Steering mechanism for shallow draft container ships and inland waterway container transport ships

Abstract

A steering mechanism for a container transport ship hull, the hull including a bow, a stern and a container compartment between the bow and the stern. The bow is provided with a group of suspended lateral thruster pods, the group including a first pod arranged along the longitudinal centerline of the hull, a second pod arranged to be rearward of the first pod and outward from the centerline, and a third pod arranged to be rearward of the first pod and outward from the centerline and opposite to the second pod. The first pod and the second pod define a first longitudinal flow channel to one side of the centerline, and the first pod and the third pod define a second longitudinal flow channel to the opposite side of the centerline. A fourth pod as an omissible thruster mechanism can be arranged behind the first, second and third pods along the centerline to define first and second cross-centerline flow channels together with them.

Description

Technical Field

[0001] The present disclosure relates generally to intermodal cargo container transport vessels for transportation along inland waterways, and more particularly to a steering mechanism for limited radius or zero radius turning maneuvers in riverine, shallow draft container transport vessels. Background Art

[0002] A container ship, which may also be referred to as a container ship or container transport vessel, is a cargo ship that uses standardized containers to carry its load. The method of transporting cargo in standardized containers may be referred to as containerization. Containerization is an intermodal cargo transportation system using standardized containers that can be accommodated by container ships, rail cars, and trucks. The capacity of a container ship may be measured in twenty-foot equivalent units (TEUs). It should be understood that container ships are a popular mode for transporting non-bulk cargo. In fact, most non-bulk cargo is transported by container ships.

[0003] Some factors that may hinder ships (such as container ships) from traveling along inland waterways include but are not limited to shoals and sandbars, low water waves, ice flows and high curved water sections. Each of these factors has shown or aggravated challenges for ships with limited maneuverability to move at high speeds. For example, although the main channel of the estuary of the Mississippi River is currently maintained as approximately 45 feet deep and 500 feet wide, it should be understood that in the Mississippi River, upstream of the city of Baton Rouge, the main channel can be shallowed and narrowed quite a lot. The control depth of the entire Mississippi River inland waterway system is 12 feet, and this depth becomes particularly critical during low water runoff periods, such as the annual seasonal variation of water runoff in late summer and early autumn or during droughts, during which the Army Corps of Engineers requires that the main channel be maintained at this control depth. Low water levels, natural and artificial obstacles and even shoals in the main channel may limit the navigable channel width to being substantially less than 200 feet.

[0004] Vessels operating in the Mississippi River basin north of the city of Baton Rouge, especially during periods of low water runoff, may have to operate in close proximity to opposing traffic flows and maneuver around obstacles near and within the waterway. However, conventional barge and tugboat equipment does not have high-speed maneuverability because they are typically powered only by so-called "propulsion devices" at the stern of the tugboat, and the effects of the river on the bow of the tugboat must be used or overcome in order to perform turning maneuvers. Such maneuvers may require crossing a navigable channel for a wider trip while slowing the vessel so that the water current contributes to the turn or simply to yield to the opposing riverside traffic flow. Therefore, there is a need for a steering mechanism for shallow draft vessels such as container carriers and transport vessels that provides enhanced maneuverability for high-speed passage through shallow waterways. Summary of the invention

[0005] The present disclosure relates to a container transport ship, which includes an outer hull, the outer hull including a bow, a stern and a container compartment, the container compartment having lateral sides extending between the bow and the stern and opposite to each other, the bow having a group of suspended lateral thruster pods, the group of suspended lateral thruster pods including: a first pod, which is arranged along the longitudinal centerline of the outer hull; a second pod, which is arranged to be behind the first pod and outward from the longitudinal centerline of the outer hull; and a third pod, which is arranged to be behind the first pod, outward from the longitudinal centerline of the outer hull and opposite to the second pod; wherein the first pod and the second pod define a first longitudinal flow channel leading to one side of the longitudinal centerline of the outer hull, and the first pod and the third pod define a second longitudinal flow channel leading to the opposite side of the longitudinal centerline of the outer hull.

[0006] In an embodiment of the present disclosure, the outer hull also includes a fourth pod, which is arranged behind the first pod, the second pod and the third pod along the longitudinal centerline of the outer hull, and wherein the fourth pod is combined with the first pod, the second pod and the third pod to define a first cross-centerline flow channel and a second cross-centerline flow channel, wherein the first cross-centerline flow channel and the second cross-centerline flow channel intersect near the longitudinal centerline of the outer hull.

