CA1155307A - Apparatus for raising and lowering a floating offshore platform - Google Patents
Apparatus for raising and lowering a floating offshore platformInfo
- Publication number
- CA1155307A CA1155307A CA000370878A CA370878A CA1155307A CA 1155307 A CA1155307 A CA 1155307A CA 000370878 A CA000370878 A CA 000370878A CA 370878 A CA370878 A CA 370878A CA 1155307 A CA1155307 A CA 1155307A
- Authority
- CA
- Canada
- Prior art keywords
- rope
- platform
- winch
- legs
- drum
- 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.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
- E02B17/02—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto
- E02B17/021—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto with relative movement between supporting construction and platform
- E02B17/024—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto with relative movement between supporting construction and platform shock absorbing means for the supporting construction
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Jib Cranes (AREA)
- Earth Drilling (AREA)
- Replacing, Conveying, And Pick-Finding For Filamentary Materials (AREA)
- Load-Engaging Elements For Cranes (AREA)
- Revetment (AREA)
Abstract
ABSTRACT
Apparatus for raising and lowering a floating offshore platform provided with legs which are movable relatively to it and which, in the operating condition, are supported on the bottom of the sea or on a substruc-ture lowered to the bottom of the sea, characterized in that the jacking equipment is blocked against downward movement whenever the floating platform is at the highest point of the wave motion in the touched-down position of the legs.
Apparatus for raising and lowering a floating offshore platform provided with legs which are movable relatively to it and which, in the operating condition, are supported on the bottom of the sea or on a substruc-ture lowered to the bottom of the sea, characterized in that the jacking equipment is blocked against downward movement whenever the floating platform is at the highest point of the wave motion in the touched-down position of the legs.
Description
This invention relates to equipment for raising and lowering a floating offshore platform which is provided with legs movable relatively to it and supported, in the operating condition, on the bottom of the sea or on a substructure lowered to the bottom of the sea.
In order to establish the working position of such offshore plat-forms, the legs are lowered to the bottom of the sea and the platform is then raised out of the water on the firmly seated legs until the necessary - i height above sea level has been reached. Lowering the legs onto the sub-structure is always a critical operation which, unless special measures are taken, can only be carried out under favourable weather conditions.
Under unfavourable sea conditions the platform oscillating up and down with the waves may several times tmpinge upon the substructure with the extending legs before it is finally fixed. This may cause considerable damage.
This invention is an improvement on known equipment which permits lowering of the legs under unfavourable conditions without, or substantially without, shock loading which leads to damage.
According to the invention this improvement relates to the jacking equipment being blocked against downward movement whenever the floating platform is at the highest point of the wave motion in the lower contact position of the legs. Preferably two jacking means such as rope winches are arranged so that, with the legs in contact with ground, the drive of one jacking means will be switched off, while the rope winch of the other jacking means will be released in the rope take-up direction and be lockable in the rope payout direction.
When the legs of an offshore platform provided with this improve-ment hnve contacted the ground, only the platform will be raised with a rising wave, while the legs will not change their position. When the plat-I
~ \~
form, floating upwardly has reached the highest point of the wave motion, it will be secured in this position and will not lower again with the c~escending wave. Should a further wave with a higher crest follow, the platform will be raised once more and will be secured at the highest point of the wave motion. In this manner the platform is prevented from lowering with the descending wave. As a result the platform can no longer oscillate up and down with the waves and cannot cause damage to the legs or the sub-structure.
An embodiment of the invention is represented in the drawing and is described below in greater detail.
In the drawings:
Fig. 1 is a schematic side view of an offshore platform with a jacking apparatus according to this invention;
Fig. 2 is a side view of the jacking apparatus of Fig. l;
Fig. 3 is a plan view of the jacking apparatus of Fig. 2i L
Fig. 4 is a longitudinal section through the rope drum of a jacking means; and Fig. 5 is the flow diagram of a ratchet locking means.
