Note: Descriptions are shown in the official language in which they were submitted.
CA 02434903 2003-07-09
SIMULATOR AND METHOD FOR PERFORMING
UNDERWATER SUBMARINE ESCAPE TRAINING
TECHNICAL FIELD
The present invention relates to a simulator and a method for performing
underwater submarine escape training.
BACKGROUND
Military submarines are highly complex machines which proved to be relatively
safe for the submariners aboard them. However, serious accidents did happen in
the past and there is always the risk that some may happen in the future. Any
7 0 submariners must then be ready for all kinds of emergencies and training
is an
essential part of this preparation. Extensive training is often a factor that
allowed
people to come out of difficult situations without any or serious harm.
Among all potential dangers of being in a submarine, one of them is to be
stuck
underwater with no other option but to leave the submarine before outside help
~ 5 can arrive. Some naval forces do have small submarines which can be
attached
over a hatch and provide an escape vehicle to leave a submerged submarine in
distress. Unfortunately, it is not always possible to use such vehicle since
it is
almost never immediately available. Submariners must then be able to leave a
submerged submarine by themselves if that is required. This is the reason why
20 military submarines are conventionally provided with one or more exits
called
"escape towers". One escape tower is usually provided near the front of the
submarine and one at the rear.
Escape suits conventionally found in submarines allow the submariners to
escape
without pressurized air from a compressed air cylinder. One of the reasons is
that
25 there are many persons in a military submarine so that the number of air
cylinders
would be too important. Another reason is that air inside a submarine is not
pressurized and is maintained at the sea level. There are thus no
decompression
stages to follow in that case.
CA 02434903 2003-07-09
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An escape suit is designed to be watertight and air inflatable. An example of
suit
is the "Mark X" escape suit. The suit is used with glove and a nose clip. The
escape suit keeps the submariner dry and warm while he is in water or aboard a
life raft. Air inside the suit increases the thermal insulation. Once
inflated, the suit
also allows the submariner to quickly reach the surface. The suit is equipped
with
a hood inflation system (HIS) which further allows the submariner to keep his
face
out of the water. The HIS consists of a hood, partly made of transparent
plastic,
which completely covers the head and face of the person. Small air vents in
the
suit, at the upper chest, allow air to flow from the suit into the hood
compartment.
A small space is maintained between a part of the hood on the chest and the
outside. The HIS retains air therein, thereby allowing the head to remain
clear of
the water and the submariner to breathe if necessary. However, during an
ascent,
the submariner must expel air. Pressurized air is forced into the escape suit
immediately before leaving the submarine through the escape tower. This is
possible by using a push fit connector insertable in a pressurized air outlet
called a
"stole charging valve".
Escape suits are usually equipped with a compact individual raft to be
inflated
once at the surface using a C02 canister. This allows the submariner to get
out of
the water and wait for rescue. The rafts of two or more persons may be
attached
together so as to facilitate the search and rescue operations. Usually, the
first
vehicle to reach the scene in a search and rescue operation is an airplane.
The
airplane typically drops one or more large life rafts provided with supplies.
Submariners climb on board these larger rafts and wait for surface rescue or
rescue helicopters to arrive.
Training far escaping out of a submerged submarine through the escape tower
was usually done without ever having the submariners experiencing the complete
escape procedures itself. Submarines are not adequate locations for this kind
of
training because the escape procedure involves a certain level of danger. Some
hands-on training was possible only using fixed towers filled with water and
at the
bottom of which a submariner can exit through a hatch and experience an assent
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using the submarine escape suit. One o~f such training facility is located in
Gosport, United Kingdom.
Considering this background, it clearly appears that 'there was a need to
provide a
simulator and a method of performing underwater submarine escape training in a
body of water, thereby allowing submariners to have hands-on training on
submarine escape procedures in a controlled and safe environment.
SUMMARY
In brief, the simulator of the present invention comprises a submersible
structure
to be used in a body of water, for instance a pool. This structure comprises a
bell
defining a main chamber. An escape tower is provided over the bell. This
escape
tower defines an escape chamber communicating with the main chamber. The
escape tower has a lower hatch between the main chamber and the escape
chamber, and an upper hatch separating the escape chamber from outside the
submersible structure. The simulator also comprises means for vertically
moving
the submersible structure relative to the water surface.
