US3078820A - Dry cargo ships - Google Patents

Description

Feb. ze, 1963 R. K. o. FREDRIKSON 3,078,820

DRY CARGO SHIPS z sheets-smet 1 Filed Feb. 24, 1958 Feb. 26, 1963 R. K. o. FREDRlKsoN 3,078,820

DRY CARGO SHIPS Filed Feb. 24. 195e 2 sheets-sheet a United States Patent fliee 32,078,820- Patented Feb. 26, 17,963

3,078,820 y DRY CARGO SHIPS Robert Knut @Shar Fre'drikson, 35 Stigbergsgatan, Stockholm, Sweden Filed Feb. 24, 195g, Ser. No. 7 17,151 Claims priority, application Sweden Feb. 26,1957 6 Claims. (Cl. 114-172) The object of the present invention is to construct a dry cargo ship in such a way that fthe 'strain on the hull in its longitudinal direction is reduced 'by such a construction of the ships 'hull that 4heavy loads can always be placed amidships and lighter loads 'wherever desired, while the accessibility of the different/loads 'is better than in dry cargo ships of vconventional design.

Normally'dry cargo ships have va hull which in its longitudinal direction is provided with a plurality fof transverse bulkheads and in vertical direction with Aone `or more decks. The cargo-'holds and tween-decks between the transverse bulkheads, decks and the tank top or inner bottom plating are loaded and `unloaded through cargohatche's arranged on the centre-line of the ship.

As a rule, the decks are supported either by means of longitudinal bulkheads arranged 'in the 'centre Iline :or by vertical pillars in one or more rows stretching from the tank 'top via .the dilierent decks 'up to the weather deck. The construction of the ships dou-ble bottom, containing the so-called internal bottom (floors, centre flinefand intercostal longitudinals, margin plates and ltank top) Sis so stili" that 'by its nature it serves as a foundation yfor 'said pillars Aand/or centre-'line Abulkheads. If a deck were to be arranged without supports from vthe internal'bottom or tank top 'it would be necessary vconsiderably -to strengthen the deck beams and their joints to the side frames. Thus it would be necessary to use a plurality lof bulky deck beams in the-cargo-space Aat'tac'hedt'o verydeepframes, all resulting in a considerable decrease of lthe vuse/ful space ofthe cargo-hold and '?tween-'decks and increase of 'the weight-of steel, in consequence whereof the load capacity of vthe ship is decreased.

The V'requirement of adequate longitudinal strength olfv the ship has developed a construction wherein 'that one dec'k, the strength deck, is given such a 'thicknes's :that the lhull, considered as a ybeam, will be suficiently strong. For ships with slim hulls and high speed, *the` requiremerit lfor vlorigitutlinal vrstrength :is accentuated. -Such ships must often fulfill the `requirernent of -being fable to transport cargos 'with very different weights per cubic foot of lload, as for instance so-called refrigerated space load, which as afrule is a light load, and case-goodsand/or bulk Vgoods (corn, ore), which are heavy loads. AObviously it is not lof advantage to fhave .refrigerated rooms, i.e. rooms .provided for light loads, .concentrated amidships where the displacement (upward forces) -`is largest and the `load smallest, while :heavier loads are place'd towards the ends .of lthe ship, where 'the displacement 'is smallest. The 'experiences -of the 'past unequivocally fshow thatsuc'h arrangements 'are 4not vadv'antageous and vthis .due to the fact that vthehull'is exposed tto vlarge 4stresses and that the possibility of permanent damage to the ship hull increases. The vdesire to be able to place heavy load where the ldis placement -o`f Ithe ship is large can, however, lbe fulfilled provided :that -it is possible to place this heavy doad on thet-ank -top -of the double bottom ofthe hull, which is best suited to 'carry heavy load. This in itsturn is conditional among other things upon the tank top not being provided with insulation for vrefrigerated cargo, and, com sequently, `that refrigerated spaces are not arranged on the tank top. It is thus necessary to .provide yfor lighter loads, 'foi' instance refrigerated space loads, at other yparts of the hull than on the tank top. i-Iitherto this space has been provided for by trunking-in certain tween-deck hatches, the vertical walls of the trunks being provided with trunk ports for loading and unloading. The cargo has been loaded through said trunked-in cargo-hatches at the centre-line of the ship and then been carried vor dragged inra horizontal direction through the trunk ports and placed in the tween-deck space. lt `has thus been necessary to load the tween deck cargo-spaces of the hatch last and to unload it first in order to be able to obtain access -to the llighter loads (refrigerated space loads).

