WO1991007311A1 - Locating device - Google Patents

Abstract

Deck cargo is often lost at sea, either by breaking free from its stowage lines and falling overboard or as the result of some accident such as a collision, and can cause serious problems, not only because of the expense involved but also because it may result in damage both to the environment (it may be, or contain, toxic materials) and to subsequently passing shipping (it can be a navigation hazard, or it may result, say, in torn or damaged fishing nets). The invention proposes a simple and inexpensive way of locating lost cargoes, namely a marker buoy (22) that is detachably secured to a support (14) mounted on and carried by the cargo (10), and is releasable therefrom (when the cargo is lost overboard) to float to and on the surface while remaining tethered (by line 23) so as to mark the position of the cargo.

Description

Locating Device

This invention concerns a locating device, and relates in particular to a marker buoy useful as a locating device for sea-borne cargo and the like.

Despite a fall in the world's shipping, much cargo is still carried by sea, and a great deal of that is in the form of deck cargo (stowed on deck rather than in a hold), often within containers (especially drums, crates, or the now conventional large rectangular "box" commonly meant when the expressions "container" or

"containerised" are used). It is, unfortunately, all too common for deck cargo to be lost at sea, either by breaking free from its stowage lines and falling

overboard (typical in bad weather), or as the result of some accident (such as a collision, when the ship may even sink). Clearly, such a lost cargo can cause serious problems, not only because of the expense involved but also because it may result in damage both to the environment (it may be, or contain, toxic

materials) and to subsequently passing shipping (it can be a navigation hazard, or it may result, say, in torn or damaged fishing nets). Clearly, it would be

desirable if each item of lost cargo could be easily and cheaply located, enabling its recovery or destruction, as appropriate.

At the moment there seems rather surprisingly to be no simple and in-expensive way of locating cargoes lost overboard - and the invention proposes what is hoped will be such a way, namely a marker buoy detachably secured (and tethered) to a support mounted on and carried by the cargo and releasable therefrom (when the cargo is lost overboard) to float to and on the surface while remaining tethered so as to mark the position of the cargo.

In one aspect, therefore, the invention provides a marker buoy device for marking the position of an item of cargo lost overboard from a ship at sea, which device comprises:

a base support mount able on (and carriable by) an item of cargo;

a marker buoy detachably secured to the base support by means which will release the buoy therefrom if the cargo becomes submerged, which marker buoy is long and thin, and comprises an elongate main body with a buoyancy compartment adjacent the "top" thereof and hingedly secured thereto so that it can move from a stowed position alongside the body to a deployed

position extending generally normal thereto; and

a stored mooring line by which the released buoy will remain moored to the base support (and thus the cargo), sufficient of which line may be payed out from its storage place to allow the buoy to rise and float on the surface in the vicinity of the submerged cargo.

The marker buoy device of the invention is for marking the position of an item of cargo carried by a sea-going ship when that item is lost overboard (or, indeed, when the ship sinks). The cargo item may be of any sort and size (naturally, the marker buoy device may need to be shaped or sized accordingly), but the

invention is primarily intended for use with the large rectangular containers now frequently carried as deck cargo by the so-called container ships.

The inventive device has a buoy detachably secured to a base support, and this support is mounted on the cargo item. This mounting may be accomplished in any convenient way. Indeed, it may even include the base support being built-in to the cargo item, though at the moment it is preferred to employ an "add-on" base that is bolted, riveted, glued or - and preferably - magnetically attached to the cargo item (mounting modes that allow the base to be removed if required - say, when a container becomes damaged and must be disposed of - are generally advantageous). Where, as is the primary intention, the cargo item is a container (as mentioned above) it is particularly preferred if the marker buoy device be attached in some way to and between a pair of the locking rods or bars that form part of the container door closing and securing mechanism. More specifically, it is most convenient if the device be mounted at either end on an arm that can be extended between, and

releasably grip, a pair of adjacent locking rods so that when in use the marker buoy device actually lies in the "recess" between the two rods.

