GB2381515A

GB2381515A - Engine powered vessel with auxiliary sail means

Info

Publication number: GB2381515A
Application number: GB0126369A
Authority: GB
Inventors: Richard Dryden
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-02
Filing date: 2001-11-02
Publication date: 2003-05-07
Anticipated expiration: 2021-11-02
Also published as: GB2381515B; GB0126369D0

Abstract

An engine-powered vessel 21 is provided with one or more removable sail modules 20. Each of the sail modules includes a sail (4, Fig 4) which is stored in a bundled condition and means for mechanically deploying the sail into a raised position to provide additional wind assisted propulsion of the vessel when required. The sail can be re-bundled back into the module when not in use. The sail may be supported by a mast (2, Fig 4) having a plurality of sections (31, 32, 33, 34, Fig 4) which are pivotally interconnected such as to be movable between the stored and raised positions. The modules may be fitted to ships such as bulk carriers and tankers, to provide wind assistance in order to reduce fuel consumption.

Description

WIND ASSISTED VESSELS TECHNICAL FIELD OF THE INVENTION This invention relates to sail modules for engine powered vessels.

In this specification the term "rig" shall (unless the context otherwise requires) refer to a sail and its supporting structure which will normally include a mast BACKGROUND Prior to the development of steam power and Internal combustion engines, most cargo ships relied on human or wind power to propel them along trading routes. At first, sails were used mainly for travelling downwind, but in time rigs and vessels were devised that were able to progress across wind and travel to some extent upwind by tacking from side to side. By the end of the 19t Century and Into the early decades of the 20t Century, large mainly steel-built windjammers travelled the world's oceans and carried substantial cargoes of coal, ores, minerals, food materials and other commodities between nations. However, the wind has a variable nature and this makes it difficult to keep wind-driven ships to tightly-defined schedules As the need

for reliable and rapid delivery increased with the growth in international trading, and as the reliability of steam and internal combustion engines improved, sailing cargo ships were superceded by motor-driven ships.

In the 011 crises of 1973/4 and 1979 the cost of oil rose by up to 5 times the previous pnce. This had a sufficient impact on national economies to stimulate a number of research projects Into the feasibility of modern versions of the windship. However, in recent years oil prices have stabilised at comparatively tolerable levels and to some extent the economic pressure to develop wind assistance has eased.

However, there are at least two other factors that will play a part in deciding whether wind-powered ships will be developed again in the future. Firstly, oil and gas reserves are finite and non-renewable. Secondly, there is evidence that the burning of fossil fuels is having a deleterious effect on global factors such as climate patterns. The transportation sector accounts for 1/5 of energy use, and is currently one of the main producers of greenhouse gases and other polluants.

There are two main windship options : sail power alone, or combined wind and engine power (wind assistance). The present invention addresses the latter option-wind assistance.

To be effective, a proposal for applying wind assistance to larger vessels will need to take account of the following requirements: . economy ; capital and running costs 'safety ; no requirement for crew to climb rig during operation

. environmental sensitivity 'manoeuvrability 'crew level comparable to that of a conventional ship of comparable size * the need for unobstructed loading and unloading 'an average and reliable service speed of at least 11 knots . multi-mast configuration to keep height of masts within acceptable limits - aerodynamic efficiency of rigs ; when a vessel is powered by its engines the apparent wind moves forwards, so the salling rig used for wind assistance needs to be effective when used close-hauled . simplicity of engineenng and control systems * ability to reduce sail area as needed.

The present invention seeks to provide a new and inventive form of windassisted vessel which meets many, if not all, of the above requirements.

SUMMARY OF THE INVENTION The present invention proposes an engine powered vessel which is provided with one or more removable sail modules, and the or each such module includes a sail which is in a bundled condition, and means for mechanically deploying the sail into a raised position to provide additional wind assisted propulsion of the vessel when required.

The sail module is thus distinguished by being capable of being raised when

required. Furthermore, the sail module is preferably arranged such that the sail can be rebundled and folded back to deck level when not in use.

The invention therefore provides the means whereby one or more such sail modules can be fitted to ships with relatively clear deck spaces, for example bulk carriers and tankers. The intention is to provide wind assistance in order to reduce fuel consumption rather than to eliminate the need for engine power completely. The benefits of this approach are both economic and environmental by reducing non-renewable fuel use and pollution The sail module is removable from the ship when not required or for landbased servicing. Several sail modules may be attached to the same ship to provide the requisite sail area This provides redundancy, so that if one module fails the remaining modules can still be used. In potentially dangerous situations such as storms or equipment malfunction, the rigs can be folded to deck level to reduce windage. The modular approach could be developed, provided, and serviced by companies other than the ship owners and operators. This would reduce the financial burden on shipowners and operators to a level that might encourage earlier uptake of wind assistance than if they were left to develop windships at their own expense.

