CA2163726A1 - Method and system for fluid transport between ships - Google Patents

Method and system for fluid transport between ships

Info

Publication number
CA2163726A1
CA2163726A1 CA002163726A CA2163726A CA2163726A1 CA 2163726 A1 CA2163726 A1 CA 2163726A1 CA 002163726 A CA002163726 A CA 002163726A CA 2163726 A CA2163726 A CA 2163726A CA 2163726 A1 CA2163726 A1 CA 2163726A1
Authority
CA
Canada
Prior art keywords
ship
ships
stern
drift
driftage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002163726A
Other languages
French (fr)
Inventor
Kare Breivik
Olav Wiik
Arne Smedal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Teekay Norway AS
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA002578769A priority Critical patent/CA2578769A1/en
Publication of CA2163726A1 publication Critical patent/CA2163726A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B27/00Arrangement of ship-based loading or unloading equipment for cargo or passengers
    • B63B27/24Arrangement of ship-based loading or unloading equipment for cargo or passengers of pipe-lines

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Ship Loading And Unloading (AREA)
  • Loading And Unloading Of Fuel Tanks Or Ships (AREA)

Abstract

A method and a drift anchor system (7) for fluid transport between two ships (1, 2) in the open sea. At least one of the ships is at its stern provided with a loading hose (2), a reel or similar for said hose, and a mooring hawser (4).
The drift anchor system (7) is arranged forward on the ship and is designed for providing breaked aft driftage. The system comprises a bottom weight (8) having rounded shape, a drag chain (9), an anchor wire (10), a winch (11) on the deck and a vertical or inclined chain shaft (12) from the deck and down to the ship bottom.
The method incorporates activating of the drift anchor system (7), manoeuvring of the second ship (5) towards the first ship (1), mooring of the ships to each other by means of the mooring hawser (4), and activating of a bow loading system (6) on the second ship to establish fluid transfer by means of said loading hose (2).

Description

~Q3~a~e Method and system for fluid transport between ships There are several reasons to transfer fluid such as oil or gas between two tankers in the open sea, and by having available good and flexible solutions for a such 5 fluid or load transfer, a better employment of the fleet will i.a. be possible. A good load transfer flexibility will particularly be valuable for a fleet in which the individual ships have different types of loading/discharging equipment on board.
Until now known methods to transfer fluid between tankers in the open sea have turned out problematical during so-called marginal weather conditions (by 10 significant wave heights over 6 feet [2 m]). The reason is as follows: If two ships to be interconnected for load transfer are moving by their own forward machinery to keep a minimum steering speed (the machinery in position "forward, slow"), the forward or rearward speed still may be at least approx. 5 knots, and therefore it will not be recommendable to make the connection and carry out the subsequent load 15 transfer between the ships, since the risk for collision would be too great. If, on the other hand, the ship machinery is deactivated, the ships could easily break adrift in an uncontrolled manner and end up being laterally exposed against waves and wind, and even then it will most often be problematic to arrange a load transfer from one ship to another.
Differing ways of transporting fluid, such as by fuel supply to military vessels neither can be used advantageously for tankers, because the dimensions of ships and tankers and their loading hoses are far heavier, thereby leading to more serious consequences in the event of a possible direct contact between the ships.
On this background the present invention is proposed, said invention 25 being directed towards a method for fluid transport between ships, particularly loading of hydrocarbons (HC) between tankers in the open sea and allowing the loading to be effectuated securely and effectively. The invention further comprises a drift anchor system to allow fluid transport between two ships in the open sea. In the following paragraphs the invention will be described more closely with reference to the ~ 3~a~

