GB2065489A

GB2065489A - Dredger having oil-collecting arms

Info

Publication number: GB2065489A
Application number: GB8040548A
Authority: GB
Original assignee: IHC Holland NV
Current assignee: IHC Holland NV
Priority date: 1979-12-20
Filing date: 1980-12-18
Publication date: 1981-07-01
Also published as: DE3048909C2; GB2065489B; DE3048909A1; FR2473008A1; SU1087066A3; JPS6291797U

Abstract

A suction dredger provided with the usual suction pipes for dredging the sea bed also carries a pair of oil-collecting arms 53, which in use float on the water, extending outwards and forwards of the ship, and are connected to inboard pumps and storage tanks to collect floating oil. Each arm 53 is pivoted to a support arm 52 which is pivotable about a horizontal fore-aft axis, and a pair of crane jibs 57, 58 carry respective winches whose cables are attached to arm 53 to enable the arm 53 to be moved into the storage position shown in full lines. Jibs 57, 58 are also pivotable about a fore-aft axis and are rigidly connected by a torsion pipe 44 to pivot in unison. The jibs and the inboard pivot of arm 52 are all mounted on a carriage movable along rails 56 so that the oil-collecting arms may be stowed aft of the ship when not in use, clear of the dredging apparatus. <IMAGE>

Description

SPECIFICATION A vessel in particular a trailing suction hopper dredger having a sweeping arm The invention relates to in combination a sweeping arm vessel and storage means either accomodated aboard said vessel or not for storing oil collected by said sweeping arm, in particular a trailing suction hopper dredger having her own driving and steering means and including a hold for storing dredgings such as a mixture of sand and water, and means for emptying this hold, a suction piping having a suction head, a sucking and forcing pump in this piping and pressure piping debouching into said hold, said vessel further being provided with sweeping arms operable to be put alongside of the vessel and to cut through the water surface, each one of said sweeping arms being connected to a hauling arm means of a hinge joint, each one of which hauling arms is fastened pivotingly about a horizontal axis to a support mounted at the edge of the deck, each one of said sweeping arms being provided with pumps for sucking in oil accumulated in front of said arms, which oil may be conveyed to storage spaces in the suction hopper dredger, such as the said hold present therein, by way of a pressure piping running along the hauling arm, the combination of hauling arm and sweeping arm in the folded condition being operable to pivot about a horizontal axis running parallel to the edge of the deck between an operating position in which the assembly is outboard and a storage position in which the assembly is pivoted aboard about said axis, while on the deck there are provided at least two two crane jibs operable to be pivoted about horizontal axes and mounted at mutually spaced locations, the hoisting cables of said jibs being connected to the sweeping arm. Such a trailing suction hopper dredger provided with means for recovering oil floating on the water surface is under construction and has been published in brochures. Moreover vessels having a sweeping arm are known in general in which the oil collected by said sweeping arm is stored either aboard the vessel within in tanks appropriate for this purpose or stored with the aid of other floating devices. A hauling arm is absent therein and sweeping arm is solely controlled by means of cables.

These known vessels present problems. It should be possible to stow the sweeping arm aboard the vessel and should furthermore be possible to bring the sweeping arm outboard and aboard, respectively, easily and without risk of damages under all weather conditions. In particular the trailing suction hopper dredger yet further presents the problem that the means destined for sweeping oil and the means destined for dredging should not come into conflict with each other, while in service they should yet be linked up at a location as favourable as possible present in front of or in the middle of the length of the vessel. Both the suction piping together with the suction head and also the oil sweeping arm together with the hauling arm should be stowed on deck.For that purpose the support together with the hauling arm and the sweeping arm provided tubes and pipings are arranged pivotingly about a horizontal axis and, if necessary, movably along the deck in order to enable positioning the same out of reach of the suction pipe so that this suction pipe may be brought outboard and recovered aboard, respectively, without difficulty.

