CA1055789A - Cargo vessel - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A cargo vessel comprises a deck having at least one hatch opening which is closable by means of cover panels extending between longitudinal sides of the hatch opening.
Brackets are mounted on the deck on opposite sides of the hatch opening, outside said longitudinal sides, which extend substan-tially parallel thereto. The brackets extend at least partially up along the edges of at least one of the panels and means are provided which are insertable between the brackets and the panels to transfer forces from one side of the hull to the other.

Description

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~ cargo vessel will during a voyage be subjected to severe strains and stresses, of which the -transverse ones are especially marked, when the vessel is moving through icebound waters. The hulls of vessels designed for navigating in ice must be very strong, which means that heavier steel structures than in conventional ships must be used, and thus cost correspondingly more. In many vessels, the cargo hatch openings will occupy a considerable portion of the weather deck area, which reduces the capacity of the hull to withstand transverse strains. Such reduction will obviously be especially marked when the individual openings are comparatively long, so the transverse strength members in the hull will be spaced widely apart.
The cover panels, conventionally used ~or closing a hatch opening, are ~ostly designed to span the distance between the longitudinal sides of the hatch opening, without any intermediate support, and they have a strong construction to take care of the loads they may be subjected to during a voyage.
These loads are mainly bending stresses, for instance caused by waves washing over the deck and/or deck cargo. It has not been possible, or deemed possible, to use the panels for increasing 1, the strength of the hull. By having one or more cover panels structurally interconnecting two opposite sides of the deck of ~, the vessel, it is possible to increasé, to a marked degree, the .
strength of the huIl, or to reduce the amount of steel structures included therein.
Accordingly, the present invention provides a cargo vessle comprising a deck having at least one hatch opening, said opening being closable by means of a number of` cover panels ~
extending between longitudinal sides of the hatch opening, ~, brackets mounted on the deck on opposite sides of the hatch _ opening outside-said longitudinal sides and extending substantially parallel thereto, said brackets extending at least partially up ,. ;
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~d~55~7~9t along the edges of at least one of said panels, and further means insertable between the edges of said at least one panel and the brackets in order to transfer -transverse forces from one side to -the hull to -the opposite by way oE said at least one panel.
The invention will now be described in more detail, 5 by way of example only, with re~erence to the accompanying drawings, in which:
Figure 1 is an elevation of a portion of a vessel, showing one hatch opening;
Figure 2 shows a view of the deck of the corresponding portion of the vessel;
Figure 3 shows a cross section through the vessel;
Figure 4, on a larger scale, shows the framed-in portion denoted by IV in Figure 3; and Figure 5, in the corresponding, larger scale, shows a portion of a cover panel, locked by a wedge.
The vessel shown in the drawings, is of the so called t open type, i.e. the hatch openings 10 will occupy a considerable portion of the deck area. As is best evident from Figure 3, a cargo hold is defined by the double bottom 11, the side plating 12 and 13, and the weather deck 14. The hold opening is surrounded by a coaming 15.
Deck houses 16, 17, carrying winches and other equipment, are mounted between the individual openings. These houses and their supports are essential transverse strengthening members, but between the houses the openings 10 will prevent every location of transverse members, level with the deck.
The hatch opening is adapted to be closed by covers composed of hingedly interconnected panels 18, 19 of a type intended to be raised to a vertical position at opposite, transverse ends of the coaming.
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One of these panels, l9a, which in closed ~sitinn will be located about midway in the opening, is in Figures 1 and

2 shown in hatched lines.
Outside o~ each longitudinal member 15a of the coaming and oppositely to the posi-tion occupied ~y cover l9a, a bracket 20 is built up from the deck in parallel to the adjacent coaming member, but at a distance therefrom. These brackets will reach upwards, about level with the top plate of the panel, the brackets being outwardly supported by plate stays 21.
10Wedges 2~ are provided to be forced in between these brackets 20, and the edges of panel l9a. The edges, as well as the brackets are provided with guide grooves 23, 24. Each wedge is provided with rollers 25, and is carried along a guide 26 at the coaming, when it is not engaging the panel. ~.
To remove a wedge, which may have become jammed due to deformations of the hull or of the coaming, there is a pressure fluid operated ram 27, by means of which an initial disengagement of the wedge may be brought about. The operation of the wedge, during engaging, or normal di.sengaging movements, respectlvely, will occur by conventional ramming means not shown.
The drawings show one emboaiment only, it belng obvious that the shape of the individual components may vary in many ways, within the scope of the appended claims.
With very long hatch openings it may be advantageous to use more than one panel to increase the transverse strength, for instance panels located, in closed position, at about one .
third of the length of the opening, counted from the transverse sides thereof. The type of hatch cover, i.e. the interconnection ;between the panels and the manner of operating the same, have no bearing upon the invention, as only one, or a few panels will be used for the actual strengthening purpose. It is, however, .
presupposed! that the edges of the panels are easily available.

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With panels arranged flush with the surrounding deck, the coaming shelf will have to be designed somewhat broader than with conventional arrangements, in order to provide space for the locking members. The side portions of the coaming will, furthermore, have to be strengthened in order to serve as bracke-ts.
Instead of wedges, which are rammed in along the brackets, it is possible to use knee-joints, or other devices, which are expandible transversely with respect to the brackets.
It is further important, that the locking is arranged so it does not impair the normal operation of the panels, or the sealing function thereof.

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Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A cargo vessel comprising a deck having at least one hatch opening, said opening being closable by means of a number of cover panels extending between longitudinal sides of the hatch opening, brackets mounted on the deck on opposite sides of the hatch opening outside said longitudinal sides and extending substantially parallel thereto, said brackets extending at least partially up along the edges of at least one of said panels, and further means insertable between the edges of said at least one panel and the brackets in order to transfer transverse forces from one side to the hull to the opposite by way of said at least one panel.

2. A cargo vessel according to claim 1, wherein the transverse force transferring means are provided by wedges.

3. A cargo vessel according to claim 2, wherein means adapted to release the wedges when the panels are being removed.