NL2014437B1

NL2014437B1 - Marine fall pipe system providing an intermediate opening, and marine vessel comprising such fall pipe system.

Info

Publication number: NL2014437B1
Application number: NL2014437A
Authority: NL
Inventors: Mark Izaak Haag Vincent; Philippus Van Heusden Stefan; Cornelus Wilhelmus Kerkhofs Robert
Original assignee: Van Oord Dredging And Marine Contractors B V
Priority date: 2015-03-11
Filing date: 2015-03-11
Publication date: 2016-10-14
Also published as: EP3268540A1; EP3268540B1; WO2016144178A1; DK3268540T3

Abstract

A marine fall pipe system (100) is constructed for placing blocks of stone and/or rock (R) on a seabed (SB) and configured for suspension from a marine vessel (10). The fall pipe system comprises a substantially tubular fall pipe (100) having an open end for discharging the blocks of rock and/or stone, and the fall pipe system comprises an opening arrangement constructed such as to allow opening the substantially tubular fall pipe to provide an intermediate opening (170) at a position along its length for discharging the blocks of stone and/or rock at said position from the fall pipe. The fall pipe may be locally discontinued by releasing one or more fall pipe segments (110) of the fall pipe, may comprises fall pipe segments with weakened parts where they will break, or a fall pipe segment may be movable sidewards to provide the intermediate opening.

Description

MARINE FALL PIPE SYSTEM PROVIDING AN INTERMEDIATE OPENING, AND MARINE VESSEL COMPRISING SUCH FALL PIPE SYSTEM

FIELD OF THE INVENTION

[ 01 ] The invention relates to a marine fall pipe system constructed for placing blocks of stone and/or rock on a seabed and configured for suspension from a marine vessel, the fall pipe system comprising a substantially tubular fall pipe having an open end for discharging the blocks of rock and/or stone.

BACKGROUND OF THE INVENTION

[ 02 ] Marine fall pipe system are known, for instance, from patent publication WO 2014/098576 A1 and can be applied for placing rock at the bottom of the sea to keep in place and protect a pipeline. During use it may occur that the fall pipe becomes blocked when some larger blocks of rock/and/or stone interfere with one another in the fall pipe such that they remain stuck. Additional blocks will build up within the fall pipe on the blockage that has occurred. This will considerably add to the weight and load of the fall pipe. As a result the fall pipe may break and become lost at the seabed. In the event that the fall pipe would not break it may become so heavy that the hoisting systems for the fall pipe are not able to handle the load, which may also cause loss of the fall pipe.

SUMMARY OF THE INVENTION

[ 03 ] It is an objective of the invention to provide a marine fall pipe system with which additional load due to a blockage can be prevented.

[ 04 ] It is another or alternative objective of the invention to provide a marine fall pipe system that will not become lost upon occurrence of a blockage in the fall pipe.

[ 05 ] At least one of the above objectives is achieved by a marine fall pipe system constructed for placing blocks of stone and/or rock on a seabed and configured for suspension from a marine vessel, the fall pipe system comprising a substantially tubular fall pipe having an open end for discharging the blocks of rock and/or stone, and the fall pipe system comprising an opening arrangement constructed such as to allow opening the substantially tubular fall pipe to provide an intermediate opening at a position along its length for discharging the blocks of stone and/or rock at said position from the fall pipe. When a blockage occurs the intermediate opening can be opened at an appropriate position along the fall pipe by the opening arrangement so as to discharge the blocks of rock and/or stone above the blockage. The input of new blocks into the fall pipe will be stopped. Only the blocks of rock and/or stone of the blockage and possibly some blocks on top of hat will add to the load of the fall pipe, which is only a minor load.

[ 06 ] In an embodiment the opening arrangement is constructed such as to allow to locally discontinue the fall pipe to provide an opening.