It is proposed that some existing ships would lend themselves to the fitting of sail modules of the kind described herein, with the need for only limited modifications to be made rather than the need to build new, highlyspecialised sailing ships. A typical candidate for the application of wind power would be a vessel of approximately 50,000 DWT, and a sail area of 10, 000 to 15,000 square metres Bulk carriers and tankers with relatively free deck space offer the best starting point. Bulk carriers come In two types:

'geared vessels'equipped with their own loading and unloading facilities, and 'gear-less vessels'that depend on dockside equipment for loading and unloading. Geared vessels have their deck space occupied to different degrees, and would present greater difficulties than tankers and gear-less vessels when fitting sail modules of the type proposed herein Research has shown that currently windships would cost slightly more to operate than conventional ships, given the additional investment required to develop rigs and build specialised ships. A rise In oil prices and the application of environmental taxes could change this relationship. Currently, fuel costs account for only 15% of the total operating costs for a modem bulk carrier, but if that figure begins to rise then wind assistance will become more attractive. However, it is proposed here that even before that point is reached, it will be beneficial to develop wind assistance by the use of sail modules that can be fitted to ships or removed as required.

The most favourable use of wind power could be made by ships travelling longer distances and carrying low density, relatively low value cargoes for which there is a steady demand. Dry bulk cargoes were the last to be carned by the old windjammers, and could well be the best ones to be carried by a new generation of wind assisted vessels Other possible applications for the early re-introduction of wind power are tankers, cruise vessels and research vessels. A wind-assisted ship with auxiliary engine (s) and with the help of Information technology for effective weather routing could provide a service as reliable as conventional vessels while using less non-renewable energy and producing less impact on the environment The sail module may include a housing which contains the sail In a bundled

condition but which is capable of being opened for raising of the sail.

The sad is preferably supported by a mast (spar) which is secured to a body at one end thereof and has a plurality of sections which are pivotally interconnected such as to be moveable between an extended condition and a folded condition The sail may include a membrane of flexible material secured to the mast.

The base section of the mast is preferably pivotally secured to the body.

The mast preferably comprises three sections, namely a base section adjacent to the body, a middle section and an outermost section which IS furthest from the body The middle section preferably comprises first and second spaced struts which are connected to the respective base and outermost sections by spaced pivotal connections.

Control means may be provided to move the mast sections between said conditions. Thus, by operating the control means the mast and membrane can be flexed and extended or folded Into a compact bundle without the need to detach the membrane from the mast or to detach the mast from the body The control means may be mechanical actuators such as hydraulic or pneumatic rams or electncally-operated motors.

In most embodiments of the invention the membrane will be supported by the mast along a leading edge of the membrane A supporting structure, e. g. a boom, may be connected between the mast and the membrane such that the

membrane is held taut between the mast and the supporting structure BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example In order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a general view of a ship being fitted with a sail module in accordance with the invention; Figure 2 is a general view of the ship which has been fitted with the modules, with the sails in a non-deployed condition ; Figure 3 is a similar view of the ship with the sails deployed ; Figure 4 IS a more detailed view of the deployed sail module; Figure 5 shows the steps involved in retraction of the sail ; Figure 6 is a general detailed view of part of the deployed sail module with the module doors open, and Figure 7 is a side elevation of the parts shown in Fig. 6.

DETAILED DESCRIPTION OF THE DRAWINGS

As shown in Fig. s 1 and 2, a number of sail modules 20 can be lifted by crane onto the deck of a suitably-modified ship 21 and fixed in place when required for a particular voyage. The number of modules attached to a given ship will be matched with the size and requirements of the ship and the conditions anticipated on the route to be sailed. The modules have doors 7 which can be opened when required to allow the mast and sail to extend, as shown in Fig. 3, and close again around the base of the extended ng. The extended rig (s) provide sail assistance to the ship and reduce the dependence on fossil fuel consumption. When the ship enters port, or dunng severe storms when sails might pose a safety risk, each mast and sail can be folded down and the module doors closed to minimise obstruction and wind resistance. When not required, the module can be disconnected and removed in port, becoming available for servicing and use on other ships.

