US3603428A

US3603428A - Scaffolding for the tanks of large tanker ships

Info

Publication number: US3603428A
Application number: US857663A
Authority: US
Inventors: Otto Hanses
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-09-19
Filing date: 1969-09-15
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07
Also published as: FR2019464A1; SU372790A3; SE353365B; ES177225Y; NO128702B; ES177225U; JPS4915007B1; GB1243869A; NL6914191A

Abstract

Scaffolding for the construction, cleaning and repair of the interior of the tanks of large tanker ships consists of permanently emplaced wire netting secured to the sides of the tank.

Description

United States Patent Otto Hanses P19 06 341.3and P17 81270.3

SCAFFOLDING FOR THE TANKS OF LARGE TANKER SHIPS References Cited UNITED STATES PATENTS 12/1935 Amesbury .1 9/195 3 Newland I [/1967 Cathcart FOREIGN PATENTS 12/1964 France 4/1967 France Primary Examiner-Reinaldo P. Machado Attorney-Young & Thompson 17 Claims, 14 Drawing Figs.

182/128, 182/222, I 14/222 ABSTRACT: Scaffolding for the construction, cleaning and Int. Cl E04g 3/00 repair of the interior of the tanks of large tanker ships consists Field of Search 182/ I 38, of permanently emplaced wire netting secured to the sides of 139, 82,128, 222; 114/222, 65 the tank.

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PATENTEUSEP 7m: 3,603,428

SHEEI 5 BF 7 In Ven for:

fifiAFFGlLDING FOR THE TANKS F LARGE TANKER SHIPS The present invention relates to scaffolding for the interior of the tanks of large tanker ships, for supporting workmen during the construction, cleaning and repair of the tanks. At present, during the construction of large tankers, it is customary to erect wooden scaffolding within the tanks as the construction of the tans proceeds. When the ship is completed, the scaffolding is removed. But when the tanks are cleaned or repaired, then it is necessary again to erect the scaffolding, and remove it when the cleaning or repair work is completed. A great deal of expensive labor is required to handle the scaffolding; and as the scaffolding is ordinarily wooden, its useful life is limited. It often happens that the erection and removal of this scaffolding consumes the greater portion of the time the ship is at the dock yard.

Accordingly, it is an object of the present invention to provide scaffolding for the tanks of large tanker ships, which will require relatively little labor to emplace either initially or upon subsequent cleaning or repair operations.

Another object of the present invention is the provision of such scaffolding which will provide a high degree of safety for the workers.

Finally, it is an object of the present invention to provide such scaffolding which will be relatively simple and inexpensive to manufacture and install, easy to utilize, maintain and repair, and rugged and durable in use.

Briefly, the present invention achieves these objects by providing scaffolding which can be erected at the time of construction of the tank and then left in place when the tanker is in use. For cleaning and repair, therefore, when the tank is emptied, the scaffolding will be undamaged and in place.

To achieve this, the scaffolding is constructed by wire netting strips supported by wire cables that are detachably secured to the walls of the tank. The netting is in a plurality of tiers, the upper one of which which extends from side to side of the tank and the lower ones of which extend only about the sides of the tank. The wire netting strips are secured to each other, and the tiers below the upper tier have inner guard rails of the same material. Working platforms in the form of corrugated plates rest by gravity on the netting.

Other features, objects and advantages of the present invention will become apparent from a consideration of the following more detailed description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view ofa strip of wire netting for use in the upper tier of the scaffolding;

FIG. 2 is a view like FIG. 1, but showing the strips that are used at the ends of the upper tier and also that form the lower tiers of wire netting; FIG. 3 is a top plan view of the uppermost tier of wire netting;

FIG. 4 is a somewhat schematic fragmentary perspective view of wire netting according to the present invention, showing a working platform in place on the netting;

FIG. 5 is a perspective view of a work platform according to the present invention;

FIG. 6 is a schematic bottom plan view of one of the lower tiers of scaffolding according to the present invention;

FIG. 7 is an enlarged fragmentary cross-sectional view taken on the line VII-VII of FIG. 6;

FIG. 8 is a schematic enlarged fragmentary top plan view of a portion of one of the lower tiers of scaffolding according to the present invention;

FIG. 9 is an enlarged plan view of one of the fastening members by which the ends of the support cables are secured to the walls of the tank;

FIG. 10 is an axial cross-sectional view of the structure of FIG. 9;

FIG. 11 is a cross-sectional view taken on the line XI-XI of FIG. 9;

FIG. 12 is a schematic fragmentary perspective view showing how access may be had between superposed tiers of the scaffolding;

FIG. 13 is a somewhat schematic fragmentary plan view showing another arrangement of work platforms on one of the lower tiers of scaffolding of the present invention, and

FIG. 14 is a cross-sectional view of the structure shown in FIG. 8 or FIG. 13, showing one way of crossbracing the scaffolding.

