Note: Descriptions are shown in the official language in which they were submitted.
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EMERGENCY MARINE EVACUATION CHUTE SYSTEM
Field of the Invention
The present invention relates to emergency evacuation chutes for
deployment on ships and other marine vessels, for transferring passengers from
the deck of the vessel to a life raft or the like during marine emergencies.
More
particularly, the invention relates to an apparatus and method for
conveniently
deploying the chute over the side of a vessel.
Backgiround of the Invention
Large marine vessels such as large ships and oil rigs typically have decks
that are a considerable distance from the water surface. During a marine
emergency, it is important to rapidly and safely lower individuals from the
decks
to a waiting raft, lifeboat or the like. In the past, this has been
accomplished with
ladders that are either permanently mounted or incorporated within the vessel
hull, or unfolded, lowered or unfurled when required. Ladders may be difficult
and
unsafe to use during a marine emergency, and passengers who are elderly or
infirm may have difficulty in using ladders. Further, it is necessary during
an
emergency to be able to lower a large number of people rapidly over the side
of
a ship, and the use of ladders may not permit this.
In response to this need, there has been developed an arrangement
consisting of a flexible fabric chute that takes the form of a tubular member
that
may be suspended over the side of a vessel when required, and unfurled so as
to extend vertically from the deck of the ship to the sea surface. The base of
the
chute is typically attached to an inflatable floating platform that deploys
integrally
with the chute and serves as an embarkation area for loading of passengers
into
a life raft or the like. The chute is shaped to accommodate an individual
wearing
a life vest, and individuals sequentially enter the chute at an upper end and
slide
downwardly through the chute. An exit opening at the base of the chute permits
users to exit onto the floating platform. The rate of descent of the users may
be
controlled by various means, such as the provision of a tortuous path within
the
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chute that is followed by the users as they descend through the chute. Such a
chute may be assembled from a flexible material such as heavy-weight fabric or
the like. Since the deck-to-water distance will vary with the loading of the
ship,
the arrangement must include a means to permit the chute to adjust to
different
drop lengths.
Examples of prior art fabric-type tubular emergency chutes may be found
in the following references:
Canadian Patent 1,263,092 (Koizumi) discloses a fabric chute arrangement which
is mounted to a vessel. The chute is suspended from a rigid structure which
overhangs the side of the vessel, and the chute is bunched or folded within
the
interior of the structure when the chute is within the stowed position. The
structure permanently overhangs the side of the vessel.
Canadian Patent 1,266,241 (Koizumi) discloses a similar arrangement, showing
a somewhat different means for controlling the descent of passengers through
the
chute.
A need that is not fully addressed within the prior art is for a means to
safely and securely stow the chute on board the vessel, and to easily and
rapidly
deploy the chute in the event of an emergency. An appropriate deployment
mechanism should be capable of rapid and easy operation by a single
individual,
and still provide a secure means for retaining the chute during use. The
deployment means must provide a means for suspending the chute over the side
of the vessel during use, in a position somewhat displaced from the vessel
hull
to minimize contact with the hull during use. However, it is not desirable to
permit
fixtures to overhang the sides of a ship on a permanent basis. Accordingly,
the
deployment means should be able to carry the chute within a stowed position,
substantially entirely inboard of the vessel, and a deployment position
outboard
of the vessel.
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A further aspect of the prior art chute systems relates to a means for
disconnection of the chute from the floating embarkation platform. Typically,
the
platform is integral with the chute, insofar as the platform is deployed along
with
and as a component of the chute. The provision of such a platform is
essential,
since there may not always be present a life raft to receive passengers from
the
chute. The platform is typically an inflatable fabric arrangement that
includes one
or more inflatable tubes extending peripherally around the platform, with a
fabric
web spanning the interior of the platform. The tubes may be inflated by means
of inflation canisters associated with the tubes, that are triggered to
inflate
l0 automatically upon contact with water, in the same manner as an emergency
life
raft or life vest.
A drawback within the embarkation platform of the prior art resides in the
permanent attachment of the platform to the chute. This can be an extreme
hazard if the vessel starts to list or sink while passengers are on the
platform,
since movement of the vessel would tend to either draw the platform underwater
or hoist it above the surface. There is a need for a chute having an
embarkation
platform that may be readily detached from the chute by untrained operators
acting in a panic situation.
