The present invention relates to a hoisting device for transferring cargo from a ship at sea. In more popular terms the invention relates to a ship's container unloading device. More in particular the invention is considered useful and essential for the offshore unloading of containerships, in particular those in distress.

For the shipping of goods over sea the use of standardized cargo containers has become universal practice. Increasing numbers of ships have been designed and build exclusively for the carriage of containers. Existing ships have often been modified to make them suitable for the carriage of containers in their holds. The newest generation of container vessels has lengths of approx. 400 meters, beams of approx. 55 to 60 meters and freeboard of approx. 18 meters. These latest container ships are already sailing with a loading capacity of 10,000 TEU (Twenty feet Equivalent Unit) and are under construction with 12,500 TEU or more. Taking into consideration the stack of containers on deck with a height of approx. 16 meters, the cargo of containers on board of such behemoths can reach a height above the waterline of approx. 32 meters. Apart from the big offshore cranes no sheerlegs or other commercial floating cranes will be able to unload the sea containers from such a vessel at sea. In the event the weather is rough, resulting in unfavorable sea conditions and swell, sheerlegs or standard commercial cranes are unsuitable to lift containers during such weather and sea conditions. Irrespective of the present generation of offshore cranes, operating in the oil and gas industry at sea, no seagoing cranes or sheerlegs are capable, due to their lifting height in combination with their limited outreach, to unload such container vessels of 10,000 TEU or more, when in difficulties. In addition offshore cranes are not available on short notice and at the particular time when a container vessel of the described size may have grounded. Also such a known offshore crane cannot reach the casualty or cannot come alongside due to draft restrictions. It is thus at present not possible to unload sea containers from containers vessels with a carrying capacity of more than 10,000 TEU already sailing, or even larger ships currently under construction, when such behemoths are grounded and/or are partly submerged. It has been proposed to equip containerships with onboard cranes, such as disclosed by US 2005/0220573 and EP 0879171. Such cranes are arranged to be movable over the holds of a ship by means of tracks and enable the loading and unloading of vessels at smaller ports that do not have container handling equipment. It has also been proposed in US 4932541 and US 5154561 to transfer containerized cargo between vessels at sea during periods of rough weather and high seas. Unfortunately these known hoisting systems are mostly of little use when a ship is in a condition of distress and, moreover, may have themselves become dysfunctional.

Accordingly it is an object of the present invention to propose a solution to the recognized problems. In a more general sense it is thus an object of providing a hoisting device that overcomes or ameliorates at least one of the disadvantages of the prior art. It is also an object of the present invention to provide alternative structures which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively. Alternatively it is an object of the hoisting device according to invention to at least provide the public with a useful alternative.

To this end the hoisting device according to invention provides for transferring containerized cargo, and is particularly suitable for transferring containers from and to ships at sea, the hoisting device includes a base frame, a mast stabilized by rigging wires, a boom, a turntable for supporting at least the boom for rotation with respect to the base frame in a substantially horizontal plane, and at least one winch, wherein the base frame is adapted for being supported from and secured to the top corner fittings of at least three containers of the containerized cargo to be transferred. According to a further aspect of the invention the base frame of the hoisting device includes at least two outriggers extending laterally from substantially opposite sides of the turntable. The hoisting device may also advantageously include a rotatable anchor for receiving the rigging wires at an upper end of the mast.

In one preferred embodiment of the hoisting device according to invention the base frame may include a pair of parallel first and second beams, each having a length adapted to span a distance between two lengthwise corner fittings of at least one container. In such an arrangement it is of further advantage when the base frame further includes a transverse beam at each longitudinal end of the first and second beams, and when each transverse beam is adapted to span a distance between two wide wise corner fittings of at least one container. It may also be of further advantage when the first and second beams are each assembled from a plurality of individual sections. The hoisting device according to the invention will preferably have its base frame provided with twist locks to be secured to the top corner fittings of the container load.

Another aspect of the invention provides for the turntable to be adjustable for horizontal level in respect of the containerized cargo's top corner fittings to which it is adapted to be attached. It is then of further advantage when adjustability for horizontal level is achieved by a set of fill-in elements that are each selectively inserted between the turntable and the base frame.

