EP1192317A1

EP1192317A1 - Method and device for the collection of underwater spills and for covering the sea bed

Info

Publication number: EP1192317A1
Application number: EP00911495A
Authority: EP
Inventors: Björn Grinde; Torbjörn Erga
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-17
Filing date: 2000-03-16
Publication date: 2002-04-03
Also published as: WO2000058564A1; AU3336100A; NO991282D0

Abstract

A first canvas (1) stretched over the source of a spill or an emission on or from the sea bed, with mooring elements (3) attached to the outer edges, and floating elements (4). Outlet (5) with sack (6). A second canvas (8) stretched over the first canvas (1).

Description

METHOD AND DEVICE FOR THE COLLECTION OF UNDERWATER SPILLS AND FOR COVERING THE SEA BED

The present invention relates to a method and a device which enable the covering and collection, with all the necessary precautions, of oil, chemicals, decomposed organic and mineral substances on the sea bed. In addition, the invention is intended for the covering of effluents which it is not desirable to dump in an unrestricted manner, and for the collection of toxic substances. The invention is intended for the collection, sealing under control, protection of waste tipping and storage, protection of existing landfills, dumping areas, wrecks, war remains of all types, such as gas containers, chemicals, ammunition, toxic substances.

Wrecked ships are the source of significant environment problems as they contain oil in their tanks, whether that oil is fuel oil for consumption on the vessel itself, or a product carried by the wrecked vessel in the case of an oil tanker. Wrecked ships lie on the bottom of the sea and, if they are damaged, they may leak oil in various quantities, such oil rising to the surface of the ocean. The oil will then present a danger to the marine fauna and must be collected and dealt with, taking all necessary precautions.

Oil spills from wrecks present a serious problem for the environment and for people. In many cases, the choice is made not to empty the oil remaining in the tanks of the wreck due to the prohibitive costs which such an operation entails.

From a number of wrecks, only small quantities of oil will leak over a year, and such leakage occurs mainly in special circumstances such as heavy weather with very rough seas.

In wrecks containing oil in undamaged tanks, it is in certain cases possible to empty the tanks under controlled conditions by connecting new valves to the tanks and pumping the oil up to a vessel on the surface. In the cases when the tanks are damaged and the oil seeps out and rises to the surface, it must then be collected on the surface and removed. Oil booms and other equipment such as skimmer and the like are used to this effect. A method of collecting oil which requires that leaking oil must first rise to the surface in order to be collected is at best a makeshift solution. A small quantity of leaking oil will mix with the water and pollute it before it reaches the surface. In addition, this requires a continuous monitoring of wrecks in order to be ready to place oil booms to contain the oil when the leakage finally occurs. There is a real risk that such oil spills will cause damage to sea birds or other creatures on the surface before there are discovered and contained. There also exist other potential sources of contamination on the sea bed itself or partially on it, which can release gas, liquids or particles of organic or mineral origin, which it is desirable to control, contain and remove. Examples of such sources may be ammunition depots, special waste dumps and the like.

The object of the present invention is to cover, seal and if necessary collect liquids, gases and volatile products or particles released from spills on the sea bed or from sources on the sea bed or partially on it. In addition, the method is suitable for the purpose of emptying the oiltanks of a wreck under controlled conditions and in a safe manner.

This is achieved with the help of a least one canvas which covers an oil spill and is attached at certains points to the sea bed and at other points to floating elements, so that the shape given to the canvas provides at least one collection point for the oil.

Further details of the invention appear from the following description with reference to the illustrations of a preferred embodiment of the invention. Figures la and b illustrate the device of the invention intended for the collection of oil leaking from shipwrecks, in perspective and in cross sectional view.

Figures 2a and b show the device of the invention intended for the collection of oil leaking from pipelines, in perspective and in cross sectional view. A first canvas 1 is stretched over a shipwreck 2 which lies at the bottom of the sea.

