Ship stabilizer assembly

A water vessel with a bow-mounted pitch stabilizer having a rigid support structure attached to the bow and projecting in front of it, and one or more horizontally pivoted flaps on the support structure below the vessel's water line for opposing the up or down movement of the bow in the water. Roll stabilizers on opposite sides of the vessel's hull below the water line each comprise a hinged horizontal vane which is spring-biased to position substantially coplanar with the fixed vane.

SUMMARY OF THE INVENTION 
This invention relates to a water vessel with a bow-mounted pitch 
stabilizer and/or roll stabilizers. 
A well-known stabilizer for water vessels is a bulbous nose which extends 
forward from the bow below the water line. This type of stabilizer has 
improved the stability of water vessels and the efficiency and speed at 
which they move through the water. One disadvantage is that it must be 
part of the original design and construction of the vessel; as a practical 
matter, it cannot be retrofitted to an already constructed hull. 
One aspect of the present invention is concerned with a novel pitch 
stabilizer mounted on the bow of a vessel below the water line, either as 
part of the original construction or as a later-added feature. Preferably, 
this pitch stablizer comprises a rigid support structure attached to and 
extending forward from the bow and horizontally pivoted flap means on this 
support structure for deflecting and directing aft the water just ahead of 
the bow as it pitches up and down in the water. 
Another aspect of this invention is concerned with roll stabilizers on the 
opposite sides of the hull behind the bow and below the water line. 
Preferably, each roll stabilizer comprises a fixed horizontal vane with a 
laterally outwardly and rearwardly inclined front edge, a horizontally 
pivoted flap directly behind the fixed vane and presenting a laterally and 
inwardly inclined back edge, and spring means acting between the fixed 
vane and the pivoted flap to bias the flap to a horizontal position 
directly behind and substantially coplanar with the fixed vane. 
A principal object of this invention is to provide a novel pitch stabilizer 
on the bow of a water vessel below the water line which will aid the 
forward movement of the vessel. 
Another object of this invention is to provide a novel roll stabilizer on 
the side of a water vessel's hull below the water line which will aid the 
forward movement of the vessel. 
Further objects and advantages of this invention will be apparent from the 
following detailed description of a presently preferred embodiment which 
is illustrated schematically in the accompanying drawings.

Before explaining the disclosed embodiments of the present invention in 
detail it is to be understood that the invention is not limited in its 
application to the details of the particular arrangements shown since the 
invention is capable of other embodiments. Also, the terminology used 
herein is for the purpose of description and not of limitation. 
DETAILED DESCRIPTION 
FIG. 1 shows the bow 16 of a water vessel 10 having a forwardly and 
laterally projecting bulbous nose 12 of known design below the vessel's 
water line 14. This bulbous nose has proven to be an effective way to 
reduce the vessel's pitch and roll and to increase its speed. 
In accordance with the present invention, a pitch stabilizer having one or 
more horizontally pivoted plates or fins is provided in front of the bow 
of a water vessel, either as part of the original construction or as a 
retrofitted feature added to a vessel originally designed and built 
without it. 
As shown in FIG. 2, the stabilizer has a rigid, flat support plate 24 
rigidly attached to the vessel's hull and extending horizontally forward 
from the bow 16 below the vessel's water line 14. The support plate 24 
extends laterally on opposite sides of the longitudinal centerline of the 
vessel and is symmetrical with respect to this centerline. The support 
plate on opposite sides presents narrower, forwardly projecting, flat, 
rigid arms 30 and 30'. A generally V-shaped leading end segment 26 of the 
support plate is joined to and extends between the front ends of its 
opposite side arms 30 and 30' and substantially coplanar with those side 
arms. Thus, the leading end segment 26 of support plate 24 is completely 
below the vessel's water line 14 and completely above the bottom of its 
bow 16. Behind its leading end segment 26 and between its opposite side 
arms 30 and 30' the support plate 24 presents a rectangular opening in 
which a single pivoted plate-like flap 28 is located. 
The front end of pivoted flap 28 is pivoted in a center chock 25' and in 
side chocks 25 and 25" respectively located a short distance laterally 
inward from the respective side arms 30 and 30' of the support plate. 
These chocks are all rigidly affixed to the back of the leading end 
segment 26 of the support plate and they define a horizontal pivot axis 
for flap 28 which extends perpendicular to the longitudinal centerline of 
the vessel. Thus, the flap 28 is pivoted on the support plate 24 below the 
water line 14 and above the bottom of bow 16. The rear edge 31 of pivoted 
flap 28 has a slight clearance from the rear edge of the opening in 
support plate 24, and the opposite side edges of flap 28 also have slight 
clearances from the adjacent inner longitudinal edges of side arms 30 and 
30' of the support plate. 
FIG. 5 shows a section through one of the pivot chocks 25 for flap 28. The 
flap has a rounded, slightly enlarged front end segment 28a horizontally 
pivoted in the body of the chock. A short distance behind this pivot the 
body of the chock presents upper and lower screw-threaded openings 32 and 
32', each inclined inward and rearward at a small angle to the vertical. 