The turntable, in an advantageous arrangement can be supported by a cradle. It is also an advantageous arrangement to have both the boom and mast are supported for rotation on the turntable.

In a particularly advantageous embodiment the base frame can be formed as a rectangular perimeter frame that is adapted to be coextensive with a surface perimeter defined by an upper level of the portion of the containerized cargo to be transferred. Preferably the rigging wires include a compensation element for distributing rigging forces to more than a single corner fitting of the container load. Further it is preferred that the mast and boom are each assembled from a plurality of individual sections. Hence the hoisting device according to invention will preferably be constructed in such a way that all parts can be dismantled and transported by helicopters to the casualty or shipwreck. The hoisting device according to invention will thereafter be rigged on board of the stranded ship and thereafter the unloading of the containerized cargo can commence. The unloading can take effect immediately and independently of the sea condition. Any smaller vessel or pontoon alongside, which will receive the unloaded containers, is far less subject to the sea condition. Moreover a pontoon or coaster can profit of the lee that the behemoth is offering.

The hoisting device according to invention offers the possibility to unload containers from disabled, large sized container vessels, when grounded with a considerable list and trim. In particular the invention is applicable to container ships having capacities of 10,000 to 12,500 TEU, and over. In spite of any list and trim of the ship, the hoisting device according to invention at all times can be arranged in a horizontal position. So far no hoisting device, such as provided by the present invention, has existed to solve the above described major problem when faced with a salvage situation. Hence the hoisting device according to invention is considered to be an entirely new design and a revolutionary development in salvage operations.

Further advantageous aspects of the hoisting device according to invention will become clear from the appended description of preferred embodiments. The invention will be further explained with reference to the accompanying drawings, in which:

Figure 1 is a schematic plan view of a first embodiment of a ship's container unloading device according to the invention; Figure 2 is a schematic side view of the unloading device of Figure 1; Figure 3 is a rigging anchor suitable for the mast of the device of Figures 1 and 2;

Figure 4 is a schematic plan partial top view of a second embodiment of the invention; Figure 5 is a schematic side view of the second embodiment of

Figure 4;

Figure 6 is a plan view of a support frame of the second embodiment;

Figure 7 is a side elevation of the support frame of Figure 6;

Figure 8 is an end elevation of the support frame and cradle of the second embodiment;

Figure 9 is a plan view of the cradle of the second embodiment;

Figure 10 is a transverse cross section of the support frame and cradle according to the line X-X in Figure 4;

Figure 11 is a partial side view of the cradle according to the arrow XI in Figure 9;

Figure 12 in cross section shows a boom turntable for accommodation in the cradle of Figure 8-11.

Figure 13 shows an enlarged detail of the turntable, according to the arrow XIII in Figure 12; Figure 14 is a perspective view of a ship's container unloading device according to a third embodiment of the invention;

Figure 15 is an enlarged detail of the upper end of a mast used in the third embodiment; and

Figure 16 is a perspective view of a fourth embodiment. A first embodiment of an unloading device of the invention is shown in Figures 1 to 3. Referring first to Figure 1, there is shown in top plan view a hoisting device 1. The hoisting device 1 is positioned on top of a load of sea containers 3 and comprises a substantially rectangular base frame 5 from which four outriggers 7 extend. The outriggers 7 are each pivotally connected to the base frame 5 to be swiveable in a plane parallel to the mounting surface provided by the containers 3. The outriggers also each have a distal end 9 that is connectable to individual ones of corner fittings provided on the containers. The entire assembly of base frame 5 and outriggers 7 is adjustable for level by means of jacks (9A, see Figure 2) at the distal ends of the outriggers 7. As the skilled person will understand, it is only necessary to provide a maximum of three of the four outriggers 7 with such jacks to enable the establishing of a horizontal level position for the base frame 5.

It is also advantageous when the outriggers 7 are adjustable in length over a distance of about 1.5 m. This allows adaptation to the various positions of corner fittings as these may be encountered. Once the length of the outriggers 7 has been properly adjusted, the position of the base frame may be secured by horizontally extending rigging or guy wires appropriately affixed to the container load from which the hoisting device 1 is supported.

