EP1049622A1

EP1049622A1 - Ship rig

Info

Publication number: EP1049622A1
Application number: EP99901581A
Authority: EP
Inventors: Steen Christian Olsen; Jorn Steen Nielsen
Original assignee: Olsen Design APS
Current assignee: Olsen Design APS
Priority date: 1998-01-23
Filing date: 1999-01-22
Publication date: 2000-11-08
Also published as: WO1999037537A1; AU2150099A

Abstract

A ship rig (2) especially for a motor- and sail-driven ship (1) and comprising a mast (4) preferably placed in the side. The rig (2) furthermore comprises two elongated supports (8) extending transversely to the mast (4) and placed on the mast (4) in a mutual distance corresponding to a sail. Each support (8) has a sail boom (14) which is rotatably mounted on the end part of the support (8) opposite the mast (4) by means of a rotatable connection (15) such as a bearing or a hinge. Thereby, the ship rig (2) is given a lighter construction and can be manufactured at a lower price than the conventional rigs of this kind. At the same time, the rig (2) will be easier to handle and control than known so far.

Description

Ship rig

The invention relates to a ship rig especially for a combined motor- and sail-driven ship and comprising a mast which preferably is placed in the side.

In anticipation of on reducing both the emission of C0₂ and the costs of propelling commercial ships, it has for some time been pursued to develop motor-driven ships, so-called "wind ships", which could set sail as a support to or a replacement of engine propulsion.

The early commercial sailing-ships were only propelled by the wind. In the above concept, the wind is utilised in support of the engine when the output that the engine must yield can be reduced in doing so .

As the present "wind ships" have to observe a fixed minimum speed, the sails will often be utilised with the wind from forward or from the side. In fair wind, the effect of the wind will be very limited.

At the earlier solutions, the masts were placed in the side, usually on the port side, in order to allow unobstructed crane traffic during loading and unloading. The individual mast was not stayed and obtained the necessary moment for absorbing the sail forces by being fixed in the deck. Each mast carried one large sail of the lugger type, and the reason that an unstayed mast was chosen was that it did not immediately seem possible to implement the construction with the necessary security to withstand a possible accident where the sail broke and got stuck in the stays.

The placing of the mast in the side is expedient seen on the basis of the employment of the ship but it entails that e.g.

65 metres high masts are mounted on deck above a reinforced steel-structure which constitutes a complicated modification of the construction of the hull. As the sail is hanging distended in the centre line plane and e.g. can by 60 metres high and 27 metres wide, the sail will under the stress of the wind be exposed to an immense tension that might affect the mast with a very great bending moment. To this should be added that the resultant force of the sail, of which a part is the driving component, also affects the mast with a substantial torsional moment.

The sail itself must be able to withstand a tension of e.g. 400 - 500 ton. This circumstance means that a very expensive and complicated canvas construction must be used at the same time as the sail at handling and reefing will be fluttering more or less freely in the wind.

If the sail should be damaged, it is the whole of the large sail surface that must be handled during the repairing of the sail. Spare sails which might be taken on board furthermore represent a sizeable investment.

Besides, it can in itself be a problem to find sail lofts with a size and capacity large enough to be able to handle such large sails. The arrangement for setting and taking in the sails must just as the rest of the mast construction furthermore be established with enormous dimensions.

The old square rigged vessels had sails that were divided up into small pieces which were carried by booms generally known as yards . But as the wind might come from both sides of the vessel, the profiles of the sails could not be optimised to obtain a high efficiency because what was gained on one of the tacks were lost on the other tack.

In order to optimise the sail profile, the sail must have the wind in on the same edge all the time, and it therefore has to be of the fore-and-aft type. The traditional Chinese junks have fore-and-aft sails of the lugger type, but in these cases, the sail is hanging directly against the mast. In order to prevent that the sail is drawn forward, there has, in centre of the sail, been attached some ropes which have been taken around the mast. The sail is thereby positioned, however, it is at the same time exposed to substantial wear during handling and use. Furthermore, the mast is standing in an extremely disadvantageous place seen from an aerodynamic point of view.

The object of the invention is to provide a ship rig of the kind mentioned in the opening paragraph, which has a lighter construction and can be manufactured more inexpensively than known so far .

Another object of the invention is to provide such a ship rig which is easier to handle and control than known so far.

The novel and unique features according to the invention, whereby this is achieved, is the fact that the rig comprises at least two elongated supports extending transversely to the mast and placed on the mast in a mutual distance corresponding to a sail, and for each support, a sail boom which is rotatably mounted on the end part of the support opposite the mast by means of a rotatable connection such as a bearing or a hinge .

