WO2019229294A1

WO2019229294A1 - Closure arrangement

Info

Publication number: WO2019229294A1
Application number: PCT/FI2019/050406
Authority: WO
Inventors: Mauri KALLIOMÄKI
Original assignee: Dg-Diving Group Ltd.
Priority date: 2018-05-31
Filing date: 2019-05-24
Publication date: 2019-12-05
Also published as: FI20185494A1; EP3802307A1; FI128382B

Abstract

A closure arrangement for an underwater equipment tunnel, said equipment tunnel (PT) being located in a hull (H) of a watercraft (WC), below a waterline (WL) of the water- craft. The equipment tunnel has a specific diameter (D1) and an inner surface (S). The closure arrangement (11, 2) comprises a closure element, which at least partially covers a surface corresponding to the inner surface of the equipment tunnel, and which is removably installable in the equipment tunnel. In order to provide a conveniently and quickly removable closure arrangement, the closure arrangement comprises a frame element directly and re- movably fast enable to the inner surface (S) of the equipment tunnel (PT), and an adaptation element supported on the frame element for sealing the closure element of a flexible material against the inner surface of the equipment tunnel.

Description

Closure arrangement

The present invention relates to a closure arrangement for an underwater equipment tunnel, said equipment tunnel being located in a hull of a watercraft, below a waterline of the watercraft, which equipment tunnel has a specific di- ameter and an inner surface, which closure arrangement comprises a closure element, which at least partially covers a surface corresponding to the diame- ter of the equipment tunnel and which is removably installable in the equip- ment tunnel, according to the pre-characterizing portion of claim 1.

Prior art

In watercraft, as in other waterborne structures, such as for example drilling platforms or the like structures, steering propellers are often deployed for posi- tioning or maneuvering the watercraft or waterborne structure in addition to the actual propulsion system. Such steering propeller devices can be for example so-called bow or skeg thrusters. The propeller devices are generally installed in tunnels, so-called propeller tunnels, transverse relative to the ship. The pro- peller devices require maintenance, repair, or replacement with a new device, which can be performed on-site or by removing the propeller device from the watercraft or drilling platform for such procedures. These procedures can be performed for example by docking the watercraft, which is inconvenient and time-consuming in addition to the actual procedure. Minor maintenance and repair procedures can be carried out by a diver, but it should be appreciated that underwater work involves considerable limitations regarding both working conditions and procedures to be performed.

In order to make it easier to carry out the procedures, an effort has been made to empty a propeller tunnel of water, which has first required welding a fixed bracing structure to the outer edges of the propeller tunnel. After this, on the fixed bracing structure a protective plate or cover is mounted under water, fol lowed by emptying the propeller tunnel of water. This has, first of all, called for a highly demanding underwater welding operation, after which the propeller tunnel still must be closed and emptied of water. The fixed welded structure further hinders for example entering and leaving the propeller tunnel with nec- essary tools and further moving a propeller unit or parts thereof into and out of the tunnel.

The discussed piece of equipment can be of some other type, whereby the propeller tunnel can be termed as an equipment tunnel. Summary of the invention

An objective of the present invention is to eliminate the disadvantages of prior and to provide a closure arrangement, which is simple in construction and which as a single unit is readily installable in and removable from an equip- ment tunnel, for example a propeller tunnel. This objective is attained with a closure arrangement according to claim 1.

The basic concept of the present invention is that the closure arrangement is directly and removably installable in an equipment tunnel as a single unit. This is carried out in such a way that the closure arrangement comprises a frame element fastenable directly and removably to the inner surface of the equip- ment tunnel, a closure element made of a flexible material, and an adaptation element supported on the frame element for sealing the closure element of a flexible material against the inner surface of the equipment tunnel.

The piece of equipment can be for example a propeller device, in which case the equipment tunnel can be termed as a propeller tunnel.

The frame element is preferably constructed from a circular- or circular seg- ment-shaped arch member of a rigid material, which is provided with fastening elements disposed on the arch member at intervals from each other and ena- bling the arch member to be directly and removably fastened to the inner sur- face of the equipment tunnel. In this way the frame element can be precisely and securely installed in the equipment tunnel.

If the frame element is constructed from a circular segment-shaped arch mem- ber of a rigid material, the circular segment-shaped arch member has its ends connected to each other with a cross bracket for stabilizing the installation. The adaptation element is also preferably constructed from a circular- or circu- lar segment-shaped structure of a rigid material. The adaptation element is fix edly supported by means of bracing elements on the arch member formed by the frame element and the arch member is provided with tightening elements, by means of which the adaptation element and the closure element of a flexi- ble material mounted thereon are sealable against the inner surface of the equipment tunnel. Hence, the equipment tunnel is tightly sealable by means of the closure arrangement as necessary. The closure element of a flexible material is preferably constructed from a pro- tective covering, which is installable and sealable between the adaptation ele- ment and the inner surface of the equipment tunnel for closing the equipment tunnel at least partially. This makes installation easier and lighter.

