According to one aspect, the invention relates to a lifesaving unit for rescuing crew on board ships or rigs and the like. The lifesaving unit includes:

- an encasement configured to accommodate a lifeboat, and

- means for launching a lifeboat out underneath the encasement.

It is understood that the expressions rig, platform, ship, boat or vessel, throughout this specification, are meant to denote any kind of maritime structure, floating or not, suitable for carrying persons, cargo or a combination thereof.

It is further understood that the expression fall, throughout this specification, is meant to denote any kind of wire or rope which is suitable for being wound up on, or wound from, a drum.

Background

Lifesaving systems shall, according to today's rules and requirements, be prepared and configured for deployment under all imaginable conditions and in a safe and reliable manner.

There are generally two types of lifeboats in use, one being the so called free fall lifeboat and the other being the conventional davit launched lifeboat, which is lowered to the surface of the sea by means of a dedicated launch or lowering system.

The launch systems for the above two types of lifeboats encompass hydraulic operated and relatively complex release and/or lowering arrangements.

Various rules set up safety requirements to the entire lifesaving system. In particular, oversized scantlings for the launch and retrieval means are set up by the rules. The scantlings are determined such that the systems shall be able to cope with any and all imaginable situation, and the worst case scenario on which the scantlings are based, typically is multiplied by a safety factor.

Recent developments in the area of means for lifesaving have led to provision of sheltered and/or modular lifesaving systems.

In sheltered and/or modular lifesaving systems, the entire lifesaving system may be installed inside an accommodating box.

The below two references suggests, for various reasons, isolating lifesaving equipment from the environment.

WO 09153240 A discloses a lifesaving system for rescuing crew on board ships or rigs and the like. The system includes a lifeboat and an encasement adapted to accommodate the lifeboat. The encasement including the lifeboat forms part of a modular system allowing interchange ability between similar modules arranged on shore. According to the reference, the interchange ability is beneficial as the ability allows for maintenance to be carried out on modules not being arranged onto the place of application.

WO 10092127 A discloses a launch and/or retrieval device for handling means for lifesaving to be lowered to the surface of the sea from an inside of an encasement such as the encasement according to WO 09153240 A as cited above. The launch and/or retrieval device includes a winch comprising a drum, one or more pulleys and a structure accommodating the winch and one or more pulleys. The structure includes coupling means adapted to provide a releasable connection between the structure and an interior part of the encasement.

While encapsulation of the means for lifesaving demonstrate clear advantages over conventional non encapsulated lifesaving systems, the encapsulated lifesaving systems present new challenges i.e. with respect to arranging the means for launch and/or retrieval of the lifeboat, e.g. according to WO 10092127 A, inside the encasement. One problem with arranging the means for launch and/or retrieval of the lifeboat is the sheer size and dimensions of the mechanical means such as falls, motors and brakes as well as the hydraulic systems operating the said motors and brakes.

As per above, the scantlings of the means for launch and/or retrieval of the means for lifesaving, such as the falls, motors and brakes as well as the hydraulic systems operating the said motors and brakes, are determined on basis of worst case scenarios with the addition of a safety factor.

It has been found that one of the worst case scenarios, with respect to scantlings of the means for launch and/or retrieval of the means for lifesaving, surprisingly is not always occurring during ascent and descent from the encasement. In fact, one of the worst case scenarios in terms of scantlings of the system occurs under start and stop of motors and brakes, i.e. the entire system may have to be dimensioned on basis of pulses stemming from abrupt starts and stops of the system.

The skilled person would realize that the obvious solution to this problem is to eliminate the start and stop pulses by means of configuring the systems for soft starts and stops; however this requires complicating techniques which ultimately would lead to a complex system having poor reliability, e.g. under emergency operation.

Another worst case scenario may occur during pick up or launch in waves of the means for lifesaving. In case the means for lifesaving, when suspended from falls at a level just above the water, is lifted and subsequently dropped by a wave, substantial shocks, or pulses, may be imposed to the means for launch and/or retrieval of the means for lifesaving.

