US3926002A

US3926002A - Device for excluding water from a working site located adjacent to a body of water

Info

Publication number: US3926002A
Application number: US490942A
Authority: US
Inventors: Birger Ludvigsson
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-07-26
Filing date: 1974-07-23
Publication date: 1975-12-16
Anticipated expiration: 1992-12-16
Also published as: SE7310358L; NO136529B; JPS5071096A; GB1477503A; FI225374A; FR2238809A1; ES428613A1; DK400674A; CA1008259A; BE817840A; BR7406034D0; NO742504L; IT1016940B; NO136529C; DE2434469A1; SE374710B; PL93419B1

Abstract

A ship building dock has an opening defined by a threshold and two side posts, which is closed by a door structure including a vertical waist portion forming the closure proper and a lower balancing portion, which may be vertical or horizontal. The structure is designed in such a manner that the external water pressure upon the two portions will about balance each other, and the forces of reaction will appear about at the level of the threshold.

Description

United States Patent [1 1 Ludvigsson Dec. 16, 1975 1 DEVICE FOR EXCLUDING WATER FROM A WORKING SITE LOCATED ADJACENT TO A BODY OF WATER [76] Inventor: Birger Ludvigsson, Sodra vagen 38,

Goteborg, Sweden, 41234 [22] Filed: July 23, 1974 21 Appl. No.: 490,942

[30] Foreign Application Priority Data July 26, 1973 Sweden 7310358 [52] U.S. Cl. 61/64; 61/22 [51] Int. Cl. B63C l/08 [58] Field of Search 61/64, 25, 22, 65, 8

[56] References Cited UNITED STATES PATENTS 3,133,420 5/1964 Burnett 61/64 Noguchi 61/64 Solinas 61/64 X Primary Examiner-Jacob Shapiro Attorney, Agent, or Firmllolman & Stern [5 7 ABSTRACT A ship building clock has an opening defined by a threshold and two side posts, which is closed by a door structure including a vertical waist portion forming the closure proper and a lower balancing portion, which may be vertical or horizontal. The structure is designed in such a manner that the external water pressure upon the two portions will about balance each other, and the forces of reaction will appear about at the level of the threshold.

9 Claims, 5 Drawing Figures US. Patent Dec. 16, 1975 Sheet 2 of3 3,926,002

FIG

U.S. Patfint Dec. 16, 1975 Sheet 3 of 3 3,926,002

FIGS

DEVICE FOR EXCLUDING WATER FROM A WORKING SITE LOCATED ADJACENT TO A BODY OF WATER BACKGROUND OF THE INVENTION The present invention relates to a device adapted to exclude water from a working site located below the water level. A ship building or repair dock is, usually at one of its ends (sometimes at both ends), provided with a door structure which along its bottom and sides seats against the fixed structure of the dock. When the water is pumped out of the clock, the door structure will have to take care of the hydrostatic pressure of the water outside the dock and to transfer this pressure to the bottom and the side walls of the clock, The static constructional system of the door structure is usually arranged in such a manner that a major portion of the water pressure is transferred by way of one or more horizontal girders, resting against the dock walls. The girder system is often integrated into a system of pontoons giving the necessary displacement for floating the door structure.

With the width of a door structure actual for todays docks such a support structure for taking care of the water pressure will be very uneconomical.

SUMMARY OF THE INVENTION The object of the present invention is to provide a device including a door structure, which is lighter and thus easier to handle and more economical than the traditional structure. The basic principle of the static system of a door structure according to the invention implies that the primary carrying system acts as a bracket which is supported at the level of the bottom of the entrance opening (the threshold thereof).

A device according to the invention may be used for excluding water from any working site located adjacent to a body of water and being separated therefrom by a wall having an opening defined by a threshold and two side posts, the device including a door structure operable in any suitable manner. The invention is characterized in that the portion of the door structure adapted, in mounted position, to take care of the sidewardly directed, uni-lateral water pressure is designed in such a manner that the forces of reaction substantially will appear at its lower part, to be transferred by way of the threshold, with the door structure further being designed in such a manner that the water pressure will force it against the treshold.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1, 2, 3 and 5 show various types of door structures, with the views being cross sections through the opening end of a ships dock and FIG. 4 is a top partial view of FIG. 3.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS FIG. 1 shows a portion of a dock adjacent to the opening giving access to the sea. The bottom of the dock is terminated by a threshold structure generally denoted by 11, and extending somewhat outside the side walls of the dock. Vertical end portions 12 of these walls will, together with the threshold, define the opening to the dock, and it should be remembered that the width of such an opening is considerably larger than the depth of the water.