[0007] In an embodiment of the present disclosure, the first pod, the second pod, and the third pod each include a plurality of duct thrusters, and the fourth pod is not occupied by duct thrusters.

[0008] In an embodiment of the present disclosure, the first pod, the second pod, the third pod and the fourth pod each include a plurality of duct thrusters.

[0009] In an embodiment of the present disclosure, the bow includes a double-radius pointed top profile having two side portions, each of the two side portions including a circular profile having a first radius, a tapered pointed top portion having a second radius, and an inner curved portion arranged close to the intersection of the circular profile and the pointed top portion to provide a smooth transition between the circular profile and the pointed top portion.

[0010] In an embodiment of the present disclosure, the first pod is arranged to be close to the pointed portion of the bow, the second pod is arranged on the inner side of one side of the bow, close to the position where the circular outline intersects with a lateral side of the container compartment, and the third pod is arranged on the inner side of the opposite side of the bow, close to the position where the circular outline intersects with the opposite lateral side of the container compartment.

[0011] In an embodiment of the present disclosure, the first pod is arranged to be close to the front end of the keel of the bow, the second pod is arranged on the inner side of a first point where the bow has extended to at least 85% of the width of the container compartment, and the third pod is arranged on the inner side of the opposite side of the bow and close to a second point that is mirrored with the first point.

[0012] In an embodiment of the present disclosure, the first pod has a front end, and the front end includes an inverted bow shape.

[0013] In an embodiment of the present disclosure, the second pod and the third pod have a front end, and the front ends of the second pod and the third pod include a non-inverted, single-radius, spire-shaped profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a front elevational perspective view of an exemplary container carrier;

[0015] Figure 2 yes Figure 1 Front view of a container ship;

[0016] Figure 3 yes Figure 1 Rear view of a container ship;

[0017] Figure 4 yes Figure 1 A first side view of a container carrier ship;

[0018] Figure 5 yes Figure 1 A view of a second side of the container ship;

[0019] Figure 6 is Figure 1 A top view of a container ship;

[0020] Figure 7 is Figure 1 Bottom view of a container ship;

[0021] Fig. 8A is a schematic diagram of an exemplary configuration of the disclosed steering mechanism;

[0022] Figure 8B is a graphical representation of flow through the disclosed steering mechanism during non-steering, forward motion; and

[0023] Figure 8C is a graphical representation of flow through the disclosed steering mechanism during a steering maneuver. DETAILED DESCRIPTION

[0024] The following detailed description will illustrate the general principles of the mechanism, examples of which are additionally illustrated in the accompanying drawings.In the drawings, like reference numerals indicate identical or functionally similar elements.

[0025] Figure 1 - Figure 7 generally shows an exemplary container carrier 10. With specific reference to Figure 1 , the container transport ship 10 may include an outer hull 12 having a bow 14. Figure 1 7, the bow 14 shown includes a double radius spire profile. That is, the bow 14 includes two sides, each side including a circular profile 16 having a first radius, a tapered end or spire 18 having a second radius, and an inner bend 17 disposed near the intersection of the circular profile 16 and the end or spire 18 to provide a smooth transition between them. In one embodiment, the double radius spire bow can define two intersecting radii of approximately one hundred feet to produce a bow with a length of two hundred feet and a beam of two hundred feet, thereby approximating an equilateral triangle. A person of ordinary skill in the art will readily appreciate that an equilateral triangle is a generally strong and stable structure. As explained in more detail below, the double radius spire bow 14 can provide various technical effects and benefits, however, other bow profiles including blunt and single radius spire bow profiles can also be used. The bow 14 can be connected to the stern 30 of the outer hull 12 by a container compartment 20 having sides 22 that are opposite to each other. Such shallow draft container carriers ("SDCCs") may have a length between 700 feet and 1750 feet, and a beam between 100 feet and 250 feet. In the exemplary embodiment shown, the container carrier 10 may include an overall length L of 1500 feet, and the beam may be 200 feet. In one embodiment, the container carrier 10 may operate with a draft of approximately twelve feet (+ / -10%) and an air draft of approximately 50 feet (+ / -10%), thereby allowing year-round navigation and transportation operations on waterways as shallow as the Mississippi River inland waterway system.

