Method of and Apparatus for Preventing or Lessening the Rolling of Vessels at Sea.
Year: 1889

page_text: Date of Application, 20th May, 1889
Complete Specification Left, 20th Mar., 1890-Accepted, 17th May, 1890
PROVISIONAL SPECIFICATION.
A Method of and Apparatus for Preventing or Lessening the Rolling
of Vessels at Sea.
I, JOHN ISAAC THORNYCROFT, of the firm of John L. Thornycroft & Co., of Church
Whart, Chiswick, in the County of Middlesex, Steam Yacht & Launch Builder, do
hereby declare the nature of this invention to be as follows:-
My invention has reference to a method of preventing or lessening rolling of a
vessel at sea by balancing the turning moment or forces tending to make the vessel
place her masts at right angles to a wave, maintaining the vessel's stability, preserving
her tendency to remain upright and offering resistance to any rolling motion she may
from any cause attain.
The apparatus I employ to perform the three distinct duties above indicated includes
controlling gear capable of measuring the necessities of each instant and governing
other apparatus providing forces adequate to meet them.
The controlling apparatus depends first on a pendulum (or its equivalent), herein-
after called the short pendulum, having a short period compared with the natural
period of oscillation of the vessel to be steadied or of the waves on which the vessel
floats. An equivalent of this pendulum may consist of a mass capable of horizontaļ
motion but tending to some particular position by some elastic attachment and there-
fore being capable like a pendulum of giving a definite measure of the deviation in the
apparent direction of gravity from the line it takes in the vessel when upright and not
influenced by waves. But if the vessel is inclined, the control of the apparatus by this
pendulum alone will greatly reduce stability.
A second pendulum (hereinafter called the long pendulum) is adapted to join
in control with the short pendulum and more or less balance its tendency to reduce
stability.
The long pendulum must have a long period compared with the natural period of
the vessel or of the waves acting on the vessel and should therefore have a large.
moment of inertia but be supported as near to its centre of gravity as will give it
necessary stability it being required to give as far as possible an absence of rotation
about some axis about which any rotation of the vessel may be measured.
An equivalent for this pendulum will be any device fulfilling this condition as for
instance a gyroscopic wheel.
The two pendulums are used to exercise a joint control the one modifying the action
of the other. There is also double duty obtained from the long period pendulum or
its equivalent, hereinafter included in the expression the long pendulum.
The first duty of the long pendulum is to counteract one effect produced by the short
period pendulum and restore to the vessel the stability the short pendulum takes
away. The short pendulum is to balance the tendency of a vessel to set her masts at
right angles to the surface of what is called the equivalent wave slope on which she
floats.
Thus the short pendulum will prevent the vessel righting from an inclined position
in still water; the long pendulum will give the vessel power to right again by
balancing more or less the effect of the short pendulum when the vessel is inclined.
A further duty of the long pendulum is to give control which causes resistance to
rolling motion independent of the vessel's position or the action of waves and this
control will modify the action of the short pendulum and the other action of the long
pendulum which gives stability.
The pendulums I suspend on bearings having very small friction so that they shall
not be disturbed by motion of the vessel and to enable them to exercise control also
without influencing their position I pass a current of fluid through them in such a

page_text: manner as to cause no reaction ten ling to disturbance or an electric current may be
used through contacts having small friction. By it electro magnets can be made to
work valves controlling pistons connected to the contacts so as to follow the motion of
the pendulums and thereby complete the control apparatus which may have the various
elements of control capable of being so combined as to meet the varying necessities of
a vessel at sea; that is, the period of oscillation may be varied, the stability at the same
time being altered, or the power to resist rolling motion only changed.
-
The apparatus for providing force to resist the rolling effort of waves or resistance
to retard motion may consist of either movable blades exposed to the moving water
past the vessel and provided with suitable means to adjust the angle of the surface at
each instant or a heavy mass may be made.to move in the vessel so as to balance the
forces.
When movable blades are used in order to oppose as little resistance to progress as
possible the arca of the surfaces should be large enough to control the vessel's rolling
without being placed at a large angle to the direction of motion of the passing water
and as it would be usually used when the vessel was moving ahead, the axis about
which the surface turns might be placed near the forward end so as to be controlled
with as little force as possible. To avoid waste of power, if hydraulic cylinders are
used to move the blades, pumps might be used continually driven by the main engines
but having their discharge only resisted by the pressure necessary to move the blades,
greater speed of motion being attained by the addition of one or more pumps thrown
into the circuit.
As will be evident apparatus to operate on the principle of my invention as above
set forth may be constructed in various forms.
An arrangement of controlling apparatus such as I will now describe might be used
to combine the three actions hereinabove mentioned and give motion to a valve or
valves so as to control other apparatus to steady a vessel in such a manner as to lessen
rolling. In this arrangement an extended base carries the supports for two pendulums
the short and the long. The axis about which the short pendulum oscillates is located
near to and practically in the same direction as the axis about which the ship rolls and
at about the same level as is the centre of gravity of the vessel. This pendulum con-
sists of a heavy horizontal cylinder, long in proportion to its diameter and pivotted so
as to have an axis parallel to its centre line.
It is supported on cylindrical bearings made to oscillate in opposite directions and
arranged so that the friction of the one shall balance that of the other thus giving
great freedom of turning.
