US3224403A

US3224403A - Flexible barges

Info

Publication number: US3224403A
Application number: US338151A
Authority: US
Inventors: Paddington Arthur Loftus
Original assignee: Dracone Developments Ltd
Current assignee: Dunlop Ltd
Priority date: 1963-01-18
Filing date: 1964-01-16
Publication date: 1965-12-21
Anticipated expiration: 1982-12-21
Also published as: NL6400288A; GB981167A

Description

Dec. 21, 1965 A. L. PADDINGTON FLEXIBLE BARGES 5 Sheets-Sheenl 1 Filed Jan. 16, 1964 Dec. 21, 1965 A..l PADDINGTON FLEXIBLE BARGES 5 Sheets--Sheel 2 Filed Jan. 16, 1964 FIG. 3C.

Dea 21, 1965 A. PADDINGTON 3,224,403

FLEXIBLE BARGES Filed Jan. 1G, 1964 5 Sheets-Sheet. 5

f F 4 25 'i i FIG .4

I1/ 5,@ 22 gg F\G.5. 20 :o

si@ F|G.. Z :s fi l@ FIGJ.

Patented Dec. 21, 1965 3,224,403 FLEXIBLE BARGES Arthur Loftus Paddington, Langley, England, assignor to Dracone Developments Limited, London, England, a British company Filed Jan. 16, 1964, Ser. No. 338,151 Claims priority, application Great Britain, .lan 18, 1963, 2,219/ 63 8 Claims. (Cl. 114-74) This invention relates to flexible barges (for iiuent cargo), for example of the general nature of those described in British Patent 883,813. A feature of such barges is that, when empty, they are capable of being either folded up or wound up (for example, on a reel) so that they may occupy a relatively compact space when not required for use.

In their preferred form such barges consist of a iiexible elongated envelope of a fabric coated on the inside with an elastomer (eg. a synthetic rubber) impervious to a uent cargo to be carried by the barge, whilst the outside `surface is coated with an elastomer impervious to water and sun light. When loaded with cargo, the envelope assumes a generally tubular form for at least a substantial part of its length. The ends of the envelope are preferably tapered and secured to rigid end fabrications which either include, or are suitable for the attachment of, a towing eye and/or a filler pipe. Barges of this type are designed to be used with a fluent cargo having a density less than that of the water in which the barge is to be oated and when in use the barge gains its buoyancy by the difference between the density of the cargo inside and the density of the Water outside. In a typical case where the cargo is kerosene `and the barge is supported in salt water, the barge will float 4/s submerged.

Two problems arise in the handling of these barges when used with a liquid cargo. The first proble-m is to pump out the cargo without sucking the barge iiat at some point along its length whilst portions of the barge further from the pumping outlet still contain cargo. The other problem is to keep the barge afloat when it is empty since the envelope .itself and the rigid end fabrications will almost invariably be of greater density than the surrounding water.

The word barge normally means a vessel intended for transporting cargo by sea or other waterways. However, Vessels of the kind relating to this invention are also capable of being used for the storage of cargo afloat, and the word barge in this specification is to be understood as including not only vessels which may be used for transport, but also, where the context permits, vessels which may be used for storage but are not necessarily capable of being used for transport.

According to the present invention a barge for iiuent cargo, comprising a long flexible collapsible envelope, is provided internally with inflatable means, comprising at least one liexible tube, extending substantially the full length of the barge, the said iniiatable means serving, when iniiated, to co-operate with the envelope to deiine and keep open at least one pumping channel extending substantially the full length of the barge.

The said inflatable means is preferably secured to the barge at at least one end thereof and is preferably secured at both ends of the barge.

The ability to define and keep open a pumping channel is due to the fact that the barge envelope is not infinitely flexible so that it will not be able to suck down completely on to the inflated tube or tubes, and a pumping channel will be held open even when the barge is pumped empty (or as empty as possible).

The said inflatable means preferably also serves, when inflated, to keep the barge afloat whilst its cargo is being pumped out.

It should be obvious that (for reasons of economics) the tube or tubes should be of such dimensions as to occupy as small a proportion as practicable of the maximum internal volume of the barge, consistent with the ability to keep open a .pumping channel of reasonable dimension-s, and (if applicable) also consistent with the function of keeping the barge afloat whilst its cargo is being pumped out.

According to a feature of the invention, the said iniiatable means comprises two iiexible tubes, each being preferably secured to the barge at at least one end thereof and preferably at both ends thereof. The two tubes are preferably of equal length and at each end of the barge the tube ends are preferably located closely adjacent each other, side by side. As compared with the use of a single tube having comparable ability to keep the barge aoat whilst its cargo is being pumped out, the use of two tubes (especially if they are both of the same diameter as each other, a-s would conveniently be the case) should enable a greater volume of pumping channel to be kept open.

