GB2086821A - Propulsion modules and use thereof - Google Patents

Abstract

This invention relates to a method of and means for providing a vessel with a detachable propulsion means. Known systems are unsuitable for use in confined waterways such as canals. The present invention provides vessel propulsion means comprising a propulsion module 1 for use in providing a vessel 14 with a detachable propulsion module system, which propulsion module 1 has port and starboard contact means 6-10 formed and arranged for engagement with the bow or stern 13 of a said vessel 14; port and starboard cable or rope guide means for supporting cable or rope means in spaced apart relation and extending in generally the same direction in which said contact means extend cable or rope tensioning means for tensioning said cable or rope means; and a propulsion means 5. <IMAGE>

Description

SPECIFICATION Propulsion modules and use thereof This invention relates to a method of providing a cargo or other type of vessel with a detachable propulsion means.

In the case of relatively large vessels negotiating canals, especially those provided with locks, it is important to be able to manoeuvre and control these with a high degree of precision. This is normally not practicable with the vessel's own propulsion system and it is therefore desirable to utilize a readily attachable and detachable independent propulsion means. In the case of less confined areas of water such as docks this may be achieved by the use of tugs. Unfortunately this is not readily practicable in the particularly confined areas of canals.

It is an object of the present invention to overcome or minimize the above problems.

The present invention provides a method of providing a first vessel with a detachable propulsion means which method comprises the steps of positioning a vessel with its longitudinal axis extending obliquely across a pair of cables or ropes extending in generally parallel spaced apart relationship between a bow propulsion module and a stern propulsion module vessel, moving said propulsion modules relative to said first vessel so as to align said cables or ropes with said first vessel on either side of said first vessel, and tensioning said cables or ropes so as to bring said bow and stern propulsion modules into engaged positions in engagement with the bow and stern of the first vessel, respectively, and hold said propulsion modules in said engaged positions against relative movement with respect to said first vessel during use of said propulsion modules to propel said first vessel.

The present invention also provides a shunter system for use in the method of the invention comprising a bow propulsion module and a stern propulsion module each having spaced apart port and starboard contact means for engagement with the bow and stern of a said first vessel, and each having port and starboard cable or rope guide means for holding cable or rope means extending in generally parallel spaced spart relation, at least one of said propulsion modules having cable or rope tensioning means for tensioning said cable or rope means along either side of said first vessel, in use of the system, so as to hold said bow and stern propulsion module firmly in engagement with the bow and stern, respectively, of said first vessel, and each of said propulsion modules having a propulsion means.

In a further aspect the present invention provides a propulsion module for use in the method and/or the system of the invention, which propulsion module has port and starboard contact means tormed and arranged for engagement with one or either of the bow and stern of a said vessel, in use of the propulsion module; port and starboard cable or rope guide means for supporting, in use of the propulsion module, cable or rope means in spaced apart relation and extending in generally the same direction in which said contact means extend; cable or rope tensioning means for tensioning said cable or rope means in use of the propulsion module; and a propulsion means.

By means of the present invention it is possible to quickly and simply provide a cargo or other type of vessel with a readily detachable independent propulsion means thereby making it highly manoeuvrable and controllable in confined spaces.

Preferably the contact means are made positionally adjustable for engagement with various bow and/or stern hull forms.

Advantageously also at least two vertically spaced apart port and at least two vertically spaced apart starboard, contact means are provided to maximize security and stability of engagement of the propulsion module with the first vessel. This can be still further improved by providing elongate connection means secured at each side of the propulsion module and disposable in a generally upward direction for securing to a respective securing means provided at each side of said first vessel.

Further preferred features and advantages of the invention will appear from the following description given by way of example of a preferred embodiment of the invention illustrated with reference to the accompanying drawings in which: Fig. 1 is a plan view of a propulsion module of the invention; Fig. 2 is a side elevation of the propulsion module of Fig. 1; Fig. 3 is an inboard end view of the propulsion module of Figs. 1 and 2; and Figs. 4 to 7 illustrate various stages of a method of the invention using a shunter system including two propulsion modules according to Figs. 1 to 3.