The long pendulum is similarly supported, its axis parallel to that of the short
pendulum but a short distance above. This pendulum consists of a long beam at right
angies to the axis and carrying two heavy masses one at each extremity their com-
bined centre of gravity being situated a small distance below the axis compared with
the length of the beam.
Each pendulum carries a commutator capable of distributing an electric current so
as to excite electro magnets when the positions of the pendulums are disturbed. The
electro magnets are arranged to actuate valves controlling fluid pressure which in turn
work the tongues round the commutators until the circuit is broken. In this way the
pendulums are made to control Huid pressure in cylinders and place certain levers in
positions depending on the positions of the pen lulums which have no perceptible
resistance to over-come if the contacts are made so as to work with little friction.
The long pendulum also controls indirectly a cylinder which governs the resistance
to be applied to prevent the motion of rolling.
Within a passage between one end of one of the cylinders of the apparatus and the
distributing valve, is a piston that is moved by the fluid on its way to or from the
cylinder.
This piston at either end of its stroke allows the fluid to pass. Two light springs
tend to hold this piston in the passage at midstroke and a bye-passage is arranged so
as to vary the action and allow the return of the piston to mid position to take place
in different times as desired. One end of a lever is attached to this piston and the

page_text: other end to a piston in another cylinder. The motion of the piston in this last
mentioned cylinder is controlled by a valve actuated by electro magnets and these
electro magnets are excited by a current under control of a commutator actuated by
the lever before mentioned. The action is so arranged that the magnets regulate the
valve in such a manner as to bring the commutator into a neutral position in which
both magnets are out of action.
D
1
.
1. 1990
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
A Method of and Apparatus for Preventing or Lessening the Rolling
of Vessels at Sea.
I, JOHN ISAAC THORNYCROFT, of the firm of John I. Thornycroft & Co., of Church
Wharf. Chiswick, in the County of Middlesex, Steam Yacht and Launch Builder,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:
My invention has reference to a method of preventing or lessening rolling of a
vessel at sea by (1), balancing the turning moment or forces tending to make the
vessel place her masts at right angles to a wave; (2), maintaining the vessel's
stability; and (3), offering resistance to any rolling motion she may from any cause
attain.
The apparatus I employ to perform the three distinct duties above indicated includes
controlling gear capable of measuring the necessities of each instant and governing
other apparatus providing forces adequate to meet them.
The controlling apparatus depends first on a pendulum (or its equivalent) herein-
after called the short pendulum having a short period compared with the natural
period of oscillation of the vessel to be steadied, or of the waves on which the vessel
floats. An equivalent of this pendulum may consist of a mass, capable of horizontal
motion but tending to some particular position by some elastic attachment and there-
fore being capable like a pendulum of giving a definite measure of the deviation in
the apparent direction of gravity from the line it takes in the vessel when upright and
not influenced by waves. But if the vessel is inclined, the control of the apparatus by
this pendulum alone will greatly reduce stability.
A second pendulum (hereinafter called the long pendulum) is adapted to join in
control with the short pendulum and more or less balance its tendency to reduce
stability when the vessel is inclined.
The long pendulum must have a long period compared with the natural period of
the vessel, or of the waves acting on the vessel, and should therefore have a large
moment of inertia, but be supported as near to its centre of gravity as will give it
necessary stability, it being required to give as far as possible an absence of rotation
about some axis about which any rotation of the vessel may be measured.
An equivalent for this pendulum will be any device acting in an analogous manner
and fulfilling this condition as for instance a gyroscopic wheel as hereinafter more
fully set forth.
The two pendulums are used to exercise a joint control, the one modifying the
action of the other. There is also double duty, obtained from the long period
pendulum, or its equivalent, hereinafter included in the expression the long
pendulum.
The first duty of the long pendulum is under certain circumstances before
described, to counteract one effect produced by the short period pendulum and
restore when required to the vessel the stability the short pendulum takes away.
The short pendulum is to balance the tendency of a vessel to set her masts at right

page_text: angles to the surface of what is called the equivalent wave slope on which she floats
or to the surface of still water to which she is inclined.
Thus the short pendulum would prevent the vessel righting from an inclined
position in still water; the long pendulum however will give the vessel power to
right again by balancing more or less the effect of the short pendulum when the
vessel is inclined.
A further duty of the long pendulum is to give control to apparatus which causes
resistance to rolling motion independent of the vessel's position, or the action of
waves, and this control will modify the action of the short pendulum and the other
action of the long pendulum which gives stability.
The pendulums suspend on bearings having very small friction so that they shall
not be disturbed by rolling motion of the vessel, and to enable them to exercise
control, also without influencing their position, I may, as hereinafter described pass a
current of fluid through them in such a manner as to cause no reaction tending to
disturbance. I prefer however to use an electric current through contacts having
small friction. By this electric current electro magnets can be made to work
valves controlling pistons connected to the contacts so as to follow the motion of
the pendulums and thereby complete the control apparatus which may have the
various elements of control so combined as to meet the varying necessities of a vessel
at sea; that is, the period of oscillation of the vessel may be varied, the stability at
the same time being altered, or the power to resist rolling motion only changed.