The :present invention relates to Isuch a disposition of the .cargo-spaces that, with'due consideration to the consumption of a minimum ofvvsteel for providing sufficient longitudinal strength ofthe ship, -the ship shall be adapted for carrying light loads (refrigerated space loads) -as well as heavy yloads (corn, ore, case-goods), while the loading and unloading of such diiierent cargos independently `of each other shall lbe possible. The cargo 'is stowed in cargo-holds and tween-decks which, as far as possible, are entirely free from vertical-supports, thus facilitating the handling ofthe loads. l

According to the present invention this purpose is attained by subdividing the transverse section of the fhull in the vertical direction .between the strength deck ofthe s'hip and the internal Vbottom plating (tank top) by atleast one lower deck stretching from one side of the hull to the other, without supporting said deck between the .transverse bulkheads of the cargo-'holdby anyvkind of vertical supports, centre-line bulkheads or brackets `along the side plating with accompanying deep .beams undersaid deck, and by arranging between this lower deck andthe strength deck, at least one longitudinal bulkhead extending vover the entire length of the main hold portion of theship.

This longitudinal bulkhead or bulkheads constitutes :a main `strength member of the ship and :preferablyextend through a plurality of adjacent compartments .arranged in .succession in the longitudinal direction of the :ship and also straight through the `engine room between the transverse bulkheads `enclosing this room. `This .arrangement is of considerable importance when cargolholdsare provided ahead of as well -as aft of .the vengine room.

By means of the invention the transverse section ,of the hull is subdivided into .atleast three cargo .spaces of which the lowermost, referred to lherein as vthe cargo hold and situated between the tank top `and the .lower deck nearest 'to the tank top, will .be entirely -free .-from vertical supports, centre-line bulk-heads and brackets along the sideplating. At least two tween-deck cargo spaces are ,obtained between the Vstrength deck yand the :lower deck. These cargo spaces also are :characterized :by the absence of lverticalsupportsetc.

A very vadvantageous embodiment yof the invention fis obtained by using two Vlongitudinal bulkheads 'arranged at a suitable distance v'from each other to provide room for hatches for lthe cargo-spaces llocated #outwardly of the longitudinal bulkheads and also 'for the'hatches -yfor the 'lowerrnost cargo-hold. Y

It is of particular importance lthat Athe tit/"een :decks cargo-spaces between vthe side plating Vand the longitudinal bulkheads can be provided Iwith separate cargo-'hatches instead of trunk ports in lthe .longitudinal bulkheads, which would reduce lthe lover-'all strength of the hull, in consequence of which the cargo-spaces within the transverse section may be made accessible lthroug'h three hatches, which can be'loaded and'un'loaded independently of eachother.

Two embodiments of my invention will Vbe further described with reie'rence to the accompanying drawings -in which: e e I FIG. l is a longitudinal section ltaken yalongline I-I of FIG. 2 showing a preferred embodiment of this invention the bow and stern structures being shown in elevation, and the superstructure in broken lines;

FIG. 2 is a plan View of FIG. 1;

FIG. 3 is a horizontal section taken along III-III of FIG. 1;

FIG. 4 is a schematic view taken substantially along line IV of FIG. 1, and

FIG. 5 is a view similar to FIG. 4 but showing a modication.

As shown in FIGS. 1 and 2, the ship comprises a bow structure 15, and a stern structure 16, which are connected by a main hold portion 17. The midships superstructure 1-3 is shown in broken lines.