Referring now in combination to Figures 1 and 2, it is seen that the base frame 5 carries a turntable 11. The turntable 11 may be rotated in a conventional manner through an annular truck and a rotating motor. The turntable 11 rotatably carries a mast 13 and a boom or derrick 15. The mast 13 stands up from the turntable 11 and carries a rotatable bracket 17 at its top. The mast 13 can have a length 19 of about 18 m. Attached to the rotatable bracket 17 are six rigging wires 21, which maintain the mast 13 in its vertically upright position. The other ends of the rigging wires 21 are each affixed to a suitable remote location of the container load or to other suitable anchoring points by means of a compensation system 23. The compensation system 23 distributes the rigging wire forces over several corner fittings to cope with their limited strength. The rotatable bracket 17 allows the mast 13 to rotate freely and without causing torque in its structure. The boom 15 can thereby swing through an angle between the nearest rigging wires and when the rigging wires 21 are re-arranged subject to requirement the swing of the boom 15 can extend over 260°. The rotatable bracket 17 will be further described in reference to Figure 3, which illustrates one suitable example.

The boom or derrick 15 can have a length of about 30 to 35 m. and can be angularly adjusted tot extend at an angle with respect to the horizon of between 3° negative and 75° positive. The distal end of the boom 15 may carry a conventional hoisting gear or tackle 25 for 35 tons of weight. The hoisting gear 25 may also include a conventional spreader for lifting containers by means of their top corner fittings. These spreaders may be adjusted to cope with the particular inclination of the ship that is being unloaded. Erection of the mast 13 will be accomplished by an auxiliary hoist as is conventional. The boom 15 is supported from the top of mast 13 by a cable assembly 27. Mounting means 9B for mounting the outriggers to corner fittings of the container load are spaced in accordance container dimensions at a distance 29 of increments of 20 or 40 feet. The base 5 has a height of turntable 11.

Figure 3 shows a suitable example of the rota table bracket 17 as can be used with the embodiment of Figure 1 and 2. The rota table bracket 17 has a rigging ring 33 to which rigging wires are attached in a direction of arrow 35. The rota table bracket 17 can further comprise hoisting pulleys or sheaves such as 37 and 39, for redirecting the hoisting gear 25 and the cable assembly 27 towards hoisting and topping winches provided on the turntable 11. Such hoisting and topping winches are not illustrated in Figure 1 and 2 but are conventional. Preferably such hoisting and topping winches are located laterally on the turntable 11 and rotate together with the turntable. The first embodiment of the hoisting device according to invention thus includes a rectangular frame as a base together with four outriggers, which are able to hinge and to support the frame. The support will be provided by the top corner fittings of container (s). All sea containers in common global use have a framework and corner stiles fitted with top and bottom corner fittings, in accordance with the ISO 1161 standard. The corner fittings at each corner of a container generally support the container's weight and are adapted to receive and attach securing elements, such as lashing rods and twist locks. Such twist locks are, amongst others, available from Peck & Hale, Inc. of West Sayville, N. Y under their part number F656-R-C. Depending upon container weight, a stack of up to three containers can be held by twist locks only. For higher stacks diagonally crossed lashing rods are added to the lowermost containers in a stack. In stacking containers it is also a general rule that light containers are loaded over heavy containers. Freight containers most commonly come in two main sizes, having lengths of 20 foot and 40 foot, respectively. These sizes and their individual dimensions are the subject of ISO standard 668, while their corner fittings are specified in the aforementioned ISO standard 1161. Corner fittings, provided that the container ends are firmly held, can take up to 86.6 tonnes of force. The frame of the hoisting device, once anchored to appropriate ones of these corner fittings, can be moved horizontally in the x- en y- directions with the assistance of jacks at the end of the outriggers. Horizontal displacements can be prevented by means of lashings to the other containers on deck. A turntable will be mounted on the frame together with the mast and boom plus the required appurtenances. At both sides of the mast on the turntable the various winches can be mounted, so that the whole unit with all the appurtenances will be moving at the same time. A mast with a length of preferably approx. 18 meters will be mounted on the turntable together with the required rigging. In order to limit the torque in the top of the mast due to the rigging a specifically designed anchoring device with bearings is designed and this can rotate independently from the mast. Additional rigging wires can be used to support the hoisting device according to invention in such a manner that all forces will be distributed equally over the unit. A special compensation system connected to the corner fittings of the containers will ensure that all forces remain within acceptable limits as these corners of the containers have a limited holding capacity and strength. Together with all the appurtenances the mast and boom can rotate through 360 degrees. The length of the boom can vary from 30 meters to 35 meters depending on the beam of the ship. By means of a tackle and winch the boom can be lowered and lifted from 3 degrees negative angle to plus 75 degrees positive angle. A conventional hoisting tackle is connected at the top of the boom. Container spreaders, hooked by wires to the corners of the containers in order to hoist and lower the sea containers, can be connected to the hook of the hoisting tackle. To compensate for the list and trim of the vessel the four wires conventionally connected between the spreaders and the four corners of the container can be varied in length. The rigging of the mast together with the boom on the turntable will be self-supporting with the assistance of the various winches. The entire construction can be designed to comply with the current rules and regulations for stevedoring.

