CA 02234359 1998-06-08
This inventio ' easily deployable, expendable or recoverable floating radar
reflective device. The
invention can be bui sufficient reserve buoyancy to allow the fitting of a
number of optional devices,
such as a GI'S transceiver or ' 'ng. Thus, the device can be usad for a
variety of applications includir~:
man-overboard marker, radar testing, rarity marking submerged objects or
navigatio~a pozz~ts, search
and rescue, naval gunnery practice aztdloz w s testuaa, oz az~y ether
application that requires a floating
refltc2ive station. The device is constructed of al and consists of a
tetral~edzon sluipe with a
floatation pad with an integrated radar reflector at each ape . h floatation
pod is fitted either with
scuttling devices, to cause the device to sink if recovery is not a pz d
option, or plugs if recovery is
requir. td. The use of dissimilar metal in the scuttling devices and tire pins
old the device together
allows the device to rapidly corrode once it sinks, EtlIevzatiag
e~uvix'oxtrncntal con 'fhe device is
collapsible foz ease of storage, and can be either assembled by hand, or
deployed autoba ~ , depending
upon usage requirements. the tetrahedron shape allows the device to toll dire
to the motion of ves or
the method of deployment, a~ad always present the same shape and reflective
area as a target for xadar, o
a support for optional devices mounted on the structure.
SPEC:IFICATIQN
This ii<aventioz~ relates to a device for temporarily marking positions at sea
or on other waterways.
host tenxporary marking devices currently in use, are made of plastic oz
zubber-like substaaces, and
generally depend upon air for floatation. These devices do ~uat offer any real
degree of radar reflectivity,
and are therefore useful only in conditions of good visibility. They are also
susceptible to rwiiixd, and if not
well ancb~ozed, wfll not remain in position for very long. There are also some
devices that are made of
rne2a11ie substances. These are generally difficult to deploy, and art not
well suited to temporary markiuzg
applications. 'T"he inflatable and metallic devices currently avar~able are
not designed with tnvimruntntal
concerns in mimd, noz do they offer options for mounting different devices.
~y us;in~g a common geometric shape, a tetrahedron, made of eor~o~an material,
aluminum, a unique unit
has been produced that is a marked improvement on the devices eurrrutly in
use. This invention improves
effec~xveness aztd ease of operation, while reducing the negative impact of
tlae use of such devices on the
ezwi~onment_ It combines the advantages of good zadaz zefTectivity and good
sea~ceeping chazactezistics
inherent in metallic devicesy with the advantages of ease of deploymezat and
compact stowage afforded by
inflatable devices- Tht tetrahedron shape constructed of aIumizauxn poles
produces little wind resistance,
while providing a structure that maintaizzs a consistent shape rtgard3ess of
the side that is lying in the water.
This ensures that the zequirod radar reflective component, provided by radar
reflectors incorporated iao
floatation pods at each apex of the tetrahedron, is always presented at the
required height regardless of
wave action. oz other envirorunental factors that may cause tlae uait to roll
in the water occasionally. Tla
inverrtiozt also incorporates the use of dissimilar metals to facilitate rapid
corrosion of the device, should
zecovezy not be possible or desirable, affozding a degree of environmental
acceptability not currently
available in otlxtr devices. The design, is suited to a number of uses, as
desczibed in the Abstract.
Generally, the type of application for which the device will be used will
determine the size of the unit
required, the shape remaininø constant. Some other options, such as different
hints ng meehank,~ms, can
also be used to adapt the unit to specific applications.
An embodiment of. the invention is illustrated in Figures 1 through 3. This
embodiment is a manually
ass~n~bled design option, of a sizx that would be applicable to usage in the
open ocean. In the drawings
which illustrate this embodiment of the invention, Figure 1 is an OzthogFaphie
Projection of the
embodiment which illustrates the general layout of the design- Figure 2 are
Plan and Blevatian Views,
illustrating the approximate ratio of leg length to reflector height, and the
typical dimensions of the material
used for a device of dais size- Also included in Figure 2 is a view of the
Paclmging l7etail foz a unit of this
size when collapsed into four pod assembIi.es and packaged into two bundles.
Fide 3 is a detailed view of
the pod assembly for this embodiment- It illustrates the angle of the hinge
plate that keeps the radar
refle<;toz at a prescribed angle relative to the tetrahedron shape, and other
detail of the floatation pod
lintel~attd radar reflector component of the invention,
CA 02234359 1998-06-08
The invention comprises a tetrahedroB shape, constructed of aluzn~inuzxt
tubing legs I . At each apex,
floatation pods 2 with integrated radar reflectors 3 are mounted. The primary
object of the invention is to
improve oz~ the radar reflectivity of temporary marking devices. This has been
accamplashed by
manufacturing the unit from aluminum, with radar reflectors integrated into
the desi~. The desigi,
utilizing a tetralzedcon shape, extends the radar reflector an appropriate
distance about the surface of the
water. The distance of the radar reflector above xhe water is determined by
the requirements of the
application for which the unit is to be used. (hxce the distance required is
determined, ~e unit is
manufactured to that specification. The ratio of distance above the water
required vs_ the length of the
tetrahedmn's legs is zelatively caaustaz~t, being a standard geomeu~ic shape,
and only affected by the size of
rice floatation pods and very minimally by the density of the water in which
the unit will be used. This is
illustrated by the Elevation View in F acute 2. The size of the floatation
pads 2, and associated integrated
radar reflectors 3, can be altered as necessary to achieve the required radar
reflective area far a particular
application.