This and other aspects of the present invention are described in or apparent
from
the following detailed description of a preferred embodiment, made in
conjunction
with the accompanying figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a simulator in accordance with the preferred embodiment of
the present invention.
FIG. 2 is a side view showing the upper part of the submersible structure of
FIG. 1.
FIG.3 is a perspective view of the base of the submersible structure
simulator of FIG. 1.
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FIG. 4 is a cross-sectional view of the interior of the submersible structure
of FIG. 1.
FIG. 5 is a cross-sectional view of the submersible structure taken along
line V-V in FIG. 2.
FIG. 6 is a cross-sectional view of the submersible structure taken along
line VI-VI in FIG. 2.
FIGS. 7 and 8 are diagrams showing the pneumatic system in accordance
with the preferred embodiment.
FIG. 9 is a diagram showing the hydraulic system in accordance with the
preferred embodiment.
FIG. 10 shows an example of a control panel.
FIG. 11 illustrates the tower escape procedure using the submersible
structure of FIG. 1.
FIG.12 illustrates the rush escape procedure using the submersible
structure of FIG. 1.
DETAILED DESCRIPTION
The appended figures show a simulator (10) in accordance with the preferred
embodiment of the present invention. It should be understood that the present
invention is not limited to the illustrated implementation and that various
changes
and modifications may be effected therein without departing from the scope of
the
appended claims. For instance, the present invention is not limited to
military
submarines and can be used with any kind of submarines, submerged
constructions or the like. It should also be noted that throughout the
figures, the
parts which are not referred to may correspond to the same parts which are
shown
in other figures.
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As shown in FlG. 1, the simulator (10) comprises a submersible structure (20).
The submersible structure (20) is used to simulate a submarine unable to
surface
and in which an immediate danger requires that it be evacuated before outside
help can arrive. The submersible structure (20) is designed to be used in a
body
5 of water. An example of a body of water is a pool, more particularly an
indoor pool
(12). This allows having full control of the operating environment. It may
otherwise be another kind of body of water, including, a lake, an ocean, etc.
If a
pool is used, as in FIG. 1, the pool (12) may comprise a cylindrical shaft
(14)
downwardly extending from the bottom portion of a shallower section (16) of
the
pool (12). This has the advantage of reducing the quantity of water inside the
pool
(12) while stilt providing the deeper portion required to perform the
underwater
training. The pool (12) may otherwise only consist of the cylindrical shaft
(14),
thereby being provided without the shallower section (16).
A traveling crane (18) may be advantageously provided above the pool (12) to
pull
the submersible structure (20) out of the water for maintenance and storage.
Cables, chains or straps are used between the hook of the traveling crane (18)
and the submersible structure (20). Also, a bridge (not shown) may be provided
over the water surface to facilitate the access into the submersible structure
(20).
The submersible structure (20) is preferably connected to a remote supply unit
(30). The connection between them is made by an element called the "umbilical
cable" (32). Nevertheless, it should be noted that it is possible to provide a
fully
autonomous submersible structure (20) which requires no supply from the
outside.
The umbilical cable (32) preferably includes a flexible but pressure-resistant
outer
tube enclosing a number of smaller tubes and cables. It allows connection of
the
remote supply unit (30) to the submersible structure (20) at all time. If
desired,
more than one umbilical cable (32) can be used. Similarly, more than one
remote
supply unit (30) can be used as well.
Air needs to be supplied to the submersible structure (20) of the preferred
embodiment. For greater safety, the air supply comes from at least two
different
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sources, namely from a low pressure system (34) and from a high pressure
system (36). The high pressure system (36) may include an air bank, which
allows maintaining a continuous air supply in case of a power failure. The
umbilical cable (32) preferably provides two breathing air links. The outer
tube of
the umbilical cable (32) may further be used to send stale air outside the
submersible structure (20). This prevents bubbles from being generated in the
pool {12), which bubbles can diminish the visibility. The umbilical cable (32)
of the
preferred embodiment further comprises a telecommunications link and an
electrical power link. The electrical system in the submersible structure (20)
advantageously uses a low voltage for safely reasons, for instance 12 or 24
Volts
DC.
The preferred embodiment uses hydraulic power from a remote hydraulic system
(38) to supply a hydraulic motor mounted on the submersible structure (20).
This
remote hydraulic system (38) is thus connected to the umbilical cable (32).
