WO2014011057A1

WO2014011057A1 - Method and device for transfer of a load

Info

Publication number: WO2014011057A1
Application number: PCT/NO2013/000033
Authority: WO
Inventors: Geir Arne Veglo; Arild LOKØY
Original assignee: UMOE SCHAT-HARDING EQUIPMENT AS
Current assignee: UMOE SCHAT-HARDING EQUIPMENT AS
Priority date: 2012-07-13
Filing date: 2013-07-15
Publication date: 2014-01-16
Anticipated expiration: 2015-01-13
Also published as: NO20120808A1

Description

METHOD AND DEVICE FOR TRANSFER OF A LOAD

The present invention comprises a method of moving cargo by use of a hoisting device, such as a crane, between two installations that are moving in relation to each other vertically and horizontally as a consequence of wave movements, as given by the introduction of claim 1 . The invention also relates to a cargo platform in form of a crib on an installation deck for intermediate storage of a load to be moved to a different installation, such as by use of a installation crane as mentioned. A hoisting device in form of a crane is used to hoist and move objects. The crane comprises a winch servicing a hoisting line (wire/chain etc.) which end comprises a hook device that may be connected to and from the load.

Here we particularly mean loads that are transferred from the deck of a supply vessel to a floating or fixed installation adjacent to the vessel.

When cargo is to be lifted between a vessel influenced by waves and wind, and over to another vessel or fixed installation on land or a oil platform, the mentioned relative movements between these lead to well known problems. The load may easily start swinging so it bumps into installations on the vessel, and is damaged. In addition dangerous situations may arise for the crew manning the loading system.

There are prior known hoisting systems with HIV-compensation in order to overcome these problems. The known systems focus first and foremost on compensating for the movements and using strong enough crane and winch systems for the load to be hoisted up from the deck as fast as possible, in order to minimize the critical time window where the damage from hitting may arise.

A specific example of this is installation of life boats in davit systems on oil installations/platforms. With today's systems for installing life boats they are not hoisted up directly from the deck to the ship delivering them. Instead they are set afloat, lead inn under the davit of the installation, connected to the hoisting wire, and lifted up the davit by means of the davits own winch. However, the life boats may only be lifted up when there is a limited wave height. When there are larger waves the relative movement between the life boat and the davit winch hook it is to be connected to is too large. In addition, the life boat might easily be damaged if a hoisting hook weighing several hundred kilos hits the life boat construction. This is also dangerous to the crew. In the North Sea there are typically only 100 days each year where the wave height is less than 2 meters, and about 200 days where the wave height is less than 3 meters. This severely limits when life boats may be lifted up and installed on the platform. Due to safety reasons the platform may not be operated without sufficient life boat capacity, so the economical losses this may cause are large, if the platform is left for some time without such a capacity.

In relation to the known art we refer to the international patent application WO 93/18999 and US-patent 4.174.188, which correspond to Norwegian patent NO- 300.369.

From the last mentioned US-4.174.188 there is also known solutions where a load may be hoisted up and off a ship's deck with a crane on an adjacent installation, and at the same time help with the disadvantages caused by the movement there between caused by waves etc. between the ship and an installation. This is done by having the load rest and supported on a deck frame on the ship. As the hook, when the ship reaches a wave top, takes hold of the load and the hoist starts, the deck frame collapses so that the load is immediately brought to a safe distance for hitting the ships constructions.

It is an aim of the invention to aid with these problems of the known art.

It is an aim to bring forth an improved method and construction where with one may hoist up a load directly from a ship's deck.

The aim is especially to bring forth a new deck crib construction for storing a life boat during transport, where the boat may be hoisted directly from the ship's deck and up to its placement in a davit system on an adjacent platform.

It is also an aim to hoist other heavy cargos, which may also easily cause damage to installations and crew, also when the weather conditions are not optimal.

The present invention brings forth a completely new construction for such a load transport crib on a ship's deck, in relation to the known art from said US-patent. The method according to the present invention is characterized by the following steps:

- The load is placed in a crib shaped frame construction in two parts, placed on a surface in connection with one of the installations, so the crib carry and partially surround the load,

- The hoisting device is connected to the load, and

- At the same time as the hoisting device starts hoisting the load, the two crib parts are disconnected and removed sideways and away from the load. The preferred modes of the method are shown by the dependent claims 2-7.

