METHOD OF ORIENTATING AN ELONGATE LOAD DURING TRANSFER BY SLINGING

Abstract: A ship load transfer slinging system comprises lines (10, 12) which pass therebetween in diverging manner, so that elongate loads such as gun barrels, missiles or torpedoes, can be rotated on passage, and thus be aligned with the side decks of the receiving ship on arrival there.

Description: METHOD OF ORIENTATING AN ELONGATE LOAD DURING TRANSFER BY SLINGING The present invention relates to a method of transferring an elongate load from one point to another, by suspending it from lines and moving it therealong to a position where it is to be deposited in an attitude appropriate to the available space. The invention has wide application, but is particular efficacous in a marine environment i.e. where elongate loads are passed between a pair of ships. In a marine environment, where there is relative movement between loading and depositing stations by virtue of heaving of the sea, it is at least extremely difficult to control the orientation of an elongate load in course of transfer, especially where the control also needs to involve changing the orientation of the load from that at the place of loading, to another at the place of depositing. So far, the means for achieving that control has been personnel with hand control lines. Examples of elongate loads which are transferred at sea, from a supply ship to a wor ship, . are missiles, torpedoes and gun barrels. Such devices may be stored in the holds of a supply- ship such that their lengths are athwartship, so as to resist shifting as a result of the ship rolling. A warship however, does not have sufficient athwartship space to safely receive elongate loads which are in that attitude when reaching it; the load has thus to be rotated through 90 , prior to being deposited on the narrow side deck thereof. The present invention seeks to provide an improved method of orientating an elongate load during slinging transfer thereof between a loading position and a depositing position. According to the present invention a method of orientating an elongate load during slinging between -a loading position and a depositing position comprises the steps of arranging a pair of slinging lines in diverging manner from the load position to the depositing position, the magnitude of divergence being such that the spacing of said lines over the depositing position equals the distance between the slinging points on the load, connecting said load via its end portions to respective lines so that there is a load leading end on one of said, lines and moving the load bodily along the mean direction of the diverging lines so as to cause that line which supports the leading end of the load to react thereon and cause the load to pivot as it moves bodily, until the load lies normal to said mean direction of line divergence over the depositing point. The invention will now be described, by way of example and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic representation of a diverging transfer line system in accordance with the present invention. Figure 2 is an illustration of the arrangement of Figure 1 applied in a marine environment. Figure 3 is a pictorial view of the arrangement of Figure 2. Fig 4 depicts an alternative embodiment of the present invention. Referring to Figure I. A pair cf lines 10 and 12 diverge from a hypothetical apex 14 and extend to span a space 16 which represents a distance over which an elongate load 18 is to be transferred by slinging. The elongate load 18 is suspended from the lines 10 and 12 at points A-A' . The means for suspending the load 18 may be any convenient apparatus of known kind e.g. hooks suspended from respective lines 10 and 12 by brackets, each of which carries a respective pully which rolls along its respective line. Each hook must be swivelable about a vertical axis. Such devices are well known and are not illustrated. The load 18 will be lifted from storage into suspending contact with the hooks, by a crane (not shown) in situ at the place of storage. When the suspending operation is completed, a pulling force is exerted on the load 18 e.g. by fixing a line to point 'B' on the load and pulling on it from the place where the load 18 is to be deposited. Preferably the pulling direction is along the mean direction of the diverging lines 10 and 12, starting at B. As the load 18 moves bodily in the mean direction of divergence of the lines 10 and 12, the divergence will cause line 12 to act upon the leading end A' to slow it down relative to the end A. The load 18 will thus start to pivot about the point A' and end A will start to catch up with A'; hence the need for swivelling suspension means. As movement of the load 19 progresses, the pulling contact point B will move to one side of the path of mean direction of the divergence. There will result a reduction in resistance to pivoting by the load 18, which reduction becomes more noticeable as the point B passes through points B 1 and B2. The trailing end A will move more easily along its line 10, than does leading end A' along its line 12. Finally, the load 18 adopts a position normal to the mean direction of divergence of the lines 10 and 12 and wherein the distance between the slinging points A and A' coincide with the magnitude of divergence of the lines 10 and 12. This latter feature ensures that the load 18 cannot travel any further, and the lines 10 and 12 are deliberately arranged so that it occurs over the position where it is desired to receive the load 18. Referring now to Figure 2 wherein the principle described hereinbefore with respect to Figure 1, is depicted in a practical context. A supply ship 20 which has a broad beam and large cargo holds, is supplying a destroyer 22 whilst at sea. the destroyer 22 has very narrow side decks 24. Gun barrels 26 are stored with their lengths athwartship of the supply ship 20, so as to be more stable in seas which induce a rolling action. As depicted in Figure 2, one barrel 26 is slung on the lines 10 and 12 and another has already been deposited on the side deck of the destroyer 22, having been rotated by the reaction generated by the diverging lines 10 and 12 during transmit over the sea, which in this example is the space 16 of Figure 1. It will be noted that return lines 28 and 30 are shown in Figure 2. These are explained hereinafter, with respect to Figure 3. Referring to Figure 3. The lines 10 and 12 extend from respective, oppositely handed cable drums 32,34 which in turn are connected to respective motors 36,38. A pillar 40 mounted on the deck 42 of the supply ship supports a pair of pulleys 44,46 at its upper end. The pillar 40 and pulleys 44,46 should be high enough for a load 18 when slung on the lines 10 and 12, to clear all deck structure. The lines 10 and 12 extend over respective pulleys 44, 46, across the space (sea) . 16, to pass around first destroyer mounted pulleys 50,52 and second, destroyer mounted pulleys 54,56 to be led back to respective tension maintaining devices 58,60 of any known, suitable kind. The latter devices 58,60 are needed, so as to cater for the relative movement which occurs between the ships 20 and 22. A load 18 illustrated diagrammatically by a straight line, has been slung onto the lines 10 and 12 and is ready for pulling along them in the mean direction of divergence of the lines 10 and 12, as depicted by the arrow 62, and for simultaneous rotation as described hereinbefore with respect to Figure 1. The pulling may be achieved via a line (not shown) connected between the load 18 and a powered winch (not shown) on the ship 22. The pulleys 44,46,50,52,54 and 56 can all be mounted to their respective structures, for swivelling about vertical axes, so as to cater for unintended movement of the ships longitudinally of each other. Further, the pulleys 50 to 56 inclusive can be mounted on sliding blocks, so that their spacing can be varied to take account of loads of differing lengths, and therefor, variable angles of divergence of the lines 10 and 12. Referring now to fig 4. In this arrangement, all of the hauling is effected from the supply ship. Thus a single line having an outward side 110 and a return side 112 extends from and returns to a common drum 35 via pulleys 144, 146, the function of this line being to support the gun barrell 26. The single line is led back to the supply ship via a pair of pulleys 150,152 which are articulately mounted on the superstructure of the destroyer, in a manner not shown but which may be any known articulated mounting, ie known in the particular field. By this means the pulleys 150,152 can always be in proper alignment with the line sides 110,112 despite the constantly changing attitudes of the two ships with respect to each other by virtue of the motion of the sea. The advantage gained by the arrangement of Fig 4 is that only one tension device of the kind described hereinbefore is utilised for both sides of the line. Tension is thus inherently equal on both sides of the line at all times. Again in Fig 4 the outhaul pulling line 262 is fastened via an end to an outhaul winch (not shown) and an inhaul line 362 is fastened to an inhaul winch (not shown) both of which are mounted on the supply ship. In the present example the line 362 is divided into portions ED and EC of equal length on the supply ship (inhaul winch) side of the load being transferred, and the free ends of portions ED and EC are fastened to a harness 'H' which has been fitted to the load prior to slinging it. The outhaul winch side of the harness 'H' is fixed at a single point to the outhaul winch side of the line 262, which then passes over a pulley 162 on the receiving ship and returns to the outhaul winch (not shown) on the supply ship. The lengths of the portions ED and EC of the line 262 are chosen such that on the load arriving over the place at which i ~ t is to be deposited on the deck of the receiving ship (the destroyer) the two portions ED and EC are both straightened. Thus the diverging line sides 110 and 112 cooperate with the line portions ED, EC to prevent further rotation of the load.

