Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Specification
Title of the invention
Emergency arrangement and method for emptying the tanks of tank vessels in
distress at
sea
Technical field
The invention concerns the technical field of watercraft, especially the
pertinent
equipment and in this respect an emergency arrangement and method for emptying
tanks
in the event of accidents in such a way that openings and hose connectors are
provided
on the side of the ship near the tank vessel through which the commodity being
transported, the dangerous liquid, especially crude oil, fuel, chemical, can
be removed from
the tanker in distress.
Prior art
It is generally known that acxording to the current knowledge and technology
relating to tanker accidents the necessary evacuation and/or emergency
emptying depend
on at least one of the following conditions being fulfilled.
- The ship concerned must still be at least partly manoeuvrable.
- Grew must be on board the ship to take the necessary action.
- The ship must still possess sources of motive power for units on board such
as
pumps, drills, crane booms and facilities or winches and must have these units
at
its disposal in a funcHonable state.
Patent specification OE Q 90 10 090.5 U1 discloses an arrangement for drilling
the sides
of tankers fdr the emergency emptying of tanks 'rf the risk of explosion is
slight. For this it
is necessary that a tanker of similar capacity go alongside and the ships be
made fast to
each other by means of lashings, fenders and spacing arrangements. Drilling
the ship sides
is too complicated, especially in view of the time frame available in the
event of such
accidents, which is often an important factor setting constraints that cannot
be overcome
by means of this technical solution. Likewise, it will rarely be possible to
make the tankers
fast to each other in this way since the ship in distress will very probably
be found to no
longer have the necessary stability. In the event of complete failure of the
energy sources
on board the ship in distress, it will also no longer be possible to fill the
voluminous hoses
if it has ctually been possible to establish a hose link between the iwo
ships, An
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arrangement for taking over oil in order to lighten tankers in distress
described in patent
specification DE OS 29 16 489 A1 consists of several hoses, each of which is
provided
with a filling Ilne and a handling or towing line, and a filling unit. The
said hoses with their
filling tines and handling ropes are to be placed in a reeled condition on
suitable ramps on
the deck of the ship. In the event of an accident, the said hoses are to be
unreeled,
lowered into the water and filled with oil. Besides the conslderabte time
needed to pump off
the necessary amounts of oil into the unreeled hoses, a very large amount of
space is
needed to locate these facilities on the deck of the ship. Moreover, this
technical solution
is no longer capable of functioning if the energy sources on board the tanker
fail completely
in the course of the accident. Patent speafication DE OS 30 26 836 A1
discloses an
arrangement for transferring liquids to and from tankers which uses flexible
hoses and has
the form of a stationary plant ashore. Such technical solutions, which are
also described in
DE G 78 03 631 U1, are unsuitable for emptying tankers at sea in accident
situations. DE
OS 37 25 307 A1 describes an encapsulation for rigid pipe lines and rigid pipe
lengths
linked by articulations. This, however, ooncems underwater pipe lines and is
intended to
protect them against leakage.
Oescrintion of the invention
The purpose of the invention in to create an arrangement and method with which
a tanker can be emptied in emergency after an accident without persons going
on board
the ship in distress and/or auxiliary tankers, islands or fadiities of any
kind having to make
fast to, m' enter the immediate proximity of; the ship in distress. With the
arrangement
described; this purpose is fuHilfed in the following manner. All tanks on
board the ship are
equipped with oompn~ssed gas cylinders and interconnected. Remotely controlled
valves
are installed in the interconnecting pipe lines. A hatch, which is nom~ally
closed in a
~tertight manner by means of a cover, is arranged preferably below the keel
line on the
sides of the ship at each tank; the said covers having an unloddng pin acuated
by wireless
remote control and an eccentrically arranged pivot joint. Hoses on reels or
laid in a zig-zag
are connected in the interior specs between the tanks and the hatch covers or
if necessary
between the tanks themselves, each of said hoses being permanently connected
to one
tank and being provided with a hose coupling, a hose propulsion device and an
air bag at
the other hose end and with handling line extending over and parallel to the
whole hose
