An improved life raft stabilizer for reducing rocking and substantially precluding capsizing is discussed. The stabilizer may be removably attached to the raft and is defined by flexible side walls which extend a considerable depth downwardly to one another in the water. The side walls, in conjunction with the floor of the raft, form a ballast enclosure. A weight is placed in the bottom of the enclosure and water port means are provided in the walls. Placement of the stabilizer in the water allows the weighted bottom to sink, producing submerged deployment thereof and permitting water to enter the enclosure through the port means, thus forming a ballast for the raft

Barnett, J. H., Jr.

Harrison, F. L.

Marak, R. J.

Radnofsky, M. I.

English

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https://ntrs.nasa.gov/search.jsp?R=19730017279 2020-03-17T08:35:03+00:00Z
United States Patent
Radnofsky et al.
[in 3,736,607
[45] June 5,1973
[54] LIFE RAFT STABILIZER
[75] Inventors: Matthew I. Radnofsky, Seabrook;
James H. Barnett, Jr., Alvin; Floyd
L. Harrison; Ralph J. Marak, both
of Houston, all of Tex.
[73] Assignee: The United States of America as
represented by the Administrator of
the National Aeronautics and Space
Administration, Washington, D.C.
[22] Filed: Nov. 30, 1971
[21] Appl. No.: 203,405
[52] U.S. Cl 9/2 A, 9/3, 9/11 A,
114/122
[51] Int. Cl B63b 7/08, B63b 39/02
.[58] Field of Search 9/2 A, 2 R, 2 C,
9/11 A, 11 R,3; 114/122
[56] References Cited
UNITED STATES PATENTS
2,223,625 12/1940 Krupp 9/11 A
2,683,269 7/1954 Harkins 114/122 X
3,155,992 11/1964 Shewmake et al 9/11 A
Primary Examiner—Duane A. Reger
Assistant Examiner—Carl A. Rutledge
Attorney— Russell E. Schlorff, Marvin F. Matthews
and John R. Manning
[57] ABSTRACT
An improved life raft stabilizer for reducing rocking
and substantially precluding capsizing. The stabilizer
may be removably attached to the raft and is defined
by flexible side walls which extend a considerable
depth downwardly to one another in the water. The
side walls, in conjunction with the floor of the raft,
form a ballast enclosure. A weight is disposed in the
bottom of the enclosure and water port means are
provided in the walls thereof. Placement of the stabil-
izer in the water allows the weighted bottom to sink,
producing submerged deployment thereof and per-
mitting water to enter the enclosure through the port
means, thus forming a ballast for the raft.
6 Claims, 3 Drawing Figures
._ ._- — ' N73-260061
Onclas
00/02 06432
13 « !!
1
13 /
j A -\ (. ij 9b
9d
I'AFENTEOJIIH 51973 3.736,607
FIG.1
15a
FIG. 2
3
FIG. 3
15a
9a
3
A ;
73 .' 13
- 9
9c 9d
3,736,607
1 2
LIFE RAFT STABILIZER corporating the improved stabilizing structure of the
The invention described herein was made by employ- invention.
ees of the United States Government and may be man- FIG. 2 illustrates a top view of the raft of FIG. 1.
ufactured and used by or for the Government of the FIG. 3 shows a side view in partial section of the raft
United States of America for governmental purposes 5 of FIG. 1.
without the payment of ,n, royalties thereon or there- DETAILED DESCRIPTION
"' BACKGROUND OF THE INVENT.ON . »»
This invention pertains to improvements in life rafts. 10 made of vinyl, rubber or other material having pneuma-
More particularly the invention pertains to ah im- tic integrity. Although the planar form of the main flo-
proved inflatable stabilizing system for use on life rafts tation tube 3 will generally be of circular, square or
and similar type vessels. rectangular configuration, it may take any shape de-
Pneumatically inflatable life rafts are characterized pending upon the demands of its use. Therefore and for
by numerous advantageous characteristics. For exam- 15 example it is shown in the drawings to be of semicircu-
ple, they occupy relatively small storage space by com- lar configuration so as to readily adapt to and dock
parison to their deployed size. They are light weight against the side of a space vehicle floating in the water,
and easily and quickly made ready for use. Their bouy- Integrally attached to the main flotation tube 3 is a
ancy and load carrying capacity are superior to practi- floor 5 adapted to support the persons and supplies in
cally all other types of floating vessels. Although these 20 the raft.