The apparatus for providing force to resist the rolling effort of waves, or resistance
to retard motion, may consist either of a heavy mass made to move in the vessel so
as to balance the forces; or of movable fins or blades exposed to the water moving
past the vessel and provided with suitable means to adjust the angle of their surface
at each instant.
As will be evident apparatus to operate on the principle of my invention as above
set forth, may be constructed in various forms.
In the accompanying drawings : -
Figs 1 to 7 illustrate an arrangement of controlling apparatus that can be used to
combine the three actions hereinabove mentioned and give motion to a valve or
valves so as to control other apparatus (hereinafter called steadying apparatus) and
shewn in Figs 8 to 10 to steady a vessel in such a manner as to prevent or lessen
rolling.
Fig. 1 is a plan, partly in section;
Fig. 2 is a longitudinal vertical section partly in elevation.
Fig. 3 is an end view, partly in section, with the pendulums and valve operating
mechanism removed for the sake of clearness.
Fig. 4 is an erd view shewing the commutators carried by the pendulum shafts,
and the brushes and means for operating the same; it also shews means for
oscillating the pendulum bearings.
Figs. 4 and 4 are detail Figs. hereinafter described.
Fig. 4 is a diagrammatic view.
Fig. 5 is a cross section of the short pendulum.
Fig. 6 shews in side elevation part of the long pendulum with adjusting devices.
Fig. 7 is a plan of an electric motor for oscillating the pendulum bearings.
Figs. 5 and 7 are drawn to a larger scale than Figs. 1 to 4.
Fig. 8 shews in plan two forms of steadying apparatus applied to the central
portion (indicated in outline) of a navigable vessel.
Fig. 8 is a detail view.
Fig. 9 shews in vertical section part of the vessel with one of the arrangements of
steadying apparatus; it also illustrates the connection between that apparatus, and
the controlling apparatus, which is shewn in elevation.
Fig. 10 illustrates in transverse section one side of a navigable vessel (shewn in
outline) having applied to it the alternative arrangement of steadying apparatus,
Figs. 11, 12, 13 14 and 15 illustrate modifications hereinafter referred to.

page_text: Referring to Figs. 1 to 7 inclusive, 1 is the short pendulum, and 2 the long
pendulum; they are fixed upon spindles mounted to turn in oscillating bearings 3,
and 4 respectively, that are supported in standards 5 carried by a base plate 6. The
short pendulum should be located with its axis of oscillation coincident with, or near
to and practically in the same direction as the axis about which the ship rolls. The
short pendulum is formed as a heavy cylinder (normally horizontal) long in
proportion to its diameter, and mounted so as to have an axis of oscillation parallel
to the axis of the cylinder that constitutes the pendulum. It may conveniently be
constructed as illustrated in Figs. 2 and 5.
In this arrangement it is hollow, with a longitudinal diaphragm 7, the space
below which is filled with suitable substance such as heavy metal 8 (such as for
example lead). The space above the diaphragm is partly filled with liquid 9 such
as mercury which will have the effect of obviating excessive vibration of the
|pendulum."
Fig. 11 represents diagrammatically an equivalent for a short pendulum, in
which a' is a mass supported on wheels or rollers so as to move with little friction
in the direction of the line c'-d and secured to a spring e, that is also attached to a
support. If the figure represents the position of the mass when - is horizontal,
then any inclination of e-d or any change in the apparent direction of gravity
which is at right angles to this line will be indicated by motion of the mass a in the
direction - or o-y.
In order to give this equivalent of a pendulum a short
period the spring e must have considerable stiffness.
The long pendulum 2 is supported with its axis of oscillation parallel to and above
that of the short pendulum. In the drawing the long pendulum is shewn as being
a built up beam comprising two lower longitudinal members and an upper or tension
member, the ends being provided with massive parts or weights 12. The centre of
gravity of this long pendulum should be (speaking comparatively with reference to
the length of the pendulum) only a small distance below the axis of oscillation.
13 is an adjustable weight for the purpose of accurately balancing the pendulum, and
14 is an adjustable weight for varying the position of the centre of gravity of the
pendulum according to requirement. 15 is a bent tube secured to the long pendulum
and partly filled with mercury with the object of obviating excessive vibration of the
pendulum.
An equivalent for this long pendulum 2 is shown in Figs. 12 and 13 which are
respectively a sectional elevation and a sectional plan. This equivalent consists of a
heavy revolving dise or gyroscopic wheel mounted in gimbals so as to allow its
axis to be free to retain its position' unaltered in space although the vessel may pitch
or roll. The gimbals may be formed as shewn by introducing a ring in place of
the shaft carrying the long pendulum 2; carried by and within this ring is a second
ring that is pivotted with its axis at right angles to the axis of the ring hand
supports the disc g' in such a manner that the disc can freely rotate on an axis which
may be turned in any direction. The axis of the disc is however given a tendency
to assume a particular position by any suitable means it may be by means of weak
springs, when balanced so as to remain in any position when the weak springs are
removed, or by arranging that the centre of gravity of the disc shall be so placed as
to give stability in the position desired.
This stability will be increased by rapid rotation of the disc. The disc may be
kept in rapid rotation by any convenient means as for instance by compressed air
forced through a hollow portion of the ring h³ from an injector k' and issuing through
a part of ring so as to propel the disc.