Aithough it is conceivable that the two tubes could be of about the same length as the effective internal length of the barge, or even slightly less than that, it is preferable that they should be slightly longer than the effective internal length of the barge. Apart from the consideration (in the case where the tubes are secured at both ends of the barge), that this should prevent undue stressing of the tubes when the barge is being towed, there is the consideration that in the case where the tubes are secured at one end to the barge by means of a manhole cover plate which is detachable and movable in a direction away from the remote end of the barge (the tubes being also secured at that remote end), the tubes should be long enough to enable that plate to be moved to a sufficient extent to provide access to the interior of the barge without the necessity of detaching the tubes from the plate. (Similar considerations may .also apply to the case where the iniiatable means comprises a single tube.)

In the case of the use of two or more tubes, these are conveniently twisted together with a coarse lay. This should enable a still greater volume of pumping channel to be kept open, and it also provides a simple means of keeping the tubes together.

The invention will now be described with reference to the accompanying drawing in which- FIGURES lA, 1B and 1C show respectively, one end of a barge, a central portion of the barge, and the other end of the barge, embodying the invention in a preferred form;

FIGURE 2 illustrates a preferred method of securing an end of a tube to a portion of a rigid end fabrication of the barge;

FIGURES 3A, 3B and 3C indicate the manner in which an arrangement of two twisted tubes keeps spaces open which form pumping channels extending substantially the full length of the barge;

FIGURE 4 illustrates schematically a bare utilising a single tube; and

FIGURES 5, 6 and 7 illustrate an alternative method of securing the ends of a tube.

In FIGURES 1A, 1B and 1C the flexible envelope of the barge is indicated at 1, a rigid bow fabrication is indicated generally at 2 and a rigid stern fabrication is indicated generally at 3. A filling and emptying pipe 4 is shown attached to the stern fabrication 3. Two juxtaposed

inflatable tubes

5 and 6 of circular cross-section twisted together with a coarse lay are shown extending from one end of the barge to the other and secured to the rigid end fabrications in a manner to be described in i connection with FIGURE 2.

In yFIGURE 2 an end section ot' one of the tubes-say 6--is shown. It is forced -ovei a cup 7 and secured thereto in an air tight manner by means of straps 8. The rigid fabrication at at least one end of the barge will contain a cover :plate 4sealing off a manhole through which access may be obtained to the 4interior of the barge for cleaning and repairing. FIGURES l and 2 show this manhole cover plate at 9. A screw-threaded stalk 10 extends from the base of cup 7 and this is threaded through a hole in manhole cover 9 and secured by a nut 11. At at least one end of each tube there is provided means for inating and deflating the tube and in FIG- URE 2 the stalk 10 has a hole 12 running along Iit-s length and a valve 13, which may be of the same general type as that used for inating a motor tyre, is Secured to the end of the stalk 10 remote from cup 7.

The rigid end fabrication 3 shown at the other end of the barge has an inwardly extending annular ange 3A to which the cargo filling and emptying pipe 4 is attached by means of an intermediate plate 4A and pipe 4 is in communication with the interior of the barge and sealed at its outer end by a cover plate 18 (FIGURE 1C). Tubesupporting cups, such as cup 7 of FIGURE 2, are also secured to the plate 4A. Alternatively, the ange 3A may be of suicient width to enable the tube-supporting cups and the .pipe 4 to be secured to the flange, enabling the plate 4A to Abe dispensed with. It is not necessary for the stalk 10 to be hollow at this end of the barge and the stalk 10 may consist of a stud welded to the base of the cup 7. Two cups such as 7 with

tubes

5 and 6 secured to them respectively, will be attached in the manner described, preferably side by side, at each end of the barge and a suitable degree of twist (say, of the order of one turn per 8 to 10 feet of length of tube) can conveniently be applied to the tubes and 6 by rotating manhole cover 9 before securing it in place. The tubes are preferably inflated (or at least partially inated) before the twisting is carried out.

The mode of construction of the rigid end fabrications of the barge (and the attachment of the envelope to them) is a matter within the scope of the person skilled in the art. Various types of end fabrication are described, for example, in British Patent 942,862 and West German Patent 1,131,113 and other foreign patents. Suitable design of the end fabrications to enable the securing of the tube or tubes should .present no serious difficulty to the person skilled in the art. The end fabrications (and the mode of attachment of the envelope thereto) shown in FIGURE l are therefore not shown in the fullest detail, but a brief description will now be given.