Having this construction, a fore-and-aft sail can advantageously be carried in a fixed distance from the mast. At the same time, the demand on the strength of the entire rig system is reduced. Furthermore, wear on the sail is avoided, and the mast do not interfere with the air currents at the sail to the same extent as is the case with the known constructions .

The construction furthermore permits dividing the rig up into a convenient number of sections, each having a size which many shipyards are able to handle. At the same time, the individual pieces of canvas will be correspondingly smaller so that they can be manufactured of known material and in common sizes.

A light mast with a relatively small moment of inertia and therefore a relatively low manufacturing price can furthermore be obtained when the mast at each support has a top which, with the sails set, is connected to an area on deck by means of a stay as the forces that are trying to affect the mast to bend thereby are largely transmitted to the deck.

It is important that each support is firmly anchored in the mast in hoisted condition so that the mast can absorb the moment from the forces affecting the sail. This is obtained when each top has means for non-rotatable engagement with corresponding means on the respective support.

As mentioned earlier, the mast is preferably placed in the side. However, the stay of the mast can to some extent still be in the way of traffic and operations on deck. The stays must therefore be arranged in such a way that their point of action on deck can be moved in to the mast when the ship is sailing by engine alone, and the sails therefore are struck.

It is furthermore an advantage when the supports can be slidingly hoisted and lowered along a rail or a groove in the mast. Thereby, the supports with their booms can e.g. be hoisted up so high that there, under the lowest support or boom, will be left a space that permits unobstructed crane traffic during loading and unloading.

When roller booms are used as booms, the hoisting and lowering of the sails is facilitated. With the above mentioned ship rig construction, the surprisingly new effect is obtained in that the moment of inertia of the mast can be reduced to a fraction, e.g. ^ of the moment of inertia of the masts previously suggested for the purpose.

A further reduction of the sail forces can be obtained by providing each canvas with a number of inflatable reinforcing channels . As an example of the advantageous effect obtained in this way, it can be mentioned that a channel-sewn balloon sail at a pressure of one bar and with a horizontal length of 27 metres and a horizontal width of 0.3 metre will be able to withstand a vertical force of about 81 tons when the sail by means of e.g. backstays is prevented from breaking out. It is furthermore advantageous when each rotatable connection of the support has a shorter distance from the front edge of the sail than its distance from the bearing to the mast so that the front edge can swing freely past the mast and thereby can be optimally adjusted to all occurring wind directions.

An optimum solution is obtained when the ship rig has so many elongated supports with relating sail booms that each sail is given a handy size.

The invention will be explained in greater detail below, describing only exemplary embodiments with reference to the drawing, in which

Fig. 1 is a side elevational view of a wind ship according to the invention with six masts,

Fig. 2 shows a single mast seen from the end of the ship,

Fig. 3 shows the mast in fig. 2, mounted with supports, rakes of the supports and movable stay, Fig. 4 shows the mast in fig. 3 but with the supports placed in position for loading and/or unloading and the stays moved in to the mast,

Fig. 5 is an enlarged view of a ship rig in the position of fig. 1,

Fig. 6 shows the ship rig from above,

Fig. 7 shows a sail placed between two roller booms,

Fig. 8 is a plan view of a channel-sewn sail according to the invention,

Fig. is a side view of the sail in fig. and

Fig. 10 is a fractional sectional view on a larger scale of the sail in fig. 8 and 9.

Fig. 1 shows a ship designated generally by the reference numeral 1. In the following, it is assumed that the ship has an engine (not shown) for driving the ship in calm and adverse wind conditions.

For, during adverse wind conditions, contributing to the propulsion of the ship or completely taking this over, the ship is furthermore provided with a total of six ship rigs 2 each with its own spread of canvas 3 indicated in the figure with phantom lines.

Fig. 2 shows a mast 4 for one of these ship rigs. On the mast is placed a total of four tops 5 each connected to the mast 4 by means of a stay 6 and to each other by a stay 7.

Fig. 3 shows the same mast rigged with four horizontally extending supports 8 and a support 9 extending obliquely upwards. The supports are mounted on the mast 4 at the tops 5 and can be hoisted and lowered along the mast by means of the rake 10. The significance of the supports will be described in detail in the following.

On the tops are fastened stays 11 which at the other end are connected to a carriage 12 running on a track 13 or the like and extending from the mast to an area at a distance from this. Instead of a carriage, a slide (not shown) can also be used.

The stays serve for staying the mast so that it, even with a relatively small moment of resistance, can absorb considerable stresses from wind affecting the spread of canvas . When the ship is driven by the engine alone, and the sails therefore are taken down, the carriage 12 is taken, as shown in fig. 4, to the mast 4 so that the stays 11 will be extending down along this and therefore not be in the way of traffic and operations on deck.

