GB1568331A - Anti-pollution boom - Google Patents

Description

(54) ANTI-POLLUTION BOOM (71) We, TKE BRITISH PETROLEUM COMPANY LIMITED, of Britannic House, Moor Lane, London EC2Y 9BU, a British Company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be perfonned to be particularly described in and by the following statement: The present invention relates to the control of oil on the surface of water, particularly sea-water, by means of an inflatable, flexible, floating barrier.

Many systems have been proposed for the containment of oil on the surface of water and many of them perform satisfactorily under suitable sea conditions. There is however the need to provide a robust system that can operate in rough sea conditions such as are frequently found in the North Sea and can at the same time be easily and rapidly deployed and then recovered at sea. There is a further need to provide a system for the control of oil on water that can be operated from existing vessels, and particularly from the various tug support vessels of the type that have been developed for use in support of the oil production platforms in the North Sea.

Oil barriers comprising continuous gas and water chambers in side by side relationship are well known and are described for example in UK patent specification 1,188,156. Essentially such barriers have an elongated gas chamber which keeps them afloat and, in side by side relationship, an elongated water chamber which gives the boom adequate stability. The preferred barrier comprises a single water chamber and a single chamber and therefore- has a figure of eiffit cross-section. There is however no reason why barriers should not have more than one gas chamber - or more than one water chamber apart from the extra complexity that this involves. The chambers are preferably substantially circular in cross-section when fully inflated.

Our British Patent Application No.

43513/76 (Serial No. 1,554,737) discloses and claims a method of deploying an inflatable, flexible, floating barrier comprising a continuous gas-inflatable gas chamber in side by side relationship to a continuous water-inflatable water chamber from a sup port vessel, which comprises securing a first end of the barrier to the vessel, connecting gas inflating means to said first end of the gas chamber and water inflating means to said first end of the water chamber and discharging the barrier progressively from the vessel while inflating at least the gas chamber so that the barrier does not sink, causing relative separation between the vessel and the discharged barrier so that the latter takes up a closed curved shape away from the vessel, passing the second end of the barrier to a second support vessel or an anchoring means, moving the barrier to its desired position and maintaining the gas and water inflation of the deployed barrier.

In this specification the verb "to inflate" is used to designate the admittance of both gas and water, as appropriate, and in both cases it implies the right quantity to confer the desired mechanical properties -on the inflated barrier. Preferably the gas chamber is inflated with air and the water chamber with sea water.

The barriers may be made from any suitable flexible material which is water or gas proof as necessary. Rubberised fabrics such as neoprene coated nylon are particularly valuable as they are sufficiently gas and water proof and have good tensile properties.

The deflated barrier utilised in British Patent Application No. 43513/76 (Serial No. 1,554,737) has negative buoyancy and because of this, it is essential during deployment to inflate- the air chamber of the barrier so that it does not sink during the deployment operation. It is important to ensure that there is relative movement between the vessel and the barrier fed into the sea during deployment so that the barrier can float away from the vessel as it is discharged. In this way it takes up a closed curved shape away from the vessel. The rate of discharge of the barrier from the vessel is principally governed by the rate at which the air chamber can be inflated in order to maintain the barrier afloat and help prevent it becoming twisted during the deployment operation.

We have now discovered that positive buoyancy can be conferred upon the deflated barrier by the incorporation of a strip of foamed rubber or plastics material.

Thus according to the present invention there is provided a pack, suitable for attachment to the deck of a support vessel, the pack comprising a deflated barrier comprising a continuous gas-inflatable gas chamber in side by side relationship to a continuous water-inflatable water chamber, at least one of the chambers incorporating a strip of foamed rubber or plastics material to confer positive buoyancy on the deflated barrier, a driven roller which can pull the barrier aboard the vessel and cause its deflation, means to attach a first end of the barrier to the vessel, means to inflate the gas chamber and means to inflate the water chamber.

Preferably the strip of foamed rubber or plastics material is attached to the air chamber and extends along the full length of the latter. Most preferably the strip covers approximately one quarter of the internal surface of the air chamber, preferably a quarter in the upper half when the chamber is in the inflated condition.

The preferred strip material is closed cell foamed polyurethane.

The strip may be secured to the barrier by means of a self-vulcanising adhesive.

Suitable adhesives are commercially available and are known to those skilled in the art.

Since the barrier has positive buoyancy in the uninflated state it is protected against sinking in the event of any malfunction of the inflation equipment during deployment or any accidential deflation during use or recovery.

Furthermore, the rate of deployment is no longer so dependent on the rate of inflation of the air tube.

The barrier may be deployed and recovered by the method described and claimed in British Patent Application 43513/76 (Serial No. 1,554,737). As an alternative for recovery, the driven roller for recovery of the barrier may be a large reel on which deflation of the barrier is caused by winding the chambers around the reel.