Refemng to Fig. 4, each module includes a housing 22 having a substantial base plate 1, a jointed rotating mast 2 which can extend upwards and fold downwards, and a pivoted horizontal boom 3 to support the lower edge of the sail 4 The base plate 1 is attached to the deck of the ship by a means that allows straightforward removal at a later time, for example by through-bolts 6 or clamps at each comer. The mast has three segments following the basic pattern descnbed in GB 2 225 760-A. The mast is formed of bottom, middle and top struts, 31, 32/33 and 34 respectively, the middle strut including front and rear sections 32 and 33 which are pivotally connected to the top and bottom struts in a pantographic arrangement The sail 4 is made from an extensible material that can accommodate the changes In mast geometry whilst at the same time being able to maintain a suitably aerodynamic shape when tensioned in use. The sail incorporates a sleeve 8 enclosing the mast to protect it from the elements and produce an

aerodynamic shape. The sail membrane extends from the rear edge of the sleeve to be held taut by attachment to the boom 3. Radially-arranged battens 9 support the upper part of the sail. An optional panel of sail material 10 may be attached in front of the mid and lower sections of the mast to improve the leading edge profile of the lower half of the sail.

The two hinged doors 7 are attached to opposite sides of the base plate 1 to form a streamlined cover for the sailing rig in its folded configuration, and the doors can open as shown in the sequence of drawings comprised in Fig. 5 to allow the rig to be deployed. When the rig is fully extended, the doors close around the base of the rig to protect the control systems within.

As shown in Fig. s 6 and 7, actuators are provided to open and close the module doors, and produce extension, folding, and rotation of the mast, which is mounted on a circular rotatable base 13 The actuators can be hydraulic, pneumatic or electncally powered In a way that best suits the ship to which the module is attached. An umbilical 11 from the module connects to the ship's power and control systems to enable control of the rig by the ship's crew. Actuator A causes elevation of the first segment 31 of the mast, and actuators B produce extension of the remaining two segments In relation to the first, the change in angle at the lower joints 12 being mirrored by similar changes at the upper joints due to the pantographic arrangement of the two struts forming the middle segment of the mast The base 13 is pivoted about the vertical axis to allow the rig to be turned in relation to the ship and tnmmed according to the direction of the apparent wind over the sail. This IS achieved by an actuator C that drives the nm of the circular mast base. An optional braking system 14 can be applied to the rotating mast base to lock the rig in the desired working position. Actuators D (only one IS shown

for reasons of clarity) open and close the module doors 7. A strut 15 between the rotating mast base 13 and the boom 3 ensures that the boom remains horizontal during elevation and folding of the mast, and also produces tensioning of the sail when the mast is raised. Because of the high stresses experienced at the foot of the mast the plate 13 is mounted on foot bearings 16 having substantial reinforcements (Fig. 7) It WIll be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.

Claims

CLAIMS 1. An engine-powered vessel which is provided with one or more removable sail modules, and the or each such module includes a sail which is in a bundled condition and means for mechanically deploying the sail into a raised position to provide additional wind assisted propulsion of the vessel when required.
2. An engine-powered vessel according to Claim 1, in which the or each sail module is arranged such that the sail can be re-bundled therein when not in use.
3. An engine-powered vessel according to Claim 1 or 2, in which the or each sail module includes a housing which contains the sail in a bundled condition but which IS capable of being opened for raising of the sail.
4. An engine-powered vessel according to any preceding claim, in which the sail is supported by a mast (spar) which is secured to a body at one end thereof and has a plurality of sections which are pivotally interconnected such as to be moveable between an extended condition and a folded condition.
5. An engine-powered vessel according to Claim 4, in which the base section of the mast is pivotally secured to the body.

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6. An engine-powered vessel according to Claim 4 or 5, in which the mast comprises three sections, namely a base section adjacent to the body, a middle section and an outermost section which is furthest from the body.
7. An engine-powered vessel according to Claim 6, in which the middle section comprises first and second spaced struts which are connected to the respective base and outermost sections by spaced pivotal connections.
8. An engine-powered vessel according to any of Claims 4 to 7, in which control means may be provided to move the mast sections between said conditions.
9. An engine-powered vessel according to Claim 8, in which the control means includes mechanical actuators.
10. An engine-powered vessel according to any of Claims 4 to 9, in which the sail comprises a membrane of flexible material secured to the mast.
11. An engine-powered vessel according to Claim 10, in which the membrane is supported by the mast along a leading edge of the membrane.
12. An engine-powered vessel according to Claim 10 or 11, in which a supporting structure is connected between the mast and the membrane such that the membrane is held taut between the mast and the supporting structure

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13. An engine-powered vessel substantially as described with reference to the drawings.