The apparatus just described can be made more compact than can be done with
the long pendulum before described, but the long pendulum has the advantage of
greater simplicity and diminished wear and tear, when compared with the equivalent
for the long pendulum in which a revolving disc is used.
16 is an electric motor adapted to oscillate the bearings 3 and 4 of the pendulums,
for the purpose herein before mentioned.
The motor 16 may be of any suitable construction but I consider it advantageous to

page_text: adopt the construction illustrated (see Figs. 1, 3, and 7) in which there are three
pairs of stationary field magnets a, b, c, and an armature d mounted upon a driving
Shaft 20. e is the upper bearing of this shaft; is its foot-step bearing. On the
shaft 20 is mounted a disc with heavy rim. This disc carries an insulated plate h,
that may be in two pieces, to serve as a commniator. ¡ is a sleeve able to move in a
vertical sense on the shaft 20 but controlled by the governor arms to which it is
connected by links as shewn. The enlarged lower part of the sleeve is of, or is covered
with, meial that is insulated from the shaft and governor arms. The terminal is
provided with a rubbing contact m that bears against the cylindrical surface of the
conducting part of the governor sleeve; and this part in turn normally bears against
the insulated plate h. n, n', n are three brushes that take the current from the
plate to the respective field magnet coils, each set of coils being served in turn by
one of the three brushes. The other ends of the coils are connected with the other
terminal of the electric generator. Should the motor attain an excessive speed the
governor arms by raising the sleeve will break the circuit until such a reduction in
speed is attained as to allow the sleeve to descend when the circuit will be again
completed.
Oscillating movement is imparted by the motor to the bearings as follows:-
Two sets of rods each comprising two rods 17 and 18 that are jointed together and
to arms projecting from the respective bearings as shown, are operated by crank
arms 19 on a rock shaft 19" which is driven from the driving shaft 20 through the inter-
vention of a worm 21, worm wheel 22, shaft 23, crank 24, connecting rod 25, and
lever arm 26. The crank arms 19 are arranged at opposite sides of the axis of the
shaft 19 (fig. 4) so that when the one set of rods 17 and 18 is raised the other set will
be lowered, and the two bearings of the short pendulum I, as also those of the long
pendulum 2, will thus be caused to oscillate in opposite directions, so that the friction
of one shall balance that of the other, thus giving each penduluin great freedom of
turning.
27 and 28 are commutators, secured on the spindles, carrying the pendulums
and 2 respectively. These commutators are provided with brush holders 29 and 30
respectively each of which is mounted to turn on an extension 32 of the adjacent
oscillating bearing 3 or 4. Each commutator comprises a metal plate supported on
insulating material. Each brush holder is fitted with two sets of brushes 33 and 34;
these normally rest upon the insulating portion of the commutator; and each set of
brushes is connected to an independent set of electro magnets in a valve operating
device hereinafter described.
35, 36 and 37 are three motor cylinders, fitted with double acting pistons 35", 36",
and 37 respectively. These cylinders are also provided with piston distributing
valves 35, 36, and 37" respectively (Figs. 1 and 2) for motive fluid (for example,
water under pressure). Each valve works in a valve chamber (see Fig. 2) and con-
trols ports and passages 40 and 41, that communicate with the respective ends of the
corresponding cylinder; also each of the valves controls other ports communicating
with the inlet and outlet passages 42 and 43 respectively of its cylinder.
The passage 40 of the cylinder 37 is enlarged at 40" to form a chamber within
which is arranged a piston 44 that is or may be moved by the fluid on its way
to or from the upper part of the cylinder. In the example illustrated in Fig. 3 the
movement of this piston is one of partial rotation. The piston 44 is connected to a
commutator 47 by means of a spindle 44" and lever 44" (Fig. 1). 45 is an external
lever that is provided with segmental teeth 46. 48 is a brush holder carried by the
lever 45 and provided with a set of brushes 49 adapted to bear normally upon an
insulating portion of the commutator. The chamber 40" is formed with channels 40
that serve as bye passages to vary the action of the fluid on the piston 44 in order to
admit of alterations in the time occupied by this piston in returning to the mid-
position (shewn in Fig. 3). The piston does not accurately fit the chamber 40" at its
sides, so as to permit Huid to pass between the two without actuating the piston if
such fluid be moving slowly.
A, B and C are devices which I find may be advantageously used for operating

page_text: the valves 35, 36b 37 respectively. Each of these devices comprises two pairs of
electro magnets 50 and 51 and an armature 52. This armature is fixed upon a
spindle 53 formed with an eccentric at 54 to which is fitted one end of an eccentric
rod 55, the other end of which is jointed to one of the distributing valves. The
pairs of electro magnets 50 and 51 of the magnetic device A are connected by
conductors 33, 34, to the sets of brushes 33 and 34 respectively of the commu-
tator 27. The magnets of the electro magnetic device Ċ are similarly connected
to the sets of brushes of the commutator 28. The electro magnets of cach device A
and C are also connected to one pole of an electric generator, the other pole of
which is connected to the insulated metal plate on each commutator 27, 28. The
pairs of magnets for operating the distributing valve 36, are connected to insulated
metal plates 47, 47" of the commutator 47, and also to one pole of an electric
generator, the other pole of which is connected to the set of commutator brushes 49.
These electrical connections are illustrated diagrammatically in Fig. 4 in which
E represents an electric generator.
