GB2130533A - Method and apparatus for securing bulk materials on general- purpose ships - Google Patents

Abstract

A general-purpose ship is provided with tweendecks consisting of cover elements 27 located by retaining members 31. The cover elements are lowered on to bulk cargoes, such as grain, and the cargo is secured as a result of the dead weight of the cover elements 27. The cover elements are adjustably fixed in such a way that they can follow variations of the bulk cargo in a downward direction but are restrained against movement directed upwards. The members 31 are rods fixed to hatch coverings and hold walls. Pivoting members are located around each rod and rest on adjacent covers to prevent upward movement. Alternatively, the pivoting members lie against longitudinal bulkheads. <IMAGE>

Description

SPECIFICATION Method and apparatus for securing bulk materials on general-purpose ships The present invention relates to a method and apparatus for securing cargoes consisting of loose bulk materials, especially grain, in cargo holds of ships with tweendecks consisting of individual removable cover elements. The invention relates, furthermore, to a generalpurpose ship with at least one tweendeck consisting of movable cover elements.

The general-purpose ships discussed here are of the type equipped with at least one tweendeck formed within the ship. For transporting unit loads, for example containers, the tweendecks are drawn in and form appropriately limited cargo holds. For transporting bulk materials, for example, the cover elements forming the tweendecks are taken up and are stacked and stored outside the ship on land or in a suitable place within the ship.

Securing cargoes consisting of bulk materials, especially grain, within the cargo space of a ship presents a special problem.

Conventionally, a layer of sacks filled with grain is distributed as a covering on a cargo consisting of loose grain. The 1 m to 1.5 m high layer of sacks of grain has to be additionally braced by means of transverse slings.

During the journey, these slings have to be retightened from time to time, since considerable changes in the bracing can occur because of the movement of the grain.

The above-mentioned conventional securing of cargoes of grain is time-consuming to execute and maintain during the journey and, furthermore, is not sufficiently effective.

An object of the invention is to provide measures which serve for securing cargoes consisting of bulk materials, especially grain, within a ship in a simple and effective manner, and in particular, to ensure the proposed securing in a way such that no reworking or readjustment will be necessary during the journey.

To achieve this object, the method according to the invention is characterised in that the cover elements of the tweendeck or tweendecks are laid on the top side of the cargo of bulk materials in such a way that they cover the cargo at least by a substantial part of their own weight.

According to a feature of the invention, the cover elements provided for forming tweendecks have a double function. When the general-purpose ship is used for transporting bulk materials, the cover elements serve to cover and secure the cargo. The cover elements, which preferably extend approximately over the entire width of the cargo hold, lie next to one another one the surface of the cargo, so that the latter is stressed by the dead-weight of the cover elements.

According to a further feature of the invention, the cover elements, preferably hinged to one another, are fixed in terms of their movability in such a way that the cover elements can (individually) follow any movements of the cargo directed downwards, but are secured, in particular locked, against (lifting) movements directed upwards. For this purpose, the cover elements are supported on guides fixed in place, for example retaining rods, by means of locking devices preferably acting on one side, in order to be locked against forces directed upwards. The guides for supporting the cover elements can be formed on side walls of the ship or by these side walls themselves.

Further features of the invention relate to the constructive design of the cover elements and their mounting and to the locking of these, acting on one side, when they function as a cargo covering.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a general-purpose ship in a diagrammatic cross-section, Figure 2 shows a side wall of a ship in elevation with devices for supporting cover elements, Figure 3 shows a detail of a device for supporting cover elements in a plan view on an enlarged scale, Figure 4 shows a horizontal section through the detail according to Fig. 3 in the plane IV-IV, Figure 5 shows a vertical section of the detail according to Fig. 3 in the plane V-V, Figure 6 shows a further detail of the device according to Figs. 3 to 5, namely an anchoring for the top end of a retaining rod, in a side view partially in section, Figure 7 shows, in a vertical section, a detail of the design of a hatch coaming of the general-purpose ship in the region where the top end of a retaining rod is attached, Figure 8 shows, in a side view on an enlarged scale, an exemplary embodiment of a way in which cover elements are supported on one side or in one direction on a vertical retaining rod, Figure 9 shows a detail of the illustration in Fig. 8 in a side veiw offset 90 , Figure 10 shows a plan view or horizontal section of the detail according to Fig. 8, Figure 11 shows, in a vertical section, edge regions which face one another, of adjacent cover elements, Figure 12 shows a horizontal section of the detail according to Fig. 11, Figure 13 shows a vertical section of the detail according to Fig. 12, offset in relation to Fig. 11, Figure 14 shows, in a side view, the arrangement of a multiplicity of cover elements mounted above one another, and having another embodiment of how they are respec tively supported or locked, Figure 15 shows a detail of the method of supporting two adjacent cover elements in the embodiment according to Fig. 14, Figure 16 shows a cover element in a side view, with a further alternative embodiment indicating how this is supported, Figure 1 7 shows a simplified perspective representation of cover elements with a support according to Fig. 16, and Figure 18 shows a further alternative for supporting cover elements in a representation corresponding to Fig. 16.