With reference now to FIGS. l, 2, 3 and 4, the hull comprises a suitable reinforced double bottom comprising bottom plating 1 and a tank top 2, together with side frames and side plating, referred to generally as the side walls 3 and 4. The hull also includes as strength members a plurality of transverse bnlkheads 5 and a strength deck 6.

Disposed below the strength deck 6 is a lower deck 7 which extends from one side wall 3 to the other side wall 4, and from one transverse bulkhead 5 to the other. One or more middle decks 8 may be provided between the top deck 6 and the lower deck 7.

The lower deck 7 as well as the middle deck 3, are supported at intermediate points by longitudinal bulkheads 9 and 10 which extend the full length of the cargo space from the bow to the stern as shown in FIGS. l, 2 and 3. The structural cooperation between the longitudinal bulkheads 9 and 1) and the decks 6, '7 and 3, to which the bulkheads are secured, longitudinally strengthens each compartment without in any way interfering with the cargo space provided in the hold. When the longitudinal bulkheads 9 and 1G extend through several compartments a very substantial longitudinal reinforcement of the entire hull is provided.

The various hatches L, later described, are provided with suitable coamings 11.

The transverse bulkheads 5 thus provide a plurality of separate compartments which are subdivided to provide the dilerent cargo spaces illustrated in FIG. 4 except that one of these compartments may serve as the engine room 12, through the upper portion of which lthe longitudinal bulkheads 9 and 10 extend as shown in FIGS. 1, 2 and 3.

Thus, as diagrammatically shown in FIG. 4 three separate cargo spaces are provided, a rst tween-decks cargo space ABGHA, a second tween-decks cargo space CDEFC, and a third cargo space BGHIKEFCB. The latter includes the hold proper HGFEKIH, and an auxiliary tween-decks space BCFGB, the nature of which is better illustrated in FIG. 1, as constituting the space available between the decks 7, 8 and 6.

Suitable cargo hatches L4 and LS provide access to tween-decks cargo space ABGHA, and similarly, separate cargo hatches L6 and L7 provide access to the tweendecks cargo space CDEFC. Cargo hatches L1, L2 and L3 provide access both to the cargo hold proper HGFEKIH and to the auxiliary tween-decks space BCFGB. Thus, access may be had to the two main tween-decks cargo spaces through hatches L4 and L6 independently of the access to the hold and auxiliary tween-decks cargo space. This permits use of the main tween-decks cargo spaces for refrigerated loads and other loads, while the heavier loads may be located in the hold proper.

As a consequence of this construction the cargo-space ABGHA with its cargo-hatches L4 and L5 is entirely independent of the cargo-space BCFEKIHGB, which is accessible through cargo-hatches L1, L2 and L3. Similarly the cargo-space CDEFC is entirely independent of the spaces mentioned, being accessible for loading and unloading through cargo-hatches L6 and L7.

A further consequence of the arrangement is that the diierent cargo-spaces, and this is particularly noticeable with regard to the largest space, the lowermost cargo-hold HEKIH, is entirely free from vertical supporting pillars, which, as far as loading and unloading is concerned, is an important and much desired advantage and, moreover, this result is attained without the necessity of using deep beams in the deck 7 and deep side frames, to which said beams are secured.

As a third consequence of the arrangement of decks and bulkheads according to the invention and due to the fact that the lowermost cargo-hold is entirely free from vertical supports, cargo handling equipment may be used without being hindered by any kind of supports. It is therefore easier to work with conveyors and with trucks on the tank top than is the case on ships of conventionai construction due to the fact that the movements of the trucks are not hindered in any respect by vertical supports' or centre-line bulkheads.

As a fourth consequence the longitudinal bulkheads contribute considerably to the strength of the ship in longitudinal direction, considered as a beam. If the longitudinal bulkheads are not only arranged through the cargo-spaces but also through an engine room located amidships or near amidships with cargo-spaces forward as well as aft, they will, as a fth consequence, contribute still more to strengthening the hull, considered as a beam.