The hauling arm and the sweeping arm are large bodies which are difficult to handle. Upon pivoting these parts should be moved simultaneously each about its own axis of rotation and by means of an own displacement mechanism.

The object of the invention is to provide a construction enabling a better performance thereof.

According to the invention this is achieved first of all in that the crane jibs are connected to each other by means of a torsion resisting construction, such as a pipe and that the support is connected thereto.

By coupling the crane jibs to each other by means of a torsion resisting construction there is created in fact a hoisting mechanism capable of extending over the larger part of the length of the sweeping arm and thus enabling a better control thereof as whole. The grade of stiffness of the assembly moreover assures that the pivoting movements may occur effectively.

An assembly of sweeping arm, hauling arm and crane jibs, which may very easily be handled is obtained if the crane jibs have a supporting arm fixedly integrated therewith said supporting arm being directed downwards in the operating position and being in substantial horizontal direction in the stowed position, said support arm forming a stop or a bearing surface, respectively, for the sweeping arm. Upon bridging the sweeping arm outboard said sweeping arm is supported till the last moment while upon lifting the sweeping arm out of the water said sweeping arm is pulled against the supporting arm by means of the hoisting cables and is then supported thereby when pivoting the same aboard.

Accordingly according to the invention the crane jibs and the torsion resisting connection, which preferably has the form of a tube, form a unit which not only support hauling arm and sweeping arm in the inboard position but take up all loads during the swinging movements of said two arms and placed outboard and during operation. During said operation the sweeping arm floats upon the waves and is held in the proper position by the hauling arm and by cables and since the hauling arm is connected to this unit, the unit is subjected to a combination of loads which vary and act from different directions.

Preferably the entire assembly including support, hauling arm and sweeping arm together with the crane jibs and the torsion resisting connection arranged therebetween is mounted on a stand which if desired is movable in the longitudinal direction of the vessel and which has stops determining the operating position and the stowed position, respectively, of the crane jibs and consequently of the sweeping means.

In this way there is obtained a firm assembly which may be governed and handled very well and which may easily be brought in the operating position and out of said position, respectively, and which may likewise be kept out of the reach of the suction means for dredging.

According to the invention the device which can be moved in the longitudinal direction of the vessel need not to be a single stand or carriage but preferably comprises two independent carriage frames, each frame by means of a horizontal pivot supporting the assembly of crane jibs and torsion resisting connection, which pivots are in line, said carriage frames which are movable on rail tracks fixed to the deck of the vessel, by being independent can adapt their position easily to deviations of the rail track, which deviations may be the result of deformations of the deck of the ship or be the result of heat expansion, without changing the position of the crane jibs.

Furthermore according to the invention the assembly of crane jibs and torsion resisting connection may carry a rail track along which a carriage or the like can be moved to which the upper end of the hauling arm has been connected, said rail track extending towards the front end of the vessel beyond the forward most crane jib. In this way the point of connection of the hauling arm can be moved further forwardly beyond the most forward position of the said assembly. This makes it possible to move the point of connection of the hauling arm and sweeping arm into a region covered on deck by the suction tube and this can be done with or without combination with the movability of this assembly in the longitudinal direction of the vessel.

According to the invention it is preferred that close to the pivot joint between the hauling arm and the support there is provided a hydraulic cylinder between said hauling arm and the torsion resisting construction or the support fastened thereto, respectively, said cylinder determining the angular rotation of the hauling arm about the vertical pivot. Thereby one obtains a good control of the position ofthe sweeping arm with respect to the hull ofthevessel.

Furthermore it may be useful if close to the pivot joint between the hauling arm and the support there is provided a spring between the crane jib and said hauling arm, said spring partially accommodating the weight of said hauling arm. By accommodating the weight of the hauling arm the sweeping arm may follow the wave motions in a more independent manner.