The floating platform 1 has a rectangular or square cross section;
it is provided with four legs which are movable relatively to it and which may be ra;sed as well as lowered. For installation, the platform 1 is towed to its sea location with raised legs 2. After the planned location has been reached, the legs are lowered by means of the jacking equipment described below. ~owering is continued until the legs 2 are seated on the bottom of the sea or on a substructure lowered to the bottom of the sea.
Thereupon the platform 1 is raised to the desired height above sea level.
In the operating condition, the legs 2 are supported on the bottom of the r 11S~307 sea directly or indirectly.
The jacking equipment consists of two unilaterally acting jacking means in the form of rope winches 3 and 4, which can be driven independently of each other. The two rope winches 3 and 4 are arranged on a joint base frame 17 located on platform 1. For better understanding the two rope winches 3 and 4 are shown as separated and rotated by 90 in Fig. 1, although, of course, they can be placed in any suitable position. Each of the four legs 2 is provided at least with one apparatus of this ~ind.
- The first rope winches 3 are for lowering and raising the leg 2;
preferably using a single rope strand. Rope 5 is secured to the attachment point at the foot of leg 2 by way of a deflecting sheave 6 arranged on platform 1.
The second rope winches 4 are for raising and lowering the platform l; using a multipleropestrand. For introducing a load onto leg 2, jacking ,`
rope 7runs by way of an upper sheave assembly 8 which is arranged on a yoke 9 of leg 2. The lower sheave assembly 10 with the rope attachment point is located directly before rope winch 4 on platform 1. '`~
The drives of the rope winches 3 and 4 are by way of an entrainment ratchet wheel 11 which is connected with the rope drum 12 or 13, respective-ly. The head of piston rod 15 engages the ratchets of the entrainment ratchet wheel 11. The piston rod 15 moves in a hydraulic cylinder 16 and . ~
is connected with a double acting pistion. The hydraulic cylinder 16 is pivoted to the base frame 17 carrying the rope winches 3 and 4. A cylinder arrangement 18 pivoted indirectly to the base frame 17 pulls the head of the piston rod 15 into a position of engagement or pushes it into an idle position. ln order to prevent the undesired reverse movement of the entrain-ment ratchet wheel 11 in the disengagedpositionof the piston rod 15, there is a ratchet locking means which consists of a swivelling pawl 19 and a l, pawl pin 20. The swivelling pawl 19 is pivoted to the base frame 17 and i, is caused to occupy the engaged position, like piston rod 15, by cylinder arrangement 1~3. '' As shown in Fig. 4, the first rope winch 3 is provided with a permanent tensioning means which consists of a low-rebound freewheel and a driving motor 30. The freewheel is a clamping-body freewheel, the clamping bodies 39 of which are arranged between the entrainment ratchet wheel 11 ~, and the rope drum 12. The driving motor 30 is flanged to the base frame 17 and drives a pinion 31 which is in engagement with gear 32 attached to the rope drum 12. The driving motor 30 exerts a torque onto the rope drum 12 in the take-up direction of rope 5.
The second rope winch 4 is likewise provided with a slack-rope preventer. This preventer consists of rope 22 which is loaded by weight 21 and which is wound around the rope drum 13 of the second,rope winch 4 against the take-up direction of the jacking rope 7. The weight 21 is connected with a loose sheave 33. The rope 22 wound around the rope drum 13 runs via sheave 33 to a compensating winch 23 installed on platform 1. A torque is produced on rope drum 13 by weight 21 in combination with compensating winch 23; in this way the jacking rope 7 is wound up or is paid out under initial stress. The compensating winch 23 ensures that the weight 21 is always kept at the same level. When the compensating winch 23 is deactivated, the weight 21 produces the torque alone and changes its level.
'~ The rope drum 13 of the second rope winch 4 consists of a hollow cylinder 24 which is slidingly carried on a statically stressed base drum 25.
When the piston rod 15 and the locking pawl 19 are disengaged, the hollow cylinder 24 is dynamically stressed at low load. During the jacking operation the hollow cylinder 24 forms one unit with the base drum 25. The inertia moment of the masses subjected to acceleration during freewheeling of the rope drum 13 is kept small by dividing the rope drum 13 into a low-mass hollow cylinder 24 and a base drum 25.
