The present invention generally relates to the field of life-saving at sea and, more specifically, it relates to improvements made in the process of launching into the water a means for life-saving at sea.
Within the context of the present invention, ‘means for life-saving’ is understood to designate any means provided for rescue, life-saving and survival at sea which is able to be launched into the water, such as in particular rescue boats, lifeboats and, most particularly, containers containing an inflatable life raft in the uninflated and folded state or any other similar device (for example, a rescue platform) designed to be implemented by being launched into the water within the context of life-saving at sea.
The means for life-saving or survival at sea are usually fitted in ships or fixed installations such as offshore platforms, for example for oil drilling. The means for life-saving or survival are often arranged at significant heights above the water, for example on an evacuation deck able to be located at a height of 20 metres or more on ships, or at even greater heights, of 30 or 40 metres, even 50 metres, on fixed platforms.
The means for life-saving or survival, whatever their type: rigid (such as a boat) or pneumatically inflatable, contained in a container and which are designed to be launched into the water, have to be launched without damaging the structure itself or the equipment with which they are fitted.
The greater the drop height and the greater their weight, the more violent their impact with the water, which for large drop heights, results in substantial reinforcement of the life-saving means with regard to its mechanical resistance to impact, solely from the point of view of its launch into the water.
This is the case, in particular, for inflatable life rafts of relatively large capacity (for example 25 to 50 people) or large, even very large, capacity (for example 80, 100 or 150 people), which are, in particular, fitted to passenger-carrying ships (liners, car ferries) and which are contained in the uninflated and folded state with their equipment in a rigid, mechanically resistant container, for example of generally cylindrical shape, which is stowed on a deck of the ship. A container containing a large capacity raft (several dozen people) weighs several hundred kilos (and even considerably exceeds a tonne for very large capacity rafts of 100-150 people).
At the moment of impact of the container with the water, the violence of the impact may cause delamination of the layers of fibreglass and/or break-up of the constituent resin of the shell of the container, even the rupture of the shell of the container. This deterioration leads to the formation of sharp fragments and sharp edges capable of piercing the flexible wall of the float of the raft during the inflation thereof.
This has led manufacturers to produce containers which have even greater reinforcement (and are therefore even heavier) by increasing the fibreglass and resin layers, the greater the anticipated launch height, and to define a maximum launch height (or nominal launch height) which the container has to be able to resist without damage.
As the increased mechanical resistance of the container is translated into a significant increase in cost, users generally wish to use containers approved only for a drop height which is strictly necessary, for optimum reduction in the cost of fitting out ships. These requirements lead manufacturers to increase the number of types of container approved for various launch heights, which poses problems for manufacture and the stocking of parts, and even maintenance. All things considered, increasing the number of different types of container does not allow their cost price to be reduced as much as would be desirable.
There is therefore a constant demand on the part of manufacturers and users and ship owners, for a greater standardization of containers for life rafts and more generally for a reduction in weight of all life-saving means whatever the type, whilst respecting the restrictions to the speed with which they come into contact with the water when they are launched, in order to avoid damage thereto.
The object of the invention is specifically to meet these expectations and to propose improved means (method and device) allowing the aforementioned drawbacks to be avoided.
To these ends, according to the first of its features, the invention proposes a method for launching into the water, from a height H greater than a predetermined height hmax (approved height), a life-saving means which is designed to be able to be launched into the water in free fall from said maximum height hmax, wherein according to the invention at least one halyard is fixedly hooked by one of its ends to the life-saving means or to the launch site and wherein the halyard functionally cooperates respectively with the launch site located at said height H or the life-saving means, so that the life-saving means falling by gravity is braked on and/or by the halyard over at least one part (H-hmax) of this drop height.
Thus, by controlling the braking effect, it is possible that the life-saving means falling from the height H in a braked manner over at least one part (H-hmax) of this height, hits the surface of the water with a kinetic energy not exceeding that which it would have at the end of a non-braked free fall from at most the height hmax.
According to a possible embodiment of the method of the invention, the length of the halyard is at least equal to said height H, the life-saving means now falling by being braked over its entire drop height H.
According to a further possible embodiment of the method of the invention, the length of the halyard is less than the height H, but at least equal to (H-hmax), the life-saving means now falling while being braked over the entire length of the halyard, then finishing by falling in free fall over a height not exceeding hmax.
In a possible embodiment, to create said functional cooperation, a woven or sewn or stitched halyard is used, for example in the form of a tubular strap or two sewn straps, having transverse calibrated rupture threads; the successive and progressive rupture of these transverse threads, by means of a rupture member displaced relative to the halyard under the action of the weight of the life-saving means, produces the braking effect.
