US3385252A

US3385252A - Method of mooring a ship to a mooring device

Info

Publication number: US3385252A
Application number: US619644A
Authority: US
Inventors: Sekkelsten Arne
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-03-01
Filing date: 1967-03-01
Publication date: 1968-05-28
Anticipated expiration: 1985-05-28

Description

May 28, 1968 A. sEKKr-:LSTEN 3,385,252

METHOD OF MOORING A SHIP TO A MOORING DEVICE Original Filed June 23, 1965 f mm ns p../, VMY MMM 5m 4 @0 mm A. w

United States Patent O 3,385,252 METHOD GF MOORENG A SHIP TU A MGGRING DEVlCE Ame Seirlrelsten, Arendal, Norway Continuation of application Ser. No. 465,279, June 23, 1965. This application Mar. 1, 1967, Ser. No. 619,644 1 Claim. (Cl. 11d- 230) ABSTRACT F THE DISCLOSURE A method for mooring a ship to a dock or buoy in which there is a drum having a lixed flange separating the drum into two portions, there being a slot in this flange through which a rope can pass. The portion of the drum on one side of the flange serves as a storage drum portion, on vwhich the full length of rope is stored when the winch is not in use, and from which the rope is payed out to moor the ship, the portion of the drum on the other side of the ange Ibeing :a tension `drum portion, on which a small length of rope is wound in one layer only by back-spooling after the free end of the rope has been secured to a mooring post or buoy.

This invention relates to improvements in mooringwinch drums and is a continuation vof my copending application, Ser. No. 466,279 filed lune 23, 1965 Iand now abandoned.

It is usual on board ships to 'use Winches for mooring to a dock, buoy or the like. In recent years it has become usual to employ automatic mooring Winches Le. Winches that can keep the mooring rope suitably tight even if the rope length changes because of tide and variation in draft during loading and unloading. The mooring rope is usually brought to the winch drum, Iand the demand for storage capacity usually is so large that the rope must be spooled in several laye-rs on the drum, unless the drum is made impracticaliy long. Having several layers of the rope on the drum presents two Igreat disadvantages. In the first place the pull of the winch decreases with increase in diameter, as the applied torque is constant. Secondly the rope easily penetrates into the underlying layers and is damaged when there is a large tension in the rope and several layers of rope. This all too readily happens when the underlying layers are loosely spooled, and loose spool-ing usually occurs during 'mooring operi tions, as the rope is payed out slackly before it is heaved in with a large pull of the winch.

In order to eliminate these disadvantages, the present invention Iprovides ya drum for a mooring winch in which the drum has a lfixed separating flange which divides the drum into two compartmented units or portions namely a rope storage portion and a portion for rope under tension (tension portion hereafter), and the said flange has a lslot in which the rope is laid across from the storage portion to the tension portion when the rope has been payed out from the storage portion and has been secured to the .mooring posts or buoys. In yautomatic ship mooring gear according to t-he present invention, la long length `ot the rope can thus :be stored in the storage portion of the drum without the pull of the winch upon the rope being reduced as the diameter due to the plurality of layers increases, and with-out the loaded rope penetrating into underlying layers `and damaging the rope. At the salme time, t-he rope, which normally lies in just one layer in the tension portion of the drum can 'be loaded into this portion after la few security turns, with the maximum pull of the winch. Stated in another Way and as shown clearly in FIGS. l and 3 of the drawings of the parent application Ser. No. 466,279, the whole length of rope present ou the power drum portion is payed out and then ice spooled-back after the rope has been disengaged from the mooring as the ship is ready to leave On to the storage drum portion, while the rope extends through the slot and lies unloaded in the storage port-ion.

Mechanism has previously been proposed in which two drum parts are bolted together and the partition between the two drum parts on one side has a radial slot through which rope can be laid. This prior mechanism merely adjusted the working length of the rope in actual use on the work-ing part of the drum in accordance with the depth of the well -or bore hole. The working length being dened as the length of rope payed out and heaved in during each cycle of oper-ations.

Accord-ing to the invention, however, the rope length on the tension part of the drum is only a lfew turns, sufiicient to give the rope Ifriction contact with the drum, so that it passes unstressed through the slot to the sto-rage part. The major portion of the rope which takes part in the actual mooring of the ship extends from the dock to the winch. This portion is not wound up on the tens-ion part of the drum. The rope length on the tension part of the drum thus is independent of the length of rope rom the dock to the ship.

The present invention is furthe-r described below with reference to the embodiment shown, by way of example in the accompanying drawing, wherein:

FIG. 1 schematically shows 'an axial section through a winch `drum accord-ing to the invention, and

FIG. 2 is a cross-section through the drum in IFIG. 1 on the line A-A of FIG. l.

FIG. 3 shows the embodiment of the invention seen in perspective View.

FIG. 4 is =a View in elevation of a ship moored to a dock in accordance with the present invention.

In the drawing a drum 1 is shown with an axially iixed separating lange 2, one portion of the drum, namely a storage portion 3, serving to store rope 4. The other portion, namely a tension portion 5, is used for the surplus length 6 of the rope with which the winch works during a mooring operation (in yaddition to the necessary security turns, which usually number from three to live). Between the storage portion and the tension portion the rope extends through a `slot 7 in the separating flange 2. 9 represents an automatic mooring actuating means of known kind, e.g. such as described and illustrated in Bulletin of the Society of Naval Architec-ts and Mar-ine Engineers, November 1956, pages 9-12.

When the Winch is in use, `as much rope is payed out from the storage portion 3 as is necessary to reach the mooring bit on the dock plus a suicient surplus length to allow for variations in the length of rope due to tensioning on heave-in and to movement of the ship relative to the dock, eg. caused by tide and by loading or unloading the 'ship and also the necessary security turns. The rope is laid in the slot 7 and the security turns `and the surplus length are laid on the tension portion 5 by back-spooling.

When the ship is to cast oit, the whole length of rope present on the tension drum portion is `payed out to slacken the rope. Thereafter the full length of free rope is spooled back on the storage drum portion so as to be ready for pay-out from that drum portion the next time the ship is to be moored.

What is claimed is:

1. A method of mooring a ship comprising the following steps:

upon arrival of the ship in correct position for mooring paying out rope from la storage drum portion, securing the free end of said payed-out rope to a mooring device,

shifting the run-off portion of the rope from the storage drum portion to .a tension drum portion rot-atable in unison therewith,

rotating said drum portions in the reverse direction to spool-back rope on said tension drum portion until the rope has acquired a predetermined tension,

during the stay of the ship turning said two drum portions slightly back `and forth to substantially maintain said predetermined tension,

preparatory to departure of the ship from the mooring device, paying out the whole length of rope present on the tension drum portion,

shifting the run-olf portion of the rope from said tendisengaging the free end of the rope from the mooring device,

shifting the run-off portion of the rope from said tension drurn portion to said storage drurn portion,

and spooling-back the full length of free rope on said storage drum portion.

References Cited UNITED STATES PATENTS MILTON BUCHLER, Primary Examiner.

15 TRYGVE M. BLIX, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,385 ,252 May 28 1968 Arne Sekkelsten It is certified that error appears in the above identified patent and that said Letter-sl Patent are hereby corrected as shown below:

Column 3, le 13, cancel "shifting the run-off portion oi the rope from said ten".

Signed and sealed this 14th day of October 1969.

(SEAL) Attest:

Edward M. Fletcher, JI. WILLIAM E. SCHUYLER, JR.l

Atteting Officer Commissioner of Patents