The remote supply unit {30) is preferably controlled from a control panel (40)
located outside the pool (12). It allows a supervisor to have a full control
of the
operations and ensure the safety of the training. For instance, the depth of
the
submersible structure (20) is controlled from the control panel (40). If there
is any
problem, the supervisor can bring the submersible structure (20) to the
surface.
FIG. 10 illustrates an example of a control panel (40).
Advantageously, all connections with the umbilical cable (32) are removable
and
with a unique pattern. A well designed simulator (10) should have no way to
mistakenly connect the connectors to the wrong connection point. Connectors of
different sizes should then be used. Inverted male and female ends are also
another technique.
The simulator (10) comprises means for vertically moving the submersible
structure (20) relative to the water surface. In the preferred embodiment,
these
means are provided as means for pulling the submersible structure (20)
downwards. Pulling the submersible structure (20) downwards allows to bring it
to
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. r
the desired depth and adjust the depth whenever it is necessary. This is
preferably achieved by means of a winch (50) operated in conjunction with a
cable
(52) connected to a bottom location in the pool (12). The winch (50) is
provided
under the submersible structure (20). The winch (50) comprises a reel around
which a cable (52) is wound. The bottom location can be a fixed point at the
bottom of the pool (12) or, preferably, one or more pulleys (54) anchored
thereto.
Two pulleys (54) are used in the illustrated embodiment. The end of the cable
(52)
is attached under the submersible structure (20). The pulley or pulleys (54)
at the
bottom of the pool (12) can be either directly anchored to the wall of the
pool (12)
or, as illustrated in FIG. 1, anchored to a dead weight (56) resting by
gravity at the
end of the pool (12). The use of the dead weight (56) is preferred since it
prevents
the pool (12) from being damaged by wall anchors. It also simplifies the
maintenance. Of course, the dead weight (56) must be heavy enough to
compensate for the buoyancy of the submersible structure (20).
In the preferred embodiment, the winch (50) comprises a hydraulic motor (58),
which is schematically shown in FIG. 9. The hydraulic motor (58) is preferably
powered through hydraulic pressure lines coming from through the umbilical
cable
(32). It can also be powered through a hydraulic system (not shown) located
inside the submersible structure (20).
It should be noted that other means for vertically moving the submersible
structure
(20) relative to the water surface may be provided. For instance, it is
possible to
use a submersible structure (20) having negative buoyancy and which is
retained
by upper pulling cables (not shown). A combination of upper and bottom pulling
cables is also possible. It may be further possible to use a vertical railing
system
(not shown) similar to the ones guiding conventional elevators. Such railing
system may even be set at an angle instead of being vertical, the depth of the
submersible structure (20) being adjusted by moving it up or down the slope.
In
case of an emergency, water in the pool (12) may be drained very quickly to
rescue the persons in the submersible structure (20).
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The telecommunications link allows two way audio-communications between the
instructor inside the submersible structure (20), and the operator standing at
the
control panel (40). Wireless communication is also possible. 'The instructor
and
the supervisor should always have a headset with a microphone in order to
communicate efficiently with one another. A back up communication system
should also be provided in case of a power failure. l~ne can also provide a
battery
(not shown) in the submersible structure (20) and the control panel (40) so
that
power remains available at all time. At worse, if there is a stale air
connection
using the flexible outer tube of the umbilical cable (32), it is possible to
have a
voice exchange from the stale air outlet and the distal end of the outer
flexible
tube.
Preferably, one or more divers assist the trainees throughout the training
procedure. ~uring training exercises, divers are preferably used to make sure
that
no trainee remains stuck when leaving the submersible structure (20). The
divers
are also the ones which assemble the parts and disassemble them between
training sessions. Because the pool (12) uses chemicals to treat the water,
for
instance chlorine, it is usually required that the submersible structure (20)
be
removed from the water between training sessions. Before the training session,
the diver or divers will install the cable (52) of the winch (50) through the
pulleys
(54) located at the bottom of the pool (12), if required. Moreover, divers
should
have tools in the pool (12) in order to cut the cable (52) retaining the
submersible
structure (20), should the pulling system become stuck or is otherwise not
functioning in spite of all the safety features.
FIGS. 2 to 6 are various views of the submersible structure (20) in accordance
with the preferred embodiment. As shown in these figures, the submersible
structure (20) comprises a bell (22). The bell (22) defines a main chamber
(24).