A further limitation within the prior art resides in the means by which the
rate of descent of passengers is controlled within the chute. The use of a
tortuous path as the sole speed control means may result in different rates of
descent for passengers of different sizes. Thus, it is desirable to provide
alternative or supplementary descent control means.
Summary of the Invention
It is an object of the present invention to provide an improved marine
evacuation chute apparatus including a deployment means for the same, whereby
a flexible fabric-type chute is safely and securely stowed within a folded
position
inboard of a vessel, on a vessel deck or the like, and whereby the chute may
be
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rapidly, safely, and easily operated by a single individual to deploy the
chute to
an overboard position suspended alongside the vessel.
It is a further object to provide an embarkation platform associated with the
chute arrangement, whereby the platform may be readily disconnected from the
chute by a passenger on the platform, in the event of an emergency.
It is a further object of the present invention to provide an improved
descent control means for slowing the rate of descent of passengers descending
through the chute.
In accordance with these and other objects, the present invention
comprises in one aspect an emergency marine chute apparatus for evacuating
passengers from a deck of a marine vessel and over the side of the vessel to
the
sea surface, comprising:
- a flexible tubular chute for transit of a passenger therethrough, said
chute being foldable or compressible to comprise a stowed position
and extendible vertically to comprise deployed position;
- descent control means to control and slow the rate of descent of a
passenger within said chute;
- a chute suspension frame engaged to said chute, for suspending
said chute in a position whereby the chute is spaced apart from the
side of said vessel when the chute is within the deployed position;
and
- pivotal mount means for mounting said chute suspension frame to
said vessel, wherein said frame is rotatable between a first position
wherein said frame is substantially inboard of said vessel and said
chute is within said stowed position, to a second position wherein
at least a portion of said frame overhangs the side of said vessel to
suspend said chute within said deployed position.
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Preferably, the apparatus includes means to carry the chute from an
inboard to an outboard position, comprising the following:
- a chute carriage for holding said chute within the stowed position;
- a carriage frame for supporting the chute carriage such that the
carriage is substantially inboard of the vessel within the stowed
position; and
- deployment means for acting on said carriage to urge the carriage
relative to said carriage frame from said stowed position to a
deployed position wherein said carriage and said chute are
overboard of said vessel;
wherein said chute suspension frame is urged from the first to the second
position by the chute carriage and chute acting on the frame when moving
to the deployed position.
The deployment means may comprise a downwardly-sloping rail within the
carriage frame, upon which the carriage may slide towards an overboard
position.
Preferably, there is further provided an embarkation platform connected to the
chute, for receiving passengers from the chute prior to embarkation on a life
raft or
other emergency craft.
The arrangement may comprise either a single chute fastened to the pivoting
support frame or dual chutes in side by side relationship.
In a further aspect, the descent control means comprises a trapeze
suspended from cord means, said cord means being payed out by a cord reel at a
controlled rate by a brake means for paying out said cord, whereby said
trapeze may
be gripped by a user to lower the user through said chute at a controlled
rate.
In a further aspect, the invention comprises apparatus for stowing and
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deploying chute from an upper deck of a vessel. In this aspect, the invention
comprises the following elements:
- a chute suspension frame engaged to the chute, for suspending the
chute in a position whereby the chute is spaced apart from the side of
said vessel when the chute is within the deployed position; and
- pivotal mount means for mounting said chute suspension frame to said
vessel, wherein said frame is moveable between a first position
wherein said frame is substantially inboard of said vessel and said
chute is within said stowed position, to a second position wherein at
least a portion of said frame overhangs the side of said vessel to
suspend said chute within said deployed position.
In a preferred version, the deployment apparatus includes means to carry the
chute from an inboard to an outboard position, comprising the following:
- a chute carriage for holding the chute within the stowed position;
- a carriage frame for supporting the chute carriage such that the
carriage is substantially inboard of the vessel within the stowed
position; and
- deployment means for acting on said carriage to urge the carriage
relative to said carriage frame from said stowed position to a deployed
position wherein said carriage and said chute are overboard of said
vessel;
wherein said chute suspension frame is urged from the first to the second
position by the chute carriage and chute acting on the frame when moving to
the deployed position.