The device in accordance with the present invention is characterized by that the transport frame has a shape that is a crib forming frame construction divided in two, and the two parts may be rearranged from a cargo storing mode where they are connected together and fully or partially surround the load, to a released mode where the two crib parts are disconnected and pulled to the side and away from the load when it is to be hoisted.

The preferred modes of the construction are shown by the dependent claims 9-1 1 .

The present invention is thus a solution contributing to a fast free height under the load object to the deck, by the load crib in accordance with the present invention, which is a managed and collapsible construction, pulling itself away as soon as soon as the hoisting devices lifting hook gets hold of the object to be hoisted.

The present invention may be used for all types of heavy loads where one is to lift the load between two surfaces moving in relation to each other, so one wish to remove the load form the surface it is hoisted from as soon as possible. The invention will now be described in more detail with reference to the following figures, and will refer to a load in the form of a life boat, that is to be transferred from the decks crib on a ship's deck and up in a davit on a platform :

Figure 1 shows the invention where a life boat is provided in two different positions on the stern deck of the ship, seen from the side: A first position where it is resting safely stored in the inventively shaped cargo crib, on the deck of a ship, and a second position where it is hoisted up and placed in the davit system belonging thereto on a adjacent platform.

Figure 2 shows the same of the ship seen from above with the life boat mounted in the crib.

Figure 3 shows a cargo crib in form of a dividable crib construction, and in a position corresponding to being a passively "closed" position where it keeps the life boat in position.

Figure 4 shows the crib as it is about to be opened.

Figure 5 shows a vertical crosscut across the cargo crib in closed position, while figure 6 shows it in its open boat releasing position.

Figures 7 and 8 shows corresponding vertical crosscuts as figures 5-6 with a life boat placed in the cargo crib.

Figure 9 shows a perspective sideways from above of the life boat standing mounted in the cargo crib.

Figure 10 shows a corresponding perspective where the cargo crib is being opened up by swinging outwards the into two parts divided crib construction, and the boat is hoisted upwards.

Such a divided in two construction in accordance with the invention may in principle be used for all types of loads, as long as there exist a relative movement between the hoisting system and the object to be lifted, for instance as a result of high waves. Thus it may be used between permanent and floating installations, or between two floating installations. This could for example be a load that is hoisted between a ship and a land based installation, another ship or a platform. The crane itself may be arranged on the ship or on the platform or on land, this is not essential for carrying out the invention. When the load is to be lifted, the critical time phase is from when the load is pulled away from or lifted from the support, to when it has attained sufficient distance there from in order for even large relative movements not to be able to cause the load to swing and hit and bang into the support. The support is typically a deck, and there may be other objects protruding upwards there from that may be damaged, for example other cargo or fixed installations or parts of the ship itself or the platform, like for example the railing or sides along the outside of the deck. When the load is hoisted sufficiently clear from both the deck itself and such another upwards protruding points on the support for it to not be able to collide with anything, even at a relatively large movement between the support and the load, the load is outside the critical time phase and the rest of the hoisting may occur directly upwards to a safe installation height.

Installation height may be defined as the distance between the lowest point on the load and the closest point there to on the support, which will normally be the highest point of the support. The support is then considered to be both the support immediately below the load, and the area right around the load that it can swing to during movement thereof. What is to be considered a safe installation height will wary not just dependent on the support, but also the relative movement between the installations the load is to be hoisted between. It will depend on waves and wind, and if both installations the load is to be hoisted between are floating installations, it will depend on the maximal swinging in the movements between them.

In the new inventive cargo frame construction this critical phase is drastically decreased by increasing the distance between the load and the closest points on the support, which the load is in most danger of colliding with. When the hoisting upward from the support is then initiated, at the same time as the ship/crib is riding on a wave crest, the ship is during the next second on its way downwards. Thus, one achieves very quickly a relatively large and safe height differential between the load and the support. This is attained because the support that the load is hoisted from is a cargo crib, which closest points to the load is lowered. This is done by rearranging the cargo platform itself from a storage position, where it keeps the load in place, by it letting go of the load and is flattened out to a position where the points closest to the load is moved away from the load. In other words, the contact areas on the cargo crib between it and the load will swing away, downwards and/or outwards from the load. According to the invention this is done by the load crib being divided in two, in order to quickly achieve a safe installation height. For cargo platforms that are to take up little space, and for example fit on a ship, it is advantageous to sue hydraulic systems that can be folded downwards without spreading out too much. But for cargo cribs on large installations, such as oil platforms, it may be preferred that the load bearing surfaces of the crib are mounted movable (the surfaces the load is resting against) against each other and from each other on rails, or by means of flattening a scissors type lifting table, and where as pushing/driving means hydraulic cylinders are used, or other well known drive motors.