The ratchet locking means consisting of locking pawl 19 and pawl pin 20 as well as hydraulic cylinders of the drive for the rope drum 13 of the second rope winch. These are provided with hydraulic safety ratchet locking means, the flow diagram of which is represented in Fig. 5. This ensures that the piston rod 15 and the locking pawl 19 are always in dis-engagement when platfonn 1 is moving downwardly.
The locking means consists of a pump 34, which is driven from rope drum 13 of the second rope winch 4, and the locking cylinders 38.
Pump 34 delivers pressurized fluid through a hydraulic line 35 to the upper piston chambers of the locking cylinders 38 only when the rope drum 13 rotates in a sense which corresponds to the downward motion of the platform 1. Piston rod 15 and the locking pawl 19 are released for engagement upon the admission of pressure to these piston chambers. For safety reasons, the hydraulic line 35 is provided, moreover, with a valve 36 which must be activated prior to disengagement.
In order to achieve a uniform load absorption of the jacking equipment on the four legs 2, the rope attachment points of the jacking rope 7 are equipped with communicated balancing cylinders 26. These balancing cylinders 26 may be rotated about a horizontal axis and are maintained in t position with a bearing fork 27 which is connected to platform 1. A piston 28 with piston rod 29 is guided within the balancing cylinders 26. The jacking rope 7 is attached to piston rod 29. L
The inventive apparatus works in the following manner. When platform 1 has reached the planned location at sea, the operation of lowering the legs 2 will be init~ated from a central control position. The driye of the first rope winch 3 will be in engagement, while the head of the piston rod 15 and the swivelling pawl 19 of the second rope winch 4 will be dis-engaged. By means of the first rope winch 3 all four legs 2 will synchron-ously be lowered.
While the legs 2 are being lowered, the floating platform 1 will be subjected to oscillations under the motion of the sea. If, while plat-form 1 is- in a wave trough, a leg 2 touches the bottom of the sea or a substructure placed onto the bottom of the sea, the hydraulic pressure in the hydraulic cylinder 16 of the first rope winch 3 will lower. When all hydraulic cylinders have undergone pressure reduction, one further lowering step will be conducted.
During the following pressure reduction, the piston rod 15 and the locking pawl 19 of the flrst rope winch 3 will be disengaged through the cylinder arrangements 18 and the first rope winch 3 will thus be placed in an idle position. In this way, the legs 2 will have touched the sea bottom. j The idling of the first rope winch 3 means- that platform 1 is able to carry out all movements under the motion of the sea without any connection, apart from friction, existing between platform 1 and legs 2. The distance between the upper sheave assembly 8 and the lower sheave assembly 10 becomes shorter during the lowering operation. The jacking rope thus slackened is wound up by the aid of the weight 21 and the compensating winch 23.
When the legs 2 have touched the sea bottom, the platform 1 moves with the motion of the sea. After blocking of the compensating winch 23, thejacking rope 7 is reeled on and off by the aid ofweiqht21 under initial j`
stress. Independently of the actual position of platform 1 in the motion L
of the sea, the command "Engaging" is given via a control. This causes the piston rod 15 and the locking pawl 19 of the second rope winch 4 to be engaged automatically as soon as platform 1 is in upward motion.
As a result rope drum 13 of the second rope winch 4 is prevented from rotating, opposite to the jacking direction, in the downward motion of platform 1. In this manner, platform 1 is hung up in the uppermost position under the motion of the sea and is thus connected with the legs 2.
When platform 1 is raised to a further extent by a higher wave that may follow, it is automatically hung up in the new uppermost position.
When piston rod 15 and swivelling pawl 19 are engaged after platform 1 has been hung up, the stepwise jacking operation of platform 1 will start automatically. All rope winches 4 will work synchronously and will horizontally raise the platfoxm. Different jacking lengths of one xope winch 4, e.g. upon changing into another rope layer, will be made up by the balancing cylinders 26 at the rope attachment point.
When,after a residence time of approximately 8 to 10 years, the platform is to be moved to another location, it will be lowered according to basically the same principle; the same operations will then proceed in e ve~
the ~v~rsc direction.
