WO2008072978A2

WO2008072978A2 - Marine structure escape system

Info

Publication number: WO2008072978A2
Application number: PCT/NO2007/000443
Authority: WO
Inventors: Thom Olsen; Geir Skaala
Original assignee: Norsafe As
Priority date: 2006-12-15
Filing date: 2007-12-14
Publication date: 2008-06-19
Also published as: WO2008072978A3; NO328531B1; NO20065827L

Abstract

A cruise ship (1) has an escape system, wherein the system comprises a lifeboat (2) and a tubular tunnel structure (4) that extends into the superstructure (6) of the ship (1), the tunnel structure (4) being formed at a fore end (5) with an opening (8) extending through an external side (10) of the ship (1) structure. The escape system also includes a securing and releasing mechanism (not shown) for the lifeboat (2). The securing and releasing mechanism includes means for retaining the lifeboat (2) within the tunnel structure (4) and may be in the form of typical known mechanical attachment assemblies. There is a supporting structure (not shown) for the lifeboat (2) situated inside the tunnel structure (4). The supporting structure may be in the form of known types of launching slide-ways. The lifeboat (2) is a free fall type lifeboat and is stowed within the tunnel (4) in contact with the supporting structure. The tunnel (4) is formed with passage access to the lifeboat (2) from several different deck levels (2a, 12b, 12c, 12d). The passage access may be in the form of access doors located adjacent the lifeboat providing direct access to the lifeboat from several decks (12a, 12b, 12c, 12d) simultaneously. The access may be through doors in the lifeboat (1) canopy directly into horizontal seating decks.

Description

Marine Structure Escape System

The present invention relates to an escape or rescue system for a marine structure, and it is particularly intended for use in connection with, but not limited to, passen- ger ships, waterborne vessels and the like, but such a system may also be used in connection with offshore structures such as, drilling rigs and production platforms. The present invention also relates to a marine structure comprising an escape or rescue system and to a lifeboat configured to be useable within such an escape or rescue system.

Background

Conventional escape or rescue systems used on ships and offshore production platforms are based on lifeboats supported in davits. The lifeboats are sowed horizontally on a lower open deck and are located inboard and adjacent an open external edge of the deck. The lifeboats are deployed by being pivoted beyond the side of the deck structure and lowered into the water. The davit assembly can comprise a complex arrangement of elements that requires routine inspection and maintenance. The complete launching operation of the lifeboat requires a relatively long time and includes, mustering of the passengers and personnel, boarding of the lifeboat and pivoting and lowering of the lifeboat. Accidents and injuries may occur during the mustering of the passengers and personnel. It is common for the majority of the lifeboats to be stowed on a lower deck, therefore in a state of emergency the passengers and personnel will normally have to negotiate one or more deck levels to reach the lifeboats and injuries to occur as people may become panicked. Another aspect of risk occurs in cases of rough seas when there is always the risk of the lifeboat crashing against the ship side during lowering or after release. There are, therefore, a number of risk issues associated with the conventional escape systems used on ships and production platforms.

Norwegian patent No. 131.236 describes a life saving system for a marine vessel where the life boats are situated in a compartment in the aft part of the vessel. An inclined tunnel structure extends from this compartment to a place in the vicinity of the vessels water line. The life boats can, depending on the weather conditions, be launched through the tunnel structure or lowered into the water from the sides of the vessel.

British patent No. 524.678 describes a life boat or a small craft where the boat comprises watertight hatchways, seats along centre and sides of the boat and also inner compartments. Particularly with regard to passenger ships and cruise ships, there is an additional aspect involved with the stowage of lifeboats onboard. The passengers normally greatly appreciate the ability to have a sea view. However, conventional lifeboats are stowed horizontally between two adjacent decks and utilise a significant amount space adjacent an open external edge of the deck. Therefore, there is a need to store the lifeboats in the most spatially economic location, which occupies the least external wall area as possible.

