1. Field of Invention
The present invention relates to ship design in general and in particular to a ship hull having increased longitudinal strength by means of a structure external to the hull.
2. Description of Related Art
Shipping goods and materials is a common and efficient method of distributing such materials around countries and the globe. In particular for use on rivers and inland waterways barges and similarly designed powered vessels are commonly used. Such shipping requires the use of marine vessels adapted to carry an adequate amount of material to make the shipping process economical. Additionally, the vessels required for such shipping need to be sufficiently strong to support cargo, resist external loads and ensure safety of navigation.
One measure of hull strength is the hull section modulus which is a measure of geometric stiffness (expressed in length unit to third power, e.g. cu ft or m3). Marine vessels are traditionally required to have a minimum hull section modulus in order to provide adequate longitudinal strength that will prevent the hull from breaking.
As illustrated in
However such approach of adding additional or thicker members for the hull or deck increases the weight of the vessel thereby limiting the cargo which may be carried thereby and increasing both the cost of the vessel to construct and operate.
An additional means of longitudinally stiffening marine vessels is to increase hull depth, or the height of the deck above the bottom of the hull shell. A disadvantage of such raised deck heights in inland waterway vessels is that any shipping containers which are located thereupon are also raised thereby limiting the number of such containers which may be carried on such a vessel that is intended to pass under bridges and the like.
According to a first embodiment of the present invention there is disclosed a marine vessel comprising a hull having a length enclosing an interior volume from above by a deck and at least one beam extending substantially along the length of the hull at a position spaced above the deck, wherein the beam is rigidly connected to and longitudinally reinforces the deck and the hull.
The at least one beam may include a plurality of rigid members extending between the beam and the main deck. The at least one beam and the rigid members may form a truss. The vessel may further include trusses adjacent to each longitudinal side of the hull. The trusses may include at least one bracing beam extending transversely therebetween
The vessel may further comprise bow and stern bodies extending above the main deck wherein the trusses are rigidly connected to the bow and stern. At least one of the bow and stern bodies may include one or more of personnel accommodation and machinery space.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
The hull may include side walls having top edges proximate to the deck. The top edges of the side walls may terminate at the deck.
In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,
Referring to
The vessel includes a pair of spaced apart horizontal beams 32 extending substantially along the length of the hull 22 at a position parallel to and spaced above the main deck 30. The beams 32 are connected to the hull 22 or the main deck 30 by a plurality of rigid angled and vertical supports 34 and 36, respectively. It will be appreciated that the beams 32 and angled and vertical supports 34 and 36 form trusses in conjunction with the main deck or hull so as to provide additional strength to the vessel. The beams 32 may be of any size or shape depending upon the size of the vessel and the strength requirements which they are to contribute to the longitudinal stiffness of the vessel such as by way of non-limiting example, H-section or box-section beams although it will be appreciated that other shapes may be utilized as well. In particular, the beams 32 may be designed to have a maximized section for a given weight. The beams 32 may be formed of any suitable material, such as by way of non-limiting example, steel, other metals, or composite materials. Similarly the angled and vertical supports 34 and 36 may be formed of similar materials and sizes and may be connected to the beams 32 and the hull 22 or the main deck 30 by any convention means such as by way of non-limiting example, welding, fasteners adhesives or a combination thereof.
The angled and vertical supports 34 and 36 may be secured to either the hull 22 or the main deck 30 and are located proximate to the side edges of the vessel to maximize the space therebetween. As illustrated in
As illustrated in
With reference to
While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.