.
In order to establish the working position of such offshore plat-forms, the legs are lowered to the bottom of the sea and the platform is then raised out of the water on the firmly seated legs until the necessary - i height above sea level has been reached. Lowering the legs onto the sub-structure is always a critical operation which, unless special measures are taken, can only be carried out under favourable weather conditions.
Under unfavourable sea conditions the platform oscillating up and down with the waves may several times tmpinge upon the substructure with the extending legs before it is finally fixed. This may cause considerable damage.
This invention is an improvement on known equipment which permits lowering of the legs under unfavourable conditions without, or substantially without, shock loading which leads to damage.
According to the invention this improvement relates to the jacking equipment being blocked against downward movement whenever the floating platform is at the highest point of the wave motion in the lower contact position of the legs. Preferably two jacking means such as rope winches are arranged so that, with the legs in contact with ground, the drive of one jacking means will be switched off, while the rope winch of the other jacking means will be released in the rope take-up direction and be lockable in the rope payout direction.
When the legs of an offshore platform provided with this improve-ment hnve contacted the ground, only the platform will be raised with a rising wave, while the legs will not change their position. When the plat-I
~ \~
form, floating upwardly has reached the highest point of the wave motion, it will be secured in this position and will not lower again with the c~escending wave. Should a further wave with a higher crest follow, the platform will be raised once more and will be secured at the highest point of the wave motion. In this manner the platform is prevented from lowering with the descending wave. As a result the platform can no longer oscillate up and down with the waves and cannot cause damage to the legs or the sub-structure.
An embodiment of the invention is represented in the drawing and is described below in greater detail.
In the drawings:
Fig. 1 is a schematic side view of an offshore platform with a jacking apparatus according to this invention;
Fig. 2 is a side view of the jacking apparatus of Fig. l;
Fig. 3 is a plan view of the jacking apparatus of Fig. 2i L
Fig. 4 is a longitudinal section through the rope drum of a jacking means; and Fig. 5 is the flow diagram of a ratchet locking means.
The floating platform 1 has a rectangular or square cross section;
it is provided with four legs which are movable relatively to it and which may be ra;sed as well as lowered. For installation, the platform 1 is towed to its sea location with raised legs 2. After the planned location has been reached, the legs are lowered by means of the jacking equipment described below. ~owering is continued until the legs 2 are seated on the bottom of the sea or on a substructure lowered to the bottom of the sea.
Thereupon the platform 1 is raised to the desired height above sea level.
In the operating condition, the legs 2 are supported on the bottom of the r 11S~307 sea directly or indirectly.
The jacking equipment consists of two unilaterally acting jacking means in the form of rope winches 3 and 4, which can be driven independently of each other. The two rope winches 3 and 4 are arranged on a joint base frame 17 located on platform 1. For better understanding the two rope winches 3 and 4 are shown as separated and rotated by 90 in Fig. 1, although, of course, they can be placed in any suitable position. Each of the four legs 2 is provided at least with one apparatus of this ~ind.
- The first rope winches 3 are for lowering and raising the leg 2;
preferably using a single rope strand. Rope 5 is secured to the attachment point at the foot of leg 2 by way of a deflecting sheave 6 arranged on platform 1.
