A transport vessel

Abstract

 A transport vessel (1) suitable for the transport of cargo (2), in particular containers, by sea. The vessel is provided at its bow with a pusher attachment (3) which can be brought into and out of an operative pushing position. The vessel can thus be arranged for taking along flat-bottom craft (7) wherein a part of the cargo transported by sea can be accommodated, so that, in view of its motor power, it can be used, without loss of total weight to be transported, on inland waterways where the maximum draught is appreciably less than at sea.

Description

[0001] This invention relates to a transport vessel suitable for the transport of cargo, in particular containers, by sea. Containers transported with such a transport vessel by sea are unloaded in a seaport and whether or not after storage, are transported further to their place of destination. In many cases the further transport takes place by means of inland boats, including combinations of a pusher tug and flat-bottom craft or barges. Such transshipment operations with possibly required intermediate storage cost time, labour and money.

[0002] It is an object of the present invention to reduce the required operations and to thus provide a less expensive transport method for cargo, in particular containers, requiring transport both by sea and by inland waterways to reach their destination.

[0003] This is achieved, according to the present invention, with a transport vessel of the above described type by the vessel being provided at its bow with a pusher attachment that can be brought into and out of an operative pushing position.These features render the transport vessel suitable in a relatively simple manner, for taking along flat-bottom craft of barges, so that, in view of its motor power, it can be used, without loss of total weight to be transported, on inland waterways where the maximum depth of water is appreciably less than at sea.

[0004] In the case of transport by sea, the transport vessel is loaded to its maximum sea draught, e.g. by means of six layers of containers, the fifth and sixth layer being carried above deck level or the upper edge of the cargohold. The pusher attachment is then brought out of its operative position into a position wherein in which it least affects sailing at sea under normal conditions.

[0005] When the transport vessel arrives in a seaport, such a number of layers of containers, e.g. two are unloaded that the transport vessel arrives at a draught that is required for the inland waterways to be used subsequently. The cargo discharged can be placed in flat-bottom craft to be taken along the river, for which purpose the pusher attachment at the bow of the vessel is brought into its operative position, after which one or two craft is/are situated in front of the bow of the transport vessel and is/are coupled to said vessel by means of ropes in the manner conventional for a combination of a pusher tug and flat-bottom craft. The cargo in the flat-bottom craft is composed of goods already placed therein and/or goods transferred from the transport vessel into said craft. Thus, there is obtained a combination of a transport vessel and flat-bottom craft allowing the major part of the cargo transported by the transport vessel by sea to be left unperturbed, which means a substantial saving in time and cost.

[0006] The pusher attachment could be installed in demountable fashion; however, according to a further, preferred embodiment of the present invention the pusher attachment is provided with a support and guide member for the actual pusher means, fixedly connected at the bow to the hull of the vessel, said pusher means being arranged for up and down movement relative to said support and guide member. In this manner, the transport vessel can be transformed in a quick and simple manner into a pusher tug, while the pusher attachment is connectable, in a highly reliable manner, to the transport vessel, in particular the hull construction thereof, which is preferable from the viewpoint of safety and time-saving.

[0007] A robust, easily operable pusher attachment to be constructed in a relatively simple manner according to a further preferred embodiment of the present invention, can be obtained when the pusher means consist of two tubular members arranged vertically and parallel to the longitudinal axis of the vessel, said member being adapted for up and down movement and securement in corresponding tubular guides of the support and guide member. An optimum transmission of forces between the flat-bottom craft and the hull of the transport vessel can be realized when, in accordance with a further embodiment of the present invention, at least one substantially horizontal supporting beam extends from each tubular guide in a direction perpendicular to the longitudinal direction of the transport vessel, one parallel thereto and one at an acute angle to the two preceding ones.

[0008] The difference in draught at sea and upon inland waterways may result in that a part of the propeller or propellers of the transport vessel, when sailing inland waterways, would partly project above the water surface. This would not only adversely affect propulsion efficiency, but moreover would make it impossible to slow down or reverse the pusher combination, the latter being required on rivers, as the propellers (mainly when the direction of rotation is reversed) suck in air, which strongly reduces the propulsion power of the propellers. With a view to achieving an optimum sailing efficiency both at sea and on inland waterways, it is preferred, according to a still further embodiment of the present invention, in a transport vessel provided, in the manner of a sea-going ship, with a vertical upper stern having a downwardly inclined bottom with two propeller shaft passages, that there is provided a skirt extending vertically downwardly from the downwardly inclined bottom on either side outside the propeller shaft passages, said skirt, together with the keel of the vessel, forming two concavely arched current guide channels in the vessel bottom, extending substantially in longitudinal direction of the vessel, i.e. one at each propeller shaft passage, and having a substantially W-shaped configuration, with the lower ends of the W lying in the plane of said upper stern, the keel extending from the central top of the W in downwardly sloping direction, and the outer legs of the W gradually merging smoothly with the side walls of the transport vessel. By virtue of these features there is provided a longitudinal water suction path, with said skirt also preventing lateral air suction, so that a propeller will always rotate fully in and under water. The special form of the skirt limits the drag at deeper draughts, so that both for sea navigation and inland navigation, there is obtained an optimum ship's form, thereby allowing to slow down and to reverse the pusher combination within the statutory standards.

[0009] One embodiment of the transport vessel according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 shows a transport vessel loaded with containers during transport by sea;

Fig. 2 is a top view of Fig. 1;

Fig. 3 is a front view of Fig. 1;

Fig. 4 is a cross section on the line IV-IV of Fig. 1;

Fig. 5 shows the transport vessel shown in Fig. 1 with flat-bottom craft coupled to the bow and loaded with containers during transport on an inland waterway;

Fig. 6 is a cross section on the line VI-VI of Fig. 5; and

Fig. 7 is a diagrammatic, perspective view of the after-body form of the transport vessel.

