EP0550682B1

EP0550682B1 - A device especially for the recovery of hydrocarbons or other chemicals from tanks of a wrecked ship

Info

Publication number: EP0550682B1
Application number: EP91919273A
Authority: EP
Inventors: Odd Sigmund Algard
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-10-01
Filing date: 1991-09-19
Publication date: 1994-05-18
Anticipated expiration: 2011-09-19
Also published as: FI931445L; NO170843C; JPH06501436A; WO1992005998A1; AU8660691A; NO904259D0; NO904259L; NO170843B; CA2093127A1; DE69102070D1; FI931445A0; DE69102070T2; EP0550682A1

Abstract

A device especially for the recovery of hydrocarbons or other chemicals from cargo tanks (4', 5', 6'), possibly also fuel tanks, of a wrecked ship (1), wherein each cargo tank, possibly also each fuel tank, is assigned an external, loosely supported floating body (9) connected to a top end (12') of a transport hose (12) which, in the position of readiness - corresponding to the ship's surface position - over the substantial length thereof is coiled on e.g. a hose drum and which, at some distance from the bottom end thereof, is connected to the ship, the lower hose portion (12') being located within the respective tank (4', 5', 6').

Description

This invention relates to a device especially for the recovery of hydrocarbons or other chemicals from the cargo tanks, possibly also from the fuel tanks, of a foundered tanker resting on the seabed, deck being under water.
Systems for offshore transfer of liquid and/or gaseous cargo from/to production plants to/from vessel are previously known. Thus, according to Norwegian patent specification No. 143,139, a method is provided for transferring a fluid from a station on the seabed to a surface vessel, or vica versa, said vessel being equipped with dynamic positioning equipment, wherein a unload/load buoy in submerged condition and anchored to the seabed carries a conduit connection for coupling to the vessel, said buoy having means for adjustment of the immersion thereof. This known method is characterized in that the conduit connection's free end including a coupling unit at the buoy is caught by a claw lowerable and liftable from the bottom portion of the vessel, to be raised and coupled to a connector on the vessel. As will appear, the solution according to said patent specification does not relate to any emergency situation.
A carge of oil or chemicals within a foundered tanker may represent enormous amounts of money and will, moreover, after a time constitute a considerable pollution risk. For the oil or chemicals within the tank or tank wherein a leak has sprung during the wreck, little or nothing can be done, but it would be of enormous economical/environmental importance to be able of recovering e.g. liquid hydrocarbons within intact cargo tanks as soon as possible subsequent to the wreck.
In order to recover oil or other liquid chemicals from foundered ships where the deck is under water, positional determination is an obvious pre-condition. Thereafter, it is extremely important to ascertain what kind of cargo the ship in fact carried, in order to start bringing the cargo to the surface as quickly as possible.
The invention is based on paying due attention to these wishes/objects in a simple and reliable way.
The following claim 1 indicates those features necessary in a device for carrying out the invention.
Thus, in accordance with the invention, at least one cargo tank and possibly also each single fuel tank of a tanker is assigned an external floating body wherein is attached a top end portion of a transport hose which in the state of readiness - corresponding to the surface position of the ship - over the major portion of its length has been coiled onto e.g. a windle or coil fastened to the ship or to the floating body, the bottom end portion which is located within the respective tank, is attached to the ship construction. Said top end portion of the transport hose carries a connector, and at the attachement point of the transport hose in the ship construction, a valve should be arranged.
When a thusly equipped tanker founders and the deck of the ship comes under water, each single floating body due to buoyancy immediately will start to move upwards through the water and bring with it its transport hose which hereby is rewound from the windle and straightens out. The longitudinal extension of the transport hose between the respective floating body and the attachment point in the ship construction determines the final position of the floating body in relation to the sea level. The transport hose would be dimensioned such that the floating body will reach the surface at normal sea depths for wrecks. According to a preferred embodiment of the invention, each floating body is connected to a smaller floating body by means of a line, rope or the like taking a coiled condition in the position of readiness, and which is adapted to come into action and float to a surface position when the larger floating body due to limited transport hose length is not in a position to do so.
Said larger and smaller floating bodies would be provided with information concerning e.g. the name of the ship, the type and amount of cargo, etc., and the smaller floating body may, moreover, have a battery-driven emergency sounding transmitter, emergency light, etc.
Said connector of the transport hose is adapted to secure connection to another pump-driven transport hose at or adjacent to sea level, for pumping-up of the ship's cargo.
In accordance with a preferred embodiment, the lower end portion of the transport hose has such a length from its attachment point in the ship construction to a heavy end mouth piece that a complete emptying of the tank is secured, said end mouth piece due to its weight at all times seeking the deepest located point within the tank.
Thus, the device according to the invention gives a quick information to the rescue crew on a foundered tanker's position and on type/amount of oil or other chemicals within the cargo and fuel tanks, so that the necessary measures may be taken as soon as possible in order to recover the oil/chemicals.
The device according to the invention will contribute substantially in reducing the contamination of the sea.
The device according to the invention which only needs a minimum and simple maintenance, is easily post-installed on existing tankers.
The device according to the invention is automatically released when the floating body comes under water and, thus, is not dependent on any form of drive means in order to function.
As mentioned introductorily, the device may as well be utilized for fuel tanks.
The invention is further explained in the following in association with an embodiment which is diagrammatically illustrated in the attached drawings, wherein:

Figure 1 shows a situation view of a foundered tanker resting on the seabed, laying on its side, ship's deck being under water, and wherein the device according to the invention is shown in two positions, one in fully drawn lines at shallow water, the other in dotted lines at deeper water;
Figure 2 shows, on a larger scale, a partial lateral view, partly in section (perpendicularly to the deck), of a device according to the invention in the position of readiness thereof, corresponding to the surface position of the tanker;
Figure 3 shows, on an even larger scale, a top plane view of a floating body incorporated in the device according to the invention.

First, reference is made to figure 1, wherein reference numeral 1 denotes a foundered tanker resting on the seabed 2, laying on the side, ship's deck 3 being under water.
The ship's cargo tanks, the hatches thereof being denoted 4 - 8, are each assigned a device according to the invention, herein represented by a floating body 9. The ship's fuel tank is also assigned such a device (floating body 9').
Figure 2 shows three of the ship's cargo tanks, denoted 4', 5' and 6' . The device according to the invention is shown only for the intermediate cargo tank 5' and comprises said floating body 9, which is loosely supported in a seat frame 10. The latter is carried by a hose housing 11. The hose housing 11 is attached to the hull in a manner not shown, e.g. on the tank hatch 5. The "loose" suspension of the floating body 9 will cause it to float towards the surface as soon as it comes under water.
Within the floating body 9 is anchored a top end portion 12' of a transport hose 12 which, in the position of readiness, corresponding to the ship's 1 surface position, over the substantial length thereof is coiled within the hose housing 11, e.g. onto a windle or coil fastened to the ship or to the floating body, the bottom end portion 12'' of the transport hose 12 being located within the cargo tank 5' itself, wherein the level of the cargo is denoted 13.
It goes without saying that the top end portion 12' of the transport hose 12 may be replaced by a rigid pipe coupled to the upper end of the hose 12. The top end portion 12' of the transport hose 12 is provided with an end connector 14 which, preferably, is assigned an open/close valve 15. The connector 14 is formed with a view of enabling a rapid coupling to a pump-driven transport conduit (not shown) at or adjacent the surface 16 for recovery of the cargo within the foundered ship.
When a tanker 1 equipped with devices according to the invention founders, the floating bodies 9,9' due to buoyancy will leave their respective seat frames 10 and move upwards through the water, whereunder they rewind their respective transport hoses 12, each having an attachment point 17 in the ship at the upper limitation of said bottom hose end portion 12'' where, preferably, a valve is arranged. The length of the transport hose 12 determines the highest possible position of the floating bodies 9,9' above the foundered ship.
In figure 1, in solid lines, a position has been shown wherein the floating bodies 9 have reached the surface 16, and the length of the hose would be dimensioned such that this will occur in most cases (at normal depths for wrecks).
In order to enable positional determination/recovery of cargo also from ships foundered at larger sea depths, at least one floating body 9 may be provided with a smaller floating body 18 connected to the larger floating body 9 by means of a coiled rope or line 19.
In figure 1, in dotted lines, a position where the floating bodies 9 have not reached the surface 16 has been indicated, but where the smaller floating bodies 18 have reached the surface by means of the respective ropes or lines 19.
In order to secure that the inlet to the bottom end portion of the transport hose 12 at all times will be located at the deepest point of the cargo tank and, thus, enable a complete discharge of the tank, said bottom end portion 12'' has such a length from its attachment point 17 in the ship construction that the hose end may reach any point within the tank. To this end, the hose end is equipped with a heavy mouthpiece 20 which, due to its weight, will seek to the deepest positioned place within the tank.
The floating bodies 18 are provided with battery-driven emergency sounding transmitter 21 and emergency light 22.
The top face of the floating body 9 may, as shown in figure 3, carry an information board 23 indicating name of ship, kind and amount of cargo, etc. The small floating body 18 may have a corresponding information board (not shown).
Suitably, the large floating body 9 may be equipped with hand grip, steps and (walking) mat in order to facilitate mounting through the establishment of a connection between the transport hose 12 and a pump conduit. I should be appreciated without saying that several tanks 4',5',6' might be interconected through a pipe and valve arrangement, so that substantally one device according to the invention may be used for a plurality of tanks.