The second rope winches 4 are for raising and lowering the platform l; using a multipleropestrand. For introducing a load onto leg 2, jacking ,`
rope 7runs by way of an upper sheave assembly 8 which is arranged on a yoke 9 of leg 2. The lower sheave assembly 10 with the rope attachment point is located directly before rope winch 4 on platform 1. '`~
The drives of the rope winches 3 and 4 are by way of an entrainment ratchet wheel 11 which is connected with the rope drum 12 or 13, respective-ly. The head of piston rod 15 engages the ratchets of the entrainment ratchet wheel 11. The piston rod 15 moves in a hydraulic cylinder 16 and . ~
is connected with a double acting pistion. The hydraulic cylinder 16 is pivoted to the base frame 17 carrying the rope winches 3 and 4. A cylinder arrangement 18 pivoted indirectly to the base frame 17 pulls the head of the piston rod 15 into a position of engagement or pushes it into an idle position. ln order to prevent the undesired reverse movement of the entrain-ment ratchet wheel 11 in the disengagedpositionof the piston rod 15, there is a ratchet locking means which consists of a swivelling pawl 19 and a l, pawl pin 20. The swivelling pawl 19 is pivoted to the base frame 17 and i, is caused to occupy the engaged position, like piston rod 15, by cylinder arrangement 1~3. '' As shown in Fig. 4, the first rope winch 3 is provided with a permanent tensioning means which consists of a low-rebound freewheel and a driving motor 30. The freewheel is a clamping-body freewheel, the clamping bodies 39 of which are arranged between the entrainment ratchet wheel 11 ~, and the rope drum 12. The driving motor 30 is flanged to the base frame 17 and drives a pinion 31 which is in engagement with gear 32 attached to the rope drum 12. The driving motor 30 exerts a torque onto the rope drum 12 in the take-up direction of rope 5.
The second rope winch 4 is likewise provided with a slack-rope preventer. This preventer consists of rope 22 which is loaded by weight 21 and which is wound around the rope drum 13 of the second,rope winch 4 against the take-up direction of the jacking rope 7. The weight 21 is connected with a loose sheave 33. The rope 22 wound around the rope drum 13 runs via sheave 33 to a compensating winch 23 installed on platform 1. A torque is produced on rope drum 13 by weight 21 in combination with compensating winch 23; in this way the jacking rope 7 is wound up or is paid out under initial stress. The compensating winch 23 ensures that the weight 21 is always kept at the same level. When the compensating winch 23 is deactivated, the weight 21 produces the torque alone and changes its level.
'~ The rope drum 13 of the second rope winch 4 consists of a hollow cylinder 24 which is slidingly carried on a statically stressed base drum 25.
When the piston rod 15 and the locking pawl 19 are disengaged, the hollow cylinder 24 is dynamically stressed at low load. During the jacking operation the hollow cylinder 24 forms one unit with the base drum 25. The inertia moment of the masses subjected to acceleration during freewheeling of the rope drum 13 is kept small by dividing the rope drum 13 into a low-mass hollow cylinder 24 and a base drum 25.
The ratchet locking means consisting of locking pawl 19 and pawl pin 20 as well as hydraulic cylinders of the drive for the rope drum 13 of the second rope winch. These are provided with hydraulic safety ratchet locking means, the flow diagram of which is represented in Fig. 5. This ensures that the piston rod 15 and the locking pawl 19 are always in dis-engagement when platfonn 1 is moving downwardly.
The locking means consists of a pump 34, which is driven from rope drum 13 of the second rope winch 4, and the locking cylinders 38.
Pump 34 delivers pressurized fluid through a hydraulic line 35 to the upper piston chambers of the locking cylinders 38 only when the rope drum 13 rotates in a sense which corresponds to the downward motion of the platform 1. Piston rod 15 and the locking pawl 19 are released for engagement upon the admission of pressure to these piston chambers. For safety reasons, the hydraulic line 35 is provided, moreover, with a valve 36 which must be activated prior to disengagement.
In order to achieve a uniform load absorption of the jacking equipment on the four legs 2, the rope attachment points of the jacking rope 7 are equipped with communicated balancing cylinders 26. These balancing cylinders 26 may be rotated about a horizontal axis and are maintained in t position with a bearing fork 27 which is connected to platform 1. A piston 28 with piston rod 29 is guided within the balancing cylinders 26. The jacking rope 7 is attached to piston rod 29. L
The inventive apparatus works in the following manner. When platform 1 has reached the planned location at sea, the operation of lowering the legs 2 will be init~ated from a central control position. The driye of the first rope winch 3 will be in engagement, while the head of the piston rod 15 and the swivelling pawl 19 of the second rope winch 4 will be dis-engaged. By means of the first rope winch 3 all four legs 2 will synchron-ously be lowered.