In FIGURE 1A the end fabrication 2 comprises a shaped tubular metal shell shown in cross-section in a diametrical plane. The shell has an internal annular ange 2A, to which the manhole cover plate 9 is attached. A towing eye 2B has finned extension plates secured to a short sleeve 2C which is attached to the left-hand end of the shell 2. The tapered end of the envelope 1 passes through .a ring 2D and is folded back on itself, the overlapping layers being stitched and/or stuck together. An annular 4clamp 2E is also provided, deforming the overlapping layers into a shallow annular recess in the shell 2.

In FIGURE 1C the end fabrication 3 also comprises a shaped tubular metal shell, also shown in cross-section in a diametrical plane. The shell 3 has an inwardly extending annular flange 3A to which the plate 4A is attached. The mode of attachment of the tapered end of the envelope 1 is substantially identical to that described in connection with FIGURE 1A. As suggested earlier the ange 3A `may extend further towards the longitudinal axis of the barge, enabling the tube-supporting member-s and the pipe 4 to be secured to the flange, in which case the plate 4A may be omitted.

FIGURES 3A, 3B and 3C show three cross-sections at different positions along the

twisted tubes

5 and 6 with the barge envelope 1 clinging around them in the ultimate condition when the barge is empty or practically empty, showing how the inated tubes co-operate with the envelope to define pumping channels and keep them open.

The cross section of FIGURE 3A is taken at a position where the

tubes

5 and 6 lie side by side horizontally. It will be seen that four pumping-

channel spaces

14, 15, 16 and 17 are kept open between the flattened barge envelope and the

tubes

5 and 6. The cross-section of FIG URE 3B is taken at a position where the

twisted tubes

5 and 6 lie obliquely to one another. Pumping-channel spaces are still kept open, except that in this case spaces 14 and 17 merge into a single and larger space. FIG- URE 3C is a section taken at a position along the barge where the

twisted tubes

5 and 6 lie vertically, one above the other. Here again,

spaces

14, 15, 16 and 17 are seen to be kept open.

As mentioned earlier in this specication, the barge envelope is not infinitely flexible, and it will be appreciated that when the barge is `approaching the empty condition, the material of the envelope will not be able to follow the contours of twisted tubes as easily as it could follow the :contours of similar tubes running Iside by side but not twisted together. Hence a greater volume of pumpingchannel space should be obtainable as a result of the tubes being twisted together.

An inevitable price of keeping open a pumping channel along the whole length of the barge when it is being emptied is that an amount of cargo fluid, equivalent to the total cubic -contents of these pumping passages, remains as a residue when the barge is nominally empty. This is not important when the barge is to be used for repeated journeys with the same type of cargo and in any event, by suitable choice of the size and ination pressure of the

tubes

5 and 6 in relation to the stiffness of the barge envelope 1, the unpumped residue can be maintained at a low percentage of the normal cargo capacity of the barge.

The

tubes

5 and 6 may be made of a conventional type of hose preferably somewhat reinforced and proofed against the barge cargo and they should be of such size that they will hold aoat the parts of the barge envelope immediately in -contact with them. If the barge is left in this condition the envelope will soon hang down in the manner of a curtain either partly at one side, and partly at the other side, of the

tubes

5 and 6 or in a single -curtain so that the draught of the barge will be half of the -circumference of the envelope. This latter condition will eventually obtain in any event with the

tubes

5 and 6 secured in the manner previously described.

The empty barge may now be towed, though care must be taken in shallow waters to ensure that the hanging ydown envelope does not become damaged by contact with sharp objects at the bottom of the water. When a oertain speed is reached, which varies according to the size of the barge, the envelope will come to the surface and plane along the surface in the form of a flat bag. In this manner the barge may make a return journey in the empty condition and this procedure has considerable advantages over other methods of making an empty return journey. For instance, in the case of an inammable cargo liquid, it is dangerous to introduce su'cient gas to render the barge buoyant if the gas contains free oxygen (e.g. air) and it has hitherto been necessary to use an inert gas for rendering the barge buoyant for a return journey after being emptied of its original cargo.

The following is an example of the sort of relative dimensions involved in a barge employing two tubes as described above:

(a) The barge may beflOO feet in length from ange 2A to -ange 3A.

(1b) The envelope of such a barge would have a circumference of approximately 151/2 feet for most of its length.

(c) The envelope would have an loverall thickness Iof one-eighth of an inch, and is conveniently formed of a strong nylon fabric coated both inside and outside as mentioned earlier in this specification.