By positioning the crane jibs in intermediate positions it is furthermore possible to move the lower end of the hauling arm rotating for that matter solely about the horizontal transverse shaft at the location of the support, more or less far outboard so that the position of the inner end of the sweeping arm may be determined in this way with respect to the hull of the vessel.

The invention will now be elucidated further in detail with reference to the drawings.

Figs 1 and 2 show the trailing suction hopper dredger under construction.

Figs. 3 and 4 relate to the invention and show the improved construction in a plane view and a view in cross section of the vessel.

Fig. 5 shows diagrammatically an upper embodi ment of supporting the crane jibs on the deck of the vessel.

Fig. 6 is a top view of another embodiment of the invention.

Fig. 7 is a front view of the embodiment of Fig. 6 and Fig. 8 is a rearview of the embodiment of Fig. 6 and 7.

The trailing suction hopper dredger shown in Figs.

1 and 2 consists of a hull 1 together with the usual superstructure 2, propelling screws 3 and the rudder 4.

The hold is indicated by the reference numeral 7, in the bottom of which there are provided bottom flaps 8 shown in Fig. 1.

On the deck a movable crane 9 is present as well as the suction piping 10 with the suction mouth 11 destined for dredging. This suction piping at two locations is provided with a hinge joint 13 and 14, respectively, and with a connecting device 15 at the upper end remote from the suction head. At 16 and 17 hoisting means have been indicated by means of which the suction piping may be lifted and may be brought outboard and may be lowered. In this operation of bringing the suction piping outboard, the device 15 is also moved outwards over the guide tracks 18 and 19 whereby a coupling is brought about in known manner with the pressure piping 20 serving for filling the hold. This connection has not been shown but is known per se in general.

With reference to Fig. 2 there is shown at one side in interrupted lines the position of the suction piping brought outboard. Figs. 1 and 2 show furthermore how this vessel may be provided with an oil sweeping installation. This installation consists of a support 21 having connected thereto a hauling arm 22 and a sweeping arm 23. At its ends the sweeping arm may possess floats 24 and 25.

The hauling arm 22 is connected to the support 21 by means of a horizontal pivot joint 26 arranged transversely with respect to the vessel. The support itself may have a vertical pivot joint 27 with said hauling arm.

The left end or lower end in the drawing of the hauling arm 22 possesses a pivot joint with the sweeping arm 23. By means of these pivots joints 26 and 30 the sweeping mechanism may float in the water beside the hull ofthe vessel at any desired draught while the hauling arm runs slantingly downwards from the support. The sweeping arm is kept in its operating position by means of cables, like 32.

The oil collected by the sweeping arm is recovered at the location of the inner end by means of pumps 33 which may discharge the mixture of oil and water directly aboard within the hold 7 by means of a piping running along the hauling arm 22. Figs. 1 and 2 at the left hand side show the stowed position of the sweeping mechanism. For that purpose the support may be pivoted about an axis 34 running in the longitudinal direction of the vessel, the support being mounted on a carriage 35 movable on rails 36. In the operating position the support together with the hauling and the sweeping arm will thus be present approximately in the middle of the vessel and in the stowed position at the aft of the vessel so that the normal dredging mechanism is not hampered in serving its function. Fig. 1 shows the sweeping mechanism in its pivoted aboard stowage position.

In this position the hauling arm and sweeping arm are pulled against each other while being suspended from inwards and outwards pivotable hoisting means 37,38, respectively. From Fig. it is apparent that the sweeping mechanism in the aboard pivoted position has the sweeping arm 23 on top of the hauling arm 22. The same position is shown in the lower part of Fig. 2 whereas in the left hand upper part of Fig. 2 that position is shown which occurs when the sweeping mechanism is pivoted outboard while the hauling arm 22 and the sweeping arm 23 are however yet in the horizontal position.

When these arms are now lowered by hoisting means 37 and 38 into the operating positions shown further to the right hand side in Fig. 2 the hoisting means will lower the sweeping arm 23 until reaching the water surface whereupon the sweeping arm starts to float, this occurring from the points 39 and 40.