While the legs 2 are being lowered, the floating platform 1 will be subjected to oscillations under the motion of the sea. If, while plat-form 1 is- in a wave trough, a leg 2 touches the bottom of the sea or a substructure placed onto the bottom of the sea, the hydraulic pressure in the hydraulic cylinder 16 of the first rope winch 3 will lower. When all hydraulic cylinders have undergone pressure reduction, one further lowering step will be conducted.
During the following pressure reduction, the piston rod 15 and the locking pawl 19 of the flrst rope winch 3 will be disengaged through the cylinder arrangements 18 and the first rope winch 3 will thus be placed in an idle position. In this way, the legs 2 will have touched the sea bottom. j The idling of the first rope winch 3 means- that platform 1 is able to carry out all movements under the motion of the sea without any connection, apart from friction, existing between platform 1 and legs 2. The distance between the upper sheave assembly 8 and the lower sheave assembly 10 becomes shorter during the lowering operation. The jacking rope thus slackened is wound up by the aid of the weight 21 and the compensating winch 23.
When the legs 2 have touched the sea bottom, the platform 1 moves with the motion of the sea. After blocking of the compensating winch 23, thejacking rope 7 is reeled on and off by the aid ofweiqht21 under initial j`
stress. Independently of the actual position of platform 1 in the motion L
of the sea, the command "Engaging" is given via a control. This causes the piston rod 15 and the locking pawl 19 of the second rope winch 4 to be engaged automatically as soon as platform 1 is in upward motion.
As a result rope drum 13 of the second rope winch 4 is prevented from rotating, opposite to the jacking direction, in the downward motion of platform 1. In this manner, platform 1 is hung up in the uppermost position under the motion of the sea and is thus connected with the legs 2.
When platform 1 is raised to a further extent by a higher wave that may follow, it is automatically hung up in the new uppermost position.
When piston rod 15 and swivelling pawl 19 are engaged after platform 1 has been hung up, the stepwise jacking operation of platform 1 will start automatically. All rope winches 4 will work synchronously and will horizontally raise the platfoxm. Different jacking lengths of one xope winch 4, e.g. upon changing into another rope layer, will be made up by the balancing cylinders 26 at the rope attachment point.
When,after a residence time of approximately 8 to 10 years, the platform is to be moved to another location, it will be lowered according to basically the same principle; the same operations will then proceed in e ve~
the ~v~rsc direction.
.
Claims (8)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An arrangement for raising and lowering a floating offshore platform, comprising: a platform with legs which are movable relatively to said platform, said legs in the operating condition being supported on the bottom of the sea; and jacking means on said platform and blocked against downward movement whenever said floating platform is at a highest point of sea wave motion in a touched-down position of said legs; said jacking means comprising two rope winches, the drive of one first rope winch being switched off and the other second rope winch being released in take-up direction and being blockable in pay out direction in touched-down position of said legs and floating platform.
2. An arrangement as defined in claim 1, including rope drums on said rope winches; mounting means for holding said drums; each of said drums being connected with an entrainment ratchet wheel with ratchet teeth; a hydraulic cylinder pivotably mounted on said mounting means; said hydraulic cylinder having a piston rod engaging said ratchet teeth; ratchet locking means on said mounting means and having a pivotable blocking member engaging said ratchet teeth.
3. Apparatus according to claim 2, characterized in that each rope winch is provided with a permanent rope tensioning means consisting of a low-rebound freewheel, which is arranged between the rope drum and the entrainment ratchet wheel, and a driving motor exerting a torque onto the rope drum in take-up direction.
4. Apparatus according to claim 2, characterized in that the drive of the second rope winch is provided with a safety ratchet locking means consisting of the locking cylinders which are loaded with a pressure fluid by way of pump driven from the rope drum and producing pressure only on the upward movement of platform.
5. Apparatus according to claim 2, characterized in that terminal points of ropes on the rope drums are attached to piston rods which are guided in balancing cylinders connected with platform.
6. Apparatus according to claim 2, characterized in that the first rope winch is provided with a slack rope preventer having a rope loaded by a weight which is wound around the rope drum of the first rope winch against the reeling direction of the rope on the first rope winch.