Adjusting screws 36 and 36' are threadedly received in these openings, and 
coil springs 34 and 34' are engaged under compression between these screws 
and the top and bottom, respectively of the pivoted flap 28. These springs 
center the pivoted flap 28 horizontally in a generally V-shaped opening in 
the chock which is bounded by rearwardly-diverging top and bottom surfaces 
38 and 38'. The pivoted flap 28 can move up through an angle A or down 
through an equal angle A' from its centered horizontal position, as shown 
in phantom in FIGS. 3 and 5. 
Except during violent pitching of the vessel, the stabilizer is below the 
vessel's water line 14. Downward movement of the bow causes upward 
pivoting of the flap 28 in the stablizer, which is opposed by the upper 
spring 34. Upward movement of the bow causes the water to pivot the flap 
28 downward, which is opposed by the lower spring 34'. In either 
situation, water in front of the bow is deflected rearward by the flap 28 
before the bow reaches it. The overall effect of this stabilizer is to 
reduce the amplitude of the pitch and consequently to increase the 
efficiency and speed of the vessel's movement forward in the water. 
As shown in FIGS. 3 and 4, the vessel also has roll stabilizers 20 
projecting out from the hull below the water line 14 and at a lower level 
than the bow-mounted pitch stabilizer 18. These roll stabilizers may be 
constructed as shown in either FIG. 13 or FIG. 14 and described in detail 
hereinafter. 
FIGS. 6-8 show a second embodiment of the bow-mounted pitch stabilizer 
according to the present invention. It has a support plate 24 identical to 
the one in FIGS. 2-5, including opposite side arms 30 and 30' and a 
generally V-shaped leading end segment 26. It has a pivoted flap 28 like 
the one in FIGS. 2-5 which is pivoted to the support plate across the back 
of the support plate's leading end segment 26. The pivotal axis of flap 28 
extends horizontally and perpendicular to the longitudinal centerline of 
the vessel. 
A rigid diagonal brace or strut 66 extends forward and downward at an acute 
angle from the bow 16 of the water vessel to the leading end segment 26 to 
reinforce the entire support plate 24. 
The horizontally pivoted flap 28 has rigid, plate-like, vertical fins 68 
and 68' extending above and below it along its opposite side edges close 
to the opposite side arms 30' and 30 of support plate 24. Each of these 
fins has a streamlined curvature above and below the flap 28, presenting a 
convex front edge away from the bow 16 of the vessel and a convex back 
edge of greater curvature. Fin 68' carries upper and lower projections or 
chocks 70 and 70' which project out laterally from it near the top and 
bottom. These projections are engageable with the adjacent side arm 30 of 
support plate 24 to limit the pivotal movement of flap 28 upward and 
downward with respect to the support plate. The fin 68 on the opposite 
side of flap 28 carries similar upper and lower projections or chocks, the 
upper of which is designated by reference number 70 and 72 in FIG. 7. 
These projections on fin 68 are engageable respectively with the top and 
bottom of the adjacent side arm 30' of support plate 24 to limit the 
pivotal movement of flap 28. 
The flap 28 in this embodiment may be horizontally pivoted in the absence 
of centering springs as shown in FIG. 5 or in the presence of such 
springs. In either case, the vertical fins 68 and 68' on flap 28 causes it 
to act as a sluice for channeling the flow of water past the pitch 
stabilizer as the vessel moves forward thus increasing forward progress. 
FIGS. 9 and 10 show a third embodiment of the invention in which the 
centering springs 34 and 34' of FIG. 5 are replaced by a sleeve 58 (FIG. 
10) of rubber or rubber-like material which is bonded to the flap 28 in 
the enlarged rounded front end 60 of the flap. Sleeve 58 is fastened 
around a horizontal shaft 62 which defines the pivot axis of flap 28. 
A pair of rigid, vertical, generally V-shaped struts or braces 48 and 48' 
(FIG. 9) extend forward from the bow on opposite sides of the longitudinal 
centerline of the vessel parallel to each other. These struts support a 
generally V-shaped leading end segment 26, which is positioned 
horizontally in front of the bow as in the preceding embodiments of the 
invention. The struts 48,48' and the leading end segment 26 together 
provide a rigid bow-mounted support for the horizontal flap 28. 
Shaft 62 has its opposite ends received in struts 48 and 48' at their front 
ends. At each end of shaft 62, a cross pin 64 anchors it to the 
corresponding strut. 
The rubber-like sleeve 58 acts as a torsion spring between the support 
struts 48,48' and the pivoted flap 28, normally positioning the flap 28 
horizontal, extending rearward from the leading end segment 26 of the 
support, and yieldingly opposing the pivotal displacement of the flap up 
or down from this centered horizontal position. 
As shown in FIG. 10, strut 48 carries inwardly projecting upper and lower 
stops 50 and 52 which limit the pivotal movement of flap 28 in either 
direction. The opposite strut 48' has similarly located inwardly 
projecting stops (not shown) for engagement by flap 28. 
