Door, in particular door for bulkheads in ships

TECHNICAL FIELD: The present invention relates to a door, in particular a bulkhead door for vessels, and especially a watertight bulkhead door for vessels with large cargo decks to which access for loading and unloading is gained via doors in the plating of the vessel. Vessels of this kind are designed to permit cargo to enter and leave on its own wheels, and the type of vessel is accordingly known as a roll-on-roll-off vessel, or it may be of the car ferry type.

DESCRIPTION OF THE PRIOR ART: The main deck of a vessel is designed to perform several functions. On a car ferry or a ro-ro vessel, several functional requirements are mutually contradictory. One wish associated with the loading and unloading of vehicles is for them to be able to be driven under their own power onto the deck and into their parking space, and for the deck to be as smooth and free as possible from obstructing pillars, walls and transverse variations in level. This requirement conflicts with the requirement for the greatest possible safety and stability of the vessel in the event of water finding its way onto the deck, when, amongst other things, the extent of the uncontained areas of liquid must be restricted as far as possible.

The conventional way of satisfying this requirement is with a number of watertight bulkheads running fore and aft or athwart-ships, or with a combination of these. In order to permit vehicles to be driven to all parts of the deck, all or parts of these bulkheads are executed so that they can be opened. If an elevating deck is installed over all or part of the main deck, this must also function with the bulkheads in a number of combinations of the loading and unloading procedure, as well as with the bulkheads closed.

These constructions and their operation has an adverse effect in terms of space and time on the parking areas and manoeuvring of the vehicles.

DESCRIPTION OF THE PRESENT INVENTION:

The door in accordance with the invention fully exposes the deck in the open position. In its closed position, it constitutes whole or part of a watertight bulkhead. Closing of the door can take place once all the vehicles have been driven to their final parking places on either side of the door. Opening is possible without having to move any of the vehicles. Elevating car decks can be integrated into the arrangement so as to retain all their functions. The space necessary for the door in the open position is small and can be integrated fully or partially into normally unutilized parts of the structure of the vessel. The door takes up very little space on the car deck in its closed position.

Each door can be operated independently of all the other doors irrespective of their relative positioning. The size of the door can be varied freely in height and width within the dimensions currently encountered on vessels. The positioning of the doors can be selected with considerable freedom in order to accommodate other arrangements on the vessel.

DESCRIPTION OF THE DRAWINGS: The accompanying drawings show two illustrative examples of the invention, in respect of which:

Fig. l shows the door viewed from the front in the closed position;

Fig. 2 shows the door as a section along the line II-II in Fig. 1, and also in the closed position;

Fig. 3 shows the door as the same section, but in the open position;

Fig. 4 shows an enlarged section illustrating a part in the

open position;

Fig. 5 shows a partial section of a component part of the door;

Fig. 6 shows a number of the same components joined together and adopting the position for the closed door; Fig. 7 shows a section along the line VII-VII in Fig. 1, with the section viewed from above;

Fig. 8 shows a section along the line VIII-VIII in Fig. 2, with the section viewed from the side of the door; in conjunction with which Figs. 1-8 illustrate the general principles of the invention, in the case of the first illustrative embodiment adapted for installation between two fixed vessel decks, whereas Figs. 9-12 relate to the second illustrative example, in respect of which: Fig. 9 shows a section comparable with the section in Fig. 4;

Fig. 10 shows the door in its closed position in an installation with an elevating deck between two fixed decks, with the former in an upper position; Fig. 11 shows the door in its open position in the same installation and with the same deck position as in Fig. 10; Fig. 12 shows the door in its closed position, but with the elevating deck in a lowered position; and Fig. 13 shows the door in its open position with the elevating deck in its lowered position.