Claims: Claims:- 1. A method of orientating an elongate load during slinging between a loading position and a depositing position characterised by the steps of arranging slinging lines (10,12) (110,112) in diverging manner from the load position to the depositing position, the magnitude of divergence being such that the spacing of said lines (10,12) (110,112) over the depositing position equals the distance between the slinging points (A'A' ) on the load (18,26), slinging a said load (18,26) via its end portions from respective lines (10,12) (110,112) so that there is a load leading end slung from one of said lines (10,12) (110,112) and moving the load bodily along the mean direction (62) of the diverging lines so as to cause the line (12) which supports the leading end of the load (18) to react thereon and cause the load (18) to pivot as it moves bodily, until the load (18) lies normal to said mean direction of divergence (62), over the depositing point. 2. A method of orientating an elongate load during slinging as claimed in claim 1 characterised .by the step of pulling the load (18,26) towards the depositing point, by a line extending between the load and the depositing point. 3. A method of orientating an elongate load as claimed in claim 2 characterised by the step of attaching the end of the pulling line remote from the load (18,26), to a powered winch. 4. A method of orientating an elongate load during slinging or claimed in claim 3 characterised in that said powered winch is at or adjacent the loading position. 5. A method of orientating a elongate load during slinging as claimed in any previous claim wherein the load (18,26) is moved by outhaul line (262) means connected to a load slinging harness ( 'H' ) which is also connected to an inhaul line (362) and both outhaul and inhaul lines are connected for pulling by respective winches situated at or adjacent the loading position. 6. A method of orientating an elongate load during slinging as claimed in claim 5 wherein the inhaul line (362) is divided at the harness (H) so as to connect thereto via two connecting points, the divided portions (EC,ED) being of equal lengths. 7. A method of orientating an elongate load during slinging characterised in that said diverging slinging lines (10,12) (110,112) comprise a single line connected to a common winch (35).

Inventors: ALLEN JOHN, ALLEN, JOHN
Applicants: NORTHERN ENG IND, NORTHERN ENGINEERING INDUSTRIES PLC
Application year: 1992
Main classification: B63B27
IPC codes: B63B27, B63G3