The deployment means may comprise a downwardly-sloping rail within the
carriage frame, upon which the carriage may slide towards an overboard
position.
Having thus summarized various aspects of the invention, the present
invention will now be further described by way of illustrations and
descriptions of
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particular embodiments of the invention.
Brief Description of the Drawings
Figure 1 is a perspective view of the chute deployment apparatus according
the present invention, within a stowed position;
Figure 2 is a side elevational view of the deployment apparatus, within the
stowed position ;
Figure 3 is a front elevational view of the invention;
Figure 4 is a plan view;
Figures 5 (a)- (c) are perspective views of the apparatus within the deployed
position;
Figures 6a to 6i illustrate the steps of deploying a chute in accordance with
the present invention;
Figure 7 is a side elevational view of a further embodiment of the invention;
Figure 8 is a side elevational view, exploded, of a third embodiment of the
invention;
Figure 9 is a side sectional view of a portion of the apparatus;
Figure 10 is a perspective view of a fourth embodiment of the invention; and
Figure 11 is a perspective view of a further portion of the apparatus.
Detailed Description of the Preferred Embodiments
A chute deployment apparatus according to the present invention is
designated globally as 10, and is mounted on a vessel 12, a portion of which
is
shown for illustration. The vessel may comprise any large floating or non-
floating
vessel such as an oil rig, ocean liner, ferry or other vessel.
Referring to Figures 1-5, the apparatus comprises a chute suspension frame
16 for suspending the chute 18 from an upper deck of the vessel. Figure 5
illustrates
the chute within a suspended, deployed position for use by disembarking
passengers. The frame 16 consists of parallel spaced apart generally vertical
struts
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24, spanned at their upper ends by a cross bar 26. The vertical supports are
each
pivotally mounted to the ship deck by pivot mounts 27. The pivot mounts permit
pivotal movement of the support about a horizontal axis, from an inboard
position
shown in Figures 1 to 4 wherein the support angles slightly from the vertical
in the
inboard direction, to the deployed position shown in Figure 5, wherein the
support
angles outwardly over the side of the ship. The pivot mounts 27 each comprise
a
base 28 bolted or otherwise permanently mounted to the ship deck, and a pivot
pin
29, for pivotally attaching a corresponding strut to the base.
The term "inboard" as used herein is a directional reference meaning
generally oriented or positioned within the confines of the ship hull. The
term
"outboard" refers to the positioning of an element over the side of the
vessel.
The apparatus 10 is housed within its own compartment 30 (seen in Figure
6(a)) which during normal operation of the vessel is fully closed. The
compartment
will typically be located adjacent to the side of the vessel, either on an
upper deck
or elsewhere. The compartment may be accessed from the inboard side by way of
an interior door 32, which may incorporate protective release means to prevent
unauthorized access during normal marine operation. The compartment
communicates at the outboard side with the exterior of the vessel by means of
an
exterior door 34, which may be released by means of a release cord 36 operable
from within the interior of the compartment.
The chute suspension frame 16 is associated with a chute carriage structure,
designated globally as 40. The carriage structure is fixedly mounted either
directly
to the ship deck or to the pivot mounts 28. The carriage structure comprises a
chute carriage 42, which holds the chute in a folded or bunched position
within the
stowed position, and a carriage frame 43, to which the carriage is slidably
engaged.
The carriage frame is composed of two co-planar rigid elongate members, namely
a pair of spaced-apart parallel side rails 44. Each rail is fixedly mounted at
its
proximate end to the ship deck or the base 28 of a corresponding pivot mount
27,
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such that the rails 44 angle upwardly in an inboard direction. The rails 44
are each
fixedly supported in their angled position by a vertical support pillar 48
extending
from the ship deck to the distal end of the rail 44. The carriage frame 43 and
the
chute suspension frame 16 thus comprise two planar structures arranged in
separate
planes meeting along a line generally adjacent the side of the vessel.
The rails 44 of the chute carriage frame 43 are sufficiently angled to permit
the carriage 42 when released to slide downwardly along the rails solely by
the
action of gravity acting on the carriage. The required angle at which the
rails are
disposed will depend on the structure of the rails and carriage. For example,
in one
version (described below) the carriage or the rails may be provided with
rollers to
facilitate relative movement of the carriage along the rails. It will also be
seen that
the angle of the rails must take into account the fact that during a marine
emergency,
the ship may have a list and this will effectively reduce the angle of the
rails.