In Figs. 1 to 3 is shown a propulsion module 1 having a generally arcuate hull form when viewed in plan with a convex outboard end 2, which is advantageous in lock shunting operations due to its minimal bow wave formation, and a concave inboard end 3. At its port and starboard sides the propulsion module 1 is provided with generally cylindrical hull sections 4 at the bottom of which are provided propellor units 5 mounted so as to be rotatable about a generally vertical axis. In proximity to the lower and upper ends of said hull sections 4 are provided lower and upper contact means in the form of arms 6, 7 in the form of generally triangular and generally arcuate arms 8 which are provided at their distal ends 9 with rollers 10 and which are rotatable around the vertical axes of said hull sections 4.

Intermediate the upper and lower ends of said hull sections 4 are provided annular drums 11 around which are wound ropes or cables 12.

As may be seen in Fig. 1 the contact arms 6, 7 are each rotatable between an engaged position in which they contact the bow or stern, 13, of a vessel 1 4 on either side thereof and in which they extend generally parallel to the longitudinal axis of the latter (the precise direction depending of course on the particular shape of the bow and stern of the individual vessel and the dimension of the shunter vessel) and a disengaged outwardly extending position shown partially in phantom for the upper contact arms 7 only.

The upper contact arms 7 are provided with downwardly depending rope or cable guide means 1 5 which engage the rope or cable 12 as the contact arms 7 are moved to their disengaged positions and hold the ropes or cable 12 further out from the vessel 14.

The inboard end 3 of the propulsion module is provided with a generally part cylindrical downwardly extending recess 1 6 to ensure the propulsion module clears the, for example, rudder of the vessel 14. The rudder will normaily be locked in a straight aft position during use of the propulsion module 1. Desirably the inward end of the recess 16 and the outer edges are provided with engagement means such as pads 1 7 which can also engage the vessel 1 3 depending on the particular bow and stern form thereof. Additional rotatable contact means may also be provided to further increase the security of the engagement e.g. rudder contact means.

in addition further protection to the propulsion module 1 as well as the vessel 14 and any external structures such as for example the upstream and breast wall of a canal lock may be provided by means of a resiliently biased (e.g. by springs or hydraulic dampers) buffer means 18 at the outboard end 2 and annular fender means 1 9 on the cylindrical hull sections 4 approximately at the water line. Ths hull of the propulsion module is advantageously of multi-compartment construction with one or more buoyancy tanks which can be employed to adjust the trim of the propulsion module thereby permitting variation of the relative levels of the contact arms 6, 7 with respect to the vessel 14 to best suit its particular bow or stern form and or its trim e.g. depending whether it is fully loaded or in ballast.Further, the compartmentation of the hull improves safety in the event of collision damage.

The cylindrical hull sections 4 in addition to housing drive means e.g. diesel or gas turbine drive engines for the propellor units 5, also house rope or cable tensioning means in the form of drive means arranged for rotating the rope or cable drums 14 to unwind or wind the rope or cable 1 2 thereonto or therefrom respectively.

Fig. 4 shows a shunter system comprising a bow propulsion module 20 and a stern propulsion module 21, each of which is identical with the propulsion module 1 described hereinbefore, and two ropes or cables 12 extend in generally parallel spaced apart relationship between them. At this stage little or no additional tension is placed on the ropes or cables 12 by the propulsion modules 20, 21 so that they hang in the water in a catenary configuration enabling the vessel 14 to position itself obliquely across and above the central portions of the cables 12. It will be appreciated that with the length of rope or cable required there would be relatively substantial forces exerted on the propulsion modules by steel cables.For this reason alternative, lower density, materials such as aramid fibre (e.g. "Kevlar", Trade Name, from the Du Pont Company) which provide near-neutral density in water rope together with high strength (double that of nylon), are preferred as these minimize such forces.

At this stage the vessel 14 is brought substantially to a halt or advantageously is maintained, for purposes of course stability, under way at a small speed e.g. 1 knot. The upper contact arms 7 are at this stage in their outwardly extending disengaged positions so as to hole the ropes 1 2 spread out.