Brief description of the invention

It is an object of the present invention to set forth a lifesaving system which presents a solution wherein the scantlings of the means configured for launch and/or retrieval of the means for lifesaving may be reduced by reducing or eliminating the abovementioned pulses without requiring delicate control of the launch and/or retrieval means.

According to the present invention, the above object is met by providing a lifesaving unit as per the introductory part of this specification wherein the unit further include shock absorbing means interposed in-between the means for launching a lifeboat or equivalent and a site of installation of the unit.

The effect of suspension obtained by resiliently coupling the means for launching a lifeboat or equivalent to a site of installation is that the spikes or pulses produced by the machinery of the launching equipment is absorbed by the resiliently coupling. The benefit of this is that the machinery it selves incl. hydraulic system is not required to be dimensioned to cope with the pulses, and therefore the scantlings of the machinery is not determined on basis of these pulses.

The sites of application may include sites such as in or in-between davits, on the side of a rig or on a deck of a ship, etc.

According to one embodiment, the means for launching a lifeboat may include falls configured for lowering a lifeboat out underneath the encasement.

According to one embodiment, the means for launching a lifeboat may further include at least one hydraulic motor.

According to one embodiment, the shock absorbing means may be interposed in between the encasement and a site of installation such that the lifesaving unit is resiliently connected to a site of installation. Further, the displacement of the shock absorbing means may be in the range of 3 mm - 150 mm, preferably in the range of 10-40 mm. In some embodiments, the shock absorbing means may operate in conjunction with other shock absorbing means.

According to one embodiment, the unit may further include hydraulic means for launching a lifeboat wherein scantlings of the hydraulic means are determined on basis of the hydraulic means being connected to the site of installation via shock absorbing means, i.e. the scantlings of the hydraulic system is determined as if the system is provided with soft start/stop.

According to one embodiment, the unit may be configured for resilient coupling to a site of installation by means of shock absorbing means disposed in the four lowermost corners of the encasement or module.

According to one embodiment, the shock absorbing means may include springs such as Belleville washers or coiled springs. Further, the springs may be progressive or conical etc.

According to one embodiment, the shock absorbing means may include flexible cushions.

According to one embodiment, the unit may further include a lifeboat.

According to one embodiment, the encasement may be configured for detachable connection to a ship or rig and the like by means of shock absorbing couplings.

According to one embodiment, the encasement may constitute a box having substantially parallel sides and a closed top.

Brief description of the drawing

Figure 1 illustrates a principal side view of an encased lifeboat.

Detailed description of the invention with reference to the figures

Figure 1 illustrates a side view of a one embodiment of a lifesaving unit 1 according to the present invention. The lifesaving unit 1 comprises a lifeboat 50 of optional type arranged at least partially within an encasement 100, and in the depicted scenario, the encasement 100 accommodates a twin fall lifeboat 50 suspended by two falls 1 10.

One end of the falls 1 10 is, as shown, secured to the lifeboat 50 e.g. via hooks or other coupling means (not shown) which are decoupled after launch while the opposite end of the falls 100 is secured to not shown hoisting and/or lowering means. The hoisting and/or lowering means may include one or more winches, hydraulic motors, falls, brakes and hydraulic control systems etc. Alternatively, the hoisting and/or lowering system may include electric motors and control systems.

The resilient installation may be obtained by:

- interposing various forms of, in a combination or not, shock absorbing rubber, springs, Belleville washers, oil dampers or equivalent in-between the encasement and e.g. the deck of a ship, and/or

- interposing or incorporating various forms of, in a combination or not, shock absorbing rubber, springs, Belleville washers, oil dampers or equivalent in- between the lifeboat and the encasement.

The lifesaving unit 1 include a shock absorbing means interposed in-between the means for launching the lifeboat 50 and a site of installation 20, the site of installation being the surface or installation which the lifesaving unit 1 rests on during installation on the ship, rig or the like.