In a general sense, just where the base support is mounted on the cargo item depends very much on the nature of the item, but usually it will preferably be carried on a side or end surface (on a top or bottom surface it is too vulnerable during stacking), and most advantageously it will be in a recessed area (keeping it even further out of harm's way). Many containers have suitable recessed panels at the side adjacent one or other end, but other possible places on containers are: actually inside the corner support posts; within the forklift pick-up points; between the underfloor cross members; and - as described above - between a pair of door locking rods.

The base support may take any convenient form, though to some extent this may be dictated by the manner in which it is to be mounted, the nature of the marker buoy, the way in which the buoy is detachably secured, and the storage of the mooring line. One particularly preferred form of base support is that of an elongate shallow box (in which, as described further hereinafter, is held a correspondingly elongate flat marker buoy.

It is always possible that in operation the marker buoy will fail to be released from the base support, that the mooring line will not pay out properly

(preventing the buoy rising to the surface), that the mooring line will break (so the buoy drifts away), or ... For these reasons it is preferred if the base support include a quite separate "marker" device in the form of a sonar transmitter, which transmitter is activated either when the cargo item (and the base support mounted thereon) is submerged or when it is positively triggered by some suitable emissions from a search and recovery vessel.

Detachably secured to the base support is the marker buoy, whose purpose, as the cargo item submerges, is to break free and float up to the surface (paying out the mooring line as it goes) to mark the position of the (sunken) cargo. Although in principle the buoy might take any form - having any convenient shape, and

achieving its buoyancy in any convenient way - in practice, however, it more or less has to be long and thin, with its main buoyancy component somewhat nearer the "top" end. It is long so that when floating it extends both well above the surface, properly to mark the position, and well below the surface, to give it stability, and it is thin so that it and its base support take up as little room on the cargo item as possible.

Such a long, thin marker buoy - for example, a long tube-like body with its buoyancy component hinged thereto roughly two-thirds of the way up - looks

remarkably like a fishing float, and, indeed, much the same principles apply. In the case of the marker buoy, however, it may be desirable so to construct the

buoyancy component that it takes up least room when the buoy is stowed in its base. For example, the buoyancy component could be an inflatable bag (triggered to inflate, and so breaking the buoy free, as the buoy submerges with the sinking cargo), or - and preferably - it could be an elongate float pivotally mounted so as to be stowed aligned with the long thin body but to be deployed by turning through 90º normal thereto. The use of one or more hinged buoyancy component, especially one that is itself flat and thin, enables the buoy to be stowed in a folded, flat, state taking up little room, but to deploy in an unfolded, bulky, state, with the buoyancy component (s) extending normal - and preferably laterally either side - of the main body, to provide a buoyancy effect that is reasonably stable against wave motion. The buoyancy component is advantageously two separate but attached tubular floats, or buoyancy members, one either side of the main body. It (or each part) is very preferably pivoted at a middle point along its length, and conveniently it is biassed, by a spring (for example), towards the deployed position. This biassing, and the resultant tendency of the buoy to unfold, assists in ejecting the buoy from the base support when it is freed to deploy. The marker buoy is detachably secured to the base support by means which, when the support submerges (with the cargo), releases the buoy to rise up to the surface tethered by the mooring line. The buoy may be

detachably secured in any convenient way, provided it is not likely to be released until the device - and cargo - is actually submerged (sunk or sinking). For example, in one very simple form the buoy might merely sit in an open-topped box (the base support), retained therein solely by gravity (and perhaps a little friction), and freeing itself therefrom purely by means of its

buoyancy. Alternatively, the buoy may be held by conventional spring clips (the U-shape sort commonly used for tools), again being freed by its buoyancy.

However, the way may require a firmer securement, with a more positive release mechanism, in which case it is easy to provide a latch system activated open by, say, a float switch (using a ballcock, perhaps) or a pressure- responsive switch (using a bellows or moving diaphragm, possibly). One preferred possibility is that the buoy sit loose in a lidded box-like base support, the lid of the box being released once the whole is submerged, allowing the buoy to float free.