Referring to the drawings, Fig. 1 shows as a practical example of part of a generalpurpose ship in a greatly simplified crosssection. A cargo hold 20 of the ship is limited laterally by longitudinal bulkheads 21. These are installed at a distance from outer side walls 22. A cavity formed between the longitudinal bulkheads 21 and the side walls 22 serves as a ballast tank 23. Below, the cargo space 20 is limited by a bottom 24 which likewise limits a ballast tank 23 in relation to an outer ship's bottom 25.

A tweendeck 26 can be installed approximately halfway up within the cargo space 20.

It consists of individual cover elements 27 arranged next to one another in the longitudinal direction of the ship. For the removable mounting of these, brackets 28, on which the cover elements 27 rest to form the tweenback 26, extend along the side of the cargo hold 20, particularly along the longitudinal bulkheads 21.

To form the tweendecks 26, the cover elmenents 27 are introduced from above into the cargo hold 20 via a hatchway 29 and are placed on the brackets 28, for example buy means of a crane (on board ship) which in the present case conveys the cover element 27 via carrying members 30. The brackets 28 are designed so that when the tweendeck 26 is removed they can be moved back or pivoted into orifices in the longitudinal bulkheads 21, with the result that the entire cargo hold 20 is free of projecting supporting means.

When the tweendeck 26 is removed, the ship can be used preferably for transporting bulk materials, especially grain. In this case, the cover elements 27 are laid on the ship's cargo, that is to say, for example, on the cargo of grain, in order to cover and secure this. The arrangement of the cover elements 27 preferably corresponds to the relative positioning when the tweendeck 26 is formed.

Accordingly, the cover elements 27 are arranged with their longitudinal extension transverse to the longitudinal plane of the ship from one longitudinal bulkhead 21 to the other.

In their function as a grain covering, the cover elements 27 not only rest on the ship's cargo by their own weight, but are also secured in a special way against movements directed upwards, whilst they can follow any downward movements of the cargo.

In the embodiment of Figs. 2 to 10, the cover elements 27 are supported, in their function as a cargo securing means, on vertical retaining rods 31. These are removably attached in the region of the longitudinal bulkheads 21, that is to say on the ship's sides. In the present embodiment, each retaining rod 31 of rectangular cross-section is provided at the top and bottom ends with anchoring means which allow it to be releasably attached to the longitudinal bulkheads 21.

As is evident, especially from Figs. 3 to 5, an anchoring hook 32 is attached to the bottom end of each retaining rod 31. Its dimensions are such that when the cover elements 27 stressed by the ship's cargo are supported on the retaining rods 31 the forces directed upwards can be transmitted reliably into the ship's structure, in the present case into the longitudinal bulkheads 21. For this purpose, these are provided with an anchoring fitting, in particular an anchoring plate 33 of sufficient dimensions, which is welded into an appropriate recess. In this anchoring plate there is an orifice 34 into which the anchoring hook 32 made of flat material can be introduced by means of a hook lug 35. A supporting nose 36 resting against the outside of the anchoring plate 33 ensures, in conjunction with the dimensions of the anchoring hook 32, that the anchoring hook 32 is fixed free of play.

The anchoring plate 33 is mounted in the region of a vertical stiffening stay 37 attached to the outside of the longitudinal bulkhead 21. A portion of this is formed, by means of walls 38 welded to it, into a leak-proof housing which surrounds the orifice 34 and which prevents water, etc., from flowing into or through it.