Summary of the invention According to a first aspect of the invention there is provided an escape system for a marine structure, wherein the escape system comprises a lifeboat; a tunnel structure that extends into the marine structure, the tunnel being formed at a fore end with an opening extending through an external side of the marine structure; a securing and releasing mechanism for the lifeboat; a supporting structure for the lifeboat situated inside the tunnel; and passage access to the lifeboat from the marine structure, the lifeboat being receivable within the tunnel in contact with the supporting structure, whereby the lifeboat is launchable end first from the tunnel structure.

The term marine structure is used herein to mean all forms of structures, both fixed and free to move, on which or within which people may be located. It is intended that the term marine structure includes such structures as, but not limited to, passenger ships, waterborne vessels and the like, but such a system according to the present invention may also be used in connection with offshore structures such as, drilling rigs and production platforms. The term escape system is used herein to include a rescue system.

One feature of the tunnel structure is that it provides a sheltered region within which the lifeboat may be stowed. Such a sheltered region allows for additional protection for the lifeboat and the people using the lifeboat. The orientation of the lifeboat within the tunnel such that the lifeboat is launchable end first provides for a simplified launching arrangement. The lifeboat is held within the tunnel in a state of readiness for launching.

Preferably, the tunnel extends at an acute angle from the horizontal upwardly into the marine structure above water level. The raised angle of the tunnel containing the lifeboat provides the possibility for the lifeboat to be launched with the aid of gravitational force and the lifeboat is preferably a free fall type lifeboat being launchable from the tunnel only under a gravitational force. The feature of a tunnel extending upwardly at an angle from the horizontal and a free fall lifeboat provides a simplified system that requires less maintenance than a conventional davit arrangement. The lifeboat preferably comprises a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks on the marine structure. The plurality of closeable access hatches provides a system that does not require the passengers and personnel on the structure to negotiate one or more deck levels to reach the lifeboat. Hence, the amount of time taken to reach the lifeboat should be reduced and the ease of reaching the lifeboat is increased.

In a preferred embodiment of the first aspect of the present invention the lifeboat comprises a series of tiered rows of personnel securing stations. The personnel se- curing stations may conveniently be in the form of seats but the stations may also be in the form that allows the person to stand. The person may be secured using one or more belts and/or bar members. The tiered rows are preferably inclined relative to the longitudinal axis of the lifeboat.

The lifeboat preferably comprises a plurality of inner compartments for personnel. The inner compartments may comprise passage access between at least two adjacent inner compartments. It may be desirable to have more than one compartment within the lifeboat particularly for larger lifeboats. The passage access may be in the form of doors/hatches provided in bulkheads separating the respective adjacent inner compartment. Alternatively, the inner compartments are formed by respective bulkheads separating the compartments, the bulkheads being formed with openings allowing free passage there-between.

According to a second aspect of the invention there is provided a marine structure comprising the features of the first aspect of the invention. The present invention also includes a marine structure that is configured with one or more of the escape system features of the first aspect of the invention.

According to a third aspect of the invention there is provided a marine structure comprising a lifeboat; a tunnel that extends inwardly into the marine structure, the tunnel being formed at a fore end with an opening extending through the side of the marine structure; a supporting structure for the lifeboat situated inside the tunnel; a securing and releasing mechanism for the lifeboat; and passage access to the lifeboat from the marine structure, the lifeboat being receivable within the tunnel in contact with the supporting structure, wherein the lifeboat and tunnel comprise a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks on the marine structure.

The third aspect of the present invention allows passage access to the lifeboat from a plurality of levels or decks on the marine structure provides a system that does not require the passengers and personnel on the structure to negotiate one or more deck levels to reach the lifeboat. The lifeboat provides easy access from several decks simultaneously. The lifeboat may be accessed directly from various corresponding corridors of the different decks. Hence, the amount of time taken to reach the lifeboat should be reduced and the ease of reaching the lifeboat is increased and also has a tunnel that provides a sheltered region within which the lifeboat may be stowed.