The marker buoy may, of course, bear all sorts of adjuncts - thus, to enable it to be a "visible" as possible. Accordingly: it may carry a flag or a radar reflector; it may have an in-built light or radio transmitter (possibly a satellite beacon and position indicator device) triggered on by the buoy's release to the surface; or it may carry a (hydrogen or helium) balloon tethered to it by a "mooring" line and inflated and released as it reaches the surface (in much the same way as the buoy itself is released on its mooring line on submerging). It may also identify itself (and the cargo it is moored to) in any suitable way, from a simple label to a coded message transmitted by its light or radio. If, as seems likely, any of these devices need a power source, then naturally the buoy can carry batteries, make use of solar power (also to re-charge its batteries), or even use a sea-water voltaic cell as the source.

Once released from its base support, the marker buoy rises to the surface, and floats there, at the "end" of its mooring line. This line, which can be of any suitable substance (including non-buoyant and/or bio-degradable materials), is payed out from a storage compartment (in the base support or, and preferably, in the buoy itself) as the buoy rises via some drive so that once the buoy surfaces little more, if any, is released. A suitable drive might be a spindle-carried spool with a friction brake either overcome by the buoyancy forces or positively released only by a

pressure- or float- actuated switch itself operable only when the buoy is still submerged. However, the

presently very much pref erred system is a simple one involving no moving parts, wherein the line merely pays out from its storage - it may, for example, pull off the free (lower) end of an elongate fixed (non-rotating) spool mounted by its other (upper) end co-axially within the bottom half of the buoy body - and runs out from the buoy vi a a small orifice (conveniently in the bottom end of the body) which has been adjusted in size so as to form a friction braking constriction around the line.

The marker buoy device of the invention, and its various component parts, may be made of any suitable materials. Modern plastics are especially appropriate in the rather corrosive atmospheres encountered at sea, though many metal alloys, especially aluminium, can also stand that sort of environment. Possibly the bouy body could be a long thin aluminium tube, for strength, the floats thereon being a polyurethane or polystyrene foam for enhanced buoyancy.

Embodiments of the invention are now described, though by way of illustration only, with reference to the accompanying Drawings (which are essentially

diagrammatic) in which:

Figure 1A shows (in perspective from above and one side) a container having mounted thereon a marker buoy device of the invention;

Figure 1B shows an end view of a container having mounted thereon, by its door locking rods, a marker buoy device of the invention;

Figures 2A & B show (in see-through perspective

from above and one side) a marker buoy device as in Figure 1, the buoy being seen in (2A) and out (2B) of an elongate shallow box base support;

Figure 3 shows in more detail a see-through

elevation of the buoy of Figure 2B; and

Figure 4 shows a see-through elevation like that of Figure 3 but of a different buoy struct ure.

The container (generally 10) of Figure 1A is conventional, and has four main corner posts (as 11) adjacent each of which there is in the long side (as 12) a recessed area (as 13). Mounted (by means not shown) in one of these recesses 13 is the base support (14) of a marker buoy device of the invention. This base support is an elongate shallow box, and - as best shown in Figure 2A - it contains, detachably secured

therewithin by spring clips (as 21), the marker buoy itself (generally 22) attached to the base support 14 by a mooring line (23).

A different way of mounting the marker buoy device on a container is shown in Figure 1B. Here the device (again, as a flat elongate box 14) is attached at either end to arms (as 101) that clamp onto the container's door locking rods (as 102), so that the device is between but secured to a pair of these rods.