The top end of the retaining rod 31 is fixed, for example according to the proposal in Fig.

6, that is to say in the region of a longitudinal coaming 39 surrounding the upper hatchway 29 of the cargohold 20. Formed in an inner wall 40 of the longitudinal coaming 39 is a hook-in orifice 41 into which a supporting hook 42 of the retaining rod 31 is introduced.

The supporting hook 42 is adjustable relative to the retaining rod 31, specifically, here, by being arranged on a threaded bolt 43 connected to the retaining rod 31 and having an adjusting screw 44. Because the supporting hook 42 is adjustable, the retaining rod 31 can be braced in the vertical assembly position, so that it is retained non-displaceably in relation to the longitudinal bulkhead 21. A head 45 designed with a sloping supporting face and located in the upper end region of the retaining rod 31 rests positively against a matching sloping face of the inner wall 40 of the longitudinal coaming 39.

As is evident from Fig. 2, a retaining rod 31 is located in the upper region of the cargo hold 20 between every two adjacent cover elements 27, for example in the region of a gap 46. Consequently, the adjacent cover elements 27 are supported on the oppositely located sides of a common retaining rod 31 and are secured against movements in an upward direction.

In the embodiment of Figs. 8 to 10, separate supporting and locking means independent of the cover elements 27 are provided.

These consist, here, of two interacting clamping levers 47 and 48 which are each respectively assigned to a cover element 27 and which are supported on the opposite sides of the retaining rod 31 by means of clamping jaws 49,50. The two-armed clamping levers 47,48 rest by means of a foot 51,52 so as to be supported on the top side of the adjacent cover elements 27. The clamping levers 47,48 are hinged to one another via (two) shackles 53 and 54. Relative pivotability is guaranteed by means of hinge pins 55,56 which extend through the shackles 53,54 and the respective clamping levers 47,48.

The clamping means constructed in this way are arranged on the retaining rod 31 loosely, that is to say displaceably in the unstressed state. When the cover elements 27 are stressed in an upward direction by the cargo, a spreading movement is exerted on the clamping levers 47,48 connected to one another by the shackles 53,54 so that they rest with an increasing clamping force against the retaining rod 31 via the clamping jaws 49,50.

In the present embodiment, the shackle 53 can be pivoted away by loosening the hinge pin 55, in such a way that the entire clamping means can be brought into the clamping position, the retaining rod 31 being introduced between the clamping levers 47,48.

For this purpose, the hinge pin 55 is loosened from its anchoring by rotation and is then drawn out of the mounting position. The shackle 53 is thereby released on one side.

So that the relatively heavy clamping means can be handled by means of a lifting conveyor (crane) coupling means 57 are attached laterally to the two clamping levers 47,48 in the upper region of the clamping jaws 49,50.

These coupling means are grasped by a carrying gear 58 in the form of a clove hook, which is attached to a crane rope, a lifting rod or the like. The carrying gear 58 is shown by dot-and-dash lines in Fig. 9.

The cover elements 27 resting on the cargo as a covering or securing means are appropriately hinged or connected pivotably to one another. As is evident from Figs. 11 and 12, hinge joints are provided on the facing longitudinal side walls 59 and 60 of the cover elements 27. These hinge joints consist of a double shackle 61, on the one hand, and of a single shackle 62 introduced into this, on the other hand. A hinge pin 65 is received in joint orifices 63,64 directed along the same axis.

To release the hinge joint described above, the hinge pin 65 is axially displaceable, in particular can be moved to disengage from the double and single shackles 61,62. For this purpose, a pipe socket 66 projecting transversely or radially can be attached to the hinge pin 65. A lever or handle can be inserted in this to adjust the hinge pin 65.

Fig. 1 2 shows the second end position of the pipe socket 66 by dot-and-dash lines.

Figs. 14 and 1 5 show an embodiment in which clamping levers 67 and 68 are pivotably connected, namely in a pivot bearing 69, at one end to the associated cover element 27. Otherwise, the clamping levers 67,68 are connected to one another by shackles 70 in a similar way to the exemplary embodiment of Figs. 8 to 10, in such a way that the clamping levers 67,68 are supported by means of clamping jaws on opposite sides of the retaining rod 31 in the even of upward-directed stress on the cover elements 27.