PREFERRED EMBODIMENT:

A door in accordance with the invention is constructed from a number of horizontally arranged sections 1. The sections, which are illustrated most clearly in Figs. 4 and 5, are mutually identical. With the door in its closed position, they are unfolded from one another and form a zig-zag shape; see Fig. 2. In the open position of the door, they are folded against one another to form a stack of low height; see Fig. 3. The cross-section of the sections 1 is designed so as to permit them to be connected together in the manner shown in Fig. 4 without any loose coupling elements, thereby forming holders for sealing elements 2

between the sections. The uppermost section is attached to a part of the structure of the vessel with a profile 3 attached to it.

The lowermost section is attached in accordance with Fig. 4 to a magazine 4 for collecting the sections with the door open. The section is attached for this purpose to the magazine by means of a profile 5, which is connected to the lowermost section by means of a sealing element of the same type as the element 2.

The expression magazine denotes that the unit in question to some extent encloses the sections, more specifically those when the door is open and the sections are stacked closely on top of one another. This is also an advantageous design, which was selected for the described embodiment. Such a magazine thus offers the following functions: enclosure of the raised sections with the door open, offering protection against damage and dirt, etc., protection of the lower part of the door when it is closed, so that damage is prevented to the lower sections and the attachment of the lowermost section, for instance caused by objects sliding over the deck as a result of movement of the vessel, and stable retention of the lowermost section and thus of the bottom edge of the main section, in that the lowermost section can be permanently attached to the magazine, which can in turn be executed to permit very robust attachment to the structure of the vessel. This attachment must be detachable when the door is to be opened, and the need to make the sections slender so as not to be excessively heavy and demanding of space when hoisted up would pose considerable problems in finding a detachable and, at the same time, reliable means of attachment if engagement were to be with the actual section. Designing the magazine for such reliable attachment does not present any difficulties, however, nor does the provision of a robust permanent attachment between the undermost section and the magazine.

Since the last-mentioned function is the most important - attachment of the lower edge of the door is a condition for its overall reliability - it is conceivable to execute the unit not as a magazine, but rather as a plate or the like. Although this results in the loss of the aforementioned protective functions, the attachment function can nevertheless be assured.

The door consisting of the sections 1, which in its entirety is designated as 6, is designed for installation in an opening in the structure of the vessel, formed on one side by a bulkhead 8 and on the other side by a bulkhead or wall 9 and at the top by the aforementioned structure 9, to which the profile 3 is attached and which can be said to constitute an upper, fixed deck 10, and the opening is finally terminated on the underside by a fixed deck 11. The door is thus installed between two fixed decks.

Guide arrangements for the movement of the sections 1 and the magazine 4 during opening and closing are present along the vertical sides 8 and 9 of the door opening. Also present along the vertical sides are sealing arrangements for sealing against the end edges of the sections and against the magazine 4. This sealing arrangement in turn is sealed against the surrounding structure in the vessel when the door is closed. A hoisting mechanism is provided for the purpose of opening and closing the door, which mechanism is shown here by cables 12 attached to the magazine 4 and so arranged as to be wound by means of an electrically powered winch (not shown here) for cables, which is attached to the magazine by an arrangement of corner blocks. The hoisting system is self-braking, and separate locking mechanisms for the open door are not necessary for its function. The positioning of the components within the hoisting system is intended to maintain water-tightness with the door closed. Remote control and/or automatic operation can be provided as an

integral part of the structure.

The principal components of the bulkhead door have now been described, and the following is a more detailed description with reference primarily to Figs. 4, 5 and 7, 8.

The sections 1 consist of sheet-like elements with rounded curved edges viewed in cross-section, referred to here as the longitudinal edges because they extend between the sides 8 and 9 of the door opening. It can be appreciated from Figs. 4 and 5 that one longitudinal edge 14 exhibits a wider rounding than the other longitudinal edge 15, such that the edge 15 is accommodated inside the edge 14. The sections are assembled so that every other section has one of the different longitudinal edges facing to one side of the door, and every other section with its edge shaped in the same way facing in the other direction. In this way, the sections can be assembled as shown in Fig. 4 with the larger rounding enclosing the smaller rounding in the whole stack of sections, so that these are held together in this way by means of flexible connections. The narrower edge 15 thus forms a seat for the sealing profile 2, in which case this will seal against the inside of the enclosing edge; see Fig. 5.