Referring now to the drawings in greater detail, and first to the embodiment of FIG. 1, there is shown a strip of wire netting 10 which by itself may be conventional wire netting. Strip 10 is bounded by a frame 12 consisting of a wire cable surrounding and secured to the strip. Sections 14 at the ends of the strip are more closely woven than in the midportions of the strip, and exhibit meshes 16 whose width is much less than that of meshes 18 in the central portion of the strip, preferably by a ratio of 2:].

FIG. 2 shows a different embodiment of strip, for use by itself or in combination with strips as in FIG. 1. The FIG. 2 strip 20 comprises wire netting having meshes 16' of the same width as meshes 16 of FIG. 1.

FIG. 3 shows the uppermost tier of scaffolding, in the form of a net N which is of a size to stretch from side-to-side and from end-to-end of the uppermost portion of the tank in question. Net N is comprised of end strips 20a and 20s as in FIG. 2, and

intermediate strips

10,, 10 etc. as in FIG. 1. All the strips are arranged side by side and parallel to each other with overlapping edges thereby to define a large central field comprised by wide meshes l8 and a marginal area comprised by narrow meshes l6 and 16. If desired, the entire net N can be of uniform mesh width.

Cables 24 are interwoven between the overlapping edges of netting strips to secure together the overlapping longitudinal edges of the individual strips. As seen in FIG. 4, the ends of cables 24 are secured to the sidewalls of the tank by means of fastenings 26 whose structure will be described in detail later On. The cables 12 that bound the individual strips can also be secured to the tank walls in the same fashion.

In the direction perpendicular to cables 24, cables 22 are threaded through the net N adjacent and parallel to opposite longitudinal sides thereof, on the inner sides of the sections 14 of small meshes 16. Cables 22 are secured to the tank walls at their ends by means of fastenings 27, which are the same as fastenings 26 and whose structure will be described later on.

As is also seen in FIG. 4, tensioning devices 13 are provided in cables 12 from place to place thereabout, so as to impart the proper tension to the net N.

The square fields 32 thus defined between

cables

22 and 24 may for example be two meters on a side and thus have an area of about four square meters.

Work platforms 30 are disposed on these square fields 32. The platforms 30 are best seen in FIGS. 5 and 8. The platforms 30 are of corrugated metal characterized by downwardly extending depressions 38 at least one of which has a downwardly extending bolt 36 thereon that is designed to extend through the wire netting and prevent lateral move ment of the platform 30. Preferably, the platforms 30 are so disposed that the sides of the bolts 36 bear laterally against a

cable

22 or 24.

As will also be seen from FIG. 5, the platforms 30 are provided with slots 34 therethrough each of which terminates at one end at a bolt 36. The purpose of this construction is so that the platforms can be stacked and will nest with each other, laterally displaced from each other only by the width of a bolt 36, with a series of bolts extending through each slot 34 in stairstep fashion. Of course, in use, the platforms will be arranged one by one on the netting and will not be stacked.

FIGS. 6-8 show one of the lower tiers of scaffolding of the present invention. In FIG. 6, the tier is shown roughly square, for use in a tank whose cross section at that point is roughly square; so of course the FIG. 6 embodiment is not used with the FIG. 3 embodiment.

In FIG. 6, the walls of the tank are shown at 110, 112 and 112'. The gallery 114 of wire netting consists of horizontal strips of wire netting adjoining and secured to the tank walls, and upright wire netting 115 along the inner margins of the gallery to provide railings for safety purposes. The netting 115 is integral with the horizontal wire netting of the gallery 114.

Gallery 114 is supported by

wire cables

116, 116', 116", and 120, 120', 120" attached to

respective walls

110, 110 and 112, 112 and extending across the tank from wall to wall thereof. The ends of the cables are secured to the sidewalls of the tank by fastenings 122 to be described later on.

Thus, in the illustrated embodiment, a wire cable 116 extends along the tank wall in the immediate vicinity thereof and a second wire cable 116" along the inner edge of the gallery. A third wire cable 116 is disposed along the midline of the gallery parallel to and between the

cables

116 and 116". Two

further wire cables

118 and 118 are provided above cable 116" for the purpose of reinforcing the netting l 15 that forms the guard rail.

FIG. 8 also shows another possibility for the interconnection of two strips endwise: a wire coil 124 is woven through overlapping end regions of two strips of netting.

FIGS. 9, 10 and 11 show the fastenings for releasably securing the ends of the wire cables to the tank walls. A substantially U-shaped fastener 122 is welded at its closed end to the tank wall and the two legs of the fastener 122 extend outwardly away from the tank wall. An inwardly opening hollow keeper 128 is welded to the free ends of these legs and is characterized by an upwardly open slot 130 and an axial opening for the reception of the cable 120. Each cable end has secured thereto a sleeve 134 whose inner shoulder 132 abuts against keeper 128 when sleeve 134 is fully seated in keeper 128. To insert and remove the cable end, the sleeve 134 must be sufficiently near the tank to clear the keeper 128 entirely and to permit the cable 120 to be laid in the full length of slot 130, after which a pull on the cable will seat the sleeve 134 in the keeper 128.