The invention is illustrated with reference to the accompanying drawing which is a cross-section of a typical oil barrier when fully inflated.

In the drawing, 1 is the gas chamber which is side by side with the water chamber 2. Both chambers are fabricated from neoprene coated nylon sheet and are 685 mm in diameter. A strip 3 of closed cell foamed polyurethane 6 mm thick and 500 mm wide is glued to the interior surface of the air chamber 1 to cover approximately one quarter of the internal surface of the air chamber. The air chamber 1 floats above the water level 4 and the water chamber 2 is below.

WHAT WE CLAIM IS:- 1. A pack, suitable for attachment to the deck of a support vessel, the pack comprising a deflated barrier comprising a continuous gas-inflatable gas chamber in side by side relationship to a continuous waterinflatable water chamber, at least one of the chambers incorporating a strip of foamed rubber or plastics material to confer positive buoyancy on the deflated barrier, a driven roller which can pull the barrier aboard the vessel and cause its deflation, means to attach a first end of the barrier to the vessel, means to inflate the gas chamber and means to inflate the water chamber.

2. A pack-according to claim 1 wherein the strip of foamed rubber or plastics material is attached to the air chamber and extends along the full length of the latter.

3. A pack according to claim 2 wherein the strip covers approximately one quarter of the internal surface of the air tube.

4. A pack according to any of the preceding claims wherein the material of the strip is closed cell foamed polyurethane.

5. An oil barrier as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. vessel is principally governed by the rate at which the air chamber can be inflated in order to maintain the barrier afloat and help prevent it becoming twisted during the deployment operation. We have now discovered that positive buoyancy can be conferred upon the deflated barrier by the incorporation of a strip of foamed rubber or plastics material. Thus according to the present invention there is provided a pack, suitable for attachment to the deck of a support vessel, the pack comprising a deflated barrier comprising a continuous gas-inflatable gas chamber in side by side relationship to a continuous water-inflatable water chamber, at least one of the chambers incorporating a strip of foamed rubber or plastics material to confer positive buoyancy on the deflated barrier, a driven roller which can pull the barrier aboard the vessel and cause its deflation, means to attach a first end of the barrier to the vessel, means to inflate the gas chamber and means to inflate the water chamber. Preferably the strip of foamed rubber or plastics material is attached to the air chamber and extends along the full length of the latter. Most preferably the strip covers approximately one quarter of the internal surface of the air chamber, preferably a quarter in the upper half when the chamber is in the inflated condition. The preferred strip material is closed cell foamed polyurethane. The strip may be secured to the barrier by means of a self-vulcanising adhesive. Suitable adhesives are commercially available and are known to those skilled in the art. Since the barrier has positive buoyancy in the uninflated state it is protected against sinking in the event of any malfunction of the inflation equipment during deployment or any accidential deflation during use or recovery. Furthermore, the rate of deployment is no longer so dependent on the rate of inflation of the air tube. The barrier may be deployed and recovered by the method described and claimed in British Patent Application 43513/76 (Serial No. 1,554,737). As an alternative for recovery, the driven roller for recovery of the barrier may be a large reel on which deflation of the barrier is caused by winding the chambers around the reel. The invention is illustrated with reference to the accompanying drawing which is a cross-section of a typical oil barrier when fully inflated. In the drawing, 1 is the gas chamber which is side by side with the water chamber 2. Both chambers are fabricated from neoprene coated nylon sheet and are 685 mm in diameter. A strip 3 of closed cell foamed polyurethane 6 mm thick and 500 mm wide is glued to the interior surface of the air chamber 1 to cover approximately one quarter of the internal surface of the air chamber. The air chamber 1 floats above the water level 4 and the water chamber 2 is below. WHAT WE CLAIM IS:-

1. A pack, suitable for attachment to the deck of a support vessel, the pack comprising a deflated barrier comprising a continuous gas-inflatable gas chamber in side by side relationship to a continuous waterinflatable water chamber, at least one of the chambers incorporating a strip of foamed rubber or plastics material to confer positive buoyancy on the deflated barrier, a driven roller which can pull the barrier aboard the vessel and cause its deflation, means to attach a first end of the barrier to the vessel, means to inflate the gas chamber and means to inflate the water chamber.

2. A pack-according to claim 1 wherein the strip of foamed rubber or plastics material is attached to the air chamber and extends along the full length of the latter.

3. A pack according to claim 2 wherein the strip covers approximately one quarter of the internal surface of the air tube.

4. A pack according to any of the preceding claims wherein the material of the strip is closed cell foamed polyurethane.

5. An oil barrier as hereinbefore described with reference to the accompanying drawing.