[ 07 ] In yet another embodiment the fall pipe comprises substantially tubular fall pipe segments that are each by at least one attachment element attached to and suspended from at least one longitudinal suspension element, one or more of the connection elements being disconnectable from the longitudinal suspension element to provide the opening arrangement and the intermediate opening when disconnected. [ 08 ] In yet another embodiment the one or more connection elements comprise explosion bolts.

[ 09 ] In yet another embodiment the one or more connection elements comprise a predetermined weakened part at which the connection element will break at a load exceeding a predetermined load.

[ 10 ] In yet another embodiment the fall pipe comprises substantially tubular fall pipe segments, at least one of the tubular fall pipe segments comprising a predetermined weakened part at which the tubular segment will break at a load exceeding a predetermined load to provide the opening arrangement and the intermediate opening when broken.

[ 11 ] In an embodiment the opening arrangement is constructed such that the blocks or stone and/or rock are directed at least partially sideways from the fall ppe at the intermediate opening.

[ 12 ] In yet another embodiment the fall pipe comprises substantially tubular fall pipe segments, at least one of the tubular fall pipe segments comprising a slide-out mechanism to provide the opening arrangement and the intermediate opening when slid-out.

[ 13 ] In an advantageous embodiment the fall pipe comprises - substantially tubular fall pipe segments configurable to provide at least first and second fall pipe sections of fall pipe segments; and - a suspension module configured to be suspended from the marine vessel and configured for suspending the second fall pipe section of fall pipe segments from the suspension module so as to continue the first fall pipe section of fall pipe segments, such that the first fall pipe section and the suspension module with the second fall pipe section each are independently suspended from the marine vesselthe suspension module being configured to allow shifting sideward at least one of a bottom fall pipe segment of the first fall pipe section and a top fall pipe segment of the second fall pipe section such that an end of the first fall pipe section provides the intermediate opening and any blocks of rock and/or stone passing through the first fall pipe section are not discharged into the second fall pipe section.

[ 14 ] In an embodiment the suspension module is configured to allow shifting sideward and lifting the bottom segment of the first fall pipe section.

[ 16 ] In an embodiment the suspension module comprises a segment holding arrangement configured for holding the bottom fall pipe segment of the first fall pipe section.

[ 16 ] In yet another embodiment the fall pipe segments comprise bottomless buckets configurable to provide a fall pipe section of bottomless buckets attached to and suspended from a suspension set of at least one longitudinal suspension element, such that an open bottom side of a bucket above a bottom bucket of the fall pipe section opens into an open top side of an adjacent bucket there below, and an open top side of a bucket below a top bucket of the fall pipe section receives an open bottom side of an adjacent bucket there above.

[ 17 ] In an embodiment an external perimeter of a bottom side of the bottomless buckets is smaller than an internal perimeter of a top side of the bottomless buckets.

[ 18 ] In an embodiment the buckets have a substantially conical shape.

[ 19 ] In an embodiment the suspension set of the second section of bottomless buckets is suspended from the suspension module and/or the suspension set of the first section of bottomless buckets is suspended from the marine vessel.

[ 20 ] In an embodiment the suspension set of the second section of bottomless buckets continues in the suspension set of the first section of bottomless buckets, and the suspension module is configured for releasably holding the suspension set.

[ 21 ] In an embodiment the suspension module comprises a suspension set holding arrangement configured for holding the suspension set above the top bucket of the second fall pipe section.

[ 22 ] In an embodiment the longitudinal suspension element comprising one of a cable, chain or wire.