The bell (22) is designed to be large enough so that the main chamber (24) can
accommodate an instructor and one or more trainees.
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The submersible structure (20) is preferably protected by an outer framework
(26).
This framework (26) allows various parts to be connected to the submersible
structure (20). It also provides connection points for its handling, for
instance
using the traveling crane {18).
An escape tower (60) is provided over the bell (22). The escape tower (60)
defines an escape chamber (62). The escape tower (60) used on the simulator
(10) is preferably identical or very similar to the one found on the submarine
on
which the trainees will be submariners. The escape tower (60) is preferably
centered with reference to the bell (22). Other designs are also possible. It
should
be noted that the illustrated escape tower (60) is for a Victoria class
submarine of
the Canadian Navy.
The escape tower (60) further comprises an upper hatch (64) separating the
escape chamber (62) from outside the submersible structure (20). A typical
diameter for the upper hatch (64) is 30 inches. The upper hatch (64) is
hingedly
connected at the top of the escape tower (60). It comprises a locking system
operated from inside and outside. The upper hatch (64) also advantageously
comprises a port. This allows a diver in the pool (12) to see what is going on
in
the escape chamber (62).
The submersible structure (20) may further comprise at least c>ne
pneumatically
inflatable float (70) connected to the outer framework (26) The inflatable
float or
floats (70) are provided to adjust the buoyancy of the submersible structure
(20).
Ideally, the upward force created by the positive buo~eancy must be high
enough to
prevent the submersible structure {20) from easily moving sideward. It must
otherwise remain reasonable so as to minimize the stresses on the winch (50)
and
the pulleys (54). furthermore, one or more large emergency inflatable floats
(72)
may be provided to bring the submersible structure (20) to the surface in case
the
main chamber (24) becomes flooded. The submersible structure (20) is designed
so that the upper hatch (64) of the escape tower (50) will always be above the
CA 02434903 2003-07-09
water surface when the submersible structure (20) is floating at the water
surface.
This allows the persons in the submersible structure (20) to escape.
If desired, as in a real submarine, a remote closing mechanism (80) can be
provided for moving the upper hatch (64) between an open position and a closed
5 position from the main chamber (24). Such remote closing mechanism (80) is
quite important in a real submarine since once a submariner escapes through
the
escape tower (60), it cannot close the upper hatch (64) behind him. This
mechanism (80) is schematically illustrated in FIG. 5. It is not required in
the
simulator (10). Instead, the diver or divers may close the upper hatch (64)
10 manually and only a fake handle (81 ) is provided in the main chamber (24)
for
training purposes.
The bell (22) preferably comprises a side maintenance hatch (82) located on
the
side thereof. This side hatch (82) is pivotally connected outside the bell
(22). It is
used to access the main chamber (24) when the submersible structure (20) is
completely out of the water. It advantageously comprises a port to see into
the
main chamber (24) from outside. A typical diameter for the side hatch (82) is
30
inches. It may otherwise be used to evacuate a wounded person from the main
chamber (24). However, this would require that the submersible structure (20)
be
moved out of the water using the traveling crane (18).
A bottom emergency hatch (84) is preferably provided under the bell (22). This
bottom hatch (84) separates the main chamber (24) from outside the submersible
structure (20). It opens towards the outside, thereby being maintained in a
closed
position by the water pressure during training, in addition to the usual
locking
mechanism. It can be used as an emergency exit in the unlikely event of a
dramatic failure of the simulator (10). If no other means of escaping out of
the
submersible structure (20) is possible, the main chamber (24) can be
pressurized
and the bell (22) can then be used as a diving bell. The bottom hatch (84)
opens,
when unlocked, as soon as the pressure is the main chamber (2.4) is higher
than
CA 02434903 2003-07-09
11
that of the surrounding water. Opening the bottom hatch (84) will allow
persons
therein to dive out.
The submersible structure (20) of the pmeferred ernbodiment comprises a base
(90) that is removably connected under the bell (22). The base (90) is
individually
shown in FIG.3. This base (90) is preferably connected under the outer
framework (26) by a plurality of removable fasteners, for instance galvanized
steel
bolts and nuts. Removable fasteners facilitates the storage of the submersible
structure (20) outside the pool (12) or its transportation. The base (90)
preferably
comprises a side plate (92) under which the winch (50) is installed.