When the carriage 35 is then moved to the front on the rails 36 accompanied by the sweeping arm swinging outwards simultaneously the hoisting cables will show the course like indicated by the lines 41 and 42 in the lower part of Fig. 2.

With reference to Figs. 3 and 4 there is shown the improvement according to the invention. In Fig. 3 the sweeping arm 53 is shown in folded position in which the sweeping arm lies as close as possible against the hauling arm 52 whereas the operating position is indicated in interrupted lines. The support 51 is fastened to a torsion resisting pipe 44 connecting the two crane jibs 57 and 58 to each other. These crane jibs are supported pivotingly about the horizontal pivot shaft 54 on the carriage 55 which may be movable on the rails 56.

By means of the hydraulic cylinder 45 which is connected to the hoisting means at the level of the pipe 44 they may be brought from the horizontal operating position shown in Fig. 4.

On each crane jib there has been mounted a winch 46 and 47 respectively. Each crane jib has a leg 48 fixedly fastened thereto, said leg forming a stop or a support, respectively, for the sweeping arm 53 when the sweeping arm has been pulled thereagainst by the hoisting cable 49.

The carriage 55 has stop surfaces 59 and 60, respectively for the stowage position and the operating position, respectively, of the mechanism.

In this embodiment the oil pumps have been indicated at 63 receiving the oil by way of overflow 64.

When the carriage 55 is moved on the rails 56 to the operating position i.e. moved to the front, the hydraulic cylinder 45 is released unless this cylinder is also mounted on the carriage.

With reference to Fig, 3 there is furthermore shown a hydraulic cylinder 29 between the hauling arm and the pipe 44, by means of which cylinder the angular position of the arm 52 may be determined.

With reference to Fig. 4 there is yet shown a pneumatic cylinder or spring 66 between the crane jib 58 and the hauling arm 52 by means of which cylinder or spring, respectively, part of the weight of the hauling arm is accommodated.

It should be remarked, that the cylinder 45 may not only be operated for bringing the sweeping arm and the hauling arm aboard and outboard but also to position the crane jibs into intermediate positions in which the hauling arm which is rotatable about a horizontal transverse axis has to follow these positions whereby the position of the outer end of the hauling arm and thereby the position of the sweeping arm may be determined with respect to the vessel.

In the embodiment shown in Fig. 5 the crane jibs 57 and 58 with legs 48 are interconnected by the torsion tube 44 and by means of the legs 68,69 pivotably supported about the horizontal pivot shafts 54.

The embodiment shown in Fig. 5 differs from the one shown in e.g.Fig. 4 in that instead of a single carriage 55 as shown in Fig. 4 two carriages 70 and 71 are used which independent from each other can follow deviations of the rail tracks 56.

Figs. 6,7 and 8 show an embodiment which differs from the one according to Figs. 1 to 4 inclusive in that the torsion resisting connection 44 supports a rail track 72 along which a carriage or cradle 73 can be moved from the intermediate position shown in Fig. 6towardsthe most forward position shown in Fig.7.

In this position the piping 74 fixed to the hauling arm 75 can be connected to the conduits 76 which are secured to a fixed platform 77 of the vessel 78.

Fig. 6 shows the sweeping arm 79 in the position in which it is drawn against the crane jibs 57 and 58 and not yet in the sweeping position indicated with interrupted lines 80. The hauling arm 75 is connected to the carriage 73 and the energy supply lines 81 are supported by the hauling arm 75 for the supply of energy to the pumps 82 of the sweeping arm. In the position shown in Fig. 6the hauling arm and sweeping arm can be lowered and moved forwardly to a more forward position in which no conflict is possible with the suction head 83 indicated with interrupted lines on deck of the vessel 78.