Accordingly, the rails should be positioned at an angle that will take into
account
such an eventuality.
The chute carriage 42 comprises an enclosed structure, having a base 45 and
a lid 46. The base 45 is generally rectangular and has flat bottom 50 and
peripheral
upwardly extending sidewalls 56 along the four sides of the base, comprising
front,
rear and side sidewalls. Conveniently, the tray is fabricated from a strong
and rigid
material, such as rigid plastic, hardened aluminum alloy or stainless steel
plate. The
base 45 includes a release means to fixedly engage the carriage to the
carriage
frame during normal marine operation. The release means comprises an arm 60
rotatably mounted at generally its midpoint to the front sidewall by way of a
mount
62, and having handles 64 extending from the ends of the arm for ease of
rotation
by a user. In the stowed position (i.e., during normal marine operation, with
the
chute carriage fixed to the chute frame), the arm 60 is oriented generally
vertically
to abut an end of one of the rails 44 of the carriage frame, thus preventing
the
carriage from sliding downwardly off the frame. The arm 60 is maintained in
the non-
deployment position by means of a removable pin 70 extending through the arm
and
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into either of the chute support or the tray. Upon removal of the pin by a
user, the
arm may be rotated to a generally horizontal position, which permits the
carriage to
slide downwardly along the rails and over the side of the vessel.
In another version, shown in Figure 7, the rails 72 of the carriage frame
incorporate rollers 74 on their upper surface for facilitating movement of the
carriage
42 along the rails. Alternatively, as seen in Figure 8, the carriage may
incorporate
rollers 76 that roll within corresponding channels 78 within the rails 80. In
either of
these versions, the reduced friction between the carriage and the rails
permits the
use of a shallower angle and also minimizes the risk that the carriage will
not slide
along the rails upon release.
The chute 52 comprises a generally conventional tubular fabric chute of any
convenient type known to the art, and which includes descent control means to
slow
the speed of descent of users, as seen in Figure 9. Conventionally, the chute
comprises inner and outer fabric layers 89 and 91, with the outer layer 91
comprising
a generally straight-walled tube and the inner layer 89 forming a tortuous
path to
slow the rate of descent of users. As well or alternatively, the user may grip
an
overhead trapeze 90 that descends through the chute at a controlled speed. The
trapeze is suspended by a cord 92 that is attached at its upper end to a cord
reel 94
having brake means 96 to pay the cord out a controlled speed as the user
descends.
Upon completion of the descent, the cord reel may automatically rewind the
cord
upon release of the trapeze by the user, for use by a subsequent passenger.
The upper region of the chute 52 is characterized by an entry portal 100
within .
the sidewall of the chute, permitting users to walk into the chute. A similar
exit
portal 102 is disposed at the lower end. The upper end of the chute is capped
with
a generally circular rigid cap 104. The cap maintains the tubular form of the
chute
and prevents its collapse. The chute terminates at its upper end in an array
of
bowsing lines 110 for suspending the chute the crossbar 26 of the suspension
frame
16.
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The apparatus may include with a single chute (as seen in Figure 10) or dual
chutes 52, as seen in Figure 5. The dual chute version comprises two chutes
52,
which are otherwise identical to the chute 52 of the single chute version,
positioned
for deployment in side by side relationship. On deployment, both chutes are
suspended from the common crossbar 26 of the suspension frame 16. When in the
stowed position, both chutes are folded into a single chute carriage for
simultaneous
deployment.
The fabric chute 52 has attached to its lower end an integral inflatable
embarkation platform 110, shown in Figure 11. The platform 110 is engaged to
the
chute 52 by means of an array of cords 112, which preferably comprise elastic
"bungee" cords which have a breaking strength calibrated to permit the cords
to
break when the strain exceeds a predetermined amount approximating the weight
of the embarkation platform loaded with at least one passenger. This permits
the
platform to disengage from the vessel in the event the vessel lists or sinks
before the
passengers disembark from the platform to a life raft or the like.
Conveniently, the
platform is engaged to the chute by means of two pairs of cords, a first pair
fastening
to the outer chute layer 91 and a second pair fastening to the inner chute
layer 89.