As a sixth consequence the buoyancy of the ship is increased in case of a leak, due to the fact that the hull will contain a higher number of cargo-spaces which are hermetically separated from each other.

As a seventh consequence of the construction the proportions of a tire in any one of the spaces will be more limited than with constructions of conventional design.

As an eighth consequence it may be emphasized that the load can be brought into place with smaller movement in the longitudinal as well as in the transverse direction of the ship due to the fact that the load-hatches can easily be arranged so as to cover greater parts of the deck surface below the hatches compared with the conventional arrangement with hatches only one the centre-line of the shi gs a ninth consequence it may be mentioned that the vertical longitudinal bulkheads will act as feeders if the ship is loaded with corn.

In part, the above-mentioned advantages are also attained in the modified arrangement shown in FIG. 5 in which the corresponding elements are designated by the same reference numerals, primed. However, instead of having two longitudinal bulkheads 8 and 9, only a single longitudinal bulkhead 13 is provided along the centreline of the ship. Here the tween-decks cargo spaces OPSRO, and PQTSP are provided in addition to the cargo hold RSTVUR. Access to the tween-decks cargo spaces is provided by hatches L8 and L10, whereas these same hatches together with hatches L9 and L11 also provide access to the main cargo hold. Thus the tween-decks cargo spaces in the FIG. 5 embodiment of my invention are more nearly analogous to the auxiliary tween-decks cargo space BCFGB of FIG. 4, since access is not attained through separate hatches such as L4 and L6 of FIG. 1.

What I claim is:

l. In a dry cargo ship having a bow structure, a stern structure, and a main hold portion extending between said bow and stern structures, and which includes as strength members, a double bottom, side walls, a strength deck, and a plurality of transverse bulkheads, said transverse bulkheads dividing said main hold portion into a plurality of compartments, the combination of additional longitudinal hull reinforcing means which includes longitudinal bulkhead means extending continuously from said bow structure to said stern structure and intersecting and being secured to said transverse bulkheads, said longitudinal bulkhead means constituting a main strength member, a lower deck supported in part by said side walls and transverse bulkheads and in part by said longitudinal bulkhead means, said longitudinal bulkhead means being secured to said strength deck and extending only between said lower deck and said strength deck, whereby those portions of said compartments which are located beneath said lower deck and between said transverse bulkheads provide a plurality of cargo holds which are free from vertical deck supporting means, and a plurality of sets of hatches in said strength deck and said lower deck and located one above the other to provide access to at least some of said cargo holds, said lower deck providing a tween decks cargo space located adjacent to the lower deck hatch of each set, the strength deck hatch of each set also providing access to said tween decks cargo spaces, said longitudinal bulkhead means being free from trunk ports formed therein and forming at least one wall of said tween decks cargo spaces.

2. A dry cargo ship as claimed in claim 1 in which said longitudinal bulkhead means comprises ytwo longitudinal bulkheads arranged on either side of the center line of said ship, said sets of hatches comprising hatches centrally located between said bulkheads.

3. A dry cargo ship as claimed in claim 2 in which said two longitudinal bulkheads and said lower deck cooperate with each other to provide two tween decks cargo spaces disposed outwardly of each of said rst mentioned tween decks cargo spaces and which are entirely separated from each other and from said cargo hold, and in which said sets of hatches further comprise separate cargo hatches formed in said strength deck outwardly of said longitudinal bulkheads to provide access to said outwardly disposed tween decks cargo spaces, said rst mentioned tween decks cargo space providing an auxiliary cargo space which extends fore and aft of said centrally located sets of hatches, said outwardly disposed and said auxiliary tween decks cargo spaces being constructed and arranged to receive lighter loads so that the heavier loads can be received in said cargo holds and supported directly on said double bottom.

4. A dry cargo ship as claimed in claim 1 in which said longitudinal bulkhead means comprises a single longitudinal bulkhead disposed along the center line of said ship, there being two of said sets of hatches for eac-h of said cargo spaces, one on either side of said single -longitudinal bulkhead.

