remaining propellers E and E are located in essentially the
same manner as that shown in Figures 18 and 21, and in a plane slightly forward
of the front stern post and on opposite sides of the centre line of the vessel.
Figures 27 to 32 represent a hull in which the stern is constructed with three
stern posts at different longitudinal points and in the centre line of the vessel, but
at different depths below the load water line. The foremost post C₁, rises from the
keel or lowermost portion of the hull. The second post C³, located some distance
aft of the foremost post C', rises about half the distance to the load water line,
while the third post C³ at the extreme stern of the vessel, rises from the level of
the top of the intermediate post C³ to the top of the hull. The lines of the vessel
converge to the respective stern posts on their different levels, as shown in
Figures 29 to 31. It will be observed that this hull involves the same principles
of construction as those previously described, that is to say, a plurality of stern
posts located at different depths and at different points in the length of the vessel
with the hull shaped to give a free run of the water past each of the posts. This
hull, with its three posts, is propelled by three pairs of twin propellers located
just forward of the respective stern posts, and at corresponding depths, the two
propellers of each pair being located on opposite sides of the middle line of the
vessel.
The foremost propellers E and E' are preferably arranged at a greater distance
from the middle of the vessel than the others, and the two upper shafts are
preferably placed on each side of the vessel in the same longitudinal vertical plane
as represented in Figure 32, but their relative positions may be modified as the size
of the propellers to be employed may demand. Each of the three stern posts has a
rudder hung upon it, as shown at G G and G³.
In Figures 33 to 37, a hull is represented having three stern posts, as in the
preceding example, but the middle post instead of being straight is curved forward,
as shown in order to permit the use of a balanced rudder G, which is thus hung at
a considerable depth below the surface and in a position of safety. This hull is
provided with four propelling screws arranged in pairs, the after propellers being
hung at a higher level and forward of the rearmost stern post, while the forward
propellers, which are more widely separated are located forward of the foremost
post.
In Figures 38 to 42, the hull is represented having three stern posts of essentially

page_text: the same form and arrangement as those in Figure 33, and with a balanced rudder
hung upon the middle post. In connection with this hull, two pairs of propeller-
screws are shown, one pair forward of the middle stern post, the other forward of
the forward post. The two propellers of each pair are in opposite sides on the
middle line of the vessel, and the lower propellers are more widely separated than
the upper.
In Figures 43 to 48, a hull is shown with three stern posts differing from that in
Figures 33 and 38 only in having the aftermost post curved downward similarly
to that in Figure 22, in order to permit the use of a large propeller at the extreme
stern. As here shown, the vessel is provided with five propellers, a centre
propeller at the middle line at the extreme stern, a pair of propellers forward of
the middle post and below the level of the rear propeller; and a second pair
forward of the front post at a lower level than the first pair and more widely
separated.
It is to be noted that, in each example of the vessel, as here illustrated, the lines
are adapted to permit the free run of the water to and past each of the stern posts,
and that the propeller shafts are in each case projected through and so that they
may be sustained outside of the vessel, either in the ordinary manner or by supports
of any other construction adapted to maintain them in position.
From the foregoing description and explanation of the drawings, it will be seen
that the invention embraces and admits of a great variety of combinations, and
varied positions of any desirable number of propellers, either in the middle line or
in the sides of the vessel, or in front or rear of the stern posts; the number of which
may also vary as desired, as well as the number and position of the rudders. An
immense aggregate engine power and weight may be consequently divided between
several comparatively light engines, propellers and shafts, which may be easily and
adequately supported, and safely operated at high speed.
The invention, as regards the shape of the hull, also affords means of giving to
each and all of the propellers such positions that the lines of the vessel will permit
à free and direct run of the water to the discs of the propellers.
The invention also admits of the rudders and propellers being placed at such
great depth below the surface of the water that, in the case of war vessels, they are
free from liability to injury by the enemy.
The shape of the hull and the arrangement of the rudders give greatly increased
handiness and steering and manoeuvring power:
First because the vessel has more than one rudder, either of which may be large
enough to alone steer the vessel,
Second, on account of the diminished vertical surface of the after part of the hull
below the water line, so that it offers less resistance to the lateral motion effected
by the rudders,
Third, because of the greater distance of all forward and deeper propellers from
the middle line of the vessel.
This invention secures greater economy in vessels of war when cruising, as only
one or two small engines need be used, and, in all vessels, gives greater safety by
reason of the employment of several independent engines and screws, and greater
speed in consequence of the diminished surface and correspondingly diminished
frictional resistance of the after part of the hull.
The upper propellers, owing to their position near the middle line of the vessel
are not exposed to the liability of racing when the ship rolls in a heavy sea. The
lower propellers, owing to their depth, are never uncovered, and they must there-
fore act steadily in all weathers, while their greater distance from the vessel's
middle line gives them a greatly increased manoeuvring power.
The propellers on each vessel may be made of the same or different diameters as
preferred, and they may be placed either forward of the adjacent stern post, which,
if preferred, is placed further aft, or even astern of the stern posts, if desired, as
represented in Figures 49 and 50.