accompanying drawings, wherein:
Fig. 1 demonstrates a connection between two tankers in order to carry out fluid transport according to the invention, Fig. 2 illustrates a drift anchor system on one of the ships, and Fig. 3 shows schematically the drift anchor system in 5 activated condition.
Referring to Fig. 1 there is shown a first ship 1 having a loading hose 2 at its stern and a reel 3 or a similar storing device for the loading hose, which also may be stored in a horizontal support. At the stern there is also provided a mooring hawser 4. Further is illustrated the bow portion of a second ship 5, moored to the 10 first ship 1. The second ship is preferably a buoy loading ship having excellent manoeuvring properties due to a system for dynamic positioning (DB) for the control of trusters forward and aft and turnable main propellers. When the DP system is activated the mooring hawser 4 has the function of an extra safety mechanism between the ships. A typical distance between the ships may be 80 - 100 m during1 5 mutual mooring.
The free end of the loading hose 2 from the first ship is connected to a bow loading system 6 of traditional type on the other, second ship 5.
At its bow portion the first ship 1 is provided with a drift anchor system 7 (Fig. 2) comprising: A bottom weight having a rounded shape, without anchor 20 hooks and secured to the lower free end of a drag chain 9, an anchor wire 10 having a considerable length, for example 1000 - 2000 m and being secured to the upper end of said drag chain, a winch 11 mounted on deck and adapted for reeling of the anchor wire, and a vertical or inclined chain shaft extending from the ship deck and down to its bottom.
When the drift anchor system is inactivated, the winch 1 1 is keeping the anchor wire 10 reeled, while the drag chain 9 is hanging vertically and extendedwithin the chain shaft 12. The winch pull on the wire may be slightly greater than the combined weight of bottom weight 8 and drag chain, or the upper end of said chain may be secured under tension by means of a stopper 13 on the deck, in which case30 the winch is relieved. In both situations the bottom weight 8 will be drawn with a certain force 3~

against the shaft mouth 14 in the ship bottom in order to close the shaft. For this reason the bottom weight may be conical or spherical at least at its upper portion, and the shaft mouth 14 will be correspondingly complementary shaped.
During use the first ship forward machinery is stopped, the drag chain 5 with bottom weight connected is lowered down to the sea floor, and the anchor wire is reeled out gradually when the ship breaks adrift and turns into the direction of the wind and sea current. The turning will partly be under control due to the friction of the drift anchor system. Fig. 3 illustrates this situation, and it is obvious that also a portion of the anchor wire will be positioned along the sea floor and slowly being 10 dragged forwards. It is of importance that the bottom weight is not designed as an anchor but instead is rounded to be drawn alongside the sea bottom under resistance, together with the drag chain. The drag resistance acting upon a ship having a such drift anchor system will depend upon the weight and length of the drag chain and its connected anchor wire. If a particularly great drag resistance should be wanted, for 15 example if a ship serving as a barge vessel has a considerable tonnage, a coarse drag chain and a corresponding large and heavy bottom weight 8 may be used. The drag resistance may also be varied within certain limits by adjusting the length of the portion of the anchor wire being dragged along the sea floor.
Preferably the drift anchor system of the ship is provided with two sets 20 of wire/chain equipment, as illustrated in Fig. 3. Thereby is given the possibility to adjust the ship heading or deviation direction to a certain extent by arranging a different length of the wire/chain equipment along the sea floor on the steerboard and port side of the ship, respectively.
By letting the ship heading in this way be under control of the drift 25 anchor system, the angular or azimuth direction of the ship during its aft driftage will approximately become in line against the prevailing weather forces. In this way the wind influence can be kept relatively small due to that the wind facing area will be far less than if the ship should be allowed a free driftage, since it then probably would end up in an azimuth perpendicular to the wave and wind direction. A such 30 uncontrolled driftage therefore would be considerably greater and 3~