The propulsion modules 20, 21 are then brought round under their own power so as to bring the ropes 12 into alignment with the longitudinal axis of the vessel 14 whilst at the same time operating the rope tensioning means to maintain the cables extended while bringing the propulsion modules 20, 21 in towards the bow 13 and stern 22 of the vessel 14 (see Figs. 5, 6). As the propulsion modules 20,21 finally come up to the bow 13 and stern 22, the ropes still being held clear of the sides of the hull of the vessel 14 (see Fig. 6), the upper contact arms 7 are swung inwardly into contact with the sides of the bow 1 3 and stern 22 bringing the ropes 12 close into the sides of the vessel 14.The ropes 12 are increasingly tensioned until they hold the propulsion modules 20,21 firmly in engagement at the opposite ends of the vessel 1 3 "clamping" the latter therebetween. In order to minimize any tendency for the propulsion module to pitch under the torque exerted thereon by its propulsion means, a further connection conveniently by rope or cable is made between the upper part of each propulsion module and the bow or stern deck, as appropriate, of the vessel 14 at both port and starboard sides. Desirably the latter is provided with suitable securing means e.g. cruciform bollards or mooring points at these locations. The vessel 14 can now be accurately and precisely controlled and manoeuvred in any desired direction by the directionally adjustable propellor means 5 of the propulsion modules. Thus, for example, the vessel 14 may be precisely stopped when it is brought into a lock thereby minimizing the risk of damage to the lock gate or breast wall at the far end of the lock. Also the vessel may be sharply moved to one side almost immediately upon exiting a lock thereby permitting a second vessel passing in the opposite direction to approach the lock much more closely whilst it is being used by the first vessel, thereby reducing the delay in the entry into the lock of the second vessel. By this means the overall efficiency and vessel handling capacity of the canal can be significantly improved, possibly by as much as 30%.It will also be appreciated that this can be achieved with little or no modification at all to the vessel being handled by the shunter system in accordance with the present invention and minimal labour involvement in the effecting of the connection between the propulsion modules and the vessel.

It will be appreciated that various modifications can be made to the above described embodiments without departing from the scope of the present invention as defined herein. Thus for example although the above embodiment utilizes separate port and starboard ropes or cables with independent tensioning means, a single rope or cable extending around both sides with a single tensioning means could be employed. Also other forms and arrangements of contact means could be employed though in general it is desirable that any such means should be able to accommodate the greatest possible variation of bow and stern forms. Various forms of shock absorption means at various locations may also be employed. Thus for example the collision buffers need not be spring loaded but could be backed by water bags with controlled release valves and suitable replenishment means.Although conveniently the bow and stern propulsion modules are made identical, this is not essential and different propulsion modules specifically adapted for use at one end only could be employed.

The propulsion means of the modules may conveniently be any suitable form of multidirectional propulsion unit, for example a Voith Schneider cycloidal type propulsion unit. It will be appreciated that with an arrangement as shown in the above described specific embodiment the propellor units and drive means are mounted well inboard of the outboard end of the propulsion module and buffer means thereof and is thus protected against any accidental impact at said outboard end. It may also be noted that the general configuration of the propulsion modules of the present invention and the utility thereof, in particular the high manoeuvrability thereof is described in our earlier British Patent No.

1,567,756.

EXAMPLE Attachment Procedure using Shunter System 1. Port and Starboard ropes are wound onto grooved winch drums in one full layer, at which point half length of each rope is on the four winch drums. In this condition the bow and stern shunters are locked together and would be either moored to wharf wall or riding at mooring buoy below the first Lock or above the last Lock.

2. Bow and Stern Propulsion Modules or Shunters are boarded by two operators, motors started in one shunter, moorings cast off, and locked pair of shunters manoeuvred into path of approaching vessel.

3. Motor started in second shunter and shunters disengaged with opposed propellor thrusts drawing out the ropes until shunters are lying across path of the approaching vessel.

4a. Vessel approaches at an ahead speed of approximately 1 metre/second.

b. Shunters in position at an angle of about 30 degrees to path of vessel, and at a distance apart of vessel length plus an allowance of about 80 metres.

c. Ropes (of high strength synthetics and specific gravity in the range 1.15 to 1.75) submerged in natural catenaries -- possibly resting on the bottom. Low propellor thrusts on bow and stern shunters to avoid ropes going completely slack.

d. Upper locating arms on the shunters rotated to spread ropes to about 25 metres separation.

e. Vessel's main propulsion shut down.

5. Vessel continues forward motion and shunters commence manoeuvring into position forward and after of the vessel with stern shunter ensuring that cables maintain at least minimal tension.