According to one embodiment the shock absorbing means 30 are interposed between the encasement 100 and the site of installation 20 such that said lifesaving unit 1 is resiliently connected to the installation site 20. Placing the shock absorbent elements at this position will dampen pulses arising from lowering down the lifesaving unit 1 . According to this embodiment shock absorbing couplings 30 such as springs i.e. Belleville washers or coiled springs or units of flexible material will be placed between the encasement 100 and the installation site 20. Normally, the shock absorbent coupling(s) 30 are/is an integrated part of the lifesaving unit 1 meaning that the shock absorbent coupling(s) are moved together with the lifesaving unit 1 . However, shock absorbing couplings can alternatively be attached to the installation site 20.

According to one embodiment, the encasement 100 may constitute an open frame having a framework defining six planes where the opposite planes respectively are substantially parallel.

Alternatively, the top and sides of the framework can define a rounded top.

All embodiments of the encasement 100 may be provided with open, partially open or closed faces. It may be preferred to provide the encasement 100 with an open or a substantially open bottom in order to allow rescue equipment to be lowered to the surface of the sea through the bottom of the encasement 100. It will however also be possible to provide the encasement 100 with a suitable form of bottom closure, e.g. an easy burstable cloth or hinged and/or slidable panels etc. (not shown).

The encasement 100 may advantageously be produced in sizes corresponding to sizes of standardised container units, e.g. high or low cube TEU, FEU or even 43 or 45 foot units.

In summary, the lifesaving unit 1 may, in its entirety or not, be incorporated into an encasement such as a modular encasement according to WO 09 153 240 A.

The not shown hoisting and/or lowering means may form an integrated part of the encasement 100, and the hoisting and/or lowering means may, in accordance with an aspect of the present invention, be resiliently coupled to the encasement 100.

The not shown hoisting and/or lowering means may constitute a common winch system, e.g. comprising single or dual drums, and the winch system may be driven by means of electricity and/or by means of hydraulic power. Although not illustrated in the figure, the lifesaving unit 1 may be arranged such that the stored position of the lifesaving unit 1 is equal to the position from where the lifeboat 50 may be launched meaning that the lifesaving unit 1 may be arranged such that the lifesaving unit 1 extends, either totally or partially, over ships or rigs sides.

As the lifeboat 50 is normally launched substantially vertical through the bottom of the encasement 100, it is preferred that the lifesaving unit 1 is arranged substantially upright, i.e. with the bottom or bottom opening defining a substantially horizontal plane and if the encasement 100 is essentially box-shaped its sides define substantially vertical planes and the topsides define a substantially horizontal plane.

Further, it will be possible to arrange the lifesaving unit 1 within pivoting means allowing the lifesaving unit 1 , e.g. by means of gravity, to assume an upright orientation.

In any type of installation, it will be possible to resiliently install the encasement 100 in such a way that any pulses originating from start and stop of the means for hoisting and lowering the means for lifesaving is dampened.

The entire hydraulic system has to be able to cope with peak loads, such as sudden shocks created by start and stop operations etc.

It has been found that by resiliently installing the encasement and/or, including at least the winch of the system, at its place of application, scantlings of the hydraulic system may be significantly reduced as shocks etc. are absorbed by the resilient installation.

Conclusively, a lifesaving unit for rescuing crew on board ships or rigs and the like is disclosed. The unit includes an encasement configured to accommodate a lifeboat and means for launching a lifeboat out underneath the encasement. The unit further include shock absorbing means interposed in-between the means for launching a lifeboat and a site of installation. The application and combination of features and solutions presented by the present invention is not limited to the presented embodiments. One or more features of one embodiment can and may be combined with one or more features of other embodiments, whereby not described but valid, embodiments of the present invention may be obtained.

The term "comprises/comprising/comprised of" when used in this specification incl. claims is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.