Figure 4 schematically illustrates a partial top plan view and Figure 5 a side elevation of a second embodiment of hoisting device 101. A base frame 105, mounted on a layer of containers 103 comprises first and second elongate beams 151, 153. The first and second beams 151, 153 each have a length 155 corresponding to the length of a 40-feet container. Preferably these beams 151, 153 are assembled from smaller lengths to assist in their transportability. Also these beams can be made shallower at their opposite front and rear ends 151A, 151B, respectively 153A, 153B to further reduce their weight.

Similar to the first embodiment, the hoisting device 101 is further provided with mast 113 of about 18 m, a boom 115, and rigging wires 125. The boom 115, which may have a length of about 28m, is provided at its distal end with a hoisting gear 125 and a cable assembly 127 extends between the top of mast 113 and the distal end of boom 115 to control the angular position of the boom 115 and to raise or lower the hoisting gear 125.

As best seen in Figures 6 to 8, the first and second beams 151 and 153 are supported at their forward and rearward ends by transverse beams 157, 159, 161, 163. The transverse beams 157, 159, 161 and 163 each distribute the supporting forces over two corner fittings of a container, so that the support frame is supported by a total of eight corner fittings of two 40-feet containers arranged side-by- side in a ship's container load. To this end, the transverse beams are each provided with twist locks 109. The base frame 105, as shown in Figures 4 and 6 is further provided with at least one compression rod 107, to which reference will be made herein below.

Adjacent to the forward end of the support frame 105, a cradle 165 is positioned. The cradle 165 carries a turntable 111. The cradle 165 is adjustably supported in a horizontal level. The horizontal position of the cradle 165 is achieved by first fill-in elements 167 at a forward end of the cradle 165 and by second fill-in elements 169 at a rearward end thereof (see Figures 8 and 10). These fill-in elements 167, 169 can each have a thickness corresponding to 2 degree angular increments. Relative angular movement between the support frame and cradle in a plane parallel to the supporting surface can be absorbed by rubber bearings while longitudinal and transverse forces can be taken care of by tension rods. Such tension rods may be provided with spherical ends to allow for the relative angular movement. A top plan view of the cradle 165, which carries the turntable 111, is shown in Figure 9. The turntable 111, in the second embodiment, only carries the boom or derrick 115. The mast 113 has its own pivot supports 171 on a cradle cross bar 173 of the cradle 165. As shown in Figure 10, which is a transverse cross section of the support frame and cradle according to the line X-X in Figure 4, and in Figure 11, a partial side view of the cradle according to the arrow XI in Figure 9, the cradle also supports a pair of pulleys 174. The pulleys 174 can deflect topping or hoisting wires extending downwardly through the mast 113 onto hoisting and topping winches. To this end the support frame 105 at a rearward portion also carries a hoisting winch 175 and a topping winch 177. The modified arrangement of the second embodiment allows the use of only three rigging wire assemblies for its mast 113. These rigging wire assemblies are each doubled over at the top 117 of the mast 113 over a sheave or pulley to equalize forces over two branches at each rigging wire assembly. The mast 113 is adjusted to a vertical position by adjustment of the rigging wire assemblies.