The closure element or the adaptation element is provided with an elastic seal- ing element for ensuring the sealing achieved against the inner surface of the equipment tunnel.

The closure element of a flexible material is preferably provided with an aera- tion means, enabling the equipment tunnel to be easily emptied of water. The aeration means is preferably an aeration valve.

The closure arrangement is preferably configured in such a way that the frame element, the adaptation element, and the closure element of a flexible material applied around the adaptation element, are introducible into the underwater equipment tunnel as a single unit for facilitating installation of the closure ar- rangement.

The closure element of a flexible material is preferably provided with a flotation means for facilitating a waterborne transport of the closure arrangement. The flotation means is preferably an air pocket. In addition, the flotation means is preferably provided with an aeration device. The aeration device is preferably an aeration valve.

Preferred embodiments of the closure arrangement are given in claims 2-13.

Brief description of the drawings

The invention will now be described by way of example only with reference to the accompanying schematic drawings, in which

Fig. 1 illustrates an example of an underwater equipment tunnel included in the hull of a watercraft,

Figs. 2A and 2B show one embodiment of a closure arrangement,

Figs. 3A and 3B show a second embodiment of a closure arrangement, and

Figs. 4A and 4B show cross-sections from the periphery of a closure arrange- ment. Detailed description

In Fig. 1 , the watercraft is indicated by reference character WC. The water- craft’s waterline is indicated by reference character WL and an underwater equipment tunnel included in the watercraft is indicated by reference character PT, which in this embodiment is presented as a so-called propeller tunnel. Subsequently, the equipment tunnel is termed as a propeller tunnel. The pro- peller tunnel has a given diameter D1 and it is mainly cylindrical, whereby the propeller tunnel has a mainly cylindrical inner surface S. In this example, the propeller tunnel has installed therein a rotatable propeller device PD fitted with a propeller P, for example a so-called azipod apparatus, whose propulsion di- rection can be varied by 360°. It is obvious that the propeller device and its ar- rangement can be other than what is presented in the figure. The discussed tunnel may include some other type of device or devices, which is why the term propeller tunnel must be understood broadly. The propeller tunnel PT has its opposite inlet openings indicated by reference characters PT1 and PT2. The closure arrangements to be mounted at the opposite inlet openings are indicated with reference numerals 11 and 12. The closure arrangements can be either consistent with the embodiment of Figs. 2A and 2B or consistent with the embodiment of Figs. 3A and 3B, as necessary at a given time. In the following the embodiments will be described in terms of the construction thereof and installation work involved therein.

Figs. 2A and 2B illustrate one embodiment of a closure arrangement 1. Figs. 4A and 4B display cross-sections from the periphery of the closure arrange- ment. Fastening elements 22, bracing elements 32 and tightening elements 33, to be described more precisely hereinafter, are spaced along an arch member 21 at various intervals as shown in Figs. 4A and 4B with dashed lines.

The closure arrangement 1 comprises a frame element 2, which is constructed from a circular-shaped arch member 21 made of a rigid material and provided with fastening elements 22 which are disposed on the arch member at inter- vals from each other and by means of which the arch can be fastened directly to the inner surface S of the propeller tunnel PT. The fastening elements may consist of threaded sleeves 221 fixed to the arch member 21 and of threaded bolts 222 fitted therein, the attachment being achieved by turning the latter. In order to obtain such an attachment, the fastening elements 22 are preferably disposed on the arch member 21 at equal intervals. On the frame element 2, i.e. on the arch member 21 , is fixedly braced an ad- aptation element 3. The adaptation element 3 can be constructed from a circu- lar-shaped flat member 31 , which is slidably disposed and supported on the arch member 21 by means of bracing elements 32 disposed at a specific dis tance from each other (Fig. 4B). The bracing elements 32 comprise preferably a bushing 321 , which is fixed to the arch member 21 and has a spindle 322 which is fastened to the flat member 31 and movable in the bushing 321. Hence, the flat member 31 is capable of being set against and away from, i.e. at a distance from, the inner surface S of the propeller tunnel PT while being supported by the spindle 322 and the bushing 321.

Clamping the flat member 31 against the inner surface S of the propeller tun- nel PT is carried out by means of tightening elements 33 (Fig. 4A). The tighten- ing elements 33 consist preferably of threaded sleeves 331 mounted on the arch member at specific intervals 21 and of threaded bolts 332 fitted therein, the turning of the latter enabling the flat member 31 to be tightened against the inner surface S of the propeller tunnel PT.

The frame element 2 and the adaptation element 3 make up a closure ar- rangement supporting structure, which is thus in the shape of a circle.

A closure element 4 made of a flexible material, comprising in this embodi- ment, by way of example, a protective covering 40, is folded around the flat member 31 for providing a closure in the same shape as the arch member 21. The protective covering 40 is circular in shape and has its periphery preferably provided with a bulge 41 to keep it better in its place installed around the flat member 31. In addition, the protective covering 40 has its periphery preferably provided with an elastic sealing element 5, which is intended to be set between the flat member 31 and the protective covering 40 so as to ensure the sealing of the protective covering against the inner surface S of the propeller tunnel PT. The sealing element 5 can be alternatively mounted on the flat member 31. The protective covering 40 can be attached to the frame element 2 and/or to the adaptation element 3 for example with a wire 7 as shown in Figs. 4A and 4B or in another similar fashion.

The protective covering 40 is provided with an aeration means 42. The aera- tion means is preferably an aeration valve (Figs. 1 -3B). The protective covering 40 is preferably provided with a flotation means 43 for enabling an underwater transport of the closure arrangement 1 to its destina- tion in the underwater propeller tunnel PT as a single unit in a desired position. The flotation means 43 is preferably an air pocket 430, which is fitted with an aeration device 44, preferably an aeration valve. The flotation means may also be some type of float or other device, by means of which the closure arrange- ment is enabled to float in the water.

The elastic sealing element 5 may consist for example of so-called sealing rubber or other such material. The frame element 2 and the adaptation ele- ment 3, as well as the above-mentioned components thereof, may consist for example of stainless steel, aluminum or the like rigid material. Preferably, the materials are appropriate for use in underwater environment and for storage on land.

Figs. 3A and 3B illustrate a second embodiment of the closure arrangement 1. Figs. 4A and 4B illustrate cross-sections from the closure arrangement’s pe- riphery. The fastening elements 22, bracing elements 32 and tightening ele- ments 33, described more precisely above in connection with figs. 2A and 2B, are distributed along the arch member 21 at various intervals as indicated in figs 4A and 4B with dashed lines.

The essential difference with respect to the above-described embodiment of Figs. 2A and 2B is that the closure arrangement’s support structure, which thus comprises the frame element 2 and the adaptation element 3, is in the shape of a circular segment. In order to install an arch member 2 in the shape of a circular segment securely in the propeller tunnel PT, the arch member 21 has its ends connected to each other with a cross bracket 6 for stabilizing the sup- port structure. Accordingly, the protective covering 40 is also the shape of a corresponding circular segment. This applies preferably also to the above- mentioned bulge 41 and sealing element 5.

In the following an installation and removal of the closure arrangement into and from the propeller tunnel will be briefly discussed with reference to Figs. 1-4B, as well as to the foregoing structural and installation description.

First is selected a support structure consistent with the size of the propeller tunnel PT, i.e. its diameter D1 , i.e. an assembly of the frame element 2 and the adaptation element 3, which thus comprises an arch member 21 provided with the above-described fastening elements 22, and an adaptation element 3 pro- vided with the above-described bracing elements 32 and tightening elements 33. This is followed by selecting a closure element 4, in other words a protec- tive covering 40, which is consistent with the size of the support structure and whose periphery preferably includes a bulge 41 and preferably also a sealing element 5. The protective covering 40 is applied around a flat member 31 of the adaptation element 3 from the side of the support structure facing the ad- aptation element 3. Thereafter, the floating means 43, i.e. the air pocket 430, is filled with air by way of the aeration device 44, i.e. an aeration valve. The pro- tective covering 40 can be attached to the frame element 2 and/or to the adap- tation element 3 for example with a wire 7 depicted in Figs. 4A and 4B or in another similar fashion.

After this, the (first) closure arrangement 11 , which in the example shown in Fig. 1 comprises a circular-shaped (Figs. 2A and 2B) frame element 2, an ad- aptation element 3 and a closure element 4, can be placed in water and trans- ported to a (first) inlet opening PT1 of the propeller tunnel PT for example by a diver. The closure arrangement 11 retains its desired position in such a way that the air pocket 430 at an upper edge of the closure arrangement supports the closure arrangement 1 in water essentially in an upright position, thereby facilitating its adaptation in alignment with the mouth of the propeller tunnel PT. When the closure arrangement 11 has been set in alignment with the inlet opening of the propeller tunnel PT, preferably in an upright position, that the closure arrangement’s support structure, comprising the frame element 2 and the adaptation element 3, can be fastened to the inner surface S of the propel- ler tunnel PT as described above.

The (second) closure arrangement 12, which in the example shown in Fig. 1 comprises a circular segment-shaped (Figs. 3A and 3B) frame element 2, an adaptation element 3 and a closure element 4, is transported in a similar fash- ion to a (second) inlet opening PT2 of the propeller tunnel PT. After installa- tion, the protective coverings 40 of both closure arrangements 11 and 12 are sealed against the inner surface S of the propeller tunnel PT as described above.

Next, the space between the closure arrangements 11 and 12 of the propeller tunnel PT is supplied with air by way of the aeration means 42, i.e. an aeration valve. Thus, in an upper part of the propeller tunnel PT is established a water- free working space WS, which extends from an upper edge of the propeller tunnel to a bottom edge of the second closure arrangement 12 as depicted in Fig. 1. Between the bottom edge of the second closure arrangement 12 and a bottom edge of the propeller tunnel is established an access opening AO into the working space WS. The closure arrangements are selected according to what sort of working space is desired to be established in the propeller tunnel. Of course, the circular-shaped closure arrangement can also be used for clos- ing the mouth of the propeller tunnel PT partially by leaving the protective cov- er partially open as denoted with a dashed line in Fig. 2A. After this, the required procedures can be readily carried out regarding for ex- ample a propeller device PD or its propeller P.

After the procedures, the air is discharged out of the working space WS by way of aeration valves included in the protective coverings and the closure ar- rangements 11 and 12 can be removed from the inlet openings PT1 and PT2 of the propeller tunnel PT and lifted back up from water. The flotation means 43 facilitate transport of the closure arrangements to the water surface.

The solution according to the invention provides simple means for procedures to be conducted in an underwater propeller tunnel in a water-free, work-friendly and safe environment. The drawings and the description related thereto are only intended to illustrate the basic concept of the invention. The details such as for example the frame element, the adaptation element and the closure element, along with additional components therefor, may vary within the scope of the appended claims.

Claims

1. A closure arrangement for an underwater equipment tunnel in a wa- tercraft, said equipment tunnel (PT) being located in a hull (H) of a wa- tercraft (WC), below a waterline (WL) of the watercraft, which equip- ment tunnel has a specific diameter (D1 ) and an inner surface (S), which closure arrangement (1 , 11 , 12) comprises a closure element, which at least partially covers a surface corresponding to the diameter of the equipment tunnel and which is removably installable in the equipment tunnel, characterized in that the closure arrangement (1 , 11 , 12) comprises a frame element (2) directly and removably fasten- able to the inner surface (S) of the equipment tunnel (PT), a closure element (4) made of a flexible material, and an adaptation element (3) supported on the frame element (2) for sealing the closure element (4) of a flexible material against the inner surface (S) of the equipment tunnel (PT).

2. A closure arrangement according to claim 1 , characterized in that the frame element (2) is constructed from a circular- or circular segment- shaped arch member (21 ) of a rigid material, which is provided with fastening elements (22) disposed on the arch member at intervals from each other and enabling the arch to be directly and removably fastened to the inner surface (S) of the equipment tunnel (PT).

3. A closure arrangement according to claim 2, characterized in that, if the frame element (2) is constructed from a circular segment-shaped arch member (21 ) of a rigid material, the circular segment-shaped arch member (21 ) has its ends connected to each other with a cross bracket (6).

4. A closure arrangement according to any of the preceding claims, characterized in that the adaptation element (3) is constructed from a circular- or circular segment-shaped structure of a rigid material, the adaptation element (3) is fixedly supported by means of bracing ele- ments (32) on the arch member (21 ) formed by the frame element (2), and that the arch member (21 ) is provided with tightening elements (33), by means of which the adaptation element (3) and the closure element (4) of a flexible material mounted thereon are sealable against the inner surface (S) of the equipment tunnel (PT).

5. A closure arrangement according to any of the preceding claims, characterized in that the closure element (4) of a flexible material is constructed from a protective covering (40), which is installable and sealable between the adaptation element (3) and the inner surface (S) of the equipment tunnel (PT) for closing the equipment tunnel at least partially.

6. A closure arrangement according to any of the preceding claims, characterized in that the closure element (4) or the adaptation ele- ment (3) is provided with an elastic sealing element (5).

7. A closure arrangement according to any of the preceding claims, characterized in that the closure element (4) of a flexible material is provided with an aeration means (42).

8. A closure arrangement according to claim 7, characterized in that the aeration means (42) is an aeration valve.

9. A closure arrangement according to any of the preceding claims, characterized in that the closure arrangement (1 , 11 , 12) is config- ured in such a way that the frame element (2), the adaptation element (3) and the closure element (4) of a flexible material applied around the adaptation element, are introducible into the underwater equip- ment tunnel (PT) as a single unit for the installation of the closure ar- rangement.

10. A closure arrangement according to any of the preceding claims, characterized in that the closure element (4) of a flexible material is provided with a flotation means (43).

11. A closure arrangement according to claim 10, characterized in that the flotation means (43) is an air pocket (430).

12. A closure arrangement according to claim 11 , characterized in that the flotation means (43) is provided with an aeration device (44).

13. A closure arrangement according to claim 12, characterized in that the aeration device (44) is an aeration valve.