Each armature 52 is provided with a pin or roller 56 that is acted upon at
opposite sides by levers 57 pivotted at 58 and held together by a spring 59. By
this arrangement the armature and connected distributing valve will be returned to
their normal positions, (shewn in Fig. 2) after they have been operated by one of the
pairs of electro magnets 50 or 51, and the circuit of these magnets has been
broken.
60, 60 are levers which directly govern the steadying apparatus hereinafter
described. They are freely mounted upon a shaft 61 carried in bearings 62, and
are connected by links 63 to another pair of levers 64. The levers 64 are connected
at one end by links 65 to a crosshead 66 carried by the rod of piston 37", and at the
other end are jointed to another pair of levers 67. The levers 67 are connected at one
end by links to crosshead 68 and at the other end are directly attached to crosshead 69.
These crossheads 68 and 69 are secured to the rods of pistons 35" and 36 respectively.
70 is a lever mounted on the shaft 61; one of its arms is a toothed segment that
gears with the rack 46 on the lever 45; the other arm of 70 is connected by a link 71
to the crosshead 69.
72 (Figs. 1, 4, 4) is a lover turning freely on the shaft. 61. One arm of this lever
is connected to the brush holder 30 by a link 73 its other arm being connected by a
link 74 to one end of one of the pair of levers 64 which end has a vertical motion
nearly similar to the crosshead 66.
75 is another lever one end of which is carried by the shaft 61 in such a manner
that it can turn freely thereon. The other end of this lever 75 is connected by a
link 76 to the crosshead 68. A link 77 attached to an intermediate point of the
lever 75 gives motion to the brush holder 29. The motion given to the brush
holders 29 and 30 by the levers 72 and 75 respectively is for the purpose of
moving over the respective commutators, the sets of brushes carried by the said
holders.
The steadying apparatus, according to one arrangement, comprises a heavy movable
weight 79 secured to a shaft 80. This shaft may advantageously be inclined as shown,
and is provided with a crank arm 81. 82 is a hydraulic motor, the piston of which
is connected by a rod 83 to the crank $1 for the purpose of turning the weight 79
from its central and normal position shewn (in Figs. 8 and 9) to one or other side of the
centre line of the navigable vessel 84, as may be necessary to balance a turning moment
or force exerted on the vessel by waves or to prevent or lessen rolling of such vessel.
85 is the distributing valve of the motor; it is operated and controlled from the
levers 6) of the controlling apparatus (marked collectively D Fig. 9) by means of
a rod 86, pivotted slotted link 87, rod 87, crank arm 88, shaft 89, crank arm 90,
rod 91, lever 92, and valve rod 93. The lever 92 is also connected by a link 94 to
a crank arm 95 that is secured to the outer end of the crank arm 81. The crank
arm 95 is of greater length than the crank arm 81. The rod 86 may be directly
connected to the valve operating lever 88, but by using a pivotted slotted link 87,
and a rod 87 adjustably connected thereto, the extent to which the valve of the

page_text: motor 82 is moved can be varied as desired. Thus the steadying apparatus may be
set to work to its full extent, or to any fraction of it; or it may have its efforts entirely
suspended should the controlling apparatus, from any cause, cease to work properly.
For a vessel of say of 250 to 300 tons displacement, a movable weight 79 of about
12 tons may be used, and be so arranged that its centre of gravity can move through
about three feel on either side of the central vertical plane of the vessel. It is
however advantageous to allow the weight to make a complete revolution if necessary,
so as to avoid any danger that might arise from striking an object if its path were
limited in extent. The inclination of the shaft 80 as shewn; enables the power
necessary to work the weight to be reduced; also it imparts to the weight a tendency
to maintain a central position in relation to the ship, instead of to give the vessel
a list one way or the other, should the hydraulic or other gear used to operate the
weight, fail from any cause.
In lieu of, or in addition to the internal movable weight 79, the vessel may be
provided with a series of movable blades 96 (Figs. 8 and 10) arranged at each side
of, and external to the vessel.
In order that these movable blades may oppose as little resistance to progress as
possible, the area of their surfaces should be large enough to control the vessel's
rolling, without being placed at a large angle to the direction of motion of the passing
water, and as they would usually be employed when the vessel was moving ahead,
the axis about which the surface of each blade would turn might be placed near
the forward end or edge as shewn so as to be controlled with as little force as
possible.
The blades in the example shewn, are capable of being turned in either direction,
each through an angle of about 15 degrees from its normal position. The blades
in each set are simultaneously operated by the piston of hydraulic motor 97
through a connecting rod 98, and levers 99, of which there is one for each blade.
To allow the blades to turn independently of the motor, when a certain turning
moment is exceeded, the spindle 100 of each blade has fixed thereto a cam or
block 101, in the underside of which is formed a recess 101" (Fig. 8). Into each
recess is forced a tongue 101 carried by a strong spring 102 which is supported
in any convenient manner. Each spring is guided by and connected to one of the
levers 99 which may be made fork shape to embrace the spring between its two
portions as shewn. Each lever 99 for turning or operating a blade through the
corresponding spring, tongue, and cam has one of its ends fitted to turn freely upon
the end of the corresponding blade spindle 100.