The first canvas 1 can be given any appropriate shape suitable to cover a wreck of any shape. The first canvas 1 is given a general saddle roof shape, with a variable curvature. Along the outer edge of the first canvas 1, are provided anchoring elements 3 such as mooring blocks or any other type of mooring to the bottom of the sea. Several floating elements 4 are provided and attached to the first canvas 1 between its outer edges so as to create a roof over the wreck, and the oil which is leaking from the wreck will rise under this roof and slide up to a highest point. At the level of this highest point, an outlet 5 is provided. Above this outlet 5, a sack 6 is provided which fills up and can be closed off by tying together over its inlet 7.

The sack 6 can be replaced by an empty sack, while the full sack is taken to the surface where the oil can be dealt with in a safe manner, or alternatively the sack 6 is moored high up in the water and divers can effect the emptying manoeuvre without the necessity of a diver support vessel. The sack 6 can also be emptied with the help of a hose connected to a boat or a barge.

The sack 6 must have some form of venting device so that gas or air which follows with the oil and collects in the sack 6 does not create undesirable buoyancy. In addition, a level gauge must be provided in the sack 6 to indicate when optimal level has been reached. Such a device can for example give an acoustic signal.

To increase the oil-capturing surface and therefore ensure that all the oil will be collected, a second canvas 8 can also be placed across the first canvas 1 , the second canvas 8 being anchored in the same manner as the first. The canvases are saddle-roof shaped, and the curvature may vary.

The method of the invention for the collection of oil leaks can also be used in the cases when the leak occurs in a pipeline 9 running on the sea bed. Figures 2a and b illustrate how the principle may be applied to such a case. The material used for the canvas may be weaved material, fiber, polyester- weaved canvas with or without reinforcement, and coated with a rubber film. This provides the necessary strength and tightness for use as canvas material for the canvases 1 , 8 and for the sack 6.

The method and the device of the invention may be used to cover over sources of emission of liquids and/or gases, chemicals, decomposing organic or mineral substances at the bottom of the sea or from sources which are entirely or partially on the sea bed. Furthermore, it will possible not only to cover over such sources, but also to collect and contain collected products for a chosen period of time, as well as remove the collected products from the sea under controlled circumstances and transfer them for example to a boat or the like.

Claims

1. Method for covering, sealing and collecting liquids, gases, chemicals, organic and mineral substances, characterized in that at least one canvas which covers the spill or emission is attached at certain points to the bottom and at other points to floating elements, in such a manner that the canvas is given a shape with at least one collection point for the oil.

2. The method for covering, sealing and collecting liquids, gases, chemicals, organic and mineral substances of claim 1 , characterized in that the outer edges of the canvas are fastened and tightened to the bottom.

3. The method for covering, sealing and collecting liquids, gases, chemicals, organic and mineral substances of claim 1, characterized in that the canvas, at the points of collection, is provided with devices which enable release of the collected products, and that such collected products may be led to a partitioned-off compartment in view of transport to the surface.

4. A device for the implementation of the method of claims 1, 2 and 3 characterized in that a first canvas (1) is stretched over a spill on the sea bed or rising from the sea bed and anchored to the bottom with the help of mooring elements (3) attached to its outer edges and, in places between the outer edges, to floating elements (4), said first canvas (1) being given a saddle-roof shape, the curvature of the saddle-roof shape being variable.

5. The device of claim 4 characterized in that from at least one of the highest points on the first canvas (1) an outlet (5) is provided to which a removable sack (6) is mounted.

6. The device of claim 4 characterized in that the sack (6) can be tightened shut and replaced.

7. The device of claim 4 characterized in that the sack (6) can, with the help of a hose, be emptied into a boat or a barge.

8. The device of claim 4 characterized in that the sack (6) is provided with a venting device for gas or air and a level gauge for oil.

9. The device of claim 4 characterized in that a second canvas (8) is stretched over the first canvas (1), said second canvas (8) being given a saddle-roof shape, and the curvature of the saddle-roof shape being variable.

10. The device of claim 8 characterized in that the outlet (5) from the canvases (1, 8) coincide.

11. The device of claim 8 characterized in that the source of the spill or of the emission may be any or several of the following: shipwreck, oil pipeline, special waste dump, bulk dump, accumulation of ammunition.