could lead to a driftage speed of for example 4- 5 knots when the wind strength is, say 50 knots. By the method and drift anchor system of the invention is assumed that a barge operation may be executed under minimum risk even during great windspeeds and at wave heights (given as significant wave height Hs) up to around 5 - 6 5 m.
A loading operation for fluid transport between two ships in open sea, for example the transfer of oil/gas from a first to a second tanker will follow these steps:
a) The first ship stops its forward machinery and activates its drift anchor 10 system, whereafter it is allowed to break adrift and turn into a position with its bow towards the prevailing weather forces (waves, wind and current). Alternatively and to save time the ship may first be turned against the wind, thereafter the forward machinery is reversed so that the ship by now means starts its aft driftage, then the machinery is switched on and the drift anchor system is activated.
15 b) When the aft driftage (rearward movement) of the first ship 1 has become stable, the second ship 5 is manoeuvred with its bow against the stern of the first ship and is positioned ahead of the bow (the expression "ahead of" here meaning: in relation to the direction of movement of the first ship). The manoeuvring may for example be effectuated in the same way as is common by 20 mooring/connection to an offshore buoy installation. Thereafter the ships areconnected together, and the second ship may keep an approximately constant distance to the first ship by means of its DP system.
c) The bow loading system 6 is activated and made to establish a fluid transport connection between the ships by means of the loading hose 2, and the fluid 25 transfer may start.
d) At the end of the loading operation the ships are disconnected, the first ship is heaving in the loading hose and the mooring hawser and winching the anchor wire until the bottom weight is lifted to close the shaft mouth, thereafter the ships may navigate to their destination sites.
Carried out in this way, hydrocarbon fluid may be transferred faster and more secure from one ship to another out at sea, compared to known methods, evenby marginal weather conditions.

Claims (5)

1. A method for fluid transport between two ships in the open sea, at least one of said ships (1, 2) having at its/their stern a loading hose (2), a reel (3) or a corresponding storing device for said loading hose, and a mooring hawser (4), and forward a drift anchor system (7) to allow breaked aft driftage due to the prevailing weather forces, and said at least one other or second ship (5) having a bow loading system (6) for fluid transfer to or from said first ship, characterized in:
stopping of the forward machinery of the first ship (1), activating of the drift anchor system (7) of said first ship (1) until its driftage is becoming stable, manoeuvring of said other ship (5) towards the stern of said first ship and to a position ahead of it, in relation to the aft driftage of said first ship, the bow of said second ship being faced against the stern of said first ship, mooring of said other ship (5) to said first ship (1) by means of the mooring hawser (4) in the stern of the first ship, and activating of the bow loading system (6) on board the other ship (5) and establishing of a fluid transport connection between the ships by means of said loading hose (2).
2. Method according to claim 1, characterized in stopping of the forward machinery of said first ship (1) and activating of its drift anchor system after turning the ship towards the wind and thereafter in a period letting its machinery work in reverse so that the ship by own means is starting its aft movement in the driftage direction.
3. Method according to claim 1, characterized in that the machinery of the other ship (5) for forward movement or positioning - even after said ship is being manoeuvred in position approximately parallel to or aligned with the first ship (1), with its bow in the direction of the stern of the first ship and connected to it by means of the mooring hawser (4) - is kept in operation to make sure that the distance between the ships is not becoming too small, but preferably being kept constant and by a value corresponding to approximately a tight mooring hawser.
4. Drift anchor system (7) to allow fluid transport between two ships (1, 2) in open sea and according to the method of one of the preceding claims, characterized in:
a bottom weight (8) having rounded shape and without anchor hooks, a drag chain (9) secured to the bottom weight (8) at its lower free end, an anchor wire (10) having a considerable length and being secured to the upper end of said drag chain (9), a winch (11) on the deck for reeling of said anchor wire (10), and a vertical or inclined chain shaft (12) from the deck of the first ship (1) and down to its bottom.
5. Drift anchor system according to previous claim 4, characterized in that said bottom weight (8) at least at its upper portion is conical or spherical, and that the shaft mouth (14) of said chain shaft (12) in the ship bottom is shaped complementary to the conical or spherical form of said bottom weight (8).
CA002163726A 1994-11-24 1995-11-24 Method and system for fluid transport between ships Abandoned CA2163726A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA002578769A CA2578769A1 (en) 1994-11-24 1995-11-24 Method and system for fluid transport between ships

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO944504A NO300536B1 (en) 1994-11-24 1994-11-24 Three anchor system for ships
NO944504 1994-11-24

Related Child Applications (1)

Application Number Title Priority Date Filing Date
CA002578769A Division CA2578769A1 (en) 1994-11-24 1995-11-24 Method and system for fluid transport between ships

Publications (1)