The cords 112 are tensioned from the vantage of the platform 110, by means of
a
tensioning lever 113 pivotally mounted to the platform 110 to one side and
somewhat
displaced from the central axis of the chute 52, to impart a curvature to the
bottom
region of the chute. The platform itself is essentially similar to a
rectangular life raft
with additional thwarts. The platform comprises in the preferred version
comprises
a peripheral tubular member 114 for flotation, which incorporates inflation
canisters
116. The canister are triggered upon contact with seawater to release a gas
into the
inflatable raft tubes for inflation of the platform upon deployment into the
sea water.
A fabric web 118 spans the interior of the platform and serves as passenger-
bearing
platform for receiving passengers prior to embarkation onto a life raft or the
like.
Upon release of the chute carriage 50 by removal of the pin 70 and actuation
of the release means, the carriage 52 and accompanying chute 52 slide
downwardly
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and outwardly along the rails and over the side of the vessel. The downward
and
outward movement of the carriage swings the suspension frame 16 outwardly,
such
that the cross bar 26 is moved to a position substantially overhanging the
side of the
vessel. The position of the cross bar 26 relative to the vessel side positions
the
deployed chute 52 in a spaced apart position relative to the vessel side, to
minimize
the chance that the chute will hit the vessel hull during use. The upper end
of the
chute 52 is fastened to the cross bar 26 of the suspension frame 16 by means
of the
bowsing lines 110, and remains suspended from the frame. The chute carriage 50
remains engaged to the embarkation platform 110 throughout, and upon
deployment
of the platform 110 the carriage is suspended below the waterline from the
platform
110. A winch 124 mounted to the deck applies tension to the bowsing lines and
permits vertical positioning of the chute. This ability is essential, since
the distance
from the vessel deck to the sea surface will vary with the load carried by the
ship,
and as well will change if the ship is listing or sinking. Thus, correct
positioning of
the chute cannot be fully pre-set and must be carried out at deployment.
Pivotal movement of the suspension frame 16 in the outboard direction is
limited by a cable 130 connecting the upper end of the support frame with the
ship
deck. Prior to deployment of the chute 52, the cable 130 is slack. As the
suspension
frame 16 rotates outwardly, the cable is drawn taught, thus limiting the
deployment
angle of the suspension frame 16 to a preselected angle suitable for
suspending the
chute in an appropriate displaced position relative to the vessel hull. The
selected
maximum suspension frame angle is selected to reflect the individual vessel
requirements. For example, certain vessel hulls may be slightly bowed
outwardly in
the vertical direction, thus necessitating a greater amount of lateral
displacement of
the chute 52. As well, a greater deck to sea distance may require a greater
amount
of displacement.
The gap between the vessel deck 20 and the entry portal 100 of the chute 52
is spanned by a pivoting bridge member 134. The bridge member in the non-
deployed position rests on the vessel deck, and is attached to the deck by
means of
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a pivot mount 136. Upon deployment, the bridge member is pivoted such that it
extends overboard of the vessel, and extends part way into the portal 100. In
some
cases, the vessel design includes a downwardly stepped portion 136 at the edge
of
the deck and the bridge member may include a locking collapsible leg 137 for
contacting the downwardly stepped portion and supporting the bridge member. In
the absence of a downwardly portion, the collapsible leg 137 may angle
inwardly and
contact the exterior vertical face of the vessel hull.
Subsequent to deployment of the chute 52, the vertical position of the chute
is adjusted to stabilize the platform 110 directly below the chute. When the
chute
is optimally tensioned, it describes a curve at its base for a final slowing
of the rate
of descent of users. For this purpose, a shock cord 140 is slidably mounted to
the
exterior of the chute, extending from its base to the support frame. The
lower, free
end of the shock cord 140 is fastened to a lever 142 , which in turn is
pivotally
mounted to the embarkation platform 110. Rotation of the lever tension the
shock
cords and imparts curvature to the lower region of the chute, as seen in
Figure 6i.
It will be apparent to those skilled in the art to which this invention
pertains
that although the present patent specification describes in detail a preferred
embodiment of the present invention, the invention encompasses numerous
departures from and variations to the embodiment described herein, as set
forth in
the accompanying patent claims.