2 A cross section through the door structure resembles an inverted T. A waist portion thereof, or a door panel proper 13, is rigidly connected to a flange portion or sole 14. The threshold 11 is provided with an inner 5 transom 17 against which the sole 14 rests at 19, and

which prevents a displacement inwards of the door structure. The horizontal portion of the threshold is arranged in such a manner that an enclosed zone will be defined between the threshold and the lower face of the sole 14. As shown, this zone preferably is formed as a recess 15, extending along a substantial part of the sole, and which, in a simple arrangement, communicates with the clock by way of a passage 16. The water pressure within the recess 15 will, in other words, depend upon the water level within the dock.

When the dock is evacuated, the water outside the dock will exert a laterally directed pressure upon the door structure.

The main horizontal component of this pressure will be taken care of by the contact between the sole and the threshold. The tilting moment upon the door structure is balanced by the load of the water externally applied to the sole being greater than the upwardly directed pressure in the recess 15, which pressure is determined by the water level within the dock.

Sealing means 18 and 20 are arranged between the door panel 13 and the side posts 12, as well as between the sole 14 and portion 21 of the sole surrounding the recess and defining the same against the surrounding water. The main components of the static system of the door structure are to be found in, and adjacent to the sole and by the balancing forces exerted by the water, a very light structure is obtained, also when the door is considerably wide. The weight of the structure, as calculated per meter thereof, will be independent of the width of the opening.

The threshold may be substantially plane, on which occasion the zone to be evacuated will be defined by the sealing means. A recess may possibly, wholly or partly, be located in the lower face of the sole.

According to a development of the invention, further sealing means 22 may also be fitted between the threshold and the sole in order to seal off completely the recess 15 towards the dock as well as towards the water outside the same. The passage 16 will then be led elsewhere than to the dock and will be connected to a pump. By removing water from the recess 15, a lower pressure will be obtained therein, which increases the stability of the door structure. In order to prevent entrance of air into the recess 15, the sealing means 22 should be located in such a manner that they are always covered by water.

With the embodiment according to FIG. 2, the threshold and the door structure are designed in a somewhat different manner.

A door structure 23 is here fonned as a substantially flat panel having an enlarged cross section at the portion intended to rest at an upper edge 24 of the threshold and including the main structural element of the door supporting system. The threshold is provided with a longitudinally running channel 25, extending all along the opening and being designed with a satisfactory clearance to receive a lower portion 26 of the door panel 23. V

The recess 15 is here formed in the inward wall defining the channel, and in the same manner as previously described, sealing means 18 are provided between the door structure and the side posts 12. Further sealing 3 means 20 are fitted between the threshold and the door structure and still further sealing means 22 around the recess 15. The latter may be evacuated by way of passage 16.

The pressure of the water upon the portion 26 of the lower door structure extending down into the channel is greater than the pressure acting upon the upper portion of the structure, whereby a balancing of the forces acting upon the panel is obtained and thus favorable conditions for a light weight structure.

The door structure may be locked with respect to the threshold by suitable means. Such means may, with the embodiment according to FIG. 1, include devices 27, adapted to pull the outwardly turned edge of the sole downwards, and with the embodiment according to FIG. 2, of rams 28 forcing the lower edge of the door panel against the inner wall of the channel. These means will thus aid in balancing the pressure upon the upper portion of the door panel.

FIGS. 3 and 4 show a further embodiment, which may be regarded as a simplification of that shown in FIG. 1.

The door structure has a basically L-shaped cross section, with a vertical waist 30, forming the closure proper and a lower, horizontal sole 31. These will together provide a single walled shell structure, the base part of which is carried by strong beams 32, and is supported therefrom by means of stays and struts 33.

The upper part of the door structure is formed as a travelling track 34, providing a passageway between the side walls 12 of the dock 10.

The door structure rests, when fitted in position, upon a threshold including an outer transom 35 and an inner row of spaced projections 36. Between the transom 35 and the row of projections 36 the zone to be emptied is formed as a trench. The projections 36 will permit water from the dock to flow into the trench, and the dock will thus be emptied by way of the connection 16.

The horizontal sole 31 and the beams 32 supporting the same are provided with downwardly directed arms 37, which engage the transom 35 and will take care of the horizontal forces acting upon the door structure. Sealing means are provided between the arms and the sill.

A floating tank 39 is fitted at each end of the door structure and means (not shown) will make it possible to fill or to empty said tanks, respectively, in order to make the door structure non-displacing or displacing, as is desirable in order to maintain the door structure in position, or make it floating for towing.

Further sealing means 18 are, as with the earlier embodiments, provided along the vertical edges of the door structure.

The door structures shown may be formed as a single unit extending all across the opening, but may also be subdivided into sections. In the last mentioned situation sealing means will have to be provided between the sections.