Out of the base support 14 the buoy is as shown in Figure 2B - and in more detail in Figure 3 (some

modifications are shown in Figure 4). It has a long tube-like body (30) on which is pivotally mounted a pair of floats (as 31). At the top of the body 30 is a radio aerial (32), with a flag (33) and a light (34)

surmounting a radar reflector (35), and inside the body below the floats 31 is a mooring line spool (36: braked by means not shown) from which the mooring line 23 is payed out via an aperture (37) in the body wall. Below the spool 36 is a radio and other electronics (38), and these - and the light 35 - are powered by batteries (39) activated by a float switch (40) at the very base of the body.

The general mode of operation of the marker buoy device of Figure 2 is as follows:- First, the container 10, with the device mounted thereon with the buoy component 22 inside its base support 14, falls overboard. Then, as it submerges, so the buoy's 22 natural buoyancy frees it from the

retaining clips 21, and, its floats 31 deployed fully, it rises to the surface (41), paying out the base- attached mooring line 23 from the spool 36 as it does so. Finally, once it reaches the surface, the float switch 40 activates the light 34 and the radio 38.

The device of Figure 4 operates in much the same way, save that is is in a base support box with a releasable lid (the box is not shown in the Figure), the springs (as 141) on the floats (241) force the floats into the deployed, laterally-extended position, and so help to eject the buoy once the box's lid has been released, and the line (43) pulls off the free end (142) of the spool (46) and runs out via the friction-brake orifice (143; this is adjustable, but by grubscrew means not shown).

Claims

CLAI MS

1. A marker buoy device for marking the position of an item of cargo lost overboard from a ship at sea, which device comprises:

a base support mount able on (and carriable by) an item of cargo;

a marker buoy detachably secured to the base support by means which will release the buoy therefrom if the cargo becomes submerged, which marker buoy is long and t hin, and comprises an elongat e main body with a buoyancy compartment adjacent the "top" thereof and hingedly secured thereto so that it can move from a stowed position alongside the body to a deployed

position extending generally normal thereto; and

a stored mooring line by which the released buoy will remain moored to the base support (and thus the cargo), sufficient of which line may be payed out from its storage place to allow the buoy to rise and float on the surface in the vicinity of the submerged cargo.

2. A buoy device as claimed in Claim 1, wherein the cargo item is a container, and the base support bears clamping means by which it can be mounted on the

container attached to and between two of the container's door locking rods.

3. A buoy device as claimed in either of the preceding Claims, wherein the base support takes the form of an elongate shallow box.

4. A buoy device as claimed in any of the preceding Claims, wherein the base support includes a quite separate "marker" device in the form of a sonar

transmitter, which transmitter is activated either when the cargo item (and the base support mounted thereon) is submerged or when it is positively triggered by some suitable emissions from a search and recovery vessel.

5. A buoy device as claimed in any of the preceding Claims, wherein the buoy's buoyancy component is one or more elongate float pivotally mounted so as to be stowed aligned with the long thin body but to be deployed by turning through 90º normal thereto.

6. A buoy device as claimed in Claim 5, wherein each float is biassed to the open, deployed, state.

7. A buoy device as claimed in any of the preceding Claims, wherein the buoy merely sits in a lidded box (the base support), freeing itself therefrom by means of its buoyancy when the lid is released.

8. A buoy device as claimed in any of the preceding Claims, wherein the buoy carries a flag or a radar reflector; has an in-built light or radio transmitter triggered on by the buoy's release to the surface;

and/or carries a lighter-than-air balloon tethered to it by a "mooring" line and inflated and deployed as it reaches the surface.

9. A buoy device as claimed in any of the preceding Claims, wherein the buoy is tethered to its support by a mooring line payed out from a storage compartment in the buoy as the buoy rises via some drive so that once the buoy surfaces little more, if any, is released.

10. A buoy device as claimed in Claim 9, wherein the buoy body contains a spool of mooring line mounted, by the spool's upper end, co-axially with the buoy body, and in use the line runs off the free lower end of the spool and out of the body via a restricted, friction- braking, orifice.

11. A buoy device as claimed in any of the preceding Claims and substantially as hereinbefore described.

12. A cargo container whenever fitted with a marker bouy device as calimed in any of the preceding Claims.