page_text: The height or depth of the several stern posts and their distance from each other
may be modified at will within reasonable limits.
The form of the hull, both in longitudinal and transverse section, may be modified
at will, provided only it is constructed with a series of stern posts at different
depths, or, in other words, reduced in draught step by step towards the stern, the
lines in the different horizontal planes being modified accordingly.
The hull represented in Figures 49 and 50 is identical with that shown in
Figures 1 and 2, but the forward propellers are arranged aft of the forward stern
post instead of being forward of the post, as shown in Figure 1.
The hull, shown in Figures 51 to 56, is of the same general character as those
shown in the preceding views, its distinguishing feature being that it has fuller lines
and greater displacement.
In Figures 17, 22 and 43, it will be observed that the shaft of the propeller in
the middle line of the vessel lies directly over the forward rudder, whence it will be
necessary to construct the rudder head in the form of a yoke, as is commonly
practised, in order that it may straddle the shaft.
In each of the plan views in the drawings, the curved dotted lines represent the
exterior lines, or water lines of the hull in the horizontal planes of the respective
propeller shafts, in other words, the dotted lines extending forward from each of
the stern posts represent the water lines of the vessel in horizontal section on a
plane passing through the post between the upper and lower ends.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. A vessel having a plurality of stern posts located in its middle line at
different points in its length and extending to different depths, substantially as
described and shown.
2. A vessel having its after end reduced in depth and draught step by step
towards its stern, with its water lines gradually converging in each horizontal plane
to the terminal point.
3. A vessel having its after end reduced in depth and draught step by step
toward the stern and terminating in a series of central stern posts at different
depths, substantially as described and shown.
4. A vessel having, in its middle line, two stern posts, one forward of the other,
the forward post extending to a greater depth than the after post, and the latter
carried below the level of the top of the forward post, whereby the use of a large
central propeller at the stern is permitted.
5. A vessel having a plurality of stern posts located at different points in its
lengths, and extending to different depths, in combination with a plurality of
rudders hung upon the respective posts.
6. A vessel provided with two or more rudders located in the centre line at
different depths and at different longitudinal points.
7. A vessel provided at the stern with two rudders, one in advance of and below
the other, in combination with steering gear common to the two rudders and acting
to remove them in unison.
8. A vessel having in its centre line a plurality of stern posts extending to
different depths in the water, in combination with a series of screw-propellers,
located adjacent to the respective posts.
9. A vessel, the after end of which converges to and terminates in two stern
posts, in combination with two pairs of propeller-screws, one pair in advance of and
at a lower level than the other pair, the two propellers of each pair on opposite
sides of the centre line of the vessel.
10. A vessel terminating in three stern posts extending each to a greater depth
than the one forward thereof, in combination with two pairs of propellers located,
one pair in advance of and deeper than the other, the two propellers of each pair

page_text: on opposite sides of the middle line, and a centrally located and still higher
propeller at the stern.
11. A vessel provided on each side with two propellers, one in advance of and at
a greater depth than the other, in combination with two rudders, located one
between the two of each pair.
12. A vessel having two pairs of propellers, one pair forward of the other, the
two propellers of each pair on opposite sides of the keel, and the forward pair at a
greater depth than the other.
Dated this 14th day of Santambas 1001
WM. P. THOMPSON & Co.,
Agents for the Applicant.