Fig. 7 shows with full lines the sweeping arm 79 held against the crane jibs 57 and 58. In this position the hauling arm 75 is shown with interrupted lines and also the guide track 72 with the carriage 73. In the shown forward position the sweeping arm can be lowered in the position indicated with the interrupted lines 80.

Fig. 8 shows the rear crane jib 58 and shows that the support 72 with its rail track for the carriage 73 is connected to the tube 44 by means of beams 84 and 85.

Claims

1. In combination a sweeping arm vessel and storage means either accommodated aboard said vessel or not for storing oil collected by said sweeping arm, in particular a trailing suction hopper dredger having her own driving and steering means and including a hold for storing dredgings, such as a mixture of sand and water, and means for emptying this hold, a suction piping having a suction inlet, a sucking and forcing pump in this piping and pressure piping debouching into said hold, said vessel further being provided with sweeping arms operable to be put along side of the vessel and to cut through the water surface, each one of said sweeping arms being connected to a hauling arm by means of a hinge joint, each one of which hauling arms is fas tened pivotingly about a horizontal axis to a support mounted at the edge of the deck, each one of said sweeping arms being provided with pumps for suck ing in oil accumulated in front of said arms, which oil may be conveyed to storage spaces in the suction hopper dredger, such as the said hold present therein, by way of a pressure piping running along the hauling arm, the combination of hauling arm and sweeping arm in folded condition being operable to pivot about a horizontal axis running parallel to the edge of the deck between an operating position in which the assembly is outboard and a storage position in which the assembly is pivoted aboard about said axis, while on the deck there are provided at least two crane jibs operable to be pivoted about horizontal axes and mounted at mutually spaced locations, the hoisting cables of said jibs being connected the sweeping arm characterized in that said crane jibs are connected to each other by means of a torsion resisting construction, such as a pipe and that said support is connected thereto.

2. The combination according to claim 1 characterized in that the torsion resisting pipe is concentric to the said horizontal axis of pivoting.

3. The combination according to claim 1 or 2 characterized in that the part operable to be pivoted about the said horizontal axis, said part consisting of hauling arm, sweeping arm and tortion resisting connection, is operable to be pivoted between stops determining the operating position and storage position, respectively.

4. The combination according to anyone of the preceding claims characterized in that the crane jibs have a supporting arm fixedly integrated therewith, said supporting arm being directed downwards in the opening position and being in substantially horizontal direction in the storage position, said support arm forming the stop surface or the bearing surface, respectively, for the sweeping arm.

5. The combination according to any one ofthe preceding claims provided with means of moving the support of said hauling arm and said sweeping arm in the longitudinal direction of the vessel characterized in that the assembly comprised of crane jibs and torsion resisting connection carrying the hauling arm and the sweeping arm is mounted on a device operable to be moved in the longitudinal direction of the vessel.

6. The combination according to any one of the preceding claims characterized in that close to the pivot joint between the hauling arm and the support there is provided a hydraulic cylinder between said hauling arm and the torsion resisting construction or the support fastened thereto, respectively, said cylinder determining the angular rotation of said hauling arm about the vertical pivot.

7. The combination according to any one of the preceding claims characterized in that close to the pivot joint between the hauling arm and the support there is provided a spring between deck crane jib and said hauling arm, said spring partially accom modating the weight of said hauling arm.

8. The combination according to claim 5, characterized in that the device which can be moved in the longitudinal direction of the vessel comprises two independent carriage frames, each frame by means of a horizontal pivot supporting the assembly of cranejibs and torsion resisting connection which pivots are in line.

9. The combination according to any one of the preceding claims, characterized in that the assembly of crane jibs and torsion resisting connection carries a rail track along which a carriage or the like can be moved to which the upper end of the hauling arm has been connected, said rail track extending towards the front of the vessel beyond the most forward crane jib.

10. A sweeping arm vessel in combination with storage means and substantially as hereinbefore described and as shown in the accompanying draws ings.