[ 23 ] In another aspect the invention provides for a marine vessel comprising a fall pipe system according to any one of the preceding claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[ 24 ] Further features and advantages of the invention will become apparent from the description of the invention byway of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Embodiments of the invention will be described with reference to the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which [ 26 ] Figure 1 shows part of a vessel carrying an embodiment of a fall pipe system according to the invention; [ 26 ] Figure 2 shows a detail of the fall pipe system of figure 1; [ 27 ] Figure 3a shows a suspension module according to the invention as incorporated in the fall pipe system of figure 1; [ 28 ] Figure 3b shows a suspension holding arrangement of the suspension module of figure 3a; [ 29 ] Figure 3c shows a bucket holding arrangement of the suspension module of figure 3a; [ 30 ] Figure 3d schematically shows a top section of the fall pipe shifted sidewards at the suspendion module of figure 3a; [ 31 ] Figure 4 schematically shows a large-scale view of a marine vessel provided with a fall pipe system according to the invention; [ 32 ] Figures 5a and 5b shows another embodiment of a fall pipe systems in which a blockage has occurred; [ 33 ] Figures 6a and 6b show another embodiment of a fall pipe system according to the invention; [ 34 ] Figures 7a and 7b show part of yet another embodiment of a fall pipe system according to the invention; and [ 35 ] Figures 8a and 8b show part of yet another embodiment of a fall pipe system according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[ 36 ] Figure 1 shows part of a marine vessel 10 on which a fall pipe system is arranged. A fall pipe 100 made up of various fall pipe segments 110 suspends down from the vessel through a shaft 11 in the vessel to a large depth just above a sea bed SB. The shaft may also be referred to as a moon pool. The fall pipe segments need not be lowered through a moon pool, but could also be lowered next to a marine vessel in an alternative embodiment. Blocks of stone and/or rock R are provided by a conveyer 12 arranged on the vessel to a top end of the fall pipe and subsequently drop down the tubular fall pipe, as indicated by unlabelled arrows shown above the conveyer and within the fall pipe. The blocks of stone and/or rock Rare discharged from the bottom end opening of the last (bottom) fall pipe segment 110.2B of the fall pipe to be positioned on the sea bed SB.

[ 37 ] A driver arrangement 140 may be provided at the end of the fall pipe for positioning the end of the fall pipe at the correct position of the sea bed. The driver arrangement can be coupled to a fall pipe segment or be supported by alternative means, such as a floating arrangement or additional suspension wires. The driver arrangement 140 may also be left out.

[ 38 ] The tubular fall pipe segments 110 are connected to one another by a suspension set of longitudinal suspension elements in the form of chains, wires, or (steel) cables, 120, which also serve to lift and lower the fall pipe segments using hoisting arrangement 130 on the marine vessel 10 through shaft 11 or otherwise. Individual fall pipe segments may be added and connected to the steel cables or chains 120 at the top end of the fall pipe, as required, when the fall pipe is lowered and disconnected and removed again when the fall pipe is being lifted. Any other suitable manner of providing or storing the fall pipe segments may be employed as well, such as storing and feeding segments 110 already attached to chains 120.

[ 39 ] Figure 2 shows some fall pipe segments 110 with connecting chains 120 of the fall pipe in more detail. A fall pipe segment 110 comprises a substantially conical shaped bottomless bucket 111. The bottomless buckets can be made of any suitable material like, for instance, steel ora medium density grade polyethylene, such as, for instance, Rigidex HD3850UA, supplied in pellet form for use in a rotational molding process to actually manufacture the bucket. The bottomless buckets 111 are attached to the chains 120 such that a top side of one bucket 111 overlaps with a bottom side of an adjacent bottomless bucket 111. An external perimeter and cross-section of the bottom side of the buckets 111 is smaller than an internal perimeter and cross-section of the top side of the buckets such that a gap G is left open between the top side of one bucket and the bottom side of an adjacent bucket. Water may flow through the gaps G as indicated by the arrows. One bucket projects into an adjacent bucket that is neighboring there below. Such configuration guarantees a reliable transport of rock downwards, while providing a flexible fall pipe system made up from the bottomless buckets 111. The conical shape of the buckets also allows the buckets to be nested into one another for the reduction of storage space on, for instance, the vessel 10.

[ 40 ] At their top sides the buckets have, in the embodiment shown, a collar 112 with an arrangement 113 for attachment to the (steel cable or) chain 120, which is known as such, such that the bottomless bucket suspends from the chains 120. A position of a fall pipe segment 110 is therefore fixed with respect to the chains 120 and substantially fixed with respect to adjacent fall pipe segments although it allows some movement of adjacent fall pipe segments 110 with respect to one another for providing flexibility to the fall pipe.