The door structure, or the sections thereof, are operated in any suitable manner when the clock has been filled with water, for instance, through floating by means of pontoons, which are permanently built into the structure, as described in connection with FIGS. 3 and 4, or are temporarily attached thereto. Due to its light weight structure, the door, especially the one shown in FIG. 2, may be operated by means of such cranes as are usually available in conjunction with a ship building dock.

FIG. 5 shows a devlopment of the door structure disclosed in FIG. 2. The same reference numerals are used for the main components.

The door structure includes a number of separate buoyancy tanks 40, with each communicating with the surrounding water by at least one opening 41 located in the lower end of the pertaining tank. Each tank further is connected to a pipe 42 for supplying compressed air.

This is supplied through a hose 43 to a distribution box 44. Valves 45 will govern the supply of air to the individual tanks 40 to drive the water therein out through openings 41, thereby determining the buoyancy of the door structure.

The lowermost tank may be filled with ballast, and the topmost one may be open towards the sea. In closing position, a sufficient number of the tanks 40 in the door structure are filled with water, so the door has no tendency to lift from the threshold.

When it is desirable to open the dock some, more tanks are filled with water, whereupon the door structure sinks down to a horizontal position outside the dock, as is indicated in the dashed lines. The threshold is designed in such a manner that the lower margin of the door structure remains within the recess 15. The sinking movement may be guided by suitable means (not shown), such as cables from capstans or cranes normally provided at the dock.

It is also possible first to increase the buoyancy of the door structure, so the same first rises vertically out of engagement with the threshold, and is then towed outside the same to be sunk to a horizontal position outside the same, as above described,

For raising the door structure, air is reintroduced into the tanks 40 in proper order, whereby water is expelled and the door structure is brought back to its vertical position.

This design is particularly suitable with repair docks, as a very rapid fitting and removal of the door structure is possible.

What I claim is:

1. A device for use in excluding water from a working site located adjacent a body of water and beneath the water level thereof in which a wall separates the working site from the body of water, with the wall having an opening providing communication between the working site and the body of water, a threshold and two side posts constituting said opening, the threshold including portions located inwardly and outwardly of the wall, the device comprising a door structure closing the opening, the door structure including a vertical waist portion defining the closure proper and a lower balancing portion rigidly connected to the waist portion, the lower balancing portion cooperating with at least one of said portions of the threshold to provide a zone communicating with the working site and the water pressure in the zone being dependent upon the water level within the working site, and means cooperable with the lower balancing portion and the threshold to prevent inward movements of the door structure in a horizontal direction, the arrangement being such that upon evacuation of the working site, the water outside the working site will exert a laterally directed pressure upon the door structure with the main horizontal component of such pressure being taken care of by the cooperation between the lower balancing portion of the door structure and said at least one portion of the threshold and the tilting moment upon the door structure being balanced by the load of the water externally applied to the lower balancing portion being greater than the upwardly directed pressure in the zone which is dependent on the water level within the working site.

2. The device as claimed in claim l in which said zone is a recess.

3. The device as claimed in claim 1 in which said lower balancing portion of said door structure is defined by a horizontal sole which is supported by said portions of the threshold located inwardly and outwardly of the wall.

4. The device as claimed in claim 3 in which the outwardly located portion of the threshold is provided with an upwardly directed transom and the sole is provided with downwardly directed arms for cooperation with the transom, the transom and arms constituting the means to prevent inward movements of the door structure in a horizontal direction.

5. The device as claimed in claim 3 in which the sole is provided with an inwardly directed extension and the inwardly located portion of the threshold is provided with an upwardly directed transom, the extension and transom constituting the means to prevent inward 6 movements of the door structure in a horizontal direction.

6. The device as claimed in claim 1 in which the threshold is provided with a longitudinally extending channel for receiving the lower balancing portion of the door structure.

7. The device as claimed in claim 6 in which the door structure is provided with buoyancy tanks, and means operably connected to the tanks for adjusting their carrying capacity, with said means being operable to lower the door structure onto the water bed outside of the wall separating the working site from the body of water.

8. The device as claimed in claim 1 including locking means provided at the threshold for aiding in counteracting the tilting movement upon the door structure caused by the unilateral pressure of the water,

9. The device as claimed in claim 1 in which the zone, at least outwardly with respect to the threshold is provided by sealing members covered by water even when the working site is dry, and means connected to the zone for removing water therefrom.

Claims

2. The device as claimed in claim 1 in which said zone is a recess.

5. The device as claimed in claim 3 in which the sole is provided with an inwardly directed extension and the inwardly located portion of the threshold is provided with an upwardly directed transom, the extension and transom constituting the means to prevent inward movements of the door structure in a horizontal direction.

8. The device as claimed in claim 1 including locking means provided at the threshold for aiding in counteracting the tilting movement upon the door Structure caused by the unilateral pressure of the water.