This arrangement will permit the blades, if displaced by a violent wave, to move
edgewise to the current to obviate bending or breakage. Rapid movement of the
vessel astern also, would cause displacement of the blades.
Two diametrically arranged recesses may be formed in each cam 101, one corre-
sponding to motion ahead, and one to motion astern. If the blades are displaced
by a wave, then, when the wave is gone, the motion of the vessel through the water
will bring the blades back nearly into the required position again, and motion of
the levers 99 will bring the tongues 101 sufficiently near to the recesses 101ª to
cause the tongues to slide into the recesses.
The distributing valve of each motor 97 is operated from the red 86, link 87,
and a rod 87 (Figs. 8 and 9) by a lever arm 88*, shaft 89ª, crank arm 90º,
rod 91, lever 92" and valve rod 93. in a similar manner to the valve of the
motor 82. The lever 92ª of each motor 97 is connected to one of the levers 99
by a rod 94".
The motive fluid for working the pistons in the various cylinders or motors
herein referred to may be supplied by any suitable apparatus such as a pump or
compressor.
The operation of the apparatus is as follows:-
When the vessel to which the apparatus is applied is subjected to a turning
moment or force tending to place the masts of the vessel at right angles to a wave,
the short pendulum 1, owing to its period of oscillation being (as hereinbefore

page_text: mentioned) short compared with that of the vessel or of the waves on which the
vessel floats, will oscillate quicker than the vessel, and will cause the commutator 27
to turn, and to complete the circuit of one or other of the pairs of magnets 50 or 51
of the device A. The direction in which the pendulum turns will determine which
magnet will have its circuit closed. The distributing valve 35 controlled by the
device A will consequently bo operated; the piston in cylinder 35 will be set in
action, and motion will be transmitted to one end of the pair of levers 67. These
levers will turn about the centre 67° (Fig. 3) and their motion will be transmitted
through the levers 64, links 63. levers 60, rod 86 and attached rods and levers to the
distributing valve of the motor or motors employed to operate the steadying
apparatus.
Thus the motor 82; or the motors 97 (whichever is employed) will act to move
either the weight 79 or the blades 96 or both (if both be employed together) into
position to offer the necessary resistance to balance the turning moment or force
exerted on the vessel. The vessel will thus be prevented from setting her masts at
right angles to a wave acting upon her. When the piston 35ª moves, motion will be
transmitted through the link 76, lever 75 and link 77 to the brush holder 29; this
will so move the brushes around the commutator 27 as to break the circuit of the
magnets 50 or 51 (as the case may be) then the armature and connected distributing
valve will be returned to their normal positions by the action of the spring 59, and
the further movement of the piston 35 will be prevented. Assuming the weight 79
to be the steadying device employed, as it is moved, the distributing valve of the
motor that moved it will be gradually returned to its normal position by the lever 92
and rod 94.
The movement of the weight will reduce the stability of the vessel. If this should
cause the vessel to be inclined, or if the vessel should be inclined by any other
cause, the vessel turning on an axis parallel to the axis of the long pendulum
will cause the commutator 28 carried by this pendulum to turn relatively to the brushes
thereon and will complete the circuit of one or other of the pairs of magnets in the
valve operating device C.
The distributing valve 37° will thus be operated and the piston 37" will be set in
action. By it movement will be imparted to the levers 64 and 60 in a direction such
as to neutralize the action on these levers of the piston 35.
When the piston 37 moves, motive fluid will flow through the passage 40 of
cylinder 27 and partly turn the piston 44. This piston will turn the attached
commutator 47 into a position in which it will complete the circuit of one of the
pairs of electro-magnets in the device B. This will cause the armature 52 of this
device to turn and admit motive fluid to one or other end of the cylinder 36 causing
motion of the piston 36". This motion will be transmitted through crosshead 69,
levers 67 and attached levers 64, links 63 and levers 60 to the distributing valve of
the motor or motors employed to operate the steadying apparatus which will then be
moved into such a position as to resist rolling motion and tend to stealy the vessel.
When the piston 36 moves, motion will also be transmitted through the link 71,
lever 70 and segmental teeth on lever 45 to the brush holder 48 and brush 49. This
will so move the brushes around the commutator 47 as to break the circuit of the
magnets in the device B.
If the vessel should roll independently of the action of waves upon it then the
pistons 35 and 37" will be set in motion but in such directions that each will tend to
balance the other and thus not to interfere with the vessel's stability; piston 36* will
at the same time be set in operation by the action of the piston 44 as just described,
and will cause the levers 67 and 64 to be set in motion, the resultant motion of
levers 64 being such as to cause the steadying apparatus to move into a position such
that it will exert a resistance that will act to lessen or extinguish the rolling motion.
This action is due to the secondary action of the long pendulum and takes place
independently of either the vessel's position, or the action of waves thereon.
Each pendulum will return to its normal position when the force which caused its
movement, or relative movement, disappears. When returning, the pendulums will
13

page_text: "
again move the commutators connected thereto, but in such a direction that a reverse
movement will be given to the pistons 35º, 36", and 37ª, so that these pistons will
return to their normal or mid-positions when the pendulums assume their normal
positions.
In order that the method of operation of the controlling apparatus may be fully
understood the following further description is given.
The position of the three pistons in the three cylinders is governed by the two
pendulums; the normal position of the pistons is at mid stroke as shown in the
drawings; and this corresponds to the pendulums being in mid position and without
motion.