Preferably, the tunnel extends at an acute angle from the horizontal and upwardly into the marine structure above water level. The lifeboat is installed inside the superstructure of the marine structure. The configuration of the lifeboat within the tunnel provides the marine structure with a better stability characteristic. This is of particular importance for marine vessels. The optimum angle from the horizontal will depend upon the size and the type of marine structure. For example, a large cruise passenger ship may require an angle of between 20 to 60 degrees inclined upwardly from the horizontal.

The lifeboat is preferably a free fall lifeboat being launchable from the tunnel with the aid of gravity.

The lifeboat is preferably launchable end first from the tunnel. The provision of an elongate tunnel allows for more flexibility regarding the size of the lifeboat stow- able and the number of lifeboats stowed in a single tunnel. A single tunnel may comprise one or more lifeboats and a single tunnel may receive various lifeboats of different lengths and people carrying capacities.

According to a fourth aspect of the present invention there is provided a lifeboat for a marine structure, the lifeboat comprising a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks within the marine structure.

Preferably, the lifeboat comprises a plurality of inner compartments for personnel

The lifeboat preferably comprises passage access between at least two of the adjacent inner compartments. Preferably, the lifeboat comprises a series of tiered rows of personnel securing stations.

According to a fourth aspect of the invention there is provided a marine structure comprising a tunnel that extends inwardly into the marine structure, the tunnel being formed at a fore end with an opening extending through an external side of the marine structure; a supporting structure for a lifeboat stowable inside the tunnel; a securing and releasing mechanism for the lifeboat; and passage access to the lifeboat from the marine structure, the arrangement being such that in use the lifeboat is receivable within the tunnel in contact with the supporting structure, wherein the tunnel comprises a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks on the marine structure.

Preferably, the tunnel extends at an acute angle from the horizontal and upwardly into the marine structure above water level.

Brief Description of the Drawings

A specific embodiment of the invention will now be described by way of example only with reference to the accompanying drawing, in which:

Figure 1 is front sectional view line sketch of a cruise ship having an escape system comprises a lifeboat stowed within a tunnel structure that extends into the superstructure;

Figure 2 is a more detailed side cross-sectional view of the lifeboat shown in Figure 1 and shows people accessing the lifeboat;

Figures 3a and 3b are schematic sectional views of the cruise ship shown in Figure 1 and shows the lifeboat stowed in an upper position and stowed in an alternative lower position within the tunnel;

Figure 3c is a schematic sectional view of the cruise ship shown in Figures 1, 3a and 3 b and shows the lifeboat being launched;

Figure 4 is a side cross-sectional view of an alternative arrangement for two lifeboats stowed within a cruise ship;

Figure 5 is a partially transparent isometric view of the lifeboat shown in Figure 1; Figure 6 is a partially transparent side view of the lifeboat shown in Figure 5; Figure 7 is a partially transparent side view of the lifeboat;

Figure 8 is a front cross-sectional view of the lifeboat shown in Figure 1 ; Figure 9 is a rear cross-sectional view of the lifeboat shown in Figure 1 ;

Figure 10 is a partial front cross-sectional view of the lifeboat shown in Figure 1 and shows the seats with the back rests in a forward position; Figure 11 is a partial front cross-sectional view of the lifeboat shown in Figure 10 and shows the seats with the back rests in a backward position;

Figure 12a is a side view of a seat and shows the seat with the back rests in a forward position; and Figure 12b is a side view of the seat shown in Figure 12a and shows the seat with the back rests in a backward position.