How fast a safe installation height must be obtained will also wary, and be

dependent on wind and current conditions. The response time - that is the time from when starting both the lifting of the load and the lowering of the closest point thereto on the cargo platform, until a safe installation height is attained, should be less than the wave frequency. Thus, the hoisting may start when a wave has passed by, and the critical face completed before the next wave arrives. In other words, in

accordance with a preferred embodiment of the present invention, one would start hoisting the load from the lifting platform when on a wave crest, so that if one uses a crane as a hoisting system one will start tightening the wire from the crane when the wave is on its way in order to get ready for the hoisting. The wave frequency may be very short for small waves, at 20-30 seconds, and many times that for swells. A preferred response time is therefore ca 20 seconds or less, in order to function for all wave frequencies, where this of course is not always necessary. Initially we refer to figure 1 , which illustrates the invention for handling life boats, especially for so called free fall life boats that are stored in their accompanying davit in an inclined position with the bow facing upwards in the position it is let go of in free fall in the sea. In figure 1 it is shown in a crosscut from the side a supply vessel 40 maneuvering in the water and shown by the surface 100 against a platform 30 in order to deliver a life boat 10. The life boat 10 is standing in the inventive crib 20 on the afterdeck of the ship 40, ready to be hoisted up in the davit 31 of the platform by the aid of a davit winch.

The figure shows both life boat positions, in other words that it shown already hoisted up and placed in the davit. It is evident that the life boat in the davit 31 has an angled position with the bow tilted forward and downward in order to be let loose in the water by free falling into the water if the platform 30 must be evacuated.

Figure 2 shows a corresponding view of the life boat 10 in the cargo crib 20 on the ship's deck seen from above. The situation may be that the life boat 31 is let go into the water during testing, and is to be hoisted up again into the davit. Instead of maneuvering the boat in under the platform in the correct position, it is picked up onto the ship's deck by means of the crane belonging to the ship, and is then placed in the crib all the way abaft, as shown in figures 1 and 2. The life boat may also for example be brought aboard the ship from land, for example from the shipyard, for shipment to the platform.

In the storage position the life boat is locked to the crib 20 that comprises one or more locking or securing mechanisms that both secure the load before it is to be lifted, but also in order to hold the two crib parts together in a press against the boat sides. These are well known releasable locking mechanisms with locking bolts or hooks that can hold the load in place and that is removed/disconnected or

inactivated when the hoist is to be initiated. The life boat is then connected to the hook on a winch line down from the davit winch/crane (or other types of cranes for other cargo, and the wire line(s) (32,33) from the crane is tightened until the life boat is ready to be lifted. This is calculated and controlled either manually of an operator, or automatically by a guiding system, which both will take into account the relative movements between the two

installations the load is to be moved between, based on how much slack or stretch the winch contains. When the lift is initiated and the load is lifted of the crib it will start to fall outwards to the side and downwards.

The construction of the storage crib is now to be explained with reference to the figures 3, 4, 5, and 6, and is constructed from a truss frame made of beams, tracks and stays, and may be constructed in many different ways.

The basic construction is a bottom-square frame of tracks 51 , 52, 53, 54 mounted on the deck of the ship. With mutual distance two erect and mutually swingable side cheeks 60 and 62 of truss work juts up from the bottom tracks that in a side view has a square shape, and makes up the crib shape. Each of the cheeks lower end poles 63a, 63b, and 64a, 64b, is hinge loaded to its corresponding lower bottom track 52 and 54 by hinges 65a, 65b, and 66a, 66b. The upper parts of these couples of poles 64a, 64b and 63a, 63b are each mutually connected by a longitudinal track 57, 58 as these tracks each belonging to a cheek are mutually parallel, and arranged to lay next to the side of the hull of a boat parked in the crib, and this is shown most clearly on figure 9, where one can see that the cheek track 57 is laying parallel and next to the boat, which thus rests on this track. In the same manner the boats other long side rests in a parked position against the corresponding other cheek track 58.