length. Alternatively, the handling lines may be reeled onto separate drums,
All valve drive,
hatch unlocking and hose and handling rope drive devices are connected to
external
energy sources which are mutually independent and are always kept fully
charged during
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normal ship operation. A unique, separate, coded radio frequency is assigned
to each
separate function in the various drive devices. A parallel wiring arrangement
with a central
receiving station on board is provided for relaying all radio commands to the
separate
drives. Catapult-launched boats with winches, pumps, compressors as accident
and life-
raffs and inflatable, flexible, permanently anchorable pontoon tanks or
balloons which can
be ventilated at the top are provided on the tanker. The tanks are equipped
with heating
devices, preferably working on the basis of induction and utilizing the known
effect of high
frequency electromagnetic waves - microwaves -, which are supplied with energy
from
accumulators or generators. This will enable the commodity being transported
to be made
readily pumpable within a relatively short time. The valves in the pipe lines
interconnecting
the tanks and the wirelessly remote controlled unlocking pins of the hatches
are equipped
with electromechanical, electropneumatic, electrohydraulic and/or explosive
drive and/or
tripping devices. The hoses consisting of elastic material are capable of
volumetric and
diametric expansion and have double walls with the interior hoses being
provided with wire
fabric, braids or netting to heat by microwaves the commodity being
transported, thereby
maintaining its pumpability, and are about 300 metres long. Both hose walls
possess heat
reflectingrnsulating layers acting outwards and inwards which also serve to
maintain the
pumpability of the commodity being transported. The handling lines of the
hoses are also
about 300 metres long and consist of a high strength material, preferably
nylon, or have
the form of thin steel ropes. A projectile driven by a gas cartridge and an
air bag which can
be inflated by wireless control are provided at the ends of the handling
ropes. The external
energy sources for the valve drive and hatch unlocking devices have the form
of electric
accumulators or gas cartridges and those for the hose and handling drives have
the form
of gas cartridges, all of the drives themselves and wireless signal receiving
devices at the
drive devices being connected by a separate wiring network in the case of
accumulator
energy supplies.
With the method described, the purpose of the invention is fulfilled by the
hatches, which
are arranged at a location suitable for the purpose, are opened by means of a
wireless
signal in that the unlocking pins are actuated by the hatch unlocking device.
The hoses
with the handling lines or the handling lines alone are driven into the open
sea by their
hose drive devices or by gas cartridges, which are also set off by wireless
signal after the
opening of the hatches, thereby being unreeled from their drums in the ship.
After a
sufficiently great distance from the hull of the ship has been reached, the
air bags at the
end of the hose and/or handling lines are filled with gas also by radio
control so that the
hose ends with the coupling devices or the handling lines alone are
transported to the
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water surface. The hoses are recovered by means of the handling lines by the
salvage
crews of the auxiliary tanker, of an auxiliary platform or island or any other
kind of assisting
facility and connected to tanks or temporary storage means such as pontoon
tanks or
balloons if tanks are not readily available. The double walled hoses are
inflated to a
previously defined diameter with compressed air in the outer chamber by means
of
compressors on the salvage units. The valves in the pipe lines permitting
optimum
emptying of the interconnected tanks in the given position of the tanker in
distress are
opened by means of their valve drive devices by means of a further wireless
signal.
Compressed air is pressed via the outer hose chambers of the hoses into the
tanks by
means of the compressors working on the salvage units, or alternatively gas is
forced into
the tanks by the compressed gas cylinder attached to the tank ooncemed , which
in
conjunction with three-way valves and pumps of the salvage units in tum force
the heated
tank contents through the inner hose chambers of the hoses into salvage tanks
or
temporary storage means. During the pumping off, the depth of immersion of the
hoses in
the water is adjusted to suit the state of the sea by varying the balance
between the weight
of the inner hose chamber through which the tank contents are flowing and the
buoyancy
of the outer hose chamber which is filled with compressed air flowing through
it and the
commodity being handled is kept at a suitable temperature by exposure to
microwaves.
