U.S. patent application number 11/910254 was filed with the patent office on 2008-12-11 for method and device for attaching a subsea cutting apparatus.
Invention is credited to Knut Bang.
Application Number | 20080304915 11/910254 |
Document ID | / |
Family ID | 37452239 |
Filed Date | 2008-12-11 |
United States Patent
Application |
20080304915 |
Kind Code |
A1 |
Bang; Knut |
December 11, 2008 |
Method and Device For Attaching a Subsea Cutting Apparatus
Abstract
A method of and a device for attaching a cutting apparatus, the
cutting apparatus comprising a framework structure and a cutting
head which can be displaced relative to the framework structure,
and where, during the cutting operation, the cutting apparatus is
tied in to the seabed by means of at least one attachment.
Inventors: |
Bang; Knut; (Stavanger,
NO) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
37452239 |
Appl. No.: |
11/910254 |
Filed: |
March 29, 2005 |
PCT Filed: |
March 29, 2005 |
PCT NO: |
PCT/NO2005/000107 |
371 Date: |
April 25, 2008 |
Current U.S.
Class: |
405/224.1 |
Current CPC
Class: |
E02D 9/04 20130101; B23D
57/0084 20130101; B63C 11/52 20130101; B63B 21/27 20130101 |
Class at
Publication: |
405/224.1 |
International
Class: |
E02D 7/20 20060101
E02D007/20 |
Claims
1. A method of attaching a cutting apparatus to the seabed, the
cutting apparatus comprising a framework structure for enclosing an
object to be cut and a cutting head which can be displaced relative
to the framework structure, the method comprising providing at
least one attachment and deploying the anchor(s) so that during the
cutting operation, the cutting apparatus is tied in to the seabed
during the cutting operation at least one attachment comprising at
least one suction anchor.
2. A device for attaching a cutting apparatus to the seabed, the
cutting apparatus comprising a framework structure for enclosing an
object to be cut and a cutting head which can be displaced relative
to the framework structure at least one attachment that can
projects into the seabed that the attachment comprising at least
one suction anchor so that during the cutting operation, the
cutting apparatus is tied in to the seabed.
3. A device in accordance with claim 2, wherein the cutting
apparatus is provided with a sawing wire comprising diamond cutting
surfaces.
4. A device in accordance with claim 2, wherein the cutting
apparatus is provided with a source of a cutting medium in the form
of a fluid to which has been added an abrasive.
5. A method in accordance with claim 1, wherein the framework
structure comprising two generally parallel, spaced apart frame
members and a cross member extending between them to form an open
u-shape, the method further comprising the step of enclosing the
object to be cut by moving the framework structure so that the
object enters the opening of the u-shape to be positioned between
the spaced apart frame members.
6. A method in accordance to claim 5, wherein the spaced apart
frame members each carry a rail and the cutting apparatus comprises
running wheel in engagement with the rails and a cutting head
mounted upon the wheels, the cutting head incorporating a cutting
mechanism, the method including the further step of causing the
cutting head to travel along the rails by means of the running
wheels to bring the cutting mechanism into contact with the object
to be cut.
7. A device in accordance with claim 2, wherein the framework
structure comprising two generally parallel, spaced apart frame
members and a cross member extending between them to form an open
u-shape, configured so that the object can enter the opening of the
u-shape to be positioned between the spaced apart frame
members.
8. A device in accordance to claim 7, wherein the spaced apart
frame members each carry a rail and the cutting apparatus comprises
running wheels in engagement with the rails and a cutting head
mounted upon the wheels, the cutting head incorporating a cutting
mechanism, the cutting head being configured to travel along the
rails by means of the running wheels to bring the cutting mechanism
into contact with the object to be cut.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and is a U.S.
National Phase of PCT International Application Number
PCT/NO2005/000107, filed on Mar. 29, 2005. The disclosure of the
above-referenced application is hereby expressly incorporated by
reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This invention regards a method of attaching a subsea
cutting apparatus. More particularly, it regards a method in which
a cutting apparatus designed to cut an object is attached to the
seabed. The invention also comprises a device for implementing the
method.
[0003] Cutting of objects located under water can according to
prior art be accomplished by e.g. sawing, grinding, clipping or
burning.
[0004] The cutting operation is normally performed by placing a
cutting apparatus at the cutting site by means of e.g. lifting
equipment or a so-called ROV (Remote Operated Vehicle). Then the
cutting apparatus may optionally be connected to the object to be
cut. It has proven to be rather difficult to achieve satisfactory
attachment of a cutting apparatus by remote control, when using
prior art.
[0005] For reasons of safety, the actual cutting operation is
normally controlled from a location remote from the cutting site,
preferably from the surface of the sea.