Motion of the short pendulum to any fixed position within the range of motion of
the piston 35 holds that piston in a particular position. Similarly the long pendulum
governs piston 37", motion of which causes a temporary displacement of piston 36"
the extent to which this piston is displaced from mid stroke depending on the rapidity
of the motion of the piston 37. Thus the motion of levers 64 and 60 depends on
the motion of all three pistons. The controlling apparatus governs the steadying.
gear by the motion of these levers.
If the vessel be inclined in smooth water by some external force such as wind
pressure, the short pendulum 1 will move its commutator 27 and cause a displacement
of one end of the pair of levers 67 by the means hereinbefore mentioned, the extent
of displacement depending on the angle to which the vessel is inclined if a small
angle only be considered. The long pendulum at the same time, will cause an equal
and opposite motion of piston 37". The levers 64 and 67 are so proportioned that
under these circumstances no motion will be imparted to the lever 60 and there will
therefore be no force brought into action tending to disturb the vessel's stability, due
to the influence of the apparatus.
Let the action of the apparatus be now considered when the vessel is rolling in
smooth water. The pistons 35 and 37", controlled directly by the short and long
pendulums respectively, will again cach neutralize the action of the other by equal
and opposite movements, keeping time with the rolling, but arriving at full stroke
after a small angle has been passed through by the vessel. The motive fluid in
passing through the passage 40 of cylinder 37 will displace the piston 44 carrying
with it the commutator 47 which brings into operation the device B (in the
manner herein before described) of cylinder 36 and causes piston 36" to follow the
motion of the piston 44 at the same time moving the brush holder 49 so as to
break the circuit of the device B by means of the link 71 and lever 70. The
piston 44 will be returned to its normal or mid position by means of a spring 44,
(Fig. 1) when not disturbed by the motive fluid passing through the passage 40.
The action of pistons 36" in the control is therefore to resist rolling motion.
The
The action of the apparatus when the vessel is situated on the slope of a wave with
its crest parallel to the length of the vessel differs from the previous cases.
direct action of the two pendulums will not then balance each other but the
secondary action of the long pendulum will remain the same. If the vessel remain
upright the long pendulum will be inactive, whilst the short pendulum 1 owing to
its short period of oscillation, compared with the waves, will hang perpendicular
to the wave slope, and will cause piston 35" to be displaced, the amount of dis-
placement depending on the steepness of the wave encountered, and if the steadying
gear balances the action of the wave, no motion of the vessel will ensue.
motion, due to a want of a correct balance, ensue, the long pendulum will first
resist the motion and will afterwards gradually adjust the stability so as to tend to
restore steadiness.
Should
If the blades 96 be employed for steadying the ship, then, when the ship is sub-
jected to a turning moment or force, or when she tends to roll, the motors 97 will be
put in operation by the controlling apparatus through the intervention of the
mechanisin hereinbefore described. The blades will consequently be turned into
positions in which the reaction between them and the water in which the vessel
floats (provided she be under way) will be such as to counterbalance the turning

page_text: moment or force, or will offer resistance such as to prevent or lessen rolling of
the ship.
The valve of the motor 82 or of each of the motors 97 instead of being connected
to and directly actuated from the controlling apparatus as shewn in Figs. 8 and 9 may
obviously be worked from an auxiliary motor the valve of which is controlled from
the controlling apparatus.
To avoid sparking between the brushes and commutators when breaking circuit, a
resistance may he introduced into such circuit just before it is broken. This resistanco
may be placed in circuit, by one of the set of brushes that controls such circuit in a
manner well understood.
The distributing valves of the motor cylinders 35 and 37 instead of being actuated
by electricity in the manner hereinbefore described may as herein before mentioned
be actuated by a current of fluid passed though each pendulum in such a manner
as to cause no reaction on the pendulums such as would tend to disturb them.
Figs. 14 and 15 are diagrammatic side and end views respectively illustrating this
arrangement.
1 represents a pendulum supported by a hollow shaft working in bearings 3 and
provided with a hollow arm 1" with outlet 1. Motive fluid entering the shaft in line
with the axis passes through the lateral arm 14 and is finally ejected in a line parallel
to the axis, and as the fluid on entering and leaving has its direction of motion
unchanged, no force will be exerted upon the pendulum tending to disturb its position.
The movement of the pendulum at the point of discharge is made to distribute the
motive fluid to one or other end of a motor cylinder 162 and control the action of
pistons 103, 103 therein. For this purpose the rod 103* connecting the pistons is
formed with two passages 104 and 104 the outer ends of which are arranged close
together and opposite to the fluid discharge aperture 1 in the arm 1". The pistons
are connected by a rod 105, lever 105", and link 106 to a bell crank lever 107, which
controls the motion of the distributing valve 35 of a motor cylinder 35 which
corresponds to one of the cylinders 3, 36 and 37 hereinbefore described.