[0026] The container transport ship 10 may include a full beam stern 30. That is, the stern 30 of the container transport ship at the location where the stern propulsion device is housed may have a width approximately equal to the midship beam of the container compartment 20. Figure 3As shown, the stern 30 can accommodate multiple propellers 32. In the exemplary embodiment shown, eight propellers 32 are used. In another embodiment, four propellers 32 may be included. It should be understood that by making the stern section of the container transport ship 10 as wide as the ship width of the midship or container compartment, there is space for a greater number of propellers along the stern 30. In other words, when compared with the traditional barge and pusher construction, the container transport ship 10 can be as wide as a tugboat, which means that the width of the container transport ship 10 can be as wide as the construction of each barge of the traditional inland waterway transport tugboat. In one embodiment, the stern propellers 32 can each be nominally rated at 3500 horsepower, and at the stern, the total is 14000 horsepower to 28000 horsepower depending on the number of propellers used. It can be understood that the power of the propeller 32 can depend on the traction motor, the prime mover performance and the desired hull speed of the container transport ship 10. The specific structure and rating of the stern propulsion system will depend on the structure of the ship's container capacity and the waterway on which the ship is built to operate.

[0027] It should be understood that the disclosed container transport vessel 10 can include an aspect ratio of overall length (LOA) to beam between 5:1 and 8:1. Preferably, the aspect ratio is about 7:1 (+ / -10%), which can produce a relatively high hull speed with low resistance and good fuel efficiency. In the exemplary embodiment shown, the container transport vessel 10 includes the following dimensions: bow: 200 feet x 200 feet; stern: 200 feet x 200 feet; and container compartment (external dimensions): 1100 feet x 200 feet. In other embodiments, these exemplary dimensions can be scaled based on the overall length and / or beam. In an exemplary embodiment, the container transport vessel 10 has a displacement of approximately 100,000 net deadweight tons and can have a speed ranging from twelve knots to approximately eighteen knots when transporting up to one thousand two hundred 40-foot standardized containers or 2400 TEUs. By comparison, a conventional tugboat may be up to 1,200 feet long and 200 feet wide, have a displacement of about 45,000 deadweight tons excluding the tugboat itself, and have a speed of about 5-6 knots.

[0028] like Figure 1As further shown in FIG. 7 , the bow 14 may include a set of suspended lateral thruster pods 100 (partially visible). In one embodiment, as shown in FIG. 7 , the set of suspended lateral thruster pods may include a first pod 102 disposed along the longitudinal centerline of the outer hull, a second pod 104 disposed rearwardly of the first pod 102 and outwardly from the longitudinal centerline of the outer hull, and a third pod 106 disposed rearwardly of the first pod 102 and outwardly from the longitudinal centerline of the outer hull and opposite the second pod 104. In the illustrated embodiment, the first pod 104 may be disposed proximate to the pointed top portion 18 of the bow 14, the second pod 104 may be disposed inboard of one side of the bow 14, proximate to where the circular profile 16 intersects one side 22 of the container compartment 20, and the third pod 106 may be disposed inboard of the opposite side of the bow 14, proximate to where the circular profile 16 intersects the opposite side 22 of the container compartment 20. For other bow profiles, such as a single radius pointed bow profile, the first pod 102 may be disposed proximate to the fore-end of the keel, the second pod 104 may be disposed inboard of a first point where the bow has extended to at least 85% of the midship beam or container compartment, preferably at least 90% of the midship beam or container compartment, and most preferably at least 95% of the midship beam or container compartment, and the third pod 106 may be disposed inboard of the opposite side of the bow 14, proximate to a second point that is a mirror image of the first point. The suspended lateral thruster pods define a longitudinal flow channel therebetween, wherein the suspended first pod 102 and the second pod 104 define a first longitudinal flow channel 110 to one side of the longitudinal centerline of the outer hull 12, and the suspended first pod 102 and the third pod 106 define a second longitudinal flow channel 112 to the opposite side of the longitudinal centerline of the outer hull 12.

[0029] In the exemplary embodiment shown, three tunnel thrusters 120 are included in each lateral thruster pod 100, each ducted thruster is nominally rated at 3,500 horsepower, with a total horsepower of 31,500 at the bow. In another exemplary embodiment, two ducted thrusters 120 may be included. It should be understood that the number and power of the ducted thrusters will vary depending on the displacement, draft, and overall length to width ratio of the vessel (related to the resistance of the hull to lateral motion). The lateral thruster pod 100 can be elongated relative to the longitudinal centerline of the vessel so that the group of lateral thruster pods forms a submerged trimaran-like structure suspended from the outer hull 12. The submerged trimaran-like structure advantageously reduces the vessel's wake and tends to deflect debris into a specific path beneath the outer hull, thereby providing some additional debris protection for the stern drive 32. In addition, the structure allows each lateral thruster pod 100 to be employed when performing turning maneuvers, including the ducted thruster 120 in the pod 100 on the inner side of the intended turn.