(d) The two tubes should each be 104 feet in length and 4 inches in diameter, and they should preferably be inflated to a pressure of the order of 18 pounds per square inch, but not less than 5 pounds per square inch.

This example (which takes into account both the provision of reasonably sized pumping channels and the function of keeping the barge afloat when it has been emptied) should be a sufllcient guide to a person skilled in the art to enable him to design barges in accordance with the invention. If the tubes were sufficient merely to provide pumping channels but not sufficient to keep the emptied barge afloat, this could involve the inconvenience of employing external flotation means, with their attendant disadvantages, and it is clearly preferably to employ tubes which are sufficient for both purposes.

As mentioned earlier in this specification, it is preferable to employ tubes which are slightly longer than the effective internal length of the barge. Otherwise, if the tubes were stretched taut between the ends of the barge, they would be subjected to undue stressing when the barge was being towed. This would not apply where the tubes were not secured to the barge, but in such a case other difllculties could arise, including, for example, difficulties in maintaining tubes in a twisted-together condition and also possibly in providing convenient facilities for inilating and deflating them. `It is preferable to secure the tube or tubes to the barge at at least one end thereof and preferably at both ends of the barge.

The embodiment of the invention described with reference to FIGURES l to 3 employs two tubes. FIG- URE 4 illustrates, very schematically, a barge employing a single tube, and in which the end fabrications, the mode of attachment of the ends of the envelope and the mode of securing the ends of the tube may be similar in principle to the arrangements described in connection with yFIGURES 1 and 2.. A single-tube arrangement is not so convenient, since, other things being equal, the tube would have to be larger in `diameter than the 4tubes in a two-tube arrangement, in order to provide comparable buoyancy effects.

On the lother hand, it is difficult to :set a definite maximum to the number of tubes to be employed. Practical manufacturing and handling considerations would discourage the employment of more than a very few tubes, and it is considered that two tubes form the best practical compromise.

FIGURES 5, 6 and 7 illustrate an alternative method of securing tube ends to end-plates of a barge. FIG-

URES

5 and 6 may be regarded as side-elevation views and FIGURE 7 as a plan View in relation to FIGURE 6. The end of each tube is flattened and clamped in an air-tight manner `between two plates 19 which are secured to rigid end-plates, which in the case of FIG- URE 5 may be a manhole cover corresponding to the plate 9 of FIGURE 1A, and in the case of FIGURE 6 the plate may correspond to plate 4A of FIGURE 1C. FIGURES 5, 6 and 7 show only a single tube, but in the case of two or more tubes, their respective clampingplate assemblies would be mounted preferably close together on their respective end-plates. With this kind of securing means, the tubes, when inflated, assume a somewhat cushion-shape at their ends, as indicated in FIG- URES 5 to 7. AIn -FIGURE 5, an inflation valve is inrdicated schematically at 20, mounted on the end-plate, and having a flexible pipe 21 connecting t-he valve to the tube via the wall of the tube at 22, where the junction of the pipe with the tube is suitably reinforced.

For stowing away an empty barge (for example w en it is not likely to be required for use for some time or when it is required to be transported over land), the tube or tubes should be deflated. The barge may then be either folded up or wound up (whichever is con- 6 sidered more convenient) into a relatively compact form.

The invention has so far been described, with reference to the accompanying drawings, in forms suitable for incorporation in a 'barge having tapered ends and lrigid end fabrications, but the invention is not limited thereto. For example, it may be used with a type of flexible barge of which at least one end is flexible or of which `at least one end has a bluff profile. In such a case the termination of

tubes

5 and 6 by means such as cup 7 or plates 19 may be inappropriate and instead the ends of

tubes

5 and 6 may be sealed lby clamps, for instance, resulting in a shape somewhat as indicated in FIGURES 5 to 7, or each end may be bonded together to give a similar form. Such ends may be secured to the adjacent end of the interior of the barge by lashing them to a handling patch secured -to the interior surface of the barge envelope.

I claim:

1. A barge for fluent cargo having a density less than that of the Water in which the barge is to be floated, comprising a long collapsible envelope of flexible material, a rigid end fabrication at each end of the barge, a detachable manhole cover means forming part of one of said rigid end fabrications, the said envelope being tapered at each end, which is secured to the respective rigid end fabrication, inflatable means within said envelope, means securing said inflatable means to said rigid end fabrication at each end of the barge, said inflatable rneans comprising at least one flexible tube extending substantially the full length of the barge and serving, when inflated, both to cooperate with the envelope to define and keep open at least one pumping channel extending substantially the full length of the barge and also to keep the barge afloat whilst it is being pumped empty of its cargo.