FIG. 12 shows a gangway produced through a gallery of the invention by bending apart overlapping

edges

144, 146 of adjacent wire netting strips. A ladder can be inserted, while the

edges

144 and 146 remain held together fore and aft of the ladder by means of wire coil 148.

FIG. 13 shows that work platforms 150 can be somewhat differently arranged from platforms 30, with their corrugations extending lengthwise of the gallery. Several of them can be arranged side-by-side, depending on the width of the gallery. Each platform 150 has two pins 151 projecting downwardly from the depressions of the corrugations, while a slot 152 adjoins each pin 151 to render the platforms nestable and stackable. FIGS. 13 and 14 also show an arrangement for increasing the stability of the scaffold. In order to avoid the necessity of stretching wire cables across the middle of the tank space between the portions of the gallery on opposite sides of the tank, transverse supports 154 are inserted between cables 116 and 116'. In the illustrated embodiment, the supports 154 are tubes of synthetic resin whose ends are in the form of forks 156 each of which embraces a wire cable to maintain the wire cables spaced against collapse toward each other when loaded. Of course other forms of supports 154 may be adopted, and other forms of securing them to the cables.

The cables and netting and plates of the present invention may be of galvanized iron but are preferably of steel coated with polyamide resin to render the steel resistant to sea water and oil.

From a consideration of the foregoing, therefore, it will be evident that all of the initially recited objects of the press invention have been achieved.

Although the present invention has been described and illustrated in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the scope of the invention, as those skilled in this art will readily understand.

Having described my invention, 1 claim:

1. A tanker ship having a tank having upright tank walls, and scaffolding for the interior of the tank, comprising wire cables attached at their ends to said walls, and horizontal wire netting strips supported by and between the cables adjacent said walls.

2. Structure as claimed in claim 1, disposed adjacent the top of the tank and extending continuously from side-to-side and from end-to-end of the upper portion of the tank.

3. Structure as claimed in claim 1, disposed only adjacent the sidewalls of the tank, and a guard railing upstanding from only the inner edges of the scaffolding.

4. Structure as claimed in claim 3, said guard railing comprising wire netting.

5. Structure as claimed in claim 4, and wire cables reinforcing said guard railing.

6. Structure as claimed in claim 1, each said strip being bordered by a wire cable, and means securing said cables to the walls of the tank.

7. Structure as claimed in claim 6, and tensioning devices for adjusting the length of the wire cables that bound the netting strips.

8. Structure as claimed in claim 16, the longitudinal edges of said strips overlapping each other, and means interconnecting said overlapping edges of the strips.

9. Structure as claimed in claim 8, said interconnecting means comprising wire coils passing through said overlapping ed es.

%0. Structure as claimed in claim 16, at least some of said wire cables being beneath portions of with said wire netting strips.

11. Structure as claimed in claim 10, and a platform resting on said wire netting strips.

12. Structure as claimed in claim 1, said cables having enlarged ends, and fasteners secured to the walls of the tank for releasably receiving said enlarged cable ends, said fasteners comprising upwardly open downwardly closed cradles aligned with said cables.

13. Structure as claimed in claim 1, and work platforms resting by gravity on said wire netting, each work platform having at least one downwardly extending projection that extends through the wire netting to restrain lateral movement of the platform on the netting.

14. Structure as claimed in claim 13, each work platform having a slot extending from said projection and of a size to receive projections from other work platforms thereby to render said work platforms stackable.

15. Structure as claimed in claim 1, whose material is steel coated with synthetic resin.

16. Structure as claimed in claim 1, and support means holding apart a pair of parallel cables against the tendencyof the cables to move toward each other under load.

17. Structure as claimed in claim 1, and a plurality of con nectors spaced along a said tank wall along which the scaffolding extends and interconnecting the scaffolding with the wall and extending perpendicular to the wall.

Claims

4. Structure as claimed in claim 3, said guard railing comprising wire netting.

9. Structure as claimed in claim 8, said interconnecting means comprising wire coils passing through said overlapping edges.

10. Structure as claimed in claim 16, at least some of said wire cables being beneath portions of with said wire netting strips.

16. Structure as claimed in claim 1, and support means holding apart a pair of parallel cables against the tendency of the cables to move toward each other under load.

17. Structure as claimed in claim 1, and a plurality of connectors spaced along a said tank wall along which the scaffolding extends and interconnecting the scaffolding with the wall and extending perpendicular to the wall.