6. Shunters continue manoeuvring to positions fore and aft of vessel.

7a. Shunters in correct fore and aft alignment with vessel.

b. Vessel and shunters making slight headway of about 0.5 metres/second.

c. Operators in contact by "walkie-talkie" radios.

d. Bow shunter eases into contact with vessel bow and stern shunter thrusts astern while simultaneously winding in ropes to raise catenaries to surface.

e. Both shunters rotate upper locating arms inboard to allow ropes to adopt direct leads to winch drums (if vessel more than 21.0 metres beam, cables will bear against ship's sides).

f. Pilor launch places pilor and shunter controls on board. Pilor launch preferably equipped with "cherry picker" type hydraulic platform.

8a. After shunter eases into contact with vessel stern by winching in repoes against propellor astern thrust.

b. Bow and stern shunters rotate upper and lower locating arms until all 1 6 tyres are bearing against the vessels hull. Locating arms locked.

c. Two mooring ropes forward and two aft lowered by vessels crew and made fast on cruciform bollards located on the tops of the upper locating arms by the operators. The four mooring ropes tensioned by vessel's crew.

d. Winches powered to give about 25-30 tonnes pull in each shunter system rope. The rope tensions compress the 1 6 tyres and effectively lock the shunters to the vessel.

e. Multi-core control cables (preferably duplicate) lowered over bow and stern and connected to sockets on shunters by operators.

f. Vessel still probably just has headway, perhaps 0.2 metres/second.

g. Pilot launch boards operators from bow and stern shunters.

Attachment now complete.

Vessel now under shunter control of pilot proceeds to Lock. Detachment procedure is generally a reversal of the above described attachment procedure.

Claims (10)

1. Vessel propulsion means comprising a propulsion module for use in providing a vessel with a detachable propulsion module system, which propulsion module has port and starboard contact means formed and arranged for engagement with one or either of the bow and stern of a said vessel, in use of the propulsion module; port and starboard cable or rope guide means for supporting, in use of the propulsion module, cable or rope means in spaced apart relation and extending generally the same direction in which said contact means extend; cable or rope tensioning means for tensioning said cable or rope means in use of the propulsion module; and a propulsion means.

2. Vessel propulsion means as claimed in Claim 1 wherein are provided at least two vertically spaced apart port and at least two vertically spaced apart starboard, contact means to maximize security and stability of engagement of the or each propulsion module with a said first vessel.

3. Vessel propulsion means as claimed in Claim 1 or Claim 2 wherein are provided elongate connection means secured at each side of the propulsion module and disposable in a generally upward direction for securing to a respective securing means provided at each side of a said first vessel.

4. Vessel propulsion means according to any one of Claims 1 to 3 wherein each of said port and starboard contact means is in the form of at least one pivotally mounted contact arm movable between an engaged position for contacting the bow or stern of the vessel and a disengaged position in which it extends outwardly.

5. Vessel propulsion means comprising propulsion module or shunter, system for use in the method of the invention comprising at least one propulsion module according to any one of Claims 1 to 5 for engagement with one or either of the bow or stern of a said first vessel and a second propulsion module for engagement with the other of the bow and stern of said first vessel, and having a propulsion means and port and starboard cable or rope guide means for holding cable or rope means extending in generally parallel spaced apart relation, the rope tensioning means of said first-mentioned propulsion means tensioning said cable or rope means along either side of a said first vessel, in use of the system, so as to hold said propulsion modules firmly in engagement with respective ones of the bow and stern of said first vessel.

6. Vessel propulsion means according to any one of the preceding claims wherein the or each module is provided with buoyancy control means for adjusting the trim thereof.

7. Vessel propulsion means according to any one of the preceding claims wherein the propulsion means of the or each module is rotatable about a vertical axis.

8. A method of providing a first vessel with a detachable propulsion means which method comprises the steps of positioning a said first vessel with its longitudinal axis extending obliquely across a pair of cables or ropes extending in generally parallel spaced apart relationship between a bow propulsion module and a stern propulsion module vessel of a vessel propulsion means according to any one of Claims 5 to 7, moving said propulsion modules relative to said first vessel so as to align said cables or ropes with said first vessel on either side of said first vessel, and tensioning said cables or ropes so as to bring said bow and stern propulsion modules into engaged positions in engagement with the bow and stern of the first vessel, respectively, and hold said propulsion modules in said engaged position against relative movement with respect to said first vessel during use of said propulsion modules to propel said first vessel.

9. Vessel propulsion means substantially as described hereinbefore with particular reference to the accompanying drawings.

10. A method of providing a first vessel with a detachable propulsion means substantially as described hereinbefore with particular reference to the accompanying drawings.