Thus, the cheeks may be swung in a bow shape outwards around respective hinges 65, 66. Two rails, 70, 71 are fastened with one of their ends to the bottom rail 52 adjoining the hinges 65b and 66b, and are arranged slanted converging in a point by 73. A corresponding slanted together fitting lower track 75 and 77 sticks up and inwards from the lower edge of each cheek, and is fitted together by a additional upper track 78, 79 jutting sideways downward and inward from the upper cheek part 63b, 64b. Seen in a vertical crosscut each cheek 63, 64 and the tracks makes up a triangular shape. When the cheek 63 on figure 5 swings inwards from the left towards the right the lower track 75 will lay against the mounted "triangular" track 70 and thus stop the inward swinging movement of the frame cheek, and the

corresponding will happen to the cheek 64 when it is swung to the right about its hinge 66.

The two upper rails 78 and 79 that together define a V-shape, forms the construction against the hull of the boat 10 that is placed in the crib, and then the parallel hull sides will rest against the vertical track parts 57 and 58. The two cheeks 63, 64 are kept in the encompassing position around the boat 10 by means of locking devices.

The swinging of the cheeks between the released position for the boat and its locked position, occurs by means of suitable slanted pressure cylinders, for example as shown by the numbers 23 and 24, where for instance the cylinder is fastened in the bottom track 52, while the end of the outwards slideable piston is fastened to the cheek.

The life boat may be lifted of the crib by suitable hooks in cables 32, 33 from a davit winch fastened in the top part of the boat, as shown in figure 9. When the hoisting starts, the hydraulically controlled cheeks are swung out to the side and downwards at the same time as the boat 10 is hoisted clear of the cargo crib 20. On figure 10 the boat is lifted even a bit further upwards.

As the load is freed from the cargo crib 20 it is set in motion and swung aside and away from the load. Specifically, the distance between the lowest point of the load, in this case the lowest handing point on life boat 1 1 , the boat bow, and the closest points that are the cribs 20 longitudinal tracks 57 and 58, i.e. the side tracks of the crib that keeps the boat in place during the storage, is decreased. This is done by folding the cribs two side cheeks outwards and downwards, and thus away from the life boat.

Figures 3 and 4 show the two crib positions without a life boat. On figure 3 the crib is in its storage position, where it is closed and keeps the life boat in place, while it is open in figure 4 so that the sides of the platform 57, 58, i.e. the closest contact lines/tracks on the crib for life boats, is tilted sideways and downwards around perspective axis 65, 66.

When the cargo crib 20 is completely opened to its lowest and most opened position, that is, when it is completely folded down against the support, the deck, the cribs highest point - closest to the life boat - should not be taller that the lowest point on the life boat. Thus, a safe distance between the life boat and crib is attained, so that the life boat cannot hit the crib 20.

The rest of the hoisting of the life boat may then continue at a sedate speed, as it is no longer in danger of movements due to waves etc. may lead to damage.

In summary, the present invention brings forth a new transport crib for safe transport of a boat, which comprises sideways against each other movable separate frame constructions (cheeks) that each comprises longitudinal track parts able to form a pressure against the long sides of the boat to be stored for transport. During the transport the locking devices are activated, which keeps the frame parts in a solid grip against the sides of the boat, optionally that the hydraulic cylinders also are press active the whole time in order to keep the crib parts connected against the boat sides, as a safety precaution.

The figures show that when the crib in its storage/transport position for the load, the cheeks 63, 64 stands straight upwards form the supportive layer and are mutually parallel, while when there is swinging outwards they form a V-shape. The invention is developed for safe transport of life boats. But with starting point therein, a skilled person may easily see how the same hoisting concept may be adapted to other types of cargo. The shape of the cargo crib may vary with the shape and design of the cargo, in order to offer it the best possible support in the storage position, and the best possible starting position for the hoist. It is

advantageous and therefore preferred for the load to have the position it is best to be lifted in, and/or the position one which for it to end the hoist in. By starting out the hoist in the position the load is best lifted in, all movement of the load during the hoist is upwards and away from the cargo crib, and this results in a safer hoist, which again secure not needing to use time on orienting it.

