US3565029A - Oceangoing ship - Google Patents

Abstract

There is disclosed an oceangoing ship of multiple-screw type in which the hull includes at the stern at least two bulbs or bulges, for the accommodation each of a separate main propulsion engine driving a separate screw. A separate rudder is provided in the slipstream of each screw, but laterally displaced from the drive shaft thereof.

Description

United States Patent [72] Inventor Jan Arie Smit Wiesendangen, Zurich, Switzerland [2]] Appl. No. 731,516 [22] Filed May 23, 1968 [45] Patented Feb. 23, 1971 [73] Assignee Sulzer Brothers Limited Winterthur, a Swiss Company [32] Priority May 31, 1967 [3 3 1 Switzerland [31 1 7701/67 [54] OCEANGOING SHIP 1 Claim, 3 Drawing Figs.

[52] U.S.Cl..... 114/57 [51] lnt.Cl B63b l/04 [50] Field of Search 1 14/57 [56] References Cited UNITED STATES PATENTS 3,162,168 12/1964 Ferris et al 115/34X 1,070 [[1839 Jackson 114/163 1,779,041 10/1930 Hogner 114/57 Primary Examiner Andrew H. Farrell Attorney-Pennie, Edmonds, Morton, Taylor and Adams PATENTEDFEB23I97I 3,565,029

SHEET 1 BF 2 F-BL L Inventor: Jon Arie Smir BY M WWQU JQ LV Aw ATTORNEYS PATENTED 555231971 35651329 SHEET 2 OF 2 Jon ie Smi'r BY W ATTORNEYS or centerline of the vessel and are symmetrically disposed with 1 respect to that centerline, each including at the bottom thereof a foundation for the support of a-propulsion engine.

The hulls of deep sea vessels of the prior art customarily end abruptly at the stern in a sternpost at which a drive screw is located. This shape is entirely suitable when the ship has a draft which is relatively deep compared to, its beam.

With the vessels of larger and larger dimensions which have recently been constructed, such as tankers of over 100,000 tons and cargo vessels of 50,000 tons and more, the draft can no longer be increased with the beam in the same proportions as heretofore. The consequence is that these vessels when viewed longitudinally have a relatively shallow cross section. With such ships, the usual shape for the stem with a sternpost amidships produces long, narrow spaces at the stern which cannot be economically exploited. If to avoid this disadvantage the stern section is shortened,- giving the ship a bluff after body, there result difficulties in streaming of the water past the screw with consequent inefficiency in propulsion.

It is an object of the invention to provide a hull shape in which these disadvantages are avoided; making possible advantageous disposition of the propulsion engines and having a stern which can be constructed of substantially shorted dimensions than in hull shapes of the prior art, and with moreover an improved utilization of space within the hull.

With the construction in accordance with the invention, it is possible to raise the floor of the hull at the stern thereof, ex-

cept for necessary rounding off, between the two bulges above referred to. In this way, there is retained'a simple shape having good water-streaming characteristics.

In this connection, it is possible to provide two rudders at the stern disposed each behind a separate one of the screws. These rudders may however advantageously be offset with respect to the screws. This gives a good efficiency to the rudders and at the same time has the advantage that the shafts can be pulled out through the stern tubes without interference from the rudders, thereby simplifying overhaul.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described in terms of a presently preferred nonlimitative exemplary-embodiment and 1-] in FIG. 2;

FIG. 2 is a plan sectional view on the line lI-II of FIG. I, the profile of the ship above the section beingshown in dot-dash lines; and 2 FIG. 3 is a body plan of the after body of the ship of FIGS. 1 and 2.

DESCRIPTION OF PREFERRED EMBODIMENT In FIGS. 1 and 2, there is shown the stem 1 of a ship according to the invention, having bulges 2 in which the beds or baseplate frames 8 of main propulsion engines 3 have been schematically indicated. The engines 3 are disposed with their crankshafts substantially parallel to the longitudinal dimension of the vessel. The engines 3 are coupled by relatively short rearwardly extending drive shafts 4 to screws 5. Two rudders 6 are provided. The rudders 6 are disposed in the slipstreams from the screws, but displaced athwartships from the shafts so that upon overhaul the shafts 4 can be pulled out aft of the vessel without unshipping the rudders. As FIGS. 1 and 3 indicate, the floor of the hull rises smoothly between the two bulges 2. See the profile at the centerline indicated by the line 7 in FIG. 1.

The cross sections of the after body are shown in FIG. 3 at the various equally spaced stations 1, /ia, is, A; A A. 0 and at the further stations A, B and C all indicated in FIG. 2.

In FIG. 3 as in FIGS. 1 and 2, the full-load-waterline is indicated by the letters LWL. The beam amounts, in the case illustrated, to more than 2.4 times the draft, which value is approximately the lower limit of that ratio for advantageous construction in accordance with the invention.

The invention makes possible a very short or bluff shape for the stem with good usage of the space at the stern of the vessel for cargo holds, and simultaneously provides low water resistance and good streaming characteristics around and past the screws.

While the invention has been described hereinabove in terms of a presently preferred embodiment, the invention itpropulsion engine, and a piston-type main propulsion engine resting on each such bed, said bulges being open to the interior of the hull above said engines.

Claims (1)

1. A ship having a hull provided at the stern with at least two bulges formed integrally with the hull and extending parallel to and symmetrically disposed with respect to the centerline of the ship, a bed in each of said bulges for support of a main propulsion engine, and a piston-type main propulsion engine resting on each such bed, said bulges being open to the interior of the hull above said engines.

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