Escape Means for Sea-Based Construction

This invention relates to escape means for use on board a rig, platform or similar sea-based construction.

In a catastrophic situation on board a sea-based construction, the availability of a satisfactory escape arrangement is vital, that is to say an escape arrangement which is suited for use under particularly difficult conditions with the appearance of strong natural forces (strong winds, heavy seas) and especially with an eye to the outbreak of fire, the danger of capsizing and the like. It is also vital that the escape arrangement is readily readjustable from an inactive to an active use conditions.

With the present invention, the objective is to utilise existing arrangements on board the rig, the platform or similar construction in an effective manner in connection with the escape arrangement. More specifically, the aim is to utilise a gangway construction--which under normal conditions forms a gangway connection between two rigs or similar constructions (for example, between a working rig and an accomodation rig)--so that it can form, in the escape arrangement, a first component which is readily readjustable, stable per se and reinforced. It is customary that the gangway construction is stationarily fastened to the one rig or similar construction in an axially displaceable manner and in a pivotable manner about a horizontal as well as a vertical axis, for adjustment of the gangway construction with respect to an arbitrary base on the remaining rig or on a similar construction. With the present invention, the aim is to employ such a known gangway construction as the main component of the escape arrangement, the objective being, immediately catastrophic-like conditions occur, to readjust the gangway construction from a position between two constructions to a position projecting freely outwards over the sea, with a suitably oblique downwardly inclined path. Here there is available a main component which is well suited for the purposes of escape in a situation of catastrophy so that persons, who are to escape the rig in a safe and controlled manner and by self-help, can get access to a region outside the rig at a level below the inner end of the gangway construction.

With the present invention, there is the further objective of combining the main component with a further component so to be able to escape the outer end of the gangway construction, in a quick and uncomplicated manner, with the aid of simple means which can be adapted in a regulatable way relative to the surface of the sea or a rescue device or a boat on the sea surface.

Accordingly, the present invention resides in an escape means for use on board a sea-based installation and comprising the combination of an axially displaceable gangway means adapted in normal circumstances to provide a self-supporting connection between two sea-based installations while being readjustable about vertical and horizontal axes from one installation relative to the other, and flexible slide means adapted to be stowed away in restricted space and to be readily activated from this position to a stretched out position of relatively large length in which said slide means is freely suspended from said gangway means at its outer end and as a direct extension thereof.

It is preferred that the slide means is fastened to a platform member which can be pivoted about vertical and horizontal axes relative to the outer end of the gangway means so that the slide means can be adjustably regulated in a directional path which deviates considerably from the directional path of the gangway construction.

In consequence, it will be possible, in practice, to allow the directional path of the slide means to extend parallel to the direction of the wind or the direction of the waves thereby ensuring an easily regulatable abutment between the slide means and the sea surface (or a rescue device or a boat on the sea surface) in an elastically yielding manner.

In order that the invention can be more clearly understood, convenient embodiments thereof will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a perspective representation of an escape means according to a first embodiment, illustrated in a condition ready for use,

FIG. 2 is a perspective representation, on a large scale, of a portion of an escape means, and

FIG. 3 is a side representation of an escape means according to a second embodiment, illustrated in a condition ready for use.

Referring to FIG. 1, there are shown portions of a rig 10 with a working deck 11. On the deck 11, there is pivotably mounted about a vertical axis 12a, a tower 12 with an upper landing portion 13 and associated flight of steps 14. The flight of steps can, for example, be swung together with the tower to different angular positions about the axis 12a.

At the opposite end of the landing portion 13, there is pivotably mounted, about a horizontal axis 13a, the lower edge of a gangway construction 15, 16, while the upper edge of the gangway construction 15, 16 is connected to a stand 17 via two parallel piston-cylinder arrangements 18, 19. As a result, the gangway construction 15, 16 can be adjusted into different angular positions about the horizontal axis 13a. The gangway construction is adjusted in a use position for escape purposes with an angle a of, for example, 16.degree. below the horizontal plane.