Claims

A device especially for the recovery of hydrocarbons or other chemicals from cargo tanks (4',5',5'), possibly also fuel tanks, of a wrecked ship (1), characterized in that at least one cargo tank (4',5',6'), possibly each fuel tank, is assigned a device substantially comprising an external, loosely supported floating body (9) connected to a top end portion (12') of a transport hose (12) which, in the position of readiness - i.e. the ship's (1) surface position - over the substantial length thereof is coiled e.g. on a hose drum, a windle or the like attached to the ship or to the floating body (9) and which, at some distance from the bottom end thereof (at 17) is connected to the ship (1), preferably over a valve, an end portion (12'') of the transport hose (12) being located within the respective tank (4',5',6').
A device as set forth in claim 1,
characterized in that said top end portion 12') or a pipe piece coupled thereto, respectively, is provided with a connector (14) and, preferably, a valve (15).
A device as set forth in claim 1 or 2,
characterized in that the loose suspension of each floating body (9) is established by means of an upwardly open seat frame (10) laterally partly surrounding the floating body (9) with a small clearance or under insignificant frictional contact, respectively.
A device as set foth in any one of the preceding claims, characterized in that the end portion (12'') of the transport hose (12) located within the tank (4',5', 6'), has such a length from its attachment point (17) in the ship (1) that the hose end may reach any point within the tank, the hose end being equipped with a heavy mouthpiece (20) which, due to its weight (and possibly shape) will seek the point being the lowermost within the tank, in order to enable complete discharge of the tank's content.
A device as set forth in any one of the preceding claims, characterized in that at least one or some of the floating bodies (9) is/are provided with a smaller floating body (18) connected to the large floating body (9) by means of a cord (19) which is coiled in the position of readiness.
A device as set forth in any one of the preceding claims, characterized in that the large floating body (9) and, preferably, also the small floating body (18) is/are adapted to carry information (24) at least stating the ship's name and the kind and amount of cargo.
A device as set forth in any one of the preceding claims, characterized in that the small floating body (18) is provided with emergency equipment, such as battery-driven emergency sounding transmitter (21) and emergency light (22).
A device as set forth in any one of the preceding claims, characterized in that the large floating body (9) is equipped with hand grips and, possibly, steps and (walking) mat in order to facilitate mounting whenever a connection between the transport hose (12) and a pump line has been established.