[0030] like Fig. 8A As shown, the set of suspended lateral thruster pods 100 may include a fourth pod 104 disposed behind the first, second and third thruster pods 102, 104 and 106 along the longitudinal centerline of the outer hull 12. The fourth pod 104 may be an empty pod without any ducted thrusters and is disposed in conjunction with the first, second and third pods 102, 104 and 106 to define a first cross-centerline flow channel 114 and a second cross-centerline flow channel 116, wherein the first and second cross-centerline flow channels intersect near the longitudinal centerline of the outer hull 12. Figure 8B As shown, when the vessel is underway, in a non-turning, forward motion, water tends to be directed into and through the longitudinal flow channels 110 and 112 until being diverted outwardly by the overall shape and displacement of the outer hull 12, i.e., such outward diversion will occur with or without the presence of the fourth pod 108. Figure 8CAs shown, when a pod, such as pod 104, is positioned inboard of an intended turn and is operated to eject water toward the longitudinal centerline of the outer hull 12, the ejected water combined with the water passing through the longitudinal flow passages 110 and 112 can be directed at least partially through the first cross-centerline flow passage 114 to the outside of the intended turn. Similarly, when pod 106 is positioned inboard of an intended turn and is operated to eject water toward the longitudinal centerline of the outer hull 12, the ejected water combined with the water passing through the longitudinal flow passages 110 and 112 can be directed at least partially through the second cross-centerline flow passage 116 to the outside of the intended turn. The first, second and third pods 102, 104 and 106 and optionally the stern thruster 32 are operatively controlled to vary the flow into the first and second longitudinal passages 110 and 112, allowing for lateral thrust vectoring within the set of suspended lateral thruster pods 100. However, the pod 100 and its collection of groups are rigid structures suspended from the outer hull 12. It will be appreciated that in the absence of the fourth pod 108, the outward turning of the ejected water still exists and may be sufficient in the embodiment not shown, but the presence of the fourth pod causes the flow to be directed in a more limited range of directions, thereby improving the thrust vectoring performance.

[0031] The pod 100 includes a multi-hull component of a bow 14 of an outer hull 12. As such, the front end of the pod 100 may be shaped and configured as a bow-like shape that is attached to or integrated into the outer hull 12. For example, in the embodiment shown in FIG. 8 , the front end of at least one of the pods 100 may include a single radius pointed profile attached to the outer hull 12 of a double radius pointed profile. In other embodiments, the front end of at least one of the pods may include a so-called "inverted bow shape" attached to the outer hull 12 of a double radius pointed profile or other profile. The inverted bow shape may be used to resist the accumulation of debris at the bow of the vessel to help keep the thruster pod submerged below the waterline and expand the wetted area of ​​the hull. The front ends of the pods 102, 104, 106, and 108 may include the same or different profiles. For example, the pod 102 may include an inverted bow shape, while the pods 104 and 106 and the fourth pod 108 may include a non-inverted single radius pointed profile. The profile, material and material thickness of at least the forward end of the nacelles, in particular the first nacelle 102, may be selected to form an ice-class structure, so as to be capable of operation in, for example, late fall, winter and / or early spring, depending on the local climate, and so as to resist damage from ice flows or non-ice debris.

[0032] In one embodiment, the container transport vessel 10 may include four generator sets, seventeen electric drive motors (eight stern motors and nine bow duct thrusters), and two power transformers. One commercial example of a generator that may be used is a 12V50 generator set (nominal 11,000 kilowatts each) available from Wärtsilä, Finland. One commercial example of an electric drive motor that may be used is an Invertex 360T available from GE Transportation, Chicago, Illinois. The traction motors and electric drive motors used within the container transport vessel 10 may be those originally used for mining applications.