As long as the pendulum remains in its normal position the fluid jet from the
aperture 1 acts equally on the fluid in the passages 104 and 104 and consequently
on the fluid at the ends of the cylinder and no motion of the pistons will result. If
however the pendulum moves from its normal position, then the orifice of one of the
passages 104, 104" will receive more of the jet from 1" than the other and the
pressure in that end of the cylinder with which that orifice communicates will be
increased and cause the piston therein to move and operate the distributing valve 35"
through the mechanism described for the purpose herein before set forth. This move-
ment of the piston will follow the movement of the pendulum, its extent depending
upon that of the pendulum. The one piston in moving, will move the hollow rod 103*
and the other piston, and will consequently cause the orifice that received the excess
of fluid to move synchronously with the discharge aperture 1 of the pendulum
arm 1" and so continue to receive the fluid jet whilst the pendulum is displaced; at
the same time fluid will escape from the other end of the cylinder through the other
outh-t. When the pendulum moves in the opposite direction there will be an excess
of pressure in the other end of the cylinder and the movement of the piston and
distributing valve will be reversed. The form of the aperture 1 and the orifices of
the passages 104 and 104 are such as to allow for the angular movement of the
arm 1".
The lever 105 is connected by a link 76 to the crosshead 68 which brings the
distributing valve to mid position as in the herein before described arrangement,
when the piston 35ª has arrived at a position corresponding to the motion of
pendulum 1.
When arrangements such as just described are used for operating the distributing
valves of the motor cylinders 35 and 37 then the distributing valve of motor
cylinder 36 would he controlled by the piston 44 and lever 67 (Fig. 3) through
suitable mechanical means.

page_text: If the fluid discharged from the pendulum issues in a line which if produced would
cut the axis, the condition of such discharge not disturbing the pendulum will still
be preserved.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The method applied substantially as herein described of preventing or lessening
the rolling of a vessel at sea by means of a steadying apparatus the motion of which
is controlled by the action of two pendulums namely a short period pendulum that
acts to cause the steadying apparatus to assume a position in which it will balance
or tend to balance the turning moment or force tending to make the vessel place her
masts at right angles to a wave, and a long period pendulum having two functions
one of which is to neutralize when required as herein described the action of the
short period pendulum on the steadying apparatus and restore to the vessel the
stability the short period pendulum takes away, and the other to cause the steadying
apparatus to move into positions to resist rolling of the vessel.
2. Apparatus such as that herein described for preventing or lessening the rolling
of a vessel at sea comprising a short period pendulum (or its equivalent) and con-
trolling apparatus and steadying apparatus acting respectively and relatively in the
manner and for the purposes hereinbefore indicated.
3. Apparatus such as that herein described for preventing or lessening the rolling
of a vessel at sea, comprising a long period pendulum (or its equivalent) and con-
trolling apparatus and steadying apparatus acting respectively and relatively in the
manner and for the purposes herein before indicated.
4. Apparatus such as that herein described for preventing or lessening the rolling
of a vessel at sea, comprising a short period pendulum (or its equivalent), and a
long period pendulum (or its equivalent), and controlling apparatus and steadying
apparatus acting respectively and relatively in the manner and for the purposes
herein before indicated.
5. In apparatus for preventing or lessening the rolling of a vessel at sea, the com-
bination of a short period pendulum (or its equivalent), an electro-magnetic device.
a motor, and steadying apparatus acting respectively and relatively in the manner and
for the purposes hereinbefore indicated.
6. In apparatus for preventing or lessening the rolling of a vessel at sea, the com-
bination of a short period pendulum (or its equivalent), a long period pendulum (or
its equivalent), two electro magnetic devices, two motors, and steadying apparatus
acting respectively and relatively in the manner and for the purposes hereinbefore
indicated.
7. For controlling steadying apparatus for the purposes specified, the combination
with the short period pendulum (or its equivalent), of a commutator 27, brushes 33
and 34 and their holder 29, a suitable motor 35, electro magnetic device A, the
arrangement of levers 67 and 60, the lever 75 with connection to the motor cross-
head and to the brush holder, an electric generator and electrical connections between
the said commutator, brushes, electro magnetic device, and electric generator arranged
and operating substantially as herein described.
8. The combination and arrangement of parts constituting the controlling apparatus
hreinbefore described with reference to and shewn in Figs. 1 to 4 inclusive of the
drawings annexed including the long period pendulum (or its equivalent), whether
with or without the short period pendulum (or its equivalent), and with or without
the motor 16 and connected mechanism for oscillating the pendulum bearings.
9. For preventing or lessening rolling of a vessel at sea my improved steadying
apparatus in which a weight such as 79 controlled as described is mounted to turn
about an axis inclined to the vertical in such manner that it shall have a tendency to
assume a fore and aft position in relation to the ship as set forth.
10. For preventing or lessening rolling of a vessel at sea the herein described

page_text: steadying apparatus constructed with movable blades such as 96 that project beyond
the side of the vessel, these blades being operated by a motor controlled substantially
as described.
11. The combination and arrangement of parts hereinabove described with
reference to and shewn in Figs. 14 and 15 of the drawings annexed for actuating
the distributing valve of the motor of the controlling apparatus for the purpose
indicated.
12. For preventing or lessening the rolling of a vessel at sea, the combined
apparatus comprising pendulums, controlling apparatus, and steadying apparatus the
whole constructed arranged and operating as shown in and described with reference
to Figs. 1, 2, 3, 4, 4", 4, 4° and of the drawings annexed, or with blades such as
are shewn in Figs. 8 and 10 caused to act in lieu of the weight 79.
Dated this 19th day of March 1890.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.