Fig. 4 shows that the supports 8,9 can be hoisted so high up by means of the rake 10 that a crane can drive unobstructedly across the ship and load and unload.

Fig. 5 shows on a larger scale a ship rig 2 in the position in fig. 1. On each support 8, seen in the figure from the end, is mounted a roller boom 14.

As appears from fig. 6 and 7, the roller boom 14 is with an articulated bearing 15 pivotally mounted at the extreme end of the support. The articulated bearing 15 is placed at a distance from the ends of both roller booms 14 and in the shown case, with a shorter distance to the end situated at the front edge of the sail than to the mast 4. Thereby, the advantage is obtained in that the front edge of the sail can swing freely past the mast 4 and adjust itself to the most favourable position under all wind conditions. Fig. 6 also shows that the support 8, in the shown case, has a triangular construction with a middle topmast 16, a foot 17 and a wire 18 for staying the middle topmast 16.

The top 5, which is plate-shaped, is secured on the mast 4 and has, as shown, a recess 19 on each side of the mast. On the foot 17 is furthermore made two corresponding projection 20. When the support is in its working position, the projections 20 of the foot engage with the recesses 19 of the top 5 so that the support is locked in a non-rotatable manner to the top 5 and thereby to the mast 4 which in this way will absorb the moment from the wind forces on the sail 23.

During hoisting and lowering, the support 8 is controlled by means of a key 21 running in the longitudinal groove 22 in the mast 4.

Fig. 6 furthermore shows stay 11, the carriage 12, and the track 13 for guiding the carriage 12.

In fig. 7 is seen how two supports 8 are hoisted and made to engage with the corresponding tops 5 after which the sails 23, shown in a phantom line, are stretched between two roller booms 14. The rig 2 is now made ready for sailing with sails.

Fig. 8, 9 and 10 show one of the sails 23 in fig. 7. In fig. 8, the sail 23 is a plan view, and as indicated with broken line, the sail 23 is provided with a number of channels 24.

These channels 24, shown more clearly in fig. 9 and 10, can be inflated with air by means of a not shown pumping set. In inflated state, the channels 24 function as reinforcing ribs for stabilising and reinforcing the sail 23.

As shown, the channels have cross sections formed so that the profile of the sail is given an aerodynamic shape which advantageously reduces the effect-reducing whirl which is generated when the wind flows to and from respectively the sail .

By using the above air-pressure reinforced sails according to the invention in combination with dividing the sail surface into smaller and more handy units, there has been opened up for the possibility of constructing a ship rig in many different ways, all with the thing in common that the forces are absorbed or eliminated locally so that no power summation takes place.

The placing of the mast in the port side as described above and shown in the drawing is only by way of example. On e.g. yachts and small vessels, the common placing of the mast at the centre line can of course be kept at the same time as it, by using the ship rig according to the invention, is advantageously avoided that the harmful whirls normally present around the front of the sail surface are avoided.

Claims

10C A I M S

1. A ship rig (2) especially for a combined motor- and sail-driven ship (1) and comprising a mast (4) preferably placed in the side, characterised in that the rig (2) comprises at least two elongated supports (8) extending transversely to the mast and placed on the mast in a mutual distance corresponding to a sail (23), and for each support, a sail boom (14) which is rotatably mounted on the end part of the support opposite the mast by means of a rotatable connection (15) such as a bearing or a hinge.

2. A ship rig (2) according to claim 1, characterised in that the distance of the rotatable connection (15) from the front edge of the sail (23) is shorter than its distance from the bearing to the mast (4) .

3. A ship rig (2) according to claim 1 or 2, characterised in that the sail boom (14) is a roller boom.

4. A ship rig (2) according to any of the claims 1, 2, or 3, characterised in that the supports (8) are slidingly placed along the mast (4) .

5. A ship rig (2) according to claim 4, characterised in that the supports (8) during displacement along the mast are guided by a track (13) on or a groove in this.

6. A ship rig (2) according to claim 4 or 5 , characterised in that a top is attached at each of the positions of the supports (8) in operational state with means for non-rotatable engagement with corresponding means on the respective support. 11

A ship rig (2) according to any of the claims 1 - 5, characterised in that the mast (4) preferably at each top (5) is connected to at least one stay (6) which at the other end is connected to an area on deck at a distance from the mast when the rig is in operational state .

A ship rig (2) according to claim 7, characterised in that the connection of the stays to the deck is movable.

9. A ship rig (2) according to any of the claims 1 - 8, characterised in that a number of inflatable reinforcing channels (24) are arranged in a sail for distending between two adjacent sail booms (14) .

10. A ship rig (2) according to any of the claims 1 - 9, characterised in that it comprises so many supports (8) with corresponding sail booms (14) that each sail (23) is given a handy size.