Before a training session, the base (90) is preferably brought into the
shallower
part (16) of the pool (12) using the traveling crane (18). The upper part of
the
submersible structure (20) is positioned over it and the removable fasteners
are
put in place by the diver or divers. If required, the removable hydraulic
connections are also attached by one of the divers. It may thus be
advantageous
to provide the base (90) with hydraulic connectors (91 ) at the inner side of
the
base (90). This way, it is easier for the diver to apply the required force to
insert
the hydraulic connectors from the umbilical cable (32) into the connectors (91
) of
the base (90). It should be noted that the base (90) may otherwise be
permanently integrated with the remainder of the submersible structure (20).
The base (90) is adapted to receive ballasts (94), for instance lead bricks or
others
which are firmly attached thereto by straps (96), in order to balance the
submersible structure (20). These ballasts (94) also allow fio control of the
buoyancy of the submersible structure {20). In the preferred embodiment, the
buoyancy is designed to be positive, i.e. that the submersible structure (20)
will
float by itself.
FIGS.4 to 6 show the interior of the submersible structure (20) without the
framework (26), the base (30) and other external parts. The instructor and the
trainees stand over gratings {100) or any other kind of flooring when they are
in
the main chamber (24). The gratings (100) prevents the persons therein from
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standing directly on the bottom hatch (84), if any, and the hull of the bell
(22).
Access to the bottom hatch (84} is possible upon lifting a removable portion
of the
gratings (100). A small rim (102) projecting from the interior wall of the
bell (22)
allows the persons to be partially seated.
The escape tower (60) has a lower hatch (110) between the main chamber (24)
and the escape chamber (62). The tower hatch (110) closes from the upper side.
Preferably, it is fully removable and maintains in place by gravity and by the
weight
of the water when the escape chamber (62) is flooded. It has a slightly oval
shape, allowing it to be passed through the opening from the main chamber (24)
into the escape chamber (62). Two handles allow it to be more easily
manipulated. It further has a port, which allows an instructor standing in the
main
chamber (24) to see what is happening in the escape chamber (52).
A removable ladder (120) is provided in the main chamber (24) to facilitate
the
access to the escape chamber (62). Other means for climbing into the escape
chamber (62) may be used as well. Another ladder (122} is provided in the wall
of
the escape chamber (62}.
The interior of the main chamber (24} is provided with all the required
equipment,
for instance communication equipment, air supply equipment, training manuals.
etc. Watertight lamps are used to provide adequate lighting in the main
chamber
(24) and in the escape chamber (62). Safety equipment is also provided,
including
an emergency breathable air supply. Flashlights and chemical lights are also
provided for any emergency. If desired, an atmosphere monitoring system (63)
can be installed in the main chamber (24) for monitoring parameters such as
the
air quality and pressure.
The submersible structure (20) comprises means for flooding the escape chamber
(62). Preferably, these means comprise a flooding valve (130) being configured
and disposed to control a flow of water into the escape chamber (62) coming
from
the pool (12). An example of flooding naive (130) is a 3-inch ball valve The
flooding valve (130) can be operated using either a flooding valve lever (132)
in
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13
the escape chamber (62) and a second flooding valve lever (134) in the main
chamber (24).
The means for draining the escape chamber (62) are also provided. They
preferably comprise a draining valve (140) configured and disposed to control
a
flow of water between the bottom of the escape chamber (62) and a sump (142)
created between the base of the bell (22) and the gratings (100). The draining
valve (140) is operated using a draining valve lever (144) in the main chamber
(24). Other configurations are also possible. preferably, when draining the
water,
it is sent in a flexible tube (146) having an end near the gratings (100). The
water
then falls into the sump (142). A sump pump (148), having a suction inlet
underneath the gratings (100), allows sending the water drained from the
escape
chamber (62) back into the pool (12). The sump pump (148) is preferably an
electrical pump supplied through the electrical link.
Means for venting the escape chamber (62) during flooding and draining are
further provided. They preferably comprise a vent air pipe (150) having an
upper
end (152) located near the upper hatch (64), and a bottom end connected to a
venting valve (156). The venting valve (156) is configured and disposed to
control
the flow of air between the escape chamber (62) and the main chamber (24). An
example of venting valve (156) is a 2-inch ball valve. ~/enting the escape
chamber
(62) is important since air would otherwise be trapped in the escape chamber
(62)
as the water level rises. Air pressure would than rise until the point that
the upper
hatch (64) opens and water rushes to fill the escape chamber (62) entirely.