[ 41 ] At about the middle of the fall pipe 100 a suspension module 200 is provided, which divides the fall pipe 100 in an upper or first fall pipe section 101 and a lower or second fall pipe section 102. The suspension module 200 is shown in more detail in figures 3a, 3b and 3c. It is suspended from longitudinal suspension elements in the form of cables or chains 220 and can be raised and lowered through hoisting arrangement 230 on the marine vessel 10. The hoisting arrangements 130, 230 are positioned one above the other on the vessel in the embodiment shown. The cables (or chains) 220 bear the weight of the suspension module and the lower (second) fall pipe section 102 of buckets 110. The bottomless buckets 110 of both the upper (first) and lower fall pipe sections 101, 102 are, in the embodiment disclosed, suspended from one suspension set of chains 120, the suspension set of one fall pipe section being continued in the suspension set of the other fall pipe section.

[42] The suspension module 200 comprises a suspension set holding arrangement 210 for holding the suspension set of cables or chains 120. The holding arrangement 210 is shown in more detail in figure 3b and comprises two blocks 211 that can be driven towards one another by hydraulic cylinders212 so as to grab and hold the chains 120 of the suspension set. The holding arrangement 210 of the embodiment disclosed is specifically suited for holding chains. Other embodiments can be envisioned as well for the holding arrangement 210 for holding chains or cables.

[ 43 ] When the fall pipe 100 has not yet been lowered from the vessel, both the driver arrangement 140 and suspension module 200 are located on the marine vessel 10 near the top suspension point of the fall pipe. To deploy the lower fall pipe section, bottomless buckets 110 attached to the suspension set are passed through a central opening 245 in a bucket holding arrangement 240 of the suspension module 200 and lowered into the sea when further unwinding chains from the hoisting arrangement 130 and lowering the driver arrangement. A diameter of the opening 245 allows passing of buckets 110 at that moment. After some time all the buckets 110 of the lower (second) fall pipe section 102 have passed through the central opening 245 of the suspension module. The blocks 211 of the suspension set holding arrangement 210 will then close by activating the hydraulic cylinders 212 so as to grab and hold the cables or chains 120 of the suspension set just above the top bucket 110.2T of the lower fall pipe section 102. By holding the cables or chains 120 at this position the suspension module 200 holds the top bucket 110.2T and bears the weight of the lower fall pipe section 102.

[ 44 ] Figure 3c shows a situation just after closure of blocks 211 of suspension set holding arrangement 210. Chains 120 of the suspension set of the lower fall pipe section 102 below the suspension module 200 show to be taut, whereas the chains 120 of the suspension set of the upper fall pipe section just above the suspension module show some slack due to further advancing of a next bottomless bucket. The central opening 245 of the bucket holding arrangement 240 of the suspension module is then decreased in diameter by an inward movement of two semi circularly shaped parts 246, which is again effected by hydraulic cylinders (not shown). Figure 3c shows the situation after inward movement of parts246 to provide a central opening 245 with decreased diameter to allow holding a bottomless bucket.

[ 45 ] Bottomless buckets 110 are subsequently further provided towards suspension module 200 to yield the top (first) fall pipe section 101. A last (bottom) bucket 110.1B of the top fall pipe section is held in reduced diameter opening 245 of the suspension module. The suspension module is lowered into the sea followed by further bottomless buckets 110 of the top fall pipe section 101. The suspension module is lowered by unwinding suspension cables220 from hoisting arrangement 230. The weight of the upper fall pipe section 101 is born by the hoisting arrangement 130, while the weight of the suspension module and lower fall pipe section 102 is born by the hoisting arrangement 230. Holding the bottom bucket 110.1B in reduced diameter opening 245 keeps the bottom end of the top fall pipe section in place with respect to the suspension module.

[ 46 ] Figures 1 and 3a show that three buckets 110 are nested into one another on top of the suspension module 200. This is to allow for some variation in length of the top fall pipe section 101 with respect to a distance between suspension module 200 and the vessel 10.