The particular means for rigging the mast are well known to the skilled person and do not in themselves form part of the present invention. A further description is therefore deemed unnecessary. The side rigging wire assemblies are preferably co-extensive with the compression rods 107 to either lateral side of the turntable 111. Each compression rod 107 is preferably aligned to have its centre line extend through the turning centre of the turntable 111. The top 117 of the mast 113 can be provided with a rigging anchor similar to that of Figure 3. The turntable 111 is shown in more detail in Figures 12 and 13.

Figure 12 is a side elevation in cross section. The boom or derrick 115 is supported from the turntable 111 by a swivel support 181 on rotating platform 183. The rotating platform 183 has a ring gear 185, as shown more clearly in Figure 13 and is engaged by a pinion of a hydraulic or electric motor 187 mounted in a stationary base 189 of the turntable 111. The stationary base 189 is cylindrical in form and has a plurality (preferably eight) support shoulders 191 around its periphery. The support shoulders 191 are arranged to rest upon a perimeter frame 193 of the cradle 165.

To enable transport of the hoisting device and its support frame 105, it is preferred to divide the frame, mast and boom into smaller and lighter sections. By way of example, the support frame 105, as shown in Figure 7, can have its first and second beams (153 in Figure 7) composed of sections each having a more or less equal length 195. For a 40-feet container length there could be four sections of each roughly 3m length. In the second embodiment of the hoisting device according to the invention the following modifications have thus been included. The frame from which the hoisting device according to invention will be mounted comprises two longitudinal beams with a length equal to a 40ft container. These beams can be divided in smaller parts for transport. The beams also have been designed and will be manufactured with varying cross sections to reduce the weights of the components to less than 2000 kg. Both beams are connected to each other and as such can be considered as a single frame. The frame will be positioned on top of two containers, placed side-by-side and with equal heights, whereby transverse beams equalise the load over the corner fittings of these containers. Obviously the corner fittings have a limited strength. At the fore part of the frame a so-called "cradle" will be mounted. In order to get the cradle horizontal fill-in elements will be used, which in turn will be mounted on the corners of the cradle. In order to cope with the effect of the longitudinal and transverse forces on the cradle, eight draw rods will be used, equipped with spherical bearings. The result is that the turntable now only has to carry the forces from the boom. An important advantage is that the total weight of the turntable, including the power system has been reduced in weight. The mast is supported on the aft part of the cradle. Inherent to this construction the dimensions of the cradle are smaller than those of the previous embodiment. Therefore the fill-in elements, in order to get the cradle horizontal, are of a much reduced height, which in turn improves the stability of the whole unit. The winches in the modified embodiment are mounted on the transverse beams between the longitudinal beams resulting in a more favourable weight distribution on the corner fittings of the two containers, on which the hoisting device is mounted. Due to these modifications only three main guy riggings are required. In the top of the mast the riggings are guided over compensation sheaves. Consequently all forces in the rigging are equalized. Sheaves at the far ends of the longitudinal beams will be used to guide the wires to an adjusting device, mounted along the beam, in order the place the mast, in longitudinal direction, in its vertical position. A similar system as above is used for the two side guy wires. Horizontal forces are transferred via a compression rod to the centre of the turntable and the vertical forces are transferred to the corner fittings of two containers via equalizing beams. With the aid of the adjusting systems at the ends of the compression rods, the mast is placed sideways in its vertical position. On the turntable now only remains the boom and this has a length of preferably about 27 meters. The length of the boom can be adjusted by means of separate sections if so required so. Separation is also preferred for transportation of the different units. In order to guide the hoisting and topping wires near the top of the mast, into the mast construction various sheaves are used. The box of the sheaves rotates around a pipe in which the wires are guided into the mast construction. At the foot of the mast a set of sheaves guide the wires to the topping and topping winch. A hydraulically operated swivel is connected to the hoisting tackle in the top of the boom, so that the container spreader frame can be rotated in the right direction to pick up the next container. If the two containers, on which the frame of the hoisting device according to invention is positioned, would not have the same level in height, auxiliary frames can be used. These auxiliary frames can be adjusted in order to obtain the right level for the base frame of the hoisting device according to invention.