The
trainee inside the escape chamber (62) would there receive a large quantity of
water at once.
The air valve (156) is usually controlled only from inside the main chamber
(24).
Therefore, the training usually takes place using the "last man" situation.
Every
trainee trains for the situation where they are the last person to leave a
submarine
in distress. They must thus have everything perfect the first time, because if
they
are the last man to leave the submarine, no one will be there to correct a
critical
CA 02434903 2003-07-09
14
mistake. One of the difficulties is to control the air vent from inside the
escape
chamber (62). The problem is that by the time the water level reaches the
upper
end (152) of the vent pipe (150), the trainee, having its suit fully inflated,
is not in
the best position to manipulate any valve. Instead, he closes the upper end
(152)
of the vent pipe (150) using a handheld cap (158), for instance made of heavy
metal, which will allow the water level to rise up to the point where the
upper hatch
(64) can be opened.
FIGS. 7 and 8 show the pneumatic system in accordance with the preferred
embodiment. The low pressure system (34) and high pressure system (36) are
usually located elsewhere in the building where the simulator (10) is located.
Air is
then supplied through supply lines, for instance using supply lines ending in
a wall
panel (200). Valves (202,204) allow the air supply to be controlled locally. A
regulator (206} further brings the pressure of the high pressure system (86)
to that
of the low pressure system (34). Of course, air is of breathable quality or
will
otherwise need to be treated before being sent inside the subrnersible
structure
(20). In the preferred embodiment, the wail panel (200) also comprises a
hydraulic
valve (210) to control the hydraulic motog- (58) of the winch (50). The
hydraulic
connections (37) are direct between the wall panel (200) and the umbilical
cable
(32). However, pressurized air goes through the control panel (40) and is
directed
to the appropriate circuits from there.
FIG. 7 shows that there are four pneumatic connections between the wall panel
(200) and the control panel (40). The reason is that the hydraulic valve (210)
is
preferably controlled using a pneumatic arrangement. This pneumatic
arrangement comprises an air inlet (212) connected to a pneumatic valve (214)
controlled by a lever (216). The valve (214) is mounted in the control panel
(40).
The pressurized air from the pneumatic valve (214) controls the position of
the
hydraulic valve (210). This eliminates the need to have pressurized hydraulic
lines
in the control pane! (40). For greater safety, the hydraulic valve (210) is
provided
with a manual control lever (218).
CA 02434903 2003-07-09
In the control panel (40}, air from the two supply systems (34,36) is
preferably
merged and then split again in two supply lines (220,222) going into the
umbilical
cable (32). Other configurations are possible as well.
An emergency air supply circuit with regulators (230), referred to as "BIBS"
and
5 shown in FIG. 8, is provided in case of a failure of the other circuits. The
BIBS
(230) will allow people inside the submersible structure (20) to have air even
if it
becomes flooded entirely. For even greater safety, portable compact air
systems
(232) can be provided as well, as shown in FIG. 4. This will give the people a
few
minutes of air, which should be enough to leave the submersible structure (20)
in
10 case of an emergency. One should also be provided in the escape chamber
(62).
Air supplied to the BIBS (230) preferably has its own supply line (224)
through the
umbilical cable (32).
The main and emergency floats (70,72) are supplied with pressurized air using
dedicated supply lines (250,252) in the umbilical cable (32). This allows the
main
15 float or floats (70) to be controlled entirely from the control panel (40).
The floats
(70,72) can also be depressurized from the control panel (40).
Air enters the main chamber (24) using appropriate distribution systems (260),
each including a muffler (262) for reducing the noise. The air distribution
systems
(260) are controlled by the instructor using appropriate valves (264). The
stole
charging valve or valves (270} are also connected to the pneumatic system of
the
submersible structure (20}. As aforesaid, stale air from the submersible
structure
(20) may be sent out through the flexible outer tube of the urrobifical cable
(32)
itself. Accordingly, a valve (not shown} is advantageously provided in the
main
chamber (24) in order to close the air outlet in case the flexible outer tube
be cut of
punctured. The valve can also be closed if the main chamber (24) needs to be
pressurized.
