DE2915196A1 - Stabilised variable loading ship's hull - has twin hull profile enclosing supporting air cushion providing draught variation - Google Patents

Abstract

A stabilising control for a ship's hull has the underside of the hull with a cavity enclosed by two side hulls and with front and rear profiled sections. The cavity is fed with a variable air supply to increase or lower the lift and hence the draught of the hull. The bow and stern profiles are shaped into the cavity for minimum drag. The reduction of hull area in contact with the water reduces drag further. The ship is able to lower its draught to dock in shallow waters, with a deeper draught in heavy seas, and with heavy loads. No other ballast control is rquired.

Description

T i t e l: bow and stern section as displacement

Body between two-hull ships to form a constructive closed monohull ship with adjustable draft by static air bubble.

Field of application: The invention relates to displacement bodies which it allows between the side hulls and the bow and stern sections, so to speak to accommodate static air bubble, for variable regulation of draft and ship displacement, especially for wide ships with large storage and loading areas: Ro-Ro OPf shore Tugs Salvage Ships Castanter Marine Research Marine Development Fisheries Working platforms Helicopter platforms.

State of the art: I. Civil: cargo ships and other ships (e.g. Ro-Ro ships) with a strongly variable draft, which both the overseas traffic as well as landings on open beaches are not known (displacer) II. Military: Systems for using both tasks are not known! Known are landing craft: II 1.) Landing craft with a large draft have the disadvantage that To have to drop off unloading units far from the coast.

II 2.) Landing craft with a small Tietgang have the disadvantage of Heavy seas and long approach routes. (Displacer II1 + 2) Hoovercraft LuPt cushions are known and levitation ships: III 1.) amphybic vehicles (with aprons on all sides and air propulsion) (air cushion) 2.) quassi-amphybic vehicles (with aprons on all sides and water propulsion) (air cushion) - or fold forward and aft + Water propulsion) (air cushion) 3.) Side wall vehicles (with strong exchangeable Side walls and aprons or - Continuation of the state of the art: III 1.-III 3. All ships are not displacers' The operating condition is the floating condition over water! Criticism of the state of the art: Regarding I and II properties that already are described under I -II 2.

All of these ships and landing craft can be used during the journey Do not change the low pitch and the displacement in a controllable manner without ball or trimming and so that they do not affect their drag coefficients in the various operating conditions.

III 1.-III 3. are not for the transport of heavy loads Long stretches across the open sea, suitable for all weather conditions, and for bulk transport uneconomical.

Task: The invention is based on the task of the gap between the large number of existing air cushion systems and displacement ships to eat too slit! Solution: According to the invention, this object is achieved in that hydrodynamically streamlined, favorably shaped and designed bow and stern displacement bodies the connection of two-hull systems to form a structurally closed monohull enable, and this resulting hull structure between the side hulls on the one hand and the bow and stern fuselage sections on the other hand a static air bubble can accommodate.

Further design: Through this combination between the repression of the four body parts and the static air bubble enclosed by them can be a Changeable and controllable ratio between trunk displacement and air / bladder displacement be brought about, which not only changes the depth, but also through the controllability the respectively possible optimal operating conditions for the desired Mission spectrum creates and also the given sea conditions and swell Can be adjusted The bow displacement body can be optimized so that it not only enables the use of the cheapest surface MACA profile but also through the setting angle through the front flow closure to the air bubble ensures the downward directed flow itself.

Continuation of further design: This is created while driving a flow termination of an equilibrium ratio between the Kp power the flow and the Kp of the air bubble bidet.

This flow closure against the flow changes its position below the bow displacement body ie. of the horizontal surface profile in the reinforcement cross-section forward at lower speed and forward at higher speed to the rear.

Achievable advantages: the structural assembly of two hulls by the bow and stern displacement bodies shown according to the invention: The with The advantages achieved by the invention are in particular that: a.) without ballast and without trimming, the displacement and draft can be changed in an adjustable manner.

b.) Rivers and shallow water areas can and also be navigated the landings in shallow water harbors and on flat beaches like landing craft is made possible, which significantly increases the economic value of the invention.

c.) the draft according to the operational areas and the swell can be adapted to the specified operating conditions.

d.) similar to catamarans, the roll moments and heel (max 160) is improved compared to the monohull ship, and the sea behavior improves with lower horsepower.

e.) Larger parking spaces are given by larger tipping widths.

f.) a considerable reduction in frictional resistance by eliminating them of the ship's bottom is to be recorded, namely with larger parking spaces and widths.

g,) better maneuverability like the ratamarans.

h.) higher curb clearance and side curb heights.

i.) a lighter trunk weight is achieved.

Description: Between two (or more) asymmetrical hulls - as with catamarans - in contrast to these, a bow and stern displacement body Arranged as bow and stern sections so that both rims become one constructive Pest closed monohull ship to be joined together.

1.) Bow displacement body.

The bow displacement body as a bow section and a fixed connection between the side hulls, is asymmetrical as a rod or surface with a long thick Streamlined profile formed, which is only flowed around on one side, while the the other side forms the deck floor of the A-deck.

2.) Flow closure at the bow displacement body.

The flow closure should also be under the profile, through the flow itself, the static air bubble between the hulls in the direction of travel forward conclude.

The profile (1) results in a cross-sectional narrowing of the flow between the hull bow formations of the side hulls and a flow acceleration, sdthat the dynamic pressure increases and the static pressure decreases.

This profile is to be designed in such a way that the dynamic pressure closes the air guaranteed below the profile against the air bubble and the static pressure static pressure of the air bubble forms an equilibrium ratio.

This results in a closure of the static air bubble towards the front at a depth that is not filled by the bow-displacement body but by the essential part is taken over by the flow.

These considerations assume that between the multiple hulls the air bubble is closed upwards.

This supporting, quasi-static air bubble between two or multiple corrugations is designed in such a way that the air bubble in the height to the lowest corner, a Occupies space of at least 50; of the maximum draft above the waterline matters.

L e r s e i t e

Claims (2)

Additional application to patent P 26 52 460 7-22 1.) The ship as well as the cargo ship are characterized in that: A load-bearing, quasi-static air bubble between two or multiple hulls is designed in such a way that the air bubble at the height of the lowest deck occupies a space which is at least 50% of the maximum draft above the waterline. 2.) The bow section as a connection between the two or multiple hulls for the inclusion of the static air bubble is characterized in that: A streamline profile, NACA profile that diverts downward flow and closes the air bubble dynamically guaranteed.