Fig. 1 4 shows how cover elements 27 in the design described above are mounted within a ship in the stowing position. The cover elements 27 mounted above one another are secured relative to one another against transverse relative movement, specifically by means of the clamping levers 67,68 which are each pivoted upwards. In a stable oblique position, the clamping levers 67,68 of a cover element 27 penetrate into a retaining device of the cover element located above it, namely into an angular profile 71. The clamping levers 67,68 located in the edge regions of a cover element 27 are directed so as to converge upwards, that is to say are inclined relative to one another. Stable fixing against transverse movements is thereby obtained, in conjunction with the dead weight of the cover elements 27.

In this embodiment, the clamping levers 67,68 are located in a recess 72 of special shape at each of the corners of the cover elements 27. The angular profiles 71 are also arranged within the recess in such a way that clamping levers 67,68 can penetrate from below or can be supported on this angular profile 71.

The upper and lower cover elements of the design according to Fig. 14 are, in the present case, provided with clamping levers 73,74, arranged in pairs, also on the longitudinal sides, that is to say in the region of longitudinal side walls 59,60. These are cover elements which are supported as end elements at the front and rear end and are also secured on the free outer face via retaining rods or the like. As is apparent, retaining rods are provided approximately amidships and are attached to a transverse coaming. The design and effect of these clamping means in the region of the longitudinal sides correspond to those of the exemplary embodiments described.

In the embodiment of Fig. 14, the cover elmements 27 stacked above one another in the stowing position are assembled together by means of a tension member, namely a chain 75 with a turnbuckle. This chain 75 is connected to a clamping lever 74 of the upper cover element and to a chain plate 76 on the lower cover element.

Figs. 16,17 and 18 show embodiments in which cover elements 27 are connected on other supporting or guide means in the manner described, in particular being secured against movements directed upwards. In the solution according to Figs. 1 6 and 17, the cover elements 27 are supported directly on the ship's wall, particularly on the longitudinal bulkheads 21. The embodiment illustrates simple one-armed clamping levers 77 in the region of the four corners of the cover elements. These pivotable clamping levers 77 are supported on the longitudinal bulkheads 21 by means of an end acting as a clamping jaw 78, specifically in the region of a vertical stiffening stay 37 on the outside.

In the embodiment according to Fig. 18, one-armed locking levers 78 are again provided for supporting and securing the cover elements 27. These locking levers 78 designed in the form of a pawl engage positively with a rack 79 attached to the ship's wall (longitudinal bulkhead 21).

When the cover element is stressed in an upward direction, the narrowing end of the locking lever 78 penetrates in a locking manner into the teeth or tooth gaps of the rack 79 which are directed correspondingly obliquely downwards. At the same time, the locking lever 78 comes up against a fixed support 80 on the cover element and now acts as a twoarmed lever. During downward movements of the cover elements, the locking lever 78 is pivoted in the opposite direction, being lifted off from the support 80. The end of the locking lever 78 is moved out of the toothing as a result.

As is apparent especially from Fig. 14, the cover elements 27 can, in their function of securing the cargo, also be supported outside the region of the gaps 46, that is to say on the side faces extending in the longitudinal direction of the ship, by means of retaining devices (clamping levers) in the way described. Furthermore, appropriate supports can be formed in the region of the gaps at a distance from the side walls or longitudinal bulkheads 21, that is to say, for example, amidships, preferably in corresponding open recesses in the cover elements. Inasmuch as supports of this type (clamping levers 73,74) are located on the cover elements at their edges, the retaining rods, for example provided for this purpose, are anchored by means of their top end in the transverse coaming 81 of the hatchway 29 (Fig. 7), in a similar way to the design according to Fig. 6.As shown in the embodiment of Fig. 7, an inner wall 82 of the transverse coaming 81 is provided with a hook-in orifice and on the outside with a welded-on stiffening profile 83. Moreover, a water-tight housing 84 is formed here on the outside in a similar way to the design according to Figs. 3 to 5.