The BIBS (230) are supplied using their dedicated distribution circuit (236)
in the
submersible structure (20}. However, a connection (238} with the regular air
CA 02434903 2003-07-09
1 ~i
supply lines (220,222) is preferably provided in case the dedicated line (224)
is not
functioning.
FIG. 9 shows the hydraulic connections of the preferred embodiment. It shows
that the hydraulic motor (58) further comprises a remotely disengagable brake
(280). The brake (280) is normally part of the standard package of the
hydraulic
motor (58) since it allows the winch (50) to remain in fhe same position
without any
hydraulic pressure. This way, although the submersible structure (20) has a
positive buoyancy, it will not move upwards when it is submerged. However, in
this case, the brake (280) can be disengaged from outside using an additional
hydraulic line (282) connected to an additional pump, for instance a manual
hydraulic pump (284) located on the side of the pool (12). The additional
hydraulic
line (282) required to disengage the brake (280) is preferably present in the
umbilical cable (32).
FIG. 10 illustrates an example of the control panel (40). The control panel
(40)
includes all the required valves, switches, gauges and light indicators that
the
supervisor must quickly access. It also comprises the communication system
(42).
In the preferred embodiment, one or more video cameras (290) are preferably
installed in the main chamber (24) and the escape chamber (62), thereby
allowing
the supervisor to see what is going on using monitors (292) provided over the
control panel (40). Tape recorders (294) or similar devices are used to record
the
training. This is very useful, among other things, for a later debriefing.
They are two main escape procedures using an escape tower. The preferred way,
which is also the less dangerous, is the tower escape. This method is
illustrated in
FIG. 11. It involves that the trainees escape one by one thought the escape
tower
(60). It should be noted that if required, a larger escape tower accommodating
two
trainees at once may be used. Such larger escape tower is provided on some
submarines and allow speeding up the evacuation process.
Initially, trainees and at least one instructor preferably take position in
the main
chamber (24) using the upper hatch (64) while the submersible structure (20)
is
CA 02434903 2003-07-09
17
floating. As aforesaid, a bridge (not shown) is preferably provided to
facilitate the
access through the upper hatch (54). The trainees and the on-board instructor
or
instructors go down through the escape chamber (62) and take their position in
the
main chamber (24). If enough room is available, trainees may also be allowed
to
put their suit on once inside the main chamber (24). Otherwise, trainees must
wear their escape suit before entering the submersible structure (20). The
upper
hatch (64) is closed and locked when everyone is on board and the submersible
structure (20) is moved underwater to the required depth.
It should be noted that an adequate training session should always be done
with
medical personal standing next to the simulator (10). An hyperbaric chamber
(not
shown) should also be next to the simulatar (10) or within a few minutes
thereof.
During the training, each trainee, under the command of the instructor, will
be
asked to climb into the escape chamber (62) and close the lower hatch (110).
The
hood of their suit will then be over their face at that point. Prior to
climbing into the
escape chamber (62), they would make sure that the mechanism (80) controlling
the upper hatch (64) is set to "idle". This refers to the position where the
upper
hatch (64) is free to open. Of course, the upper hatch (64) is unlocked at
that
point. Only the water pressure above the upper hatch (64) keeps it closed.
Before
entering the escape tower (60), each trainee must rehearse the valve operation
sequence that is required for perfiectly achieving the escape. A typical
rehearsing
is to check if the upper hatch mechanism (80) is at idle, if the venting valve
(156) is
open, if the drain valve (140) is shut, and if the cap (158) for closing the
upper end
(152) of the vent pipe (150) is in his hand. He then climbs into the escape
chamber (62) and closes the lower hatch (110). Again, because each trainee
trains for the "last man" situation, he may have to attach a rope or any other
kind
of strap to the lower hatch (110). Then, once inside the escape chamber (62),
he
must pull the lower hatch (110) into the escape chamber (62) before installing
it in
place. The suit is inflated using the stole charging valve (270) and the
flooding of
the escape chamber (62) is initiated using the flooding valve lever (132) in
the
escape chamber (62). It should be noted that the exact order of the steps can
also
CA 02434903 2003-07-09
13
be different. At the same time, the vent pipe (150) allows air to come out of
the
escape chamber (62) as the water level rises.