[0010] The figures show a transport vessel 1 arranged to be loaded with containers 2 for transport by sea. The sea draught, in the case shown, is reached by stacking six layers of containers 2, the top two layers being carried substantially above the upper edge of the cargo hold.

[0011] At its bow, the transport vessel 1 is provided with a pusher attachment 3 having cylindrical head logs 4 and a support and guide member provided with guide tubes 5 and supporting beams 6. Head logs 4 are slidable vertically into guide tubes 5 and securable in the two outermost positions. During navigation by sea, head logs 4 are in a lifted position, as shown in Figs. 1 and 3, wherein the head logs, under normal conditions, do not or hardly influence the sailing characteristics of the transport vessel 1.

[0012] After arrival in a seaport, as many containers are unloaded as needed to lift vessel 1 to the extent that the draught is adjusted to inland waterways to be navigated subsequently. To that end, in the embodiment shown in Fig. 5, two layers of containers 2 have been removed. Besides, head logs 4 have been lowered into a position wherein these are in force-transmitting engagement with two coupled flat-bottom craft 7, which, to that end, are placed in front of the bow of transport vessel 1. Flat-bottom craft 7 are coupled conventionally to vessel 1, functioning as a pusher tug, by means of ropes, not shown, trained from winches 8 (see Fig. 2). The two layers of containers 2 removed from vessel 1 can be transported both ashore and to flat-bottom craft 7. Flat-bottom craft 7 can also be ready in entirely loaded position, while during the coupling of vessel 1 and flat-bottom craft 7, the containers 2 to be removed from vessel 1 are unloaded. Thereby realizing very quick handling in the seaport.

[0013] The reduction from sea draught to inland-waterway draught may result in the propellers 9 of vessel 1 coming to project partly above the water surface. This would mean, on the one hand, that the sailing efficiency and the sailing speed are adversely affected and, on the other hand, that, due to air suction, the vessel cannot, as and when required be stopped or reversed. To remedy this, and to enable optimum sailing both at sea and on inland waterways, the after-body has a special design, the configuration of which will be discussed further hereinafter, with reference to Fig. 7, which is a perspective, diagrammatic view of the after-body of vessel 1, as viewed obliquely from below.

[0014] The after-body is provided with an upper stern 10, a keel 11, wherein a propeller shaft passage 12 is indicated, and side walls 13, each terminating in a skirt 14 extending vertically downwards, and terminating in a horizontally extending edge 15. Between keel 11 and edge 15 extends a concavely arched face 16. The two skirts 14 bend towards one another in the direction of upper stern 10, but terminate at the level of upper stern 10, spaced apart from one another, and are connected at that location by a V-shaped skirt 17, which terminates in an edge 18, at the same level as edge 15, and whose tip constitutes the beginning of a gondola 19. From the upper stern 10, a triangular wall portion 20 slopes between skirts 17 towards the V-shaped converging edges 18. In this way there is provided in its totality a substantially W-shaped skirt 14, 17.

[0015] When the vessel is loaded to sea draught, the lower end of the upper stern will be approximately at the level of the water surface. Skirt 14, 17 is then below the water surface. In order to minimize the underwater drag produced thereby, skirt 14, 17 is W-shaped. When the vessel is loaded to inland navigation draught, vessel I will be lifted relatively to the water surface. The W-shaped skirt 14, 17 is so dimensioned that at that draught the lower edges 15, 18 are below the water surface. Rotation of the propeller will produce a water flow, with water being sucked-in in fore-and-aft direction, thereby entirely filling up the space underneath the concavely arched faces 16. The skirt then prevents air from being sucked in sideways.

[0016] It is self-evident that many modifications and variants are possible within the scope of the present invention. For instance, the pusher attachment may be demountable entirely or partly or may comprise a number of head logs other than two.

Claims

1. A transport vessel suitable for the transport of cargo, in particular containers, by sea, characterized in that the vessel is provided at its bow with a pusher attachment which can be brought into and out of an operative pushing position.

2. A transport vessel as claimed in claim 1, characterized in that the pusher attachment is provided with a support and guide member for the pusher means proper, said member being fixedly connected at the bow to the hull of the vessel, said pusher means being arranged for up and down movement relative to said support and guide member.

3. A transport vessel as claimed in claim 2, characterized in that the pusher means comprise two tubular members arranged vertically and parallel to the longitudinal axis of the vessel, said members being arranged for up and down movement and securement in corresponding tubular guides of the support and guide member.

4. A transport vessel as claimed in claim 3, characterized in that at least one substantially horizontal supporting beam extends from each tubular guide in a direction perpendicular to the longitudinal direction of the transport vessel, one parallel thereto and one at an acute angle to the two preceding ones.

5. A transport vessel which, in the manner of a sea-going ship, comprises a vertical upper stern having a downwardly inclined bottom with two propeller shaft passages according to any of the preceding claims, characterized in that there is provided a skirt extending vertically downwardly from the downwardly inclined bottom on either side outside the propeller shaft passages, which skirt, together with the keel of the vessel, forms two concavely arched current guide channels in the vessel bottom, extending substantially in longitudinal direction of the vessel, i.e. one at each propeller shaft passage, and having a substantially W-shaped configuration, with the lower ends of the W lying in the plane of said upper stern, the keel extending from the central top of the W in downwardly sloping direction, and the outer legs of the W gradually merging smoothly with the side walls of the transport vessel.

Drawing