Further solutions may also be conceived, such as the engagement of the halyard through a multiplicity of calibrated passages arranged so as to create a winding trajectory which generates friction, producing the braking.
The practical implementation of these arrangements may give rise to different variants, depending on whether it is the lower end of the halyard which is fixedly attached to the life-saving means and the halyard functionally cooperates with the launch site or it is the upper end of the halyard which is fixedly attached to the launch site and the halyard functionally cooperates with the life-saving means.
Nevertheless, a further possible embodiment of the method of the invention, which is currently preferred by the applicant, consists in that a halyard formed from at least two straps sewn or stitched to one another by calibrated rupture threads is used, in that the respective ends of these two straps belonging to the same end of the halyard are fixedly attached to the launch site and/or to the life-saving means and in that these calibrated rupture threads are successively and progressively broken as the life-saving means falls: the rupture of the threads due to the force of separation applied to the straps by the weight of the life-saving means produces the braking effect.
The method according to the invention perfectly meets the respective desires of users and ship owners and manufacturers of life rafts, in particular, since a life-saving means, in particular a container containing an inflatable raft, approved for a given launch height hmax may now be dropped from a substantially greater height H without it being necessary to reinforce the life-saving means mechanically and/or to apply a new approval procedure. In particular, it is possible to conceive a simplification in the range of life rafts, an improved standardization in the equipment of ships with life rafts and as a result, substantial cost savings.
Finally, it will be emphasized that the method of the invention does not lead to significant modifications to the life-saving means and the launch sites. It is therefore perfectly conceivable, according to the invention, to equip not only new ships or platforms but also to retrofit preexisting ships or platforms at low cost by modifying the existing equipment.
According to the second of its features and in order to implement the method explained above, the invention now proposes a device allowing a life-saving means which is designed to be able to be launched into the water in free fall from said maximum height hmax, to be launched into the water from a height H greater than a predetermined height hmax, this device comprising:
According to a first possible embodiment, the length of the halyard may be at least equal to the height H, whereby the life-saving means falls whilst being braked over its entire length of fall H.
According to a second possible embodiment, the length of the halyard may be less than the height H, but at least equal to (H-hmax) , whereby the life-saving means firstly falls whilst being braked over the entire length of the halyard, then finishes by falling in free fall over a height not exceeding hmax.
In a possible embodiment, to form the above connecting means, the halyard is a woven or sewn or stitched halyard, for example in the form of a tubular strap or two straps sewn to one another, with transverse calibrated rupture threads, whereby it is the successive rupture of these transverse threads under the action of a rupture member in relative displacement relative to the halyard under the action of the weight of the life-saving means which produces the braking effect.
Further embodiments are conceivable such as a multiplicity of members with calibrated passages defining a winding trajectory for the halyard, generating the friction causing the braking effect.
The exploitation of said arrangements may consist in that the lower end of the halyard is fixedly attached to the life-saving means and in that said connecting means functionally connect the halyard to the launch site, or as a variant, the upper end of the halyard is fixedly attached to the launch site and said connecting means functionally connect the halyard to the life-saving means.
Nevertheless, a further embodiment which is currently preferred by the applicant consists in that the halyard comprises at least two straps sewn or stitched to one another by calibrated rupture threads, whereby it is the successive and progressive rupture of these sewn or stitched threads under the action of the weight of the life-saving means which produces the braking effect. Advantageously, therefore, the two respective ends of the two straps separated from one another are engaged through two guides (constituted, for example, in the form of two chain plates fixed to the container), remote from one another, of the life-saving means and are fixedly hooked to the launch site. Thus, the two straps are pulled in opposite directions to one another under the action of the weight of the life-saving means, producing the successive and progressive rupture of the sewn or stitched threads.
Due to the means proposed by the invention, the equipping of ships or fixed installations, which may be fitted with the same life-saving means whatever the stowage and launch heights thereof, is simplified and constraints of use which are inherent in the height hmax are overcome by having the facility to install the container at a height H greater than the approved height hmax; furthermore, more particularly for that which concerns life rafts contained in rigid containers, mass production of larger containers is therefore possible as a result, with a significant reduction in costs. It will also be emphasized, as it refers here to a very important feature of the invention, that the braking of the life-saving means during its fall is obtained independently and without external intervention from the moment when the life-saving means is dropped: it is therefore not necessary to provide any additional procedure, or any additional member to be operated or released and the work of the crew members strictly remains the same as that which it is currently.
The invention will be better understood by reading the detailed description which follows of certain