At one point, the trainee will have to manually close the upper end (152) of
the
vent air pipe (150) using the handheld cap (158). As aforesaid, the most
difficult
escape will be the one made by the last person to escape through the escape
tower (60). That person will have to close the lower hatch (110) himself, open
the
flood valve (130) from inside the escape chamber (62), and close the air vent
(152) at the appropriate time. If it is not closed, then the water level will
not reach
the required level for the upper hatch (64) to open. In a real submarine, this
will
only be possible once the compartment below the escape tower, and to which the
air vent is connected, is completely flooded. For training purposes, it is
possible to
skip the manual closing, at least for the first time, and have the instructor
or
anyone else closing the venting valve (156) from the main chamber (24).
Once the escape chamber (62) is filled with water, the upper hatch (64) will
open
and the trainee can then proceed towards the surface of the pool (12),
expelling air
during his ascent. He will preferably be assisted by the diver. The diver will
close
the upper hatch (64) afterwards. A fairing plate (300), shown in FIGS. 4, 11
and
12, may be used on the interior locking wheel to prevent the trainees from
being
injured by it during the escape.
Meanwhile, if there other trainees in the main chamber (24), one of them will
be
asked to operate or simulate the operation of the remote closing mechanism of
the
upper hatch (64) and bring it to the closed position. The venting valve (156)
and
the drain valve (140) is opened in order to drain the water from the escape
chamber (62). The lower hatch (110) is open when the escape chamber (62) is
almost empty and another trainee wall start or continue his training.
Another escape procedure is the rush escape. This procedure is illustrated in
FIG. 12. This is the last ditched method from a submarine and must only be
used
in the cases where there is no time to evacuate people one by one or two by
two.
In a rush escape, the lower hatch (110) of the escape tower (60) remains open.
CA 02434903 2003-07-09
19
The bottom ladder (120), if any, is removed, as well as any obstacle near the
lower
hatch (110). The stale air outlet, if any, is closed. A skirt (310) will be
pulled down
from the periphery of the lower hatch (110). This skirt (310) is made of a
highly
resistant fabric. At that point, all trainees and the instructor would be
wearing an
escape suit. The main chamber (24) is flooded arid pressurized. The flooding
valve (130) of the escape chamber (60) will than be opeined to flood the
compartment. Any other available means are used to poor water into the main
chamber (24) as fast as possible. At the same time, the pressure inside the
main
chamber (24) is increased. The flooding and pressurization of the main chamber
(24) continues until the pressure therein equals that of the surrounding water
outside the submersible structure (20). At that point, the upper hatch (64)
can be
wide open. A column of water fills entirely the escape chamber (62) and the
volume inside the skirt. The idea is that trainees, like in a real submarine
in such
situation, will need to dive under the skirt (310) and directly escape through
the
escape chamber (62) in a very quick manner. The skirt (310) prevents the water
level inside the main chamber (24) from being too high.
Rush escapes are considerably more dangerous, mainly because of the pressure
to which the trainees will be exposed. Training for the rusts escape can be
practiced at a very shallow level, thereby minimizing the danger. As
aforesaid, the
pressure inside a real submarine is usually maintained at the sea level.
However,
in the case of a rush escape, the pressure will be much higher and the
trainees will
be subjected to a very rapid increase. Obviously, anyone escaping using the
rush
escape cannot follow the decompression sequences when ditching out of a real
submarine and they will likely need to be treated as soon as possible in a
hyperbaric chamber. This condition worsens with the time spent: at the
increased
pressure in the submarine. The air quality is also likely to deteriorate more
quickly
with the increased pressure if there is a contamination. Submariners must then
use special BIBS (230') while they are waiting to escape. They would then use
a
technique called "fleeting" to move towards the escape tower of the submarine.
Fleeting is a procedure where a submariner moves from one BIBS (230') to
CA 02434903 2003-07-09
another, each time checking whether the next BIBS (230') is functioning or
not.
The reason is that they may not be able to get back because another person
will
then be breathing through the preceding one. The special BIBS (230') are
different compared to the usual BIBS (230) in that they are each provided with
a
5 stole changing valve.
During the training for the rush escape procedure, the trainees must put on
their
hood, inflate their suit through the stole charging valve of the BIBS (230')
and
manage to reach the water column by diving under the skirt (310). This is not
easy because the suit is fully inflated at that time.
10 As can be appreciated, the simulator (10) and the method in accordance with
the
present invention allow that the underwater submarine escape training to be
conducted in a safe and controlled environment.