The gangway construction consists of two (but can, if necessary, consist of more) telescopically collapsible elongated portions 15 and 16, respectively. The gangway construction can, consequently, be displaced axially with the outermost end of the portion 16 adjustable to different distances from the rig, as required, and to different levels above the surface of the sea, as required.

At the outer end of the portion 16, there is fastened a platform-forming gangway member 20 which can be adjusted to various angles relative to the lower edge of the gangway portion 16 about a horizontal axis 21. The member 20 is composed of two parallel parts which are mutually pivotable about a common vertical axis (not shown) so that the upper part of the gangway member 20 can be adjusted into various angular positions such as indicated by the arrow 22.

From the member 20, there extends an oblique, downwardly directed flexible slide means 23 which terminates in a rescue device 24 arranged floating on the sea. The slide means 23 and the rescue device 24 are preferably designed in one piece or at any rate designed as a coherent unit. The slide means 23 and the rescue device 24 are inflatable by means of one or more cooperating gas flasks. More specifically, the slide means is composed of a series of separately inflatable sausage-like, longitudinal strut members 23a and an intermediate slide-forming support member 23b, with, if necessary, extra sausage-like strut members (not shown) on the under side of the support member. Correspondingly, the rescue device 24 is composed of two or more sausage-like strut members 24a jointed together to form a ring and an intermediate base member 24b with, if necessary, extra sausage-like strut members (not shown) on the under side. The slide 23 is jointed above to the outer edge of the gangway member 20 and is correspondingly linked below to the rescue device 24 and is, in addition, elastically moveable between the ends. There is here available a first component 15, 16 which forms a stable, easily readjustable support construction and a second component 23, 24 which makes it possible to adapt the rescue device in an effective manner to the movements of the sea and the movements of the wind respectively.

A particular advantage of the inflatable second component 23, 24 is that it can be received in a manner requiring little space on the gangway member 20 in an inactive condition, preferably on the under side of the gangway member 20, and, for example, in a container (not shown) adapted for this purpose made ready for paying out in a rapid and ready manner.

As an alternative to the inflatable construction, there can be employed, for example, a stocking-like device extending more or less vertically downwards which below, for example, is connected to an inflatable rescue device of a type corresponding to that shown in the drawings or which can cooperate with another type of rescue device.

Another embodiment is shown in FIG. 2 in which an arrangement in connection with a boat 30 is illustrated, the rescue device 24 resting against the deck 31 of the boat and together with the boat being subjectable to considerable movements on the sea. The slide can compensate for movements between the gangway construction and the boat, at the same time as the connection between these is ensured. The rescue device can, in addition, serve as a cushioning means for persons who, via the slide, slide downwards towards the deck of the boat.

In the embodiment of FIG. 3, a slide (glide path) is shown in the form of a canvas chute 33 which with associated fastening rope 34, fastened to edge portions of the canvas chute, can be secured to bollards 35 on the deck 31 of a boat 30. At its opposite and upper end, the canvas chute is fastened to a container 36 via a drum 37. The drum 37 can be driven by a hydraulic motor (not shown) or a compressed air motor (driven by compressed air from a compressed air flask) or another suitable drive device. The canvas and associated fastening rope can be fastened to and wound up on the drum in an inactive position and can be payed out from the drum through an opening 38 which is normally covered with a closing cover 39.

In a condition ready for use shown in FIG. 3 in full lines, the container 36 is arranged just in front of the exit from the outer portion 16 of the gangway construction. In this position, the drum can be arranged on the under side of the outer portion 16 of the gangway construction, that is to say in a chamber which is defined on the under side of a platform (not shown). From the platform there can be effected an outward rising to the canvas chute, and just in front of the platform, there can be arranged a fence with associated gate (not shown).

In an inactive condition as represented in FIG. 3 by broken lines, the container 36 (with rope tackle and canvas received therein) is swung upwards to an upper position above the exit from the outer portion 16 of the gangway construction. By broken lines 40, 41, there is indicated a pair of lifting arms for pivoting the container 36 from a condition ready for use to an inactive condition and vice versa. The lifting arms can, for example, be pivoted by pneumatically or hydraulically controlled pressure cylinders.