FIGS. 11 and 12 show a fourth embodiment of the invention having several 
horizontally pivoted flaps in close succession from front to back instead 
of the single flap as shown in the first three embodiments. As a group, 
these flaps are indicated by the reference numeral 40 in FIG. 11. The 
individual flaps are designated by the reference numeral 44 in FIG. 12. 
The bow-mounted support for the multiple flaps 44 comprises opposite 
horizontal side rails 42 and 42' and a generally triangular, horizontal 
front end segment 26 extending between the front ends of these side rails. 
Upper diagonal struts 41 and 41' extend from the bow 16 down and out to 
the front ends of side rails 42 and 42'. Lower diagonal struts 43 and 43' 
extend from the bow up and out to the front ends of the side rails. 
As shown in FIG. 12, each flap 44 has a stream-lined cross-section, with a 
rounded convex front end and a tapered rear end. Each flap 44 is 
horizontally pivoted near its front end on the opposite side rails 42 and 
42', either with or without spring-loading to the horizontal position. The 
horizontal pivot axis of each flap extends perpendicular to the 
longitudinal centerline of the vessel. These multiple flaps distribute the 
water forces over more than one flap and along the length of the side 
rails 42,42' of the support. 
In each of the foregoing embodiments, each pivoted flap opposes or retards 
the instantaneous up or down movement of the bow in the water and thereby 
tends to reduce the amplitude of the vessel's pitching. Also, each pivoted 
flap deflects the water aft just ahead of the bow to improve the 
efficiency of the vessel's movement forward in the water. 
The roll stabilizers 20 (FIGS. 13 and 14) are mounted on the opposite sides 
of the vessel's hull below the water line 14 but they do not project below 
the keel 74. 
Referring to FIG. 14, each roll stabilizer 20 has rigid upper and lower 
struts 80 and 80' which extend out from the hull 22 of the vessel at 
slight angles respectively downward and upward. A rigid middle strut 88 
extends horizontally out from the hull and is joined at its outer end to 
the outer ends of upper and lower struts 80 and 80'. Each strut 80,80' and 
88 is a flat plate. The middle strut 88 has a rearwardly and outwardly 
inclined, straight front edge. The middle strut 88 is a fixed, horizontal 
vane of the roll stabilizer. 
A horizontal pivot shaft 78 extends out from the hull, with its inner end 
rotatably supported by an anti-friction bearing 90 inside the hull and its 
outer end rotatably supported by an anti-friction bearing 92 on the joined 
outer ends of struts 80,80' and 88. A torsion spring 45, with one end 
anchored in shaft 78, has several spiral turns wrapped around this shaft 
and has its opposite end supported inside the hull at any selected point 
along an arcuate slot 86 by a suitable clamping arrangement. The position 
to which this end of spring 45 is adjusted determines the torsional or 
rotational force which this spring exerts on shaft 78 and also will center 
vane 76. 
Shaft 78 supports the front end of a flat, rigid, plate-like flap 76. 
Spring 45 is adjusted so that normally the shaft 78 positions flap 76 
horizontally co-planar with the middle strut or fixed vane 88 and directly 
behind it. 
FIG. 13 shows an alternative arrangement in which the single torsion spring 
45 of FIG. 14 is replaced by a pair of opposed tension springs 96 and 96 
inside the hull. The neighboring ends of these springs are attached to a 
short vertical post 98 extending up from the inner end of shaft 78. The 
outer ends of these springs are connected to screw-threaded tension bolts 
97 and 97', respectively. Bolt 97 is threadedly received in nuts 100 on 
opposite sides of a fixed T-bar 99, and bolt 97' is threadedly received in 
nuts 100' on opposite sides of a fixed T-bar 99'. Bolts 97 and 97' adjust 
the opposing forces of springs 96 and 96' to normally hold the flap 76 in 
horizontal, co-planar alignment with the fixed vane 88. 
In FIG. 13, element 104 is a waterproof fitting on the inside of the hull 
through which the shaft 78 extends. A similar fitting is provided in the 
embodiment of FIG. 14. 
The pitching and rolling are reduced by the vertical resistance generated 
by the units as they are forced through the water by the ship's motion. 
When the ship is pitching and the bow rises to a wave, the plate 28 swings 
down forcing the water to run aft. When the bow falls off a wave, the 
plate 28 swings up, again forcing the water to run aft. Both of these 
actions provide additional forward effort thus increasing the ship's 
speed. 
The roll stabilizers operate in a similar manner. When the ship rolls to 
starboard, the starboard vanes 76 swing upward and the port vanes 76 swing 
down. Therefore both sides force water aft enhancing forward motion. 
When the ship rolls to port, the port vanes 76 swing upward and the 
starboard vanes swing down forcing the water aft as before. So when the 
ship rolls either way, the vanes on both sides create a forward influence. 
All the units have centering devices to reduce their drag when the ship is 
at low speed in calm water. 
Any addition to the speed of a vessel especially, as in this case, at no 
increase in operating expense is vitally important. Not only is wear and 
tear reduced, fuel costs are reduced, and crew salary costs are reduced by 
spending less time at sea. Even a small increase in speed is important 
when one considers the thousands of miles and the thousands of days a ship 
spends at sea.