5. A dry cargo ship as claimed in claim 1 having an engine room located in one of said compartments, said longitudinal bulkhead means extending through said engine room.

6. A dry cargo ship as claimed in claim l in which said lower deck extends longitudinally through a plurality of adjacent compartments and extends continuously across said compartments from one side wall to the other, and cooperates with said longitudinal bulkhead means as a strength member,

References Cited in the tile of this patent UNITED STATES PATENTS 616,780 Fraser Dec. 27, 1898 666,076 Mason et al. Ian. 15, 1901 843,390 Burney Feb, 5, -7 1,180,852 Jack Apr. 25, 1916 1,264,620 Dobson Apr. 30, 1918 1,751,756 4Paulsen Mar. 25, 1930 2,321,811 Harris June 15, 1943 2,440,408 Lackie Apr. 27, 1948 :2,895,444 Mege July 21, 1959 2,909,141 S-tatfansson Oct. 20, 1959 FOREIGN PATENTS 500,010 France Dec. 4, 1919 443,793 Great Britain Mar. 6, 1936 917,051 Germany Aug. 23, 1954

Claims (1)

1. IN A DRY CARGO SHIP HAVING A BOW STRUCTURE, A STERN STRUCTURE, AND A MAIN HOLD PORTION EXTENDING BETWEEN SAID BOW AND STERN STRUCTURES, AND WHICH INCLUDES AS STRENGTH MEMBERS, A DOUBLE BOTTOM, SIDE WALLS, A STRENGTH DECK, AND A PLURALITY OF TRANSVERSE BULKHEADS, SAID TRANSVERSE BULKHEADS DIVIDING SAID MAIN HOLD PORTION INTO A PLURALITY OF COMPARTMENTS, THE COMBINATION OF ADDITIONAL LONGITUDINAL HULL REINFORCING MEANS WHICH INCLUDES LONGITUDINAL BULKHEAD MEANS EXTENDING CONTINUOUSLY FROM SAID BOW STRUCTURE TO SAID STERN STRUCTURE AND INTERSECTING AND BEING SECURED TO SAID TRANSVERSE BULKHEADS, SAID LONGITUDINAL BULKHEAD MEANS CONSTITUTING A MAIN STRENGTH MEMBER, A LOWER DECK SUPPORTED IN PART BY SAID SIDE WALLS AND TRANSVERSE BULKHEADS AND IN PART BY SAID LONGITUDINAL BULKHEAD MEANS, SAID LONGITUDINAL BULKHEAD MEANS BEING SECURED TO SAID STRENGTH DECK AND EXTENDING ONLY BETWEEN SAID LOWER DECK AND SAID STRENGTH DECK, WHEREBY THOSE PORTIONS OF SAID COMPARTMENTS WHICH ARE LOCATED BENEATH SAID LOWER DECK AND BETWEEN SAID TRANSVERSE BULKHEADS PROVIDE A PLURALITY OF CARGO HOLDS WHICH ARE FREE FROM VERTICAL DECK SUPPORTING MEANS, AND A PLURALITY OF SETS OF HATCHES IN SAID STRENGTH DECK AND SAID LOWER DECK AND LOCATED ONE ABOVE THE OTHER TO PROVIDE ACCESS TO AT LEAST SOME OF SAID CARGO HOLDS, SAID LOWER DECK PROVIDING A ''TWEEN DECKS CARGO SPACE LOCATED ADJACENT TO THE LOWER DECK HATCH OF EACH SET, THE STRENGTH DECK HATCH OF EACH SET ALSO PROVIDING ACCESS TO SAID ''TWEEN DECKS CARGO SPACES, SAID LONGITUDINAL BULKHEAD MEANS BEING FREE FROM TRUNK PORTS FORMED THEREIN AND FORMING AT LEAST ONE WALL OF SAID ''TWEEN DECKS CARGO SPACES.

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