2. A barge according to claim 1, in which the :said inflatable means comprises a plurality of Iflexible tubes, the `said rigid end fabrication being rotatable before being secu-red in place, thereby enabling the said tubes to be twisted together with a coarse lay.

3. A barge according to claim 1, in which valve means for the inflation and deflation of said inflatable means are mounted on said rigid end fabrication.

4. A barge for fluent cargo having a density less than that of the water in which the barge is to be floated, comprising a long collapsible envelope of flexible material, tapered end portions to said envelope, a rigid end fabrication at each end of the barge, means securing said tapered end portions to the respective rigid end fabrication, a detachable manhole cover means forming part of one of said rigid end fabrications, a plurality of flexible inflatable tubes within said envelope, means securing one end of each tube to said rigid end fabrication at each end of the barge, valve means mounted on said rigid end fabrication for the inflation and deflation of said tubes, said rigid end fabrication serving as a means for twisting the said tubes together with a coarse lay, the said tubes serving, when inflated, both to co-operate with the envelope to define and keep open at least one pumping channel extending substantially the full length of the barge and also to keep the barge afloat Whilst it is being pumped empty of its cargo.

5. A barge according to claim 2 in which valve means for the inflation and deflation of said inflatable means are mounted on said rigid end fabrication.

6. A barge for fluent cargo having a density less than that of the water in which the barge is to be floated, comprising a long collapsible envelope of flexible material, a rigid end fabrication at each end of the barge, a detachable manhole cover means forming part of one of said rigid end fabrications, the said envelope being tapered at each end and being secured to the respective rigid end fabrication, inflatable means within said envelope, means securing said inflatable means to said rigid end fabrication at each end of the barge, said inflatable means comprising at least two exible tubes of substantially circular cross-section extending substantially the full length of the barge interior and serving, when inflated, both to cooperate with the envelope to define and keep open a plurality of pumping channels extending substantially the full length of the barge and also to keep the barge alioat while it is being pumped empty of its cargo.

7. A barge according to clairn 6, in which flexible tubes are twisted together with a coarse lay, the said rigid end fabrication being rotatable before being secured in place, thereby enabling the said tubes to be twisted together.

8. A barge for uent cargo having a density less than that of the water in which the barge is to be floated, comprising a long collapsible envelope of flexible material, tapered end portions to said envelope, a rigid end fabricationrat each end of the barge, means securing said tapered end portions to the respective rigid end fabrication, a detachable manhole cover means forming part of one of Vsaid rigid end fabrications, at least two juxtaposed, inflatable, tubes of substantially circular crosssection within said envelope, means securing one end of each tube to said rigid end fabrication at each end of the barge, valve means mounted on said rigid end fabri cation for the inflation and deflation of said tubes, the said rigid end fabrication serving as a means for twisting the said tubes together with a coarse lay, the said tubes serving, when inflated, both to co-operate with the envelope to deine and keep open at least one pumping channel extending substantially the full length of the barge and also to keep the barge afloat while it is being pumped empty of its cargo.

References Cited by the Examiner UNITED STATES PATENTS 1,228,914

20 FERGUS S.l MIDDLETON, Primary Examiner.

MILTON BUCHLER, Examiner.

Claims

1. A BARGE FOR FLUENT CARGO HAVING A DENSITY LESS THAN THAT OF THE WATER IN WHICH THE BARGE IS TO BE FLOATED, COMPRISING A LONG COLLAPSIBLE ENVELOPE OF FLEXIBLE MATERIAL, A RIGID END FABRICATION AT EACH END OF THE BARGE, A DETACHABLE MANHOLE COVER MEANS FORMING PART OF ONE OF SAID RIGID END FABRICATIONS, THE SAID ENVELOPE BEING TAPERED AT EACH END, WHICH IS SECURED TO THE RESPECTIVE RIGID END FABRICATION, INFLATABLE MEANS WITHIN SAID ENVELOPE, MEANS SECURING SAID INFLATABLE MEANS TO SAID RIGID END FABRICATION AT EACH END OF THE BARGE, SAID INFLATABLE MEANS COMPRISING AT LEAST ONE FLEXIBLE TUBE EXTENDING SUBSTANTIALLY THE FULL LENGTH OF THE BARGE AND SERVING, WHEN INFLATED, BOTH TO COOPERATE WITH THE ENVELOPE TO DEFINE AND KEEP OPEN AT LEAST ONE PUMPING CHANNEL EXTENDING SUBSTANTIALLY THE FULL LENGTH OF THE BARGE AND ALSO TO KEEP THE BARGE AFLOAT WHILST IT IS BEING PUMPED EMPTY OF ITS CARGO.