Figures 14 and 15 illustrate a fourth embodiment of hoisting device 201 which, to a large extend, is similar to the second embodiment.

In the third embodiment the mast 213 is formed by an A- shaped frame that has laterally spaced pivot supports 271. The laterally spaced pivot supports 271 are supported from different container 203 than the containers supporting the frame 205. The lateral adjustment of the arm 213 can now be achieved by lengthening or shortening one of the legs 213A, 213B of the mast 213. The fore/aft adjustment of the mast 213 can be done by rigging wires as in the previous embodiments. In addition to hoisting and topping winches 275, 277, additional winch 297 is provided to raise the mast 213 by an auxiliary boom (not shown but conventional). Because the mast 213 is now supported from a broader base, it has been possible to eliminate the compression rods that were used in the second embodiment. Furthermore, the derrick or boom 215 may have a length of up to 35 m.

In Figure 15 the top 217 of the mast 213 is shown in more detail. It has a first set of sheaved 296 and a second set of sheaved 298 to guide the hoisting and topping wires via a central tubular element 299 in the mast top 217 to the hoisting and topping winches 275, 277.

The third embodiment of the invention thereby provides a further improved solution by modification of the following items. The mast, of preferably 18 meters, as mentioned for the previous embodiment, is changed into an A- shape frame of about 18 meters in length and is hinged on the forward end of two containers which are spaced apart about 12,5 meters. As a result of dividing the supports onto two separate containers the capacity could be increased about 30%. Consequently, the length of the boom is increased by a total length of 35 m. The list of the container vessel is corrected by means of lengthening or shortening of one of the resp. legs of the A-frame. The two compression beams, of the previous embodiment are deleted, as well as two of the stays and their ancilliarities. The erection of the A-frame is effected by a hydraulic cylinder, which also is used as a preventer.

Figure 16 shows a fourth embodiment of the invention.

In this embodiment the hoisting device 301 has an assembled support frame 305 that itself extends substantially over the top deck of five 40- feet containers 303A-E. The support frame 305 includes pair of longitudinal first and second beams 351, 353 that are united with a ring beam 312. Each of the longitudinal first and second beams 351, 353 is provided on their longitudinal ends with pedestals 310A-D, which are arranged for twistlock connection to the corner fittings of adjacent containers. It is thus shown in Figure 16 that pedestals 310A and 310B of the first longitudinal beam 151 connect to adjacent corner fittings of the first and second containers 303A, 303B. The pedestals 310C and 310D of the second beam 353 likewise connect to adjacent corner fittings of the fourth and fifth containers 303D, 303E. In this manner the forces are distributed over eight corner fittings. In this way the corners are not overloaded by the forces exerted by the operational forces of the hoisting device 301. The frame 305 is adjusted - in its position relative to the corners - by three jacks, associated with three of the four pedestals 310A-D and one universal joint, associated with a remaining one of the four pedestals 310A-D. The three adjustable corner pedestals of the frame 305 are retained in position by appropriate lashing bars or the like (not shown, but well known to the skilled person). At least three of such lashing bars per corner are considered sufficient.

The ring beam 312 extends through an uninterrupted circle. A large turntable 314 is rotatably mounted on the ring beam 312 and covers substantially the same area as the frame 305. Thereby, the entirety of mast

313, boom 315 and winches (not shown) can be supported on the turn table

314. The turntable 314 is also large enough to offer anchorage for rigging wires, so that the hoisting device 301 can rotate through 360° without any need to reposition its rigging wires or its support frame. The unloading capacity of this fourth embodiment is more than double that of the first layout of the hoisting device according to the invention.

It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. To the skilled person in this field of the art it will be clear that the hoisting device according to invention is not limited to the embodiment represented and described here, but that within the framework of the appended claims a large number of variants are possible. Also kinematic inversions are considered inherently disclosed and to be within the scope of the present invention. The terms comprising and including when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Expressions such as: "means for ..." should be read as: "component configured for ..." or "member constructed to ..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the hoisting device according to invention. Features which are not specifically or explicitly described or claimed may be additionally included in the structure according to the present invention without deviating from its scope.