The gauge of the aluminum being used for ttte construction, indicated as 2-
inch tubing in the Plan View in
Rigure Z, is de~nined by the sire o~the application, usizr~g comzz~oz~
ez~esriz~g rnethads for determining
suvctutal rigidity and strength. Tht size of the floatation pods ~ tan be
altered as required to achieve the
required reserve buoyancy for a pazticular application.
The necessity for tfi~e device to be used safely iua a variety of sea and
weather conditions demands that the
unit be designed far ease of handling, The aluminum construction ensures that
the unit will be light, while
an open tetzahedron desi,~ reduces the wiz~dage to a level acceptable in;
nnost operating scenarios. Lifting
eyes 4. are at~thtd to the floatation pods 2 in larger models to accommodate
deployment and recovery by
lifting apparatus from the deck of a vessel or other platform.
An importgnt requirement of the device is sho nerd to be environmentally safe.
The device is designed to
be either recovered, or expended. Each floatation pod 2 is fitted with two
threaded fittings 5 to provide the
option for either mode of employment. Should the device be intended for
recovery after use, plugs are
fitted in the openings, and the afit'ect of its use on the environment is
inconsequential. Should the intent be
to expend the device, scuttling plugs ~ nr~ade o~ copper are fitted iu~ the
openings. Thtst scuttling plugs 6
are hallow in the centre, and use a sugar substance that slowly dissolves in
water. They are nnanufactured
in a variety ofthicIazesses, resultixzg iz~ a number a~tanne-delay options.
When the invention scuttles, the
dissimilar metal in the scuttling plugs 6 causes raq>id corrosion of the unit.
Sacrificial zinc hinge pins 7 are
used to attzch three aluminum tubing legs 1 to each floatation pod 2, ~oznxing
pod assemblies 8_ These pins
7 will also corrode rapidly, causing the unit to collapse oz~ the sea botiorr~
reducing the likelihood that
marine life will bCCOZtIe ezlta~agled in the unit.
Ta facilitate ease of ltaudlizxg arad assembly, and to provide for compact
stowage, larger devices are broken
down into four separate pod assemblies 8, as illustrated in the Packagnag
Detail. oz~ Figuxe 2. Each pod
assembly 8 has one flaatatioz~ pod 2 with three aluminum tubing legs 1
attached. Three of the pod
assemblies 8 art the same, and are termed "A pods". The fourth pod assembly 8
is reacted ''B pod". The
"A pods" differ from the "B pod" by the slip jaunts 9 that are pz-ovided at
the end of each leg. Each "A
pod" has two mile slip joints and one female slip joint. The "B pod" has three
female slip joirnts. The ''A
pocLs" are ~xrst fitted together i» a triangle form on a horizontal plane,
fitting one male and oz~e ~em~ale leg
~rozrA each pod to the other pods- This Leaves the middle leg of each "A pod",
with a male slip joitu, free on
tack pod. The hinge plate 10 shown in the 3D View of the Assez~abled
Floatation Pod in Figure 3 is
designed such that the nxiddle, free leg will easily hinge up_ This allows it
to achieve the required eagle to
join the male slip joint with the associated female slip joint on one of the
three legs of the "13 pod". All slip
joints 9 are held together by clip pins 11.
As indicated, the embodiment detailed in Figures 1 through ~ is a large unit,
designed for use in open ocean
for such applications as marking submerged objects, by attaching a line from
the object to the xzzarher, or as
a target for radar trials ox gunnery practice.
CA 02234359 1998-06-08
Other applications for the invention include: man-overboard marker,
temporarily marling navigation points
and ::earth and rescue. The design has many applications, of which the
aforementioned are only an
ea:ample. The design is intended to offer the potential for many applications,
and is therefore, very
adaptive. Dit~erent apptications will demand variety in the size and same of
the design elements. For
exarnpla, in larger applications, slip joizxts are used in the centre of the
legs of the tetrahedron. to allow the
unit to be disassembled and stored in a smaller space. In other applicariorns,
these joints may lx made to be
flexible andlor spring-loaded, al.lowin,g the unit to be collapsble, and
deployed mare rapidly arid
automaticalty_ 1n very small designs, the tegs may not need to be jointed at
all. 'fhe aluminum eonstrtretiozz
also allows the welding of mounting plates far a variety of additional
devices, such as GPS transceivers,
lights or lift-saving apparatus, on any part of the structure. The intent of
the invention has been to naaizztain
the versatility of the desi,~ while maintaining its specific qualities.
s~