and numerous other features make pneumatically in- Extending downwardly from the main flotation tube
datable life rafts more attractive than most other forms 3 and removably connected thereto is the life raft stabi-
of life support vessels, it is some of the very same fea- lizer 9. The stabilizer comprises a plurality of integrally
tures that contribute to their most severe drawback, connected walls 9a, 9b, 9c and 9d extending down-
namely a pronounced instability and tendency to cap- 25 wardly from the main flotation tube 3. It is most impor-
size in open water. tant that the depth of the stabilizer walls be at least sev-
Heretofore, the recognition of this disadvantage has eral times the diameter of the main flotation tube in
been accompanied by numerous and diverse resolute order to lower the center of gravity and thus produce
attempts directed to its elimination. It has, for example, a reliable ballasting force upon the raft when it is in the
been suggested that the inflatable raft incorporate a 30 water. A stabilizer depth in the range of 3 feet or more
plurality of stabilizing weights or ballast buckets de- is suggested for the configuration of the raft shown in
ployed around the perimeter and interiorly of the raft. the drawing (FIG. 1). To still further enhance the cen-
Also, it has been suggested that the inflatable rafts con- ter of gravity of the raft when the stabilizer 9 is filled
tain a compartment in the bottom thereof which may with ballasting water, the stabilizer walls 9a-d are
be filled with a weight or even with water so as to 35 adapted to slope inwardly towards one another to take
thereby form a stabilizing mass. Such a structure is the form of a keel. Disposed in the bottom of stabilizer
shown in U.S. Pat. No. 2,223,625. While this and simi- 9 is an appropriate weight 11 (FIG. 3) which, upon
lar devices might afford some stabilizing effect, they pneumatic deployment of the main flotation tube 3,
are not conducive to reliable use in heavy seas because causes stabilizer 9 to descend in the water. In so doing,
of a vulnerability to sudden capsizing from a single water passes through entry ports 13 selectively posi-
wave. Other less sophisticated approaches, such as the tioned in certain of the stabilizer walls 9a-d. The water
mere placement of a mass or weight on the floor of the thus fills the chamber defined by the walls and the floor
raft, detract from the basic features of the raft itself, 5 of the raft, and thereby provides a stabilizing keel,
that is its ease of deployment, lightness of weight and After the raft is deployed in the water, the need may
superior bouyancy. subsequently arise for towing it or for maintaining it in
The present invention thus proposes a pneumatically relatively static position despite an ocean current. Ei-
inflatable raft having a water inflatable keel as an inte- ther such objective would prove difficult, at best, with
gral part thereof and which acts to stabilize the raft in the contained water ballast described above. There is
a manner superior to any structure presently known. therefore provided zipper means 15a, ISb in opposing
The water inflatable keel is constructed of the same end walls of stabilizer 9. By opening both of the zipper
materials as the raft itself, is formed integrally there- means, the raft may be towed with relative facility since
with, and thus detracts in no way from the principal resistance of the water ballast is reduced to the resis-
features which characterize pneumatically inflatable tance produced by a current flowing through the stabi-
rafts. In addition to reliably stabilizing the raft and sub- lizer 9. Similarly, if the raft is subjected to an ocean
stantially eliminating the possibility of capsizing in even current when relative movement from a designated po-
heavy seas, the structure disclosed hereinafter contains sition is undesirable, the zipper facing the current di-
means for adjusting the ballast resistance during towing rection may be closed while the other is opened. Thus
of the raft, and means for expulsion of the water ballast the ballasting water in the stabilizer 9 will be relatively
from the keel so as to facilitate removal of the raft from static by comparison to the current, thereby substan-
the water. These and other features and advantages of tially reducing movement of the raft. Under still other