Publication Number Publication Date
CA2163726A1 true CA2163726A1 (en) 1996-05-25

Family

ID=19897679

Family Applications (2)

Application Number Title Priority Date Filing Date
CA002578769A Abandoned CA2578769A1 (en) 1994-11-24 1995-11-24 Method and system for fluid transport between ships
CA002163726A Abandoned CA2163726A1 (en) 1994-11-24 1995-11-24 Method and system for fluid transport between ships

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CA002578769A Abandoned CA2578769A1 (en) 1994-11-24 1995-11-24 Method and system for fluid transport between ships

Country Status (4)

Country Link
CA (2) CA2578769A1 (en)
GB (1) GB2295372B (en)
IE (1) IE950891A1 (en)
NO (1) NO300536B1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO304824B1 (en) * 1998-02-10 1999-02-22 Navion As Load transfer device
NL1015208C2 (en) * 2000-05-16 2001-11-19 Bluewater Terminal Systems Nv Transfer system for hydrocarbon products.
SG152055A1 (en) * 2002-10-10 2009-05-29 Singapore Technologies Marine A method and apparatus for a replenishment at sea system
US7543613B2 (en) * 2005-09-12 2009-06-09 Chevron U.S.A. Inc. System using a catenary flexible conduit for transferring a cryogenic fluid
NO336151B1 (en) * 2007-03-15 2015-05-26 Teekay Norway As Method and apparatus for connecting a tanker to an offshore loading facility
US9056658B2 (en) * 2010-03-31 2015-06-16 Maersk Supply Service A/S Icebreaking vessel
US9242705B2 (en) 2010-03-31 2016-01-26 Maersk Supply Service A/S Icebreaking vessel and method of breaking ice
NO333956B1 (en) * 2010-09-01 2013-10-28 Aker Pusnes As A snake drum station
AU2013100491B4 (en) * 2012-09-03 2014-01-16 Seacaptaur Ip Ltd Vessel

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB326008A (en) * 1929-02-27 1930-03-06 George Turnbull Improvements in ships' stockless anchors
DE2031672A1 (en) * 1970-06-26 1971-12-30 Weser Ag Line connection for two ships on the open sea
US3886882A (en) * 1973-04-23 1975-06-03 Global Marine Inc Mooring apparatus for ice-breaking drill ship
GB2025876B (en) * 1978-07-25 1982-11-03 Petroles Cie Francaise Anchorage devices
US4408943A (en) * 1981-02-27 1983-10-11 Fmc Corporation Ship-to-ship fluid transfer system
US5178087A (en) * 1991-01-16 1993-01-12 Single Buoy Moorings, Inc. Mooring device

Also Published As

Publication number Publication date
CA2578769A1 (en) 1996-05-25
NO300536B1 (en) 1997-06-16
GB2295372B (en) 1998-08-19
GB2295372A (en) 1996-05-29
NO944504L (en) 1996-05-28
GB9523966D0 (en) 1996-01-24
NO944504D0 (en) 1994-11-24
IE950891A1 (en) 1996-05-29

Similar Documents

Publication Publication Date Title
US6983712B2 (en) Offloading arrangements and method for spread moored FPSOs
US5803779A (en) Dynamically positioned loading buoy
US3525312A (en) Storage or similar vessel
US10526046B2 (en) Cargo transfer vessel
EP2534040B1 (en) Bow loading station with double deck for cryogenic fluid
EP0739290B1 (en) A vessel for production and/or loading/unloading and transport of hydrocarbons from offshore fields, and/or for carrying out well operations
CA2163726A1 (en) Method and system for fluid transport between ships
AU758786B2 (en) A system for mooring a tanker near an offshore floating unit
JPH10508556A (en) Terminal for loading / unloading, especially for loading or unloading petroleum products
AU2008239946B2 (en) System for loading of hydrocarbons from a floating vessel
US8156884B2 (en) Vessel mooring systems and methods
AU745877B2 (en) Floating loading hose
OA17499A (en) Cargo transfer vessel.

Legal Events

Date Code Title Description
EEER Examination request
FZDE Dead