The solution conforming to the invention is characterized by the following
advantageous
effects. The machinery and energy supply systems often fail on a tanker in
distress. Since
the energy reservoirs on the release and drive devices and wireless reception
plants
specked in accordance with the invention are kept in a permanently charged
state during
normal operation, wireless remote controlled manipulations can be performed on
the tanker
and connections and transfer systems can be conveyed from the tanker in
distress to the
assisting facility, which can easily take them up, connect them and use them
to pump from
the tanker as well to stabilize the hoses while pumping. It is therefore
unnecessary first to
transfer persons, crews or equipment to the ship in distress before salvaging
it and, more
importantly, the dangerous liquid cargo. The reduced risk for the salvage crew
is
simultaneously linked to savings in labour costs. The ecological advantages
are of main
importance because the solution offered by the invention largely prevents
large scale
environmental damage, especially damage due to oil pollution and damage to
flora and
fauna, and the cargo of the ship remains intact so that natural resources are
better used
or used less intensively. Costly cleaning up operations at sea, on the coast
and among
animals are unnecessary. As a concequence, considerable costs are saved since
it is
unnecessary for insurance companies to pay compensation, which should in turn
lead to
CA 02140860 2002-07-09
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a reduction in insurance premiums and thus to a reduction in costs for ship
owners. The
consequence would be lower transport costs. In the majority of cases, it will
also be
possible to save the ship as a result of the systematic reduction and shifting
of weight and
thus to stabilize and salvage the ship. The system can be re-used and this
will reduce the
cost of restoring the tanker to an operable state. The ship will not be
damaged by drilling
holes in the sides on a large scale as is foreseen, for example, in a known
specification.
Brief description of the drawings
Figure 1 is a side view of the tanker. It shows in particular the arrangement
of the
hatches with their hatch covers relative to the locations of the tanks and the
water line, the
locations of the interconnecting pipes between the tanks and the locations of
the valve and
hose drive devices.
Figure 2 shows the various components of the arrangement conforming to the
invention in
a plan view of the tanker.
Figure 3 shows in particular the arrangement of a hatch, shown in the closed
state, in one
side of the ship with the projectile and air bag and with the hose drive
device and the hose
package.
Figure 4 shows an open hatch in the side and front views with the unlocking
mechanism
in operation.
Best approach to execution of the invention
A tanker of any tonnage is in distress, drifts into a rocky area near a nature
conservation area and can no longer be manoewred. The majority of the crew on
the
tanker is out of action owing to the consequences of the accident, and all
machinery fails.
At the same time, a kcal fire breaks out on deck and can not be brought under
control with
the means available on board. The personnel on board are forced to abandon
ship. After
a sufficient large, safe distance from the ship has been reached, the means
conforming to
the invention are put into action in the following way by coded wireless
commands by a
crew member who is still able and authorized to do so:
One or more hatches 8 are unlocked by means of the bolt 9 and move downwards
around
the eccentric pivot 10 owing to the intended position of its centre of
gravity. After the
antechamber has been flooded, the projectile 25 is set into motion and draws
the handling
rope 16 into the open sea. After it has reached the intended distance, the
projectile air bag
26 is put into action. The handling rope 16 is recovered by the crew. At the
same time, the
pontoon tanks 23 catapulted overboard are anchored. The double wafted hose 12,
which
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possibly can be set into motion from the ship into the open sea by means of
its own drive
device 14 in the same way as the handling rope, is hauled in by winch and/or
muscle
power by means of the handling rope 16 and connected to the pontoon tank 23 by
means
of its coupling device 13. The appropriate valves (4) and, if necessary, the
respective
compressed gas cylinders 27 are opened also by wireless command. The contents
of the
tank are pressed in the inner hose chamber of the double walled hose 12, well
insulated
against heat losses to outside and possibly constantly heated by exposure to
microwaves,
to the pontoon tanks by the compressed gas released into the selected tank,
which has
previously been heated by exposure to microwaves, and possibly by compressed
air or
exothermically reacting gas forced towards the tanker through the outer hose
chamber of
the double walled hose' 12, i.e, the contents of the tanks on the tanker flow
off almost of
their own accord. If necessary, the contents of a tank are transferred, also
under wireless
control, by the compressed gas cylinder of that tank via the pipe line system
interconnecting the various tanks into tanks that have already been emptied
and removed
from the tanker from there. Naturally, several tanks can be evacuated
simultaneously via
their separate emergency emptying devices if the situation permits. The tank
most
endangered by the fire will prefen~bly be emptied first. All stages of the
method can be
copied for the tanks that have not yet been emptied by rescue teams that
arrive later. All
necessary wireless commands can also be initiated or executed by means of
parallel
wireless remote control from helicopters; support ships or other means.
Commerdal aonlicabilitv
The invention thus oonoems an arrangement and stages of a method which enable
a tanker in distress to be emptied by remote control: In emergencies without
peril to crews,
individual persons or equipment; a need of those oonoemed that could not be
satisfied in
~ the past. This technical solution can be used as equipment to retrofit
existing, and
dally old, tankers and as original equipment for tanks to be buiff.