The rounded edges are adapted to one another in such a way that they are able to flex in relation to one another whilst retaining their sealing, and that they cannot be disconnected at the angles which occur between the sections as the door is opened and closed. The wider edge part 14 of the lower section is so arranged as to interact with the profile 5 in the magazine 4, which exhibits the same rounded form as the edge profile 15. The upper profile 3 encloses the narrower edge profile 15 of the uppermost section, in the same way as a wider rounded edge 14.

The magazine 4 has a bottom 16 with a raised part 17 and two longitudinal parts 18. Reinforcing ribs 19 are arranged

along these. The bottom part of the magazine is designed to provide reliable, but detachable attachment to the vehicle structure. This is achieved especially in that hydraulically controlled arrangements introduce securing elements into the magazine when this is moved into contact with the lower deck with the door closed.

Fig. 4 also shows the aforementioned hoisting cable 12, which interacts with arrangements 20 on the magazine. It can also be appreciated from Figs. 7 and 8 that a guide wheel 22 provided with a groove 23 around its periphery is attached at either end of the parts 18.

Fig. 7 also shows that support arrangements 25 and 26 are arranged on the lateral edges 8 and 9 of the door opening to either side of the door. These arrangements are terminated on the inside facing the door by means of plates 27 and 28 extending outwards from the respective edge 8, 9. These plates form a support for lateral edges 29 and 30 of a U-shaped element 32 with a bottom 33 facing outwards towards the door. This is stepped inwards at 30 and supports a sealing strip 34 at this point. The bottom 33 is provided on the outside with upright flanges 36 and 37, which are shown in Fig. 8 to be terminated by a lower, inward-angled part 39, whereas the outer edge 40 is otherwise straight and extends up to the edge 10 of the door opening. Compression springs 42 are inserted between the edge 8 and 9 and the bottom 33, which attempt to force the element 32 out towards the end edges of the magazine and the sections beneath an insert consisting of an elastic covering 43 on the outside of the bottom. The wheels 22 on the magazine 4 are positioned so that pressure of this kind against the lateral edges of the sections can be exerted when the magazine is in its lower position (see Fig. 8) and the wheels are thus situated in front of the inward-angled part 39 of the flanges 36, 37. With the elements 32 in this position, the sealing strips 34 on either edge of the opening will be compressed to produce a seal against a

sheet on the fixed support element 26. If the magazine is raised so that the wheels 22 come into contact with the part 40 of the flanges, the elements 32 will be forced outwards against the effect of the springs and, in so doing, will produce a clearance with the end edges of the sections.

The door is not normally subjected to any high forces. It is only in an emergency situation with a high water level on one side of the door that it is required to withstand a high, unilateral load, applied from either side, without the risk of rupture and maintaining full sealing. Separate battening arrangements are provided for this purpose, in this case clamping arrangements for securing the door.

As far as the magazine 4 is concerned, such arrangements involve supporting the magazine by the element 32, which in turn can be held by the fixed support elements 25, 26. The magazine is protected from lateral displacement in this way when it is in its lower position with the door closed.