With reference to the Figures, there is shown a cruise ship 1 floating on a body of water 9, the cruise ship 1 having an escape system, wherein the escape system com- prises a lifeboat 2 and a tubular tunnel structure 4 that extends into the superstructure 6 of the ship 1 , the tunnel structure 4 being formed at a fore end 5 with an opening 8 extending through an external side 10 of the ship 1 structure. The escape system also includes a securing and releasing mechanism (not shown) for the lifeboat 2. The securing and releasing mechanism includes means for retaining the lifeboat 2 within the tunnel structure 4 and may be in the form of any known appropriate mechanical or electrical attachment assembly. There is a supporting structure (not shown) for the lifeboat 2 situated inside the tunnel structure 4. The supporting structure may be in the form of known types of launching slide- ways. The lifeboat 2 is a free fall type lifeboat and is stowed within the tunnel 4 in contact with the supporting structure. The tunnel 4 is formed with passage access to the lifeboat 2 from several different deck levels. The passage access may be in the form of access doors located adjacent the lifeboat providing direct simultaneous access to the lifeboat from a plurality of decks 12a, 12b, 12c, 12d. The access may be through doors in the lifeboat 1 canopy directly into horizontal seating decks. The tunnel 4 extends upwardly into the structure of the ship 1 at an angle α. The value of the angle α will depend on the type and size of the ship 1 but typically it could be in the range 20 degrees to 60 degrees. The tubular tunnel 4 forms a completely protected slide way from an embarkation area 7 to the external side 10 of the ship 1. The tubular tunnel 4 may be made from suitable metal materials. Figures 1, 2 and 3a show the lifeboat 1 stowed at a highest position. In this position the lifeboat is accessible from decks 12a, 12b, 12c and 12d simultaneously. Figure 2 shows people 14 accessing the lifeboat from deck 12b. Figure 3b shows the lifeboat 1 stowed at an alternative lower position. In this alternative position the lifeboat is accessible from decks 12d, 12e, 12f and 12g simultaneously. Figure 4 shows how a two tunnel arrangement may be located within the superstructure of the ship 1. The two free fall lifeboats 2 are installed in a back-to-back configuration in the lowest position. The system according to the present invention is very flexible and the lifeboats stowable may be designed to carry 400, 300, 200 or 100 people. The lifeboats 2 may be installed at different drop heights, but also in- dividually in parallel on different levels such that they are easily accessible from the most crowded areas onboard the ship. It will be appreciated that any practical number of additional tunnel structures 4 may be included in the superstructure of the ship 1. The launching method is a process where once the people have entered the lifeboat and are adequately secured therein, the lifeboat 2 is released and slides under the influence of gravity through the tubular tunnel 4 and from there into the sea by free fall.

The embarkation area 7 includes transverse corridors that act as safe areas in which the people may muster. The embarkation area 7, the lifeboat 2 and slipway may be protected inside the ship 1 by A60 firewalls as a minimum, eventually also sprinkler and overpressure of fresh air. Also, the tunnel structure 4 may be made of similar fire protective material.

With reference to the Figures 5 and 6, the lifeboat 2 is shown in the installed free fall angle ready to drop. The lifeboat 1 comprises passage access in the form of five entrance doors 16 on the top 18 of the lifeboat 2. The doors 16 give direct access to a series of horizontal tiered seating decks 20 through respective center aisles 22 with seat rows 24 on both sides. The seating decks 20 may be separated from each other by bulkhead wall sections so forming separate inner compartments. There is also a rear access door 26 located in the stern of the lifeboat 2. The seats are inclined backwards in a ready to drop position. Exiting from the lifeboat 2 after launching will be through the entrance doors 16 on top of the lifeboat 2 and via the rear access door 26. The people may then be lifted from the lifeboat 2 by helicopters and/or rescue vessels after abandoning ship.

The volume inside the bow section 28 of the lifeboat 2 may be used as equipment storage. The lower ends of the seating decks 20 may additional have doors for longitudinal passage inside the lifeboat 2. A maneuvering stand and power units may be provided and arranged in the stern 30 of the lifeboat 2 with a retractable hood for the view of the helmsman.

With reference to Figures 10 to 12b, the seatbacks 32 will be hinged forward, see Figure 10 and 12a for easy embarkation and will be locked in a backward position, see Figures 1 1 and 12b, for free fall. The seat foundation 34 will be hollow with a hinged uplift seat cushion 36 for use as a personal locker and/or alternative use as toilet in an emergency.