[ 47 ] The bottom bottomless bucket 110.1B of the first fall pipe section 101 can be moved sideward in the suspension module 200 by a sideward movement of the bucket holding arrangement 240. Figure 3a shows a guiding groove 241 for the sideward movement of the holding module 240, which can be moved by one or more hydraulic cylinders that are not shown in the drawings. The guiding groove246 provides for a sideward and upward movement of the holding module240 and therefore of the bottom bucket 110.1B of the first fall pipe section. The upward and sideward movement of the bucket holding arrangement240 allows the bottom bucket 110.1B to be moved upward and sideward with respect to the top bucket 110.2T of the second fall pipe section 102. Any material passing through the top fall pipe section 101 is then not discharged into the bottom fall pipe section 102, which is advantageous in case there is a blockage in the lower fall pipe section. Such blockage is further described below with reference to figures 5a and 5b. The material passing through the upper fall pipe section 101 is directly discharged into the sea through intermediate opening 170 that is the end of the first fall pipe section 101. This is schematically shown in figure 3d. No additional weight is then added to the fall pipe 100. A blockage may be detected by appropriate sensors for chain load measurement, for instance, added to the hoisting systems 130, 230, or by other suitable sensors fitted to the fall pipe for this purpose.

[ 48 ] Figure 4 shows a schematic large-scale view of a marine vessel 10 provided with a fall pipe system 100 according to the invention. The vessel is travelled to a location where stone and/or rock is to be placed on the bottom of the sea. The stone and/or rock may be taken with the vessel, provided by another vessel or supplied in another suitable manner. At the desired location the stone or rock is provided to the sea bed using the fall pipe system. The blocks of stone and/or rock R are placed at a sea depth SD of, for instance, about 1,500 meter. Figure 4 also shows the influence of dynamic loads due to, for instance, water currents. The example of figure 4 shows one current closer to sea level in a direction CD1 and another water current near to the sea bed SB in an opposite direction CD2. Such water currents may pose horizontal loads on the fall pipe system, which can be handled by the fall pipe system as disclosed.

[ 49 ] Figures 5a to 8b show another type of fall pipe system 100, which does not have a suspension module as has been described with respect to the previous figures. The fall pipe system of figure 5a does have a single section of fall pipe segments 110 in the form of bottomless buckets. The fall pipe segments 110 are again connected to a chain 120, which can be lifted and lowered by hoisting arrangement 130. The driver arrangement is suspended from another set of longitudinal suspension elements in the form of cables 320, and is lifted and lowered by hoisting arrangement 330 provided on the vessel 10. The fall pipe 100 and driver arrangement are thus independently suspended from the vessel. Blocks R of rock and/or stone are provided by conveyer 12 into the fall pipe and are discharged at the end of the fall pipe on the seabed SB. A blockage of blocks R has occurred in one of the tubular segments, as better shown in the enlarged detail of figure 5b.

[ 50 ] In the embodiment shown in figures 6a and 6b an intermediate opening 170 is provided in the fall pipe by providing a discontinuity in the fall pipe by breaking the connection 113 with the chain 120, of the fall pipe section in which the blockage has occurred. Alternatively, the connection of a fall pipe segmentHO (shortly) above the fall pipe segment having the blockage with the chain 120 may be broken. Connections of multiple fall pipe segments can be broken as well. The fall pipe segment(s) of which the connection 113A has been broken will drop down on the fall pipe segments there below, of which the connections 113 with the chain 120 are still intact to provide the intermediate opening 170 as shown in figure 6b. A connection to be broken is designated by reference sign 113A and a corresponding fall pipe segment by reference sign 110A, which fall pipe segment 110A provides for the opening arrangement. The blocks R that are still being supplied from the top end of the fall pipe will be discharged through the intermediate opening 170 out of the fall pipe in the direction of the arrows shown and do not further add to the weight and therefore load of the fall pipe and carrying hoisting arrangement 130.