the invention will become readily apparent upon a circumstances, necessity may arise to remove the raft
reading of the following detailed description, claims entirely from the water. This of course could not be
and drawings wherein like numerals denote like parts readily accomplished with the substantial water ballast
in the several views and wherein:
 65 normally contained within the walls of stabilizer 9. In
DESCRIPTION OF THE DRAWINGS SU°h eVelU> b°th Z'PperS IS° a"d I5b may be °penedDESCRIPTION F THE DRA INGS ,Q pennit quick and easy gravity expulsion of the ballast
FIG. 1 is a perspective view illustrating a life raft in- water as the raft is being removed.
3,736,607
From the above description it will be >seen that the
improved life raft stabilizer of the invention is ex-
tremely simple to construct and may, as a unit, be at-
tached or detached from the raft by use of any number
of conventional snaps or connector means. The inertia 5
of the water ballast contained within the stabilizer 9
tends to oppose sudden movement of the raft in a hori-
zontal direction. A change in a vertical direction, such
as tilting or lifting, is resisted by the weight and inertia
of the water in the stabilizer. Rocking motion of the raft i o
due to surface waves is substantially reduced by reason
of the keel-like effect of the ballasting stabilizer. In ad-
dition, the water entry ports and weighted stabilizer
provide for quick and effortless deployment while the
cooperating zipper means impart a degree and type of 15
navigational control which is unknown to pneumati-
cally inflatable vessels.
While there has been described and illustrated a par-
ticular embodiment of the invention, it is to be under-
stood that the invention is not to be restricted thereto, 20
but it is intended to cover all modifications thereof
which fall within the true spirit and scope of the claims
appended hereto.
Having thus described the invention, that which is
claimed and which is desired to be secured by United 25
States Letters Patent is:
1. A stabilizer means adapted to be affixed to a float-
ing body suspended in a fluid for reducing rocking and
generally enhancing the stability thereof comprising:
flexible wall means removably attachable to the float- 30
ing body and configured so as to extend down-
wardly from the body a substantial distance and to
one another to form a ballast enclosure,
port means in said flexible wall means, and
a weight means affixed to the bottom of said ballast 35
enclosure for producing gravitational deployment
thereof, thereby causing fluid to flow into the en-
closure through the port means and thus form a sta-
bilizing ballast for the body.
2. The stabilizer means of claim 1 wherein the flexi-
ble wall means are in the general configuration of a
keel.
3. The stabilizer means of claim 2 wherein the wall
means of the stabilizer means is characterized by fluid
control openings that may each be selectively opened
so as to allow escape of the fluid in the ballast enclo-
sure, or closed so as to maintain the fluid therein.
4. In a raft of the type generally used on open water
and which is subject to capsizing therein, the improve-
ment consisting of a stabilizer means removably at-
tached to the raft for substantially precluding capsizing
and reducing rocking of the raft, said stabilizer means
comprising:
flexible wall means extending downwardly from the
sides of the raft to one another so as to form a bal-
last enclosure,
port means in said flexible wall means, and
a weight means affixed to the bottom of said ballast
enclosure for producing submerged deployment
thereof, thereby causing water to enter the enclo-
sure through the port means and thus form a ballast
which stabilizes the raft.
5. The combination raft-stabilizer means of claim 4
wherein the flexible wall means extending downwardly
into the water are in the general configuration of a keel.
6. The combination raft-stabilizer means of claim 5
wherein the wall means of the stabilizer means is char-
acterized by water control openings that may each be
selectively opened so as to allow escape of the water in
the ballast enclosure, or closed so as to maintain the
water therein.
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Life raft stabilizer

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