Typically, the lifeboats 2 should not run through a sea trial more than every 5 years. However, after such sea trials the lifeboat 2 is stowed back in the tunnel 4 by using an extension of the slipway by the stern and then being towed back into the stowed position by a lifeboat winch with single wire. Lifeboat drills may be performed at any time with crew and passengers doing a dummy release only to let the lifeboat slide half a meter and then pulled back to stowed position.

It shall be appreciated that the area of the external side of the ship required in order to stow all of the lifeboats is reduced compared to traditional lifeboat stowage due to fact that the respective tunnels extend into the superstructure of the ship.

Claims

1. An escape system for a marine structure, wherein the system comprises:- a lifeboat; a tunnel structure that extends into the marine structure, the tunnel being formed at a fore end with an opening through an external side of the marine structure; a securing and releasing mechanism for the lifeboat; a supporting structure for the lifeboat situated inside the tunnel; and passage access to the lifeboat from the marine structure, the lifeboat comprising a plurality of closable access hatches and being receivable within the tunnel in such a way to allow access to the lifeboat from a plurality of levels or decks on the marine structure, and in contact with the supporting structure, whereby the lifeboat is launchable through the tunnel.

2. An escape system as claimed in claim 1, wherein the tunnel extends at an acute angle from the horizontal upwardly into the marine structure above water level.

3. An escape system as claimed in claim 1 or claim 2, wherein the lifeboat is a free fall lifeboat being launchable from the tunnel with the aid of gravity.

4. An escape system as claimed in claim 3, wherein the lifeboat comprises a series of tiered rows of personnel securing stations.

5. An escape system as claimed in claim 4, wherein the lifeboat comprises a plurality of inner compartments for personnel and passage access between at least two adjacent inner compartments.

6. A marine structure comprising: - a lifeboat; a tunnel that extends inwardly into the marine structure, the tunnel being formed at a fore end with an opening at the side of the marine structure; a supporting structure for the lifeboat situated inside the tunnel; a securing and releasing mechanism for the lifeboat; and passage access to the lifeboat from the marine structure, the lifeboat being receiv- able within the tunnel in contact with the supporting structure, wherein the lifeboat and the tunnel comprise a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks on the marine structure.

7. A marine structure as claimed in claim 6, wherein the tunnel extends at an acute angle from the horizontal and upwardly into the marine structure above water level.

8. A marine structure as claimed in claim 6 or claim 7, wherein the lifeboat is a free fall lifeboat being launchable from the tunnel with the aid of gravity.

9. A marine structure as claimed in any one of claims 6 to 8, wherein the lifeboat is launchable end first from the tunnel.

10. A lifeboat for a marine structure, the lifeboat comprising a plurality of close- able access hatches that allow passage access to the lifeboat from a plurality of levels or decks within the marine structure.

11. A lifeboat as claimed in claim 10, wherein the lifeboat comprises a plurality of inner compartments for personnel

12. A lifeboat as claimed in claim 11, wherein the lifeboat comprises passage access between at least two of the adjacent inner compartments.

13. A lifeboat as claimed in any one of claim 10 to 12, wherein the lifeboat comprises a series of tiered rows of personnel securing stations.

14. A marine structure comprising: - a tunnel that extends inwardly into the marine structure, the tunnel being formed at a fore end with an opening at the side of the marine structure; a supporting structure for a lifeboat stowable inside the tunnel; a securing and releasing mechanism for the lifeboat; and passage access to the lifeboat from the marine structure, the arrangement being such that in use the lifeboat is receivable within the tunnel in contact with the supporting structure, wherein the tunnel comprises a plurality of closeable access hatches that allow passage access to the lifeboat from a plurality of levels or decks on the marine structure.

15. A marine structure as claimed in claim 14, wherein the tunnel extends at an acute angle from the horizontal and upwardly into the marine structure above water level.