[ 61 ] The connections 113A that are to be disconnected can be designed such that they will break when a certain predefined load is exceeded. This can be achieved by material selection and/or configuration design. The connections may also be provided with fracture bolts that will break at a predefined load. Disconnection will then automatically occur when exceeding such predefined load. Alternatively, the connections 113A to be disconnected can be provided with explosion bolts that can be activated when a blockage is detected in the fall pipe to break the connection. A general detection system may be provided and individual explosion bolts activated from the vessel. A detection system may also be provided per tubularfall pipe segment and coupled with the connections 113A of the respective tubular fall pipe segment having the explosion bolts.

[ 62 ] In yet another embodiment shown in figures 7a and 7b one or more tubular segments 110A are provided with a slide-out mechanism 180 to allow providing an intermediate opening in the fall pipe. The slide-out mechanism 180 shown in figures 7a and 7b comprises two wall parts 181, 182 that can be pivoted about respective pivot axes 181.1, 182.1. Rotation of wall part 182.1 is driven by a hydraulic or pneumatic activation cylinder 183, but any other suitable means can be employed as well. The cylinder could be preloaded and released upon activation of an explosion bolt. A preloaded spring can be employed as will. Rotation of wall part 181 drives rotation of wall part 182 through the connection 184 between both wall parts. Wall part 182 provides the actual intermediate opening 170 from the tubular segment and therefore from the fall pipe 100. Wall part 181 directs the blocks of rock and/or stone falling downwards in the fall pipe sidewards out through the intermediate opening 170 in the direction of the arrow in figure 7b. Activiation may be triggered by an acoustic underwater signal or an umbilical cable. A small power pack or accumulator may be provided at the respective fall pipe segment(s) to power activation.

[ 63 ] Figures 8a and 8b show yet another embodiment of a fall pipe system according to the invention, in which the opening arrangement comprises weakened parts 190 in some or all tubular fall pipe segments 110. In figures 8a and 8b the fall pipe segment 110A comprises weakened parts 190, which run in the vertical direction from a top part of the fall pipe segment 110Ato the bottom edge. When a blockage occurs as shown in figure 8a, an outward force will be exerted on the wall of fall pipe segment 110A, causing the weakened parts 190 to break as shown in figure 8b. The weakened parts are designed to break at a predefined load. The blocks will then leave the fall pipe 100 sidewards and downwards in the direction of the arrows shown through intermediate opening 170. In an alternative embodiment the weakened part or weakened parts may run around the tubularfall pipe segment in, for instance, a horizontal plane. When a blockage occurs, part of the fall pipe segment will drop down on a fall pipe segment there below, and an intermediate opening is created.

[ 54 ] An embodiment of the invention has been disclosed with one specific type of fall pipe and fall pipe segments. The invention may be employed with other types of fall pipes and fall pipe segments as well. Various other embodiments of the invention will be apparent to the skilled person when having read the above disclosure in connection with the drawing, all of which as within the scope of the invention and accompanying claims.

Claims

A marine fallpipe system (100) constructed for placing blocks of rock and / or rock (R) on a seabed (SB) and configured to depend on a sea vessel (10), which fallpipe system comprises a substantially tubular fallpipe (100) with an open end for discharging the rock and / or rock blocks, and which downcomer system comprises an opening arrangement constructed to allow opening of the substantially tubular downcomer to provide an intermediate opening (170) at a position along its length for discharging the blocks of rock and / or rock at that position from the fall pipe.

The fall pipe system according to claim 1, wherein the opening feature is constructed to permit local discontinuation of the fall pipe (100) to provide the intermediate opening (170).

The fall pipe system according to the preceding claim, wherein the fall pipe system (100) comprises substantially tubular fall pipe segments (110) each attached to and suspended from at least one longitudinal suspension element (120) by at least one mounting element (113, 113A), one or more of the fastening elements are releasable from the longitudinal suspension element to provide the opening feature and, if released, the intermediate opening (170).