For free fall life boats on figure 1 it therefore holds that it during the storage in the crib on the ship's deck is situated at the same angle with the bow facing downwards, as it is to have when it is hoisted up in the davit. The shape of the loading platform will also vary with how it is to be moved from the storage position and away from the load. For the loading crib shown on the figures the cheeks are moved by running hydraulically controlled pressure cylinders 23, 24. If the cargo crib is surrounded by tall constructions, for example ship sides, etc, the cargo crib is preferably placed on a pedestal, in order for there not to be tall points around the load that it may swing into during the hoist.

There are several obvious advantages offered by the cargo crib as shown by the invention, and by using it the structure is opened around the load, and one attains a good height (the distance between the load and the support). Thus, one increases the accessibility to the load, by not being so limited by the wave height, and thus one may carry out hoists during higher wave heights. One may also use hoisting devices with less capacity, for example one may manage to do hoists with "normal" cranes that one must use HIV compensation for if the cargo platform in accordance with the present invention is not used. This does of course increase the accessibility to the load. This is possible because the loading capacity is used instead of the dynamic capacity of the crane, and thus it may be used for heavier and more difficult hoists. If one, as for life boats for davit systems, use the same davit lifting system as before, but with the cargo platform in accordance with the present invention, one will gain many meters worth of extra margin for the hoist, and may therefore carry out such hoists during more difficult weather conditions, and this makes the life boats more available for installation in davit systems, with a more safe installation.

Claims

Patent claims

1. Method for moving a load (10) by use of a hoisting device (31 ) between two installations that is moving in relation to each other vertically and horizontally as a consequence of wave movements, and where the load rests in contact with a frame construction arranged to be folded up and removed from the load as the hoist starts, characterized by the following steps:

- the load (10) is placed in a two part crib shaped frame construction (20a, 20b) arranged on a support surface connected with one of the installations, so that the crib (20a, 20b) carry and partially surround the load,

- the hoisting device (31) is connected to the load (10), and

- at the same time as the hoisting device (31 ) starts hoisting the load (10), the two crib parts (20a, 20b) are disconnected and removed sideways and away from the load (10).

2. Method in accordance with claim 1, characterized by that the crib (20) is moved away from the load (10) by rearranging it from a transport/storage position for the load where it is supports the load so that it is stabile during transport, to an active position where the two crib parts of the load platform in contact with the load during the storage position are moved downwards and/or outwards from the load.

3. Method in accordance with claim 1, characterized by that the hoist starts when the load platform is on a wave crest.

4. Method in accordance with claim 3, characterized by that a safe installation height is attained between the lowest point of the load (11) and the closest point thereto on the loading crib (21 , 22) in less time than the wave frequency the vessel is subject to.

5. Method in accordance with claim 1, characterized by that the load is a free fall life boat that is positioned in the crib (20) in approximately the same position as it is to have when mounted in the davit (31 ), i.e. with the bow (11 ) facing tilted downwards and outwards towards the open sea (100).

6. Method in accordance with claim 5, characterized by that the life boat (10) is hoisted up hanging by a winch wire connected to the davit installation (31).

7. Method in accordance with claim 5, characterized by that the two divisible crib parts are swung between the transport position for the load and a collapsed position by hinge joints on the underside adjacent to the cribs frame cheeks.

8. Transport frame device for storing a load (10) on a surface, where the load rests in contact with a frame construction arranged to be folded up and away from the load as it is to be hoisted off the surface with a crane which,

characterized by that the transport frame has a two part crib forming frame construction (20a, 20b), and the two parts may be rearranged from a load storing mode where they are connected together and fully or partially surround the load, to a released mode where the two crib parts (20a, 20b) are disconnected and pulled to the side and away from the load (10) when it is to be hoisted.

9. Device in accordance with claim 8, characterized by that a truss frame arranged to swing out from the load bearing position to the released position.

10. Device in accordance with claims 8-9, characterized by that the crib is made up of two crib parts (20a, 20b) arranged to swing out and inn between the two positions by means of a drive gear.

11. Device in accordance with claims 8-10, characterized by that the partial cribs are stored up at the lower edge, and swung outwards to form a V-shape.