7. Apparatus according to claim 6, characterized in that the drum of the second rope winch consists of a hollow cylinder which is slidingly carried on a base drum.
8. Apparatus according to claims 6 or 7, characterized in that the weight is connected with a sheave around which the rope runs to a compensating winch.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19803008585 DE3008585A1 (en) | 1980-03-06 | 1980-03-06 | DEVICE FOR LIFTING AND LOWERING A FLOATING OFFSHORE PLATFORM |
| DEP3008585.9 | 1980-03-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1155307A true CA1155307A (en) | 1983-10-18 |
Family
ID=6096438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000370878A Expired CA1155307A (en) | 1980-03-06 | 1981-02-13 | Apparatus for raising and lowering a floating offshore platform |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0035629B1 (en) |
| JP (1) | JPS57210A (en) |
| BR (1) | BR8101379A (en) |
| CA (1) | CA1155307A (en) |
| DE (1) | DE3008585A1 (en) |
| MX (1) | MX152501A (en) |
| NO (1) | NO154277C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3234177C2 (en) * | 1982-09-15 | 1985-12-05 | Dyckerhoff & Widmann AG, 8000 München | Method for lowering a platform of an artificial island on a supporting structure and device for carrying out the method |
| JPS60195324U (en) * | 1984-05-31 | 1985-12-26 | 株式会社 カノボ−リング | spat barge |
| JPS62211216A (en) * | 1986-03-08 | 1987-09-17 | Seidensha:Goushi | Lifting gear for conveying pallet in conveyor system |
| JPH0736915Y2 (en) * | 1987-03-25 | 1995-08-23 | 株式会社三隆製作 | Transfer container transfer mechanism |
| JPH0256321A (en) * | 1988-08-23 | 1990-02-26 | Matsushita Electric Works Ltd | Conveyance device |
| JP2507950Y2 (en) * | 1992-09-04 | 1996-08-21 | 碧南特殊機械株式会社 | Receiving type pitch feed conveyor for ceramic products |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB433392A (en) * | 1933-07-22 | 1935-08-14 | Kampnagel Ag | Improvements in and relating to mechanism for lifting floating bodies |
| US3003454A (en) * | 1958-12-10 | 1961-10-10 | Shatoska Henry | Propelling means for dredge barges |
| NL142746B (en) * | 1965-01-08 | 1974-07-15 | Gusto Fa Nv | DRILLING ISLAND OR SIMILAR PLATFORM. |
| NL7400716A (en) * | 1974-01-18 | 1975-07-22 | Hattum & Blankevoort Bv | Shock absorber for off-shore oil well operating platform - with legs able to be lowered to the seabed |
| NL7508496A (en) * | 1974-07-30 | 1976-02-03 | Willem Josef George Strolenber | DEVICE FOR LIFTING OR LOWERING A LOAD. |
| US4002038A (en) * | 1975-10-06 | 1977-01-11 | Raymond International Inc. | Method and apparatus for rapid erection of offshore towers |
-
1980
- 1980-03-06 DE DE19803008585 patent/DE3008585A1/en not_active Withdrawn
-
1981
- 1981-01-16 NO NO810137A patent/NO154277C/en unknown
- 1981-01-16 EP EP81100301A patent/EP0035629B1/en not_active Expired
- 1981-02-13 CA CA000370878A patent/CA1155307A/en not_active Expired
- 1981-02-13 JP JP1999781A patent/JPS57210A/en active Pending
- 1981-03-06 MX MX186259A patent/MX152501A/en unknown
- 1981-03-06 BR BR8101379A patent/BR8101379A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| BR8101379A (en) | 1981-09-08 |
| MX152501A (en) | 1985-08-14 |
| EP0035629A3 (en) | 1982-03-03 |
| NO154277C (en) | 1986-08-20 |
| JPS57210A (en) | 1982-01-05 |
| NO810137L (en) | 1981-09-07 |
| EP0035629A2 (en) | 1981-09-16 |
| EP0035629B1 (en) | 1984-08-15 |
| DE3008585A1 (en) | 1981-09-17 |
| NO154277B (en) | 1986-05-12 |
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