The fall pipe system according to the preceding claim, wherein the one or more mounting elements (113A) comprise explosion bolts.

The fall pipe system according to claim 3, wherein the one or more fastening elements (113A) comprise a predetermined weakened part where the fastening element will break at a load above a predetermined load.

The fall pipe system according to claim 2, wherein the fall pipe (100) comprises substantially tubular fall pipe segments (110, 110A), and at least one of the tubular fall pipe segments (110A) comprises a predetermined weakened part where the tubular segment will break under a load above a predetermined load to provide the opening feature and, if broken, the intermediate opening (170).

The fall pipe system according to claim 1 or 2, wherein the opening feature is constructed such that the blocks of rock and / or rock (R) are directed at least partially sideways from the fall pipe (100) at the intermediate opening (170).

The fall pipe system according to the preceding claim, wherein the fall pipe (100) comprises substantially tubular fall pipe segments (110, 110A), and at least one of the tubular fall pipe segments (110A) comprises an extension mechanism for providing the opening feature and, when extended, the intermediate opening (170).

The fall pipe system (100) according to claim 1 or 7, which fall pipe system comprises - essentially tubular fall pipe segments (110) configurable to provide first and second fall pipe sections (101, 102) from fall pipe segments; and - a suspension module (200) configured to suspend the marine vessel and configured to suspend the second fallpipe section (102) from fallpipe segments from the suspension module to continue the first fallpipe section (102) from fallpipe segments, such that the first fallpipe section (101) and the suspension module (200) with the second fall pipe section (102) is independently dependent on the marine vessel (10), which suspension module (200) is configured to allow lateral sliding of at least one of a lower segment (110.1B) of the first fall pipe section (101) and an upper fall pipe section (110.2T) of the second fall pipe section (102) such that an end of the first fall pipe section provides the intermediate opening (170) and blocks of rock and / or rock passing through the first fall pipe section (101) not be discharged in the second fall pipe section (102).

The fall pipe system according to the preceding claim, wherein the suspension module (200) is configured to allow lateral sliding and lifting of the lower segment (110.1B) of the first fall pipe section (101).

The fall pipe system according to claim 9 or 10, wherein the suspension module (200) comprises a segment holding feature (240) configured to hold the lower segment (110.1 B) of the first fall pipe section (110).

The fall pipe system according to one or more of claims 9-11, wherein the fall pipe segments comprise bottomless buckets (110) configurable to provide a fall pipe section (101, 102) from bottomless buckets attached to and suspended from a suspension set of at least one longitudinal suspension element (12) such that an open bottom side of a bucket above a bottom bucket (110.1B, 110.2B) of the downcomer section opens into an open top of an adjacent bucket below it, and an open top of a bucket below an upper bucket (110.1T, 110.2T) of the downcomer section receives an open underside of an adjacent bucket above it.

The fall pipe system according to the preceding claim, wherein an external perimeter of an underside of the bottomless buckets (110) is smaller than an internal perimeter of an upper side of the bottomless buckets,

The fall pipe system according to one or more of claims 12 and 13, wherein the buckets (110) have a substantially conical shape.

The fall pipe system according to one or more of claims 12-14, wherein the suspension set of the second section (102) from bottomless buckets depends on the suspension module (200) and / or the suspension set from the first section (101) from bottomless buckets depends on the sea vessel (10).

The fall pipe system according to one or more of claims 12-15, wherein the suspension set of the second section (102) from bottomless buckets continues into the suspension set of the first section (101) from bottomless buckets, and the suspension module (200) is configured for releasably holding the suspension set.

The fall pipe system according to one or more of claims 12-16, wherein the suspension module (200) comprises a suspension set retention device (210) configured to hold the suspension set above the upper bucket (110.2T) of the second fall pipe section (102).

The fall pipe system according to one or more of claims 3 to 5 or 12 to 17, wherein the longitudinal suspension element comprises one of a cable, a chain (120) and a wire.

A sea vessel (10) comprising a fall pipe system (100) according to one or more of the preceding claims.