For the purpose of battening the sections 1, a bar-shaped securing element 46 (Figs. 4, 6, 7), which extends partially beyond the end edge of the section, is attached to the larger rounding on the outside of the lateral edge part 14 of each of the respective sections. For the purpose of accommodating the securing elements 46, the bottoms 33 of the U-shaped elements 32 are provided with an enclosing reinforcement 47, into which the securing elements can be introduced, which takes place once the elements 32 have been displaced outwards towards one another as shown in Fig. 8. It is assumed in Fig. 7 that the sections 1 are folded together and housed in the magazine 4. The securing elements 46 to either side of the stack of sections will then be situated at their greatest distance from one another; see Fig. 4. If, on the other hand, the door is closed and the elements are unfolded at an angle in relation to one another, viewed in the transverse sense of

the door (see Fig. 6), the securing elements on both sides will be situated at a shorter distance from one another. The distances between the holes through the reinforcing rings 47 are adapted to the latter, shorter distance between the securing elements. With the door open, as shown in Fig. 7, when the securing elements adopt their greatest distance from one another, they will accordingly not align with the aforementioned holes, as shown in Fig. 7.

The sections 1 are thus battened individually by means of their respective securing elements 46 by fixing them in the aforementioned holes in the U-shaped element 32. This in turn is secured against lateral displacements in the event of high, unilateral pressure, in that it is able to lie against one of the plates 27 or 28 for the support elements 26 and 26, depending on the direction of the pressure.

As can be seen from Fig. 4, each section 1 is provided with only one securing element 46, at the end where the wider rounded part 14 is situated. This permits the tolerances to be kept low with the securing elements in position in their respective seats, which would not be possible with a number of securing points. The tolerances in the links formed by the interacting rounded parts 14 and 15 can thus be made larger than the aforementioned tolerances, making it possible to avoid exposure of the links to large forces, which are instead fully absorbed within the securing system.

It is important with regard to the overall function, strength and sealing for the dimensions of the arrangement as a whole to be kept within close tolerances, given that the position, form and size of fittings and recesses varies in a complex manner with the different heights of the different doors. In terms of the loading imposed on them, the sections must be able to move freely in relation to one another with the door closed, in order for the forces to be correctly distributed to the battening fittings, in this

case the securing elements 46. The seal 2, preferably a rubber packing, between the sections 1 must be retained securely in all directions by the form of the rounded edge, in order to avoid the need for gluing. It must be subjected to the correct compression in all the alternative positions that are capable of being adopted by the sections, and also under the varying loading imposed on one side during filling with water, as well as at different working angles depending on the different relationships between the number of sections and the total height at the different doors. It must be entirely free from compression when the door is open.

As far as the sections are concerned, they must be capable of being connected together at an angle that it is possible to achieve, both before the magazine with the sections is installed in the guides and subsequently for the necessary replacement of any sections in conjunction with repair and maintenance. The sections must be capable of being folded against one another and stacked with the door open with the least possible space requirement.

As will have been appreciated from the above description, the door in accordance with the illustrative example is intended for installation between two fixed decks. The situation may arise, however, if the vessel is intended to accommodate cargo units of different heights, in which it is equipped with an elevating deck between two fixed decks. This deck may alternatively be anchored in a position between the fixed decks, in which case it will divide the space between them into two spaces with a lower height, or else the deck can be moved to a position adjacent to one of the fixed decks, as a general rule involving hoisting it up to a position beneath the upper fixed deck. In this position, essentially the entire height between the fixed decks can be used for the cargo. In the case of a car ferry, for example, a cargo consisting predominantly of passenger cars can be loaded at two levels by anchoring the

elevating deck in its central position between the fixed decks, whereas a cargo consisting mainly of large goods vehicles with tall loads can be accommodated if the elevating deck is moved out of the way. In the case of the second illustrative embodiment described here, an adaptation has been made to the door to permit this installation case, too.

Fig. 9 shows a section that is comparable with the section in Fig. 4. The folded main element 6 can thus be found together with the stack of sections 1, the magazine 4 with its hoisting cables 12 and surrounding components, which can be of the same design as previously described. Securing profiles 3 for the uppermost section 1 are not, however, attached to the fixed structure of the vessel, but to a bridge 50 of U-shaped section. Hoisting cables 12 for the magazine pass through holes 51 in the bridge. The bridge 50 can be supported in its lowered position by so-called suspension stays. Such suspension stays can consist of steel cables, chains or hinged rods, for example. They act as fixed supports for elements in their lowered position, in this case the bridge 50, whereas with the elements in their raised position, they are folded together by the upward movement of the element. They provide very secure support at a specific vertical level. The bridge must also be provided with anchoring elements enabling it to be anchored to adjacent bulkheads at specific vertical levels. These fittings are preferably remotely controlled.