[0006] It is also known to place a cutting apparatus on the seabed
during cutting operations. This may prove satisfactory when
clipping an object, but as a rule it will not provide sufficient
stability when cutting the object by means of sawing or
grinding.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to remedy or reduce at least
one of the disadvantages of prior art.
[0008] The object is achieved in accordance with the invention, by
the characteristics stated in the description below and in the
following claims.
[0009] A framework structure is placed on or immediately above the
seabed by the object to be cut. The framework structure is provided
with a cutting head arranged to be displaced (advanced) in the
direction of the object to be cut, in a manner that is known per
se.
[0010] The cutting head may, in dependence of the cutting method
employed, comprise e.g. cutting tools that represent prior art per
se, such as a diamond wire saw, a saw blade saw, a grinding rig in
which is used an abrasive wheel or a fluid to which has been added
an abrasive. Alternatively the cutting head may comprise torch
equipment based on gas or electricity. It may also be appropriate
to combine various cutting equipment.
[0011] The framework structure is provided with at least one
fastener portion arranged to be coupled to an attachment projecting
into the seabed.
[0012] Most preferably the attachment is brought to the seabed
along with the cutting apparatus. When the cutting apparatus is in
a planned position the attachment or attachments can be moved into
the seabed. When attached to the seabed, the attachments are made
to accommodate the forces transferred from the cutting head to the
framework structure.
[0013] The attachment may be pre-mounted at the mounting site and
may in addition to the attachment also comprise a coupling portion
for coupling to the framework structure.
[0014] Advantageously the attachment is designed as a suction
anchor or a ground screw. In special cases other solutions such as
a pile or hooks may be appropriate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The following describes a non-limiting example of a
preferred method and embodiment illustrated in the accompanying
drawings, in which:
[0016] FIG. 1 is a plan view of a cutting apparatus placed in
position about an object to be cut;
[0017] FIG. 2 is a side view 1a-1a of FIG. 1;
[0018] FIG. 3 is a side view 1b-1b of FIG. 1;
[0019] FIG. 4 shows the same as FIG. 1, but here the object has
been partially cut;
[0020] FIG. 5 shows a cutting apparatus equipped with ground
screws; and
[0021] FIG. 6 shows a cutting apparatus equipped with piles.
[0022] In the drawings, reference number 1 denotes a cutting
apparatus comprising a framework structure 2 and a cutting head 4
displaceably coupled to the framework structure.
[0023] The framework structure 2 comprises two parallel
spaced-apart frame members 6. The frame members 6 are assembled by
means of a cross member 8 extending between the frame members 6
near one end of the frame members 6. The cross member 8 and the
frame members 6 together form an open U-shape. Thus the framework
structure 2 can be moved in across an object 10 to be cut, so that
the object 10 will be between the frame members 6, see FIG. 1.
[0024] The frame members 6 each have a rail 12, which rails are
mutually parallel. The rails 12 are a complementary fit to drive
and running wheels (not shown) provided in the wheelhouses 16 of
the cutting head 4.
[0025] The wheelhouses 16 are rigidly interconnected by a profile
18. The wheelhouses 16 also form the supports for the driving disk
20 and reversing disk 22, respectively, of the cutting head.
[0026] The driving disk 20 is connected to a driving motor 24. A
sawing wire 26 preferably provided with diamond cutting means runs
endlessly around the disks 20, 22.
[0027] The outside of the framework structure 2 has a number of
fastener portions 28, here three, for coupling to respective
attachments 30.
[0028] In this preferred embodiment the attachments 30 are suction
anchors 32.
[0029] The required control and power connections to the cutting
apparatus 1 are of a type that is known per se, and are not
shown.
[0030] When an object 10 is to be cut the cutting apparatus 1 is
placed on the seabed about the object 10. The suction anchors 30
are moved into the seabed 34 in a manner that is known per se, by
removing the water present inside the suction anchor 30. This
results in a negative pressure in the suction anchor 30, causing
the suction anchor 30 to move into the seabed 34.
[0031] After the cutting apparatus 1 has been tied in to the seabed
the driving motor 24 is started, thus causing the sawing wire 26 to
rotate about the disks 20, 22. Then the cutting head 4 is advanced
towards the object 10, whereby the sawing wire 26 cuts into the
body of the object 10, see FIG. 4.
[0032] When the cutting has been completed the sawed-off part of
the object 10 may be removed, whereupon the cutting apparatus 1 can
be released from the seabed 34.
[0033] In an alternative embodiment, see FIG. 5, the cutting
apparatus 1 is provided with ground screws 36. The ground screws
are designed with a screw thread 38 and are arranged to be screwed
into the seabed 34 by turning the ground screw 36 about its own
longitudinal axis. The ground screw 36 extends rotatably through a
through opening 40 in the fastener part 28.
[0034] In another embodiment the cutting apparatus 1 is provided
with piles 42 extending through respective openings 40 and into the
seabed 34, see FIG. 6.
* * * * *