[0033] The double radius pointed bow 14 can allow the container transport ship 10 to enter the area of ​​limited space carefully, allow the drag to be reduced, and allow the lateral thruster pods to provide directional control (including zero turning radius capability when the transport ship is sailing). In addition, the double radius pointed bow 14 can also allow the bow 14 to be quickly extended to the full width of the ship, which in turn increases the cargo space. It should be understood that the combination of the double radius of the pointed bow 14 and the pods 104, 106 arranged outside the longitudinal centerline of the outer hull 12 can substantially offset the main bow wake. This will allow the container transport ship 10 to have a zero turning radius and generate substantially no wake while operating at two to three times the speed of conventional traditional inland waterway transport equipment. In addition, this will also allow the container transport ship 10 to turn through a bend in the river without reversing the propeller of the stern 30 so as not to lose forward speed. Finally, whether a double radius pointed bow or other bow shape is used, the use of a distributed electric propulsion system in conjunction with a set of ducted thrusters 120 in the bow 14 can also substantially eliminate the need to cycle the container ship 10 engines, which in turn can reduce fuel burn and engine losses.

[0034] Referring generally to the accompanying drawings, the disclosed container transport vessel 10 can provide various technical effects and benefits. The disclosed container transport vessel 10 can include lateral thruster pods and ducted thruster configurations that can improve speed, efficiency, maneuverability, and safety. Specifically, the lateral thruster pod configuration that defines the longitudinal centerline flow channel and the intersecting cross-centerline flow channel allows a form of lateral thrust vectoring through the various channels and allows useful utilization of each of the individual pods when performing a turn to either side of the ship. In addition, the combination of the double-radius pointed bow 14 and the lateral thruster pod configuration provides enhanced directional control by providing improved separation of the laterally spaced thruster pods and directing surface water toward the cross-centerline flow channel on the inner side of the turn to reduce turning resistance.

[0035] Although the forms of apparatus and methods described herein constitute preferred embodiments of the invention, it should be understood that the invention is not limited to the precise forms of these apparatus and methods and that changes may be made therein without departing from the scope of the invention.

Claims

1. A container transport ship comprising an outer hull, the outer hull comprising a bow, a stern and a container compartment, the container compartment having lateral sides extending between the bow and the stern and facing each other, the bow having a set of suspended lateral thruster pods, the set of suspended lateral thruster pods comprising: a first pod disposed along a longitudinal centerline of the outer hull; a second pod disposed rearwardly of the first pod and outwardly from the longitudinal centerline of the outer hull; as well as a third pod disposed rearwardly of the first pod, outwardly from the longitudinal centerline of the outer hull and opposite the second pod; Wherein, the first and second pods define a first longitudinal flow channel leading to one side of the longitudinal centerline of the outer hull, and the first and third pods define a second longitudinal flow channel leading to an opposite side of the longitudinal centerline of the outer hull.

2. The container transport ship according to claim 1, wherein: The outer hull also includes a fourth pod, which is arranged behind the first pod, the second pod and the third pod along the longitudinal centerline of the outer hull, and wherein the fourth pod is combined with the first pod, the second pod and the third pod to define a first cross-centerline flow channel and a second cross-centerline flow channel, wherein the first cross-centerline flow channel and the second cross-centerline flow channel intersect near the longitudinal centerline of the outer hull.

3. The container transport ship according to claim 2, wherein: The first pod, the second pod, and the third pod each include a plurality of duct thrusters, and the fourth pod is not occupied by duct thrusters.

4. The container transport ship according to claim 2, wherein: The first pod, the second pod, the third pod and the fourth pod each include a plurality of duct thrusters.

5. The container transport ship according to claim 1, wherein: The bow includes a double-radius pointed roof profile having two side portions, each of the two side portions including a circular profile having a first radius, a tapered pointed roof portion having a second radius, and an inward curved portion disposed proximate an intersection of the circular profile and the pointed roof portion to provide a smooth transition between the circular profile and the pointed roof portion.

6. The container transport ship according to claim 5, wherein: The first pod is arranged to be close to the pointed part of the bow, the second pod is arranged on the inner side of one side of the bow, close to the position where the circular outline intersects with a lateral side of the container compartment, and the third pod is arranged on the inner side of the opposite side of the bow, close to the position where the circular outline intersects with the opposite lateral side of the container compartment.

7. The container transport ship according to claim 1, wherein: The first pod is arranged to be close to the front end of the keel of the bow, the second pod is arranged on the inner side of a first point where the bow has extended to at least 85% of the width of the container compartment, and the third pod is arranged on the inner side of the opposite side of the bow and close to a second point that is mirrored with the first point.

8. The container transport ship according to claim 1, wherein: The first pod has a front end, and the front end includes an inverted bow shape.

9. The container transport ship according to claim 8, wherein: The second and third pods have front ends, and the front ends of the second and third pods include a non-inverted, single-radius, spire-shaped profile.

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