GB2365386A

GB2365386A - Protection of a vessel's hull

Info

Publication number: GB2365386A
Application number: GB0019350A
Authority: GB
Inventors: Hilton Spenser Ingram
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-08-08
Filing date: 2000-08-08
Publication date: 2002-02-20
Also published as: GB0019350D0

Abstract

A method of protecting the hull 10 of a waterborne vessel comprises covering the hull with a water impervious flexible covering 18. The covering may be spaced from the hull surface by a plurality of lands (28, Fig 2) and a biodegradable chemical liquid may be passed between the hull surface and the covering. The covering may be provided with weights 22 and floats 24 to assist in the positioning of the cover around the hull while a rope 26 may be provided around an upper edge of the cover to prevent it dropping below the waterline of th vessel. The cover may be made from a non-conductive material.

Description

<Desc/Clms Page number 1> PROTECTION OF VESSELS DESCRIPTION The invention relates to methods and apparatus for the protection of vessels, in particular those parts of waterborne vessels usually immersed in water.

Whilst the superstructures of waterborne vessels may readily be cleaned, it is significantly more difficult to adequately clean the areas of the vessel e.g. hull below the waterline of a waterborne vessel.

The hulls of such vessels become contaminated with weed, slime, barnacles and the like.

Many vessels also suffer at this time from corrosion problems caused by stray leakage currents and galvanic action.

To reduce the first of these difficulties, it is necessary to put the vessel in dry dock every six to twelve months and then thoroughly clean the hull from all barnacles, weeds and other growths and then reinstate all of the various coverings e.g. water proofing, paint, Gel coat, antifouling and the like.

To overcome the corrosion problems caused by stray leakage currents and galvanic action various cathodic protection systems have been proposed for both fresh and sea water vessels.

Each of these solutions is both costly and time-consuming.

Both the growth of barnacles and other vegetation on the hulls of craft and corrosion problems caused by stray leakage currents and galvanic action Arise whether the craft is moving or not. The majority of vessels will be, most of the time, at moorings and not in use. The corrosion problems and the growth of barnacles and other life forms on the hull continues during this period effectively adding seriously to the problem.

It is an object of the present invention to provide a method and apparatus for alleviating and/or overcoming the above noted problems.

In a first aspect a method of protecting the hull of a waterborne vessel comprises the step of covering the hull of the craft with a water impervious flexible covering.

Desirably, the method comprises the use of a water impervious flexible covering which is electrically non-conductive.

The method may include spacing the covering from the surface of the hull and passing a suitable biodegradable chemical liquid for cleaning the hull to the space between the hull and the water impervious flexible covering.

The method may further include the use of pumps for passing said suitable biodegradable chemical liquid to the space between the vessel and the water impervious covering.

The method may further include positioning means on the water impervious covering to ensure the spacing of that covering from the vessel, in use.

In a second aspect, the invention provides that apparatus embodying the invention comprises a water impervious covering and means enabling that covering of material to be placed in a position in which it covers substantially all of the hull below the water line and some or all of the hull above the water line of the waterborne vessel.

Desirably the water impervious covering material is electrically nonconductive.

With advantage the water impervious flexible covering is shaped and adapted to follow the contours of the vessel with which it is to be used. Advantageously the apparatus may be provided with weights and/or floats to ease placement of the covering around the hull of a waterborne vessel.

The upper edge of the water impervious flexible covering may be provided with a rope capable of passing around the vessel to hold the covering in position

on the hull of the vessel, the rope being tied off on deck when the covering is correctly positioned.

The apparatus may further include a pump by means of which any water trapped between the covering and the hull is ejected therefrom and allowing a suitable biodegradable chemical cleaning agent for the hull of the vessel may be passed to the space between the covering and the hull.

With advantage that surface of the covering adjacent the hull may be provided with a plurality of lands or other upraised portions by means of which the spacing of the covering from the hull may be readily controlled.

The above aspects, features and advantages of the invention will become apparent from the following description and embodiment thereof now made with reference to the accompanying drawings in which: Figure 1 illustrates in general outline an arrangement embodying the invention, and Figure 2 illustrates a part of Figure 1 in more detail.

Figure 1 shows the vessel having a hull 10 with a keel 12. The superstructure of the vessel is not shown.

Running from the bow 14 to the stern 16 of the vessel there is, as shown in Figure 1, a water impervious electrically nonconductive flexible covering sheet 18 shaped and adapted to fit to the contour of the hull 10.

Sheet 18 stands off the surface of the hull 10 by a small amount x (e.g. 10-25mm) and into this space may be pumped, by a pump 20, any suitable biodegradable cleaning chemical liquid - that is to say a chemical which will clean the hull 10.

Weights 22 and floats 24 are used to hold the sheet 18 in position in the water. A rope 26 at the upper edge of the sheet (as viewed in Figure 1) holds the sheet in position in use.

As can be seen from the detail of Figure 2, the inner surface of the sheet 18 - that facing the hull 10, in use - may be provided with a series of lands 28 to ensure that the spacing of the sheet 18 from the hull 10 is as desired.

To remove the sheet 18 (for example when going to sea) the rope 26 is slackened and the sheeting rolled or bagged up at either the bow 14 or stern 16. It will be appreciated that the use of the apparatus and method now disclosed will provide real protection for the hull of a vessel whilst the vessel is not underway - which the majority of pleasure craft for example in this country, is the majority of the time.

The use of the biodegradable chemical for cleaning the hull will rid the hull of any weed, slime or barnacles, which may attach themselves to the hull whilst the vessel is making headway.

It is therefore envisaged that with the apparatus of the present invention and the method provided herein the need to dry dock the vessel in order that the hull of the vessel may be cleaned at regular intervals of say six to twelve months can be substantially reduced.

The covering may with advantage be arranged to extend when deployed above the waterline, allowing the cleaning agent to clean the sides of the vessel to a height of, say, 30-45cm above the waterline Other advantages of the arrangement now described will be apparent to the skilled reader of this Specification. It will be seen for example that should a vessel when underway become holed below the water line it will be readily easy to ensure that the water impervious flexible covering is deployed at least to an extent to cover that hole enabling the vessel to proceed to a place at which the breach may be repaired.

It will be appreciated that the method and apparatus of the invention and as described may be applied to each hull of a multi-hull vessel.

Although described with reference to a vessel capable of movement it will be seen that the arrangements now described are usable with fixed or semipermanent vessels which might be deployed in water, e.g. pontoons, large floats and the like.

Other advantages of the proposals now made will be seen by the skilled reader of this Specification.

Claims

CLAIMS 1. A method of protecting the hull of a waterborne vessel comprising the covering of the hull of a craft with a water impervious flexible covering (18).
2. A method according to claim 1 wherein said water impervious flexible covering (18) is spaced from the surface of the hull and a biodegradable chemical liquid is passed between the hull and the water impervious flexible covering (18).
3. A method according to any preceding claim wherein the water impervious flexible covering (18) includes a plurality of lands (28).
4. A method according to any preceding claim wherein the water impervious flexible covering (18) is provided with weights (22) and floats (24).
5. A method according to any preceding claim wherein the water impervious flexible covering (18) is provided with a rope (26) to prevent the water impervious flexible covering (18) from dropping below the water level.
6. A water impervious flexible covering (18) as claimed in any preceding claim which is made from a non-conductive material.
7. A water impervious flexible covering (18) substantially as herein described and illustrated in Figure 1.