In ships with transverse structures, for example with a locker beam 85, the cover elements located in this region are designed in such a way that the locker beam 85 does not impair efficiency in the event of relatively large filling quantities. As shown in Fig. 2, the free end of a cover element adjacent to the locker beam 85 has joined to it a narrow flap element 86 which extends in the region below the locker beam 85 in the event of an appropriate filling quantity, but which, when the level of bulk material is higher, is swung onto the top side of the connected cover element, so that the latter can be brought up to the locker beam 85. The flat element 86 which has approximately half the width of the locker beam 85 is connected to the cover element via a flap hinge 87.

A common feature of all the embodiments of the anchoring means for the cover elements is that in the event of downward movement of the cover elements, they pass out of lock as a result of an appropriate displacement on the cargo, but automatically pass back into lock again as soon as the cover elements move in the opposite direction, namely upwards.

Claims (20)

1. Method of securing cargoes consisting of loose bulk materials, especially grain, in cargo holds of ships with tweendecks consisting of individual removable cover elements, wherein the cover elements are laid on the topside of the cargo in such a way that they cover the cargo at least by a substantial part of their own weight.

2. A general-purpose ship with at least one tweendeck consisting of movable cover elements, wherein, when the ship is used for transporting loose bulk materials, the cover elements are arranged so as to rest on the ship's cargo.

3. A ship as claimed in claim 2, wherein the cover elements are fixed adjustably.

4. A ship as claimed in claim 1 or 2, wherein the cover elements are fixed adjustably in such a way that they can follow variations in the cargo in a downward direction, but are anchored by retaining devices against movements directed upwards.

5. A ship as claimed in claim 2,3 or 4, wherein the cover elements are connected pivotably to one another, for example by means of releasable hinge joints.

6. A ship as claimed in any of claims 2 to 5, wherein the cover elements are supported on vertical guides fixed in place, in such a way that when stressed from below the cover elements are fixed as a result of a clamping effect against or positive engagement with the guides.

7. A ship as claimed in claim 6, wheren the cover elements have assigned to them pivotable clamping levers or pivotable locking levers which, in the event of upward directed stresss on the cover elements, are pivotable by pivoting into a locking clamping or retaining position by respectively coming up against or engaging with the guide.

8. A ship as claimed in claim 6 or 7 wherein the guides for supporting the cover elements consists of vertical retaining rods at least on the side walls of the ship or on longitudinal bulkheads.

9. A ship as claimed in claim 6,7 or 8, wherein the guides are attached removably.

10. A ship as claimed in any of claims 6 to 9, wherein the cover elements can be anchored to the ship's wall or to longitudinal bulkheads, preferably by means of clamping levers, which can be supported on the latter, or respectively by means of locking levers which can be engaged with them.

11. A ship as claimed in any of claims 6 to 10, wherein there are formed on the clamping levers clamping jaws, which, in the event of upward-directed stress as a result of the pivoting of the clamping levers, come up against the particular guide in a clamping manner in a position which is at an acute angle.

12. A ship as claimed in claim 11, wherein two particular clamping levers which are each assigned to adjacent cover elements rest in a clamping manner against a common guide, especially against a common retaining rod, on sides located opposite one another.

1 3. A ship as claimed in claim 12, wherein the clamping levers designed as twoarmed levers are connected pivotably to one another by shackles.

14. A ship as claimed in claim 11,12 or 13, wherein a unit consisting to two clamping levers and of shackles connecting them to one another rests loosely on the top side of two adjacent cover elements and is supported on a common retaining rod via clamping jaws.

1 5. A ship as claimed in any of claims 9 to 14, wherein the guides, especially retaining rods, are arranged in the region of gaps between adjacent cover elements.

16. A ship as claimed in any of claims 11 to 15, wherein clamping levers or respectively locking levers are arranged in the region of recesses at the corners of the cover elements.

1 7. A ship as claimed in any of claims 7 to 16, wherein locking levers can be moved respectively into a locking or supporting position as a result of positive engagement with a fixed guide, especially with a rack.

18. A ship as claimed in any of claims 7 to 17, wherein in a stowing position of the cover elements when these are arranged above one another, clamping levers or respectively locking levers arranged pivotably on the cover elements serve to secure the cover elements against relative transverse displacements as a result of positive engagement with one another.

1 9. A method of securing cargoes consisting of loose bulk materials substantially as hereinbefore described with reference to the accompanying drawings.

20. A general-purpose ship substantially as hereinbefore described with reference to the accompanying drawings.