The aforementioned suspension stays are adapted in this way to give the bridge 50 a position in which its upper side is level with the upper side of the elevating decks 55, 56 in their common intermediate position between the fixed decks 58 and 59 to permit subdivision of the cargo space into two levels (see Figs. 12 and 13). The suspension stays thus provide the bridge 50 with secure support at a specific vertical level. The aforementioned movable anchoring fittings are so arranged as to be capable of anchoring the

bridge in a position approximately half-way between the aforementioned vertical level in accordance with Figs. 12/13 and the upper fixed deck 58; see Figs. 10 and 12. The anchoring fittings are preferably also so arranged as to be capable of anchoring the bridge adjacent to the upper deck 58; see Fig. 11. The bridge 50 must thus be capable of being held in three specific vertical positions: adjacent to the upper deck 58, between the upper deck 58 and the decks 55, 56 in their lowered positions, and on the same level as the lowered decks 55, 56.

Figs. 10-12 present schematic cross-sections of the arrangement with the elevating decks 55, 56. As can be seen, these are situated between an upper fixed deck 58 and a lower fixed deck 59. These decks may be said to correspond to the fixed structures, with their door opening forming surfaces designated as 10 and 11 in Fig. 1. Situated between these two fixed decks, therefore, are the elevating decks 55 and 56, which can be set to different vertical levels. Figs. 10 and 11 thus illustrate the decks 55, 56 in their raised position adjacent to the upper fixed deck 58, in conjunction with which essentially the entire available height between the two fixed decks 58, 59 can be utilized for loading.

Figs. 12 and 13, on the other hand, show the elevating decks 55, 56 lowered to an intermediate position between the fixed decks 58 and 59. Two cargo levels are formed in this way, on the one hand at the level of decks 55 and 56, which are situated at a common vertical level, and on the other hand at the level of the lower fixed deck 59, whereby both cargo levels can be utilized for parking cargo having quite a low height. The bridge 50 is lowered in this case to a height level with the opening 54 between decks 55 and 56. This forms a largely uninterrupted cargo level extending over the deck 55, the bridge 50 and the deck 56.

In the second illustrative embodiment, the main element of

the door is so high that closing-off can be achieved irrespective of whether the entire height between the fixed decks is to be utilized for cargo, or whether the space is to be divided up vertically by the decks 55, 56. Fig. 10 shows the space between the fixed decks closed off by means of the door arrangement. It illustrates how the elevating decks 55, 56 are hoisted up into a position directly beneath the upper fixed deck 58. According to the preferred illustrative example, the bridge 50 then adopts a position approximately half-way between the central position of the elevating decks 55, 56 and the upper deck 58, that is to say at a vertical level approximately equivalent to three quarters of the entire available height measured from the lower deck 59. The bridge is held secure in this position by means of the aforementioned movable anchoring elements.

The position of the bridge at this level with the door closed is justified on the grounds that the requirements for closing off the boundary between the dividing sections in deck spaces of great height, such as are encountered in this embodiment, permit the closing-off to be other than total. In its closed position, however, the door must extend upwards to a sufficient height for it to be located significantly above the level of the elevating decks 55, 56 when these are in their intermediate position and can be used as a parking space; see Fig. 12. Where there is a requirement for full closing-off, however, the bridge 50 may alternatively be so arranged that, with the door closed, it is situated adjacent to the upper deck 58 with the closing element extending between that position and downwards as far as the lower deck 59.

Transport of the bridge between its three positions: to a height level with the lowered decks 55, 56; to the closing height shown in Figs. 10 and 12; and to the position adjacent to the upper deck 58 in accordance with Figs. 11 and 13, takes place with the help of the magazine 4 that is capable of being hoisted by means of its cables 12. If the

magazine 4 is hoisted up, with the sections 6 folding together, until it comes into contact with the bridge 50, the latter can be hoisted up together with the magazine or lowered whilst it is supporting the magazine.

Fig. 11 shows the corresponding position for the elevating decks, but with the door arrangement open in this case. As the door is opened from the position shown in Fig. 10 to the position of the bridge and the magazine adjacent to the upper deck 58, hoisting continues to the position shown in Fig. 11, as already described, by hoisting the magazine 4 by means of its cables 12 until it makes contact with the bridge 50, whilst the latter is supported. The bridge 50 can be lowered from the position shown in Fig. 11 by lowering the magazine for anchoring by means of the moving anchoring elements in the position shown in Fig. 10, after which the magazine is lowered further as the main element l is deployed.

Thus, with the elevating decks 55, 56 lowered to divide up the space between the fixed decks 58, 59, the door arrangement in accordance with Fig. 12, with the door closed for both spaces, adopts the same position as in Fig. 10. The magazine 4 is thus lowered to the deck 59. The bridge 5D is situated in its three-quarter position already described.

If it is wished to open the door, the magazine 4 is hoisted and moves into the bridge 50; see Fig. 9. The closed position of the door with the space between the fixed decks undivided (Fig. 10); the fully open door, also with the space undivided (Fig. 11); and the closed door with the space between the fixed decks divided by the lowered position for the decks 55, 56 (Fig. 12) have now been described. With the door open when the decks 55, 56 are lowered, the bridge must be on a level with these decks at the same time as the magazine 4 is hoisted up into contact with the bridge. In this position, the bridge is supported

very securely by means of the aforementioned suspension stays. As can be appreciated from Fig. 13, the upper side of the bridge 50 is then on the same level as the upper sides of the decks 55, 56, and thus closes off the gap 54 between the two decks to give an uninterrupted driving surface. The manner in which the bridge can be transported into this intermediate position from one of its two upper positions with the help of the magazine is described above. With the door open, the bridge 50 must always be level with the decks 55, 56 in the intermediate position, so that the opening 54 between them is always closed by the bridge 50. If, on the other hand, the elevating decks 55, 56 are lowered and the space between the fixed decks is undivided and the door arrangement is required to be open, as shown in Fig. 11, the bridge 50 must adopt its uppermost position immediately beneath the deck 58, where the elevating decks 55, 56 are also situated.

The elevating decks 55, 56 can naturally be arranged for positioning at several alternative vertical levels, in which case the door arrangement must be suitably adapted. The door arrangement can also be executed for a number of elevating decks between two fixed decks.

The bulkhead door can be executed in various ways within the context of the following patent claims in relation to what is indicated above. One of the two vertical sealing arrangements can thus be executed as a fixed structure, in which case the door as a whole is forced against it by the second sealing arrangement, which for this purpose is executed so that it is movable in accordance with the previous description. The door can be executed as a water¬ tight screen from the deck and upwards to the desired height. Operation of the door can be arranged with systems other than an electrically driven winch, for example a hydraulically driven winch, linear electric motors, directly acting hydraulic cylinders, a jigger winch with hydraulic cylinders or a manual winch. It is also possible

to arrange the door with the sections vertical to permit lateral opening if the arrangement concerned are adapted to permit this.

The principal objective indicated here is the watertight subdivision of a large deck with or without an elevating intermediate deck. The door can also be executed and used to restrict the movement of free areas of liquid in vessels with cargo hold hatches, however, by suspending the door arrangement from the under side of the cargo hold hatches and lowering the sections to an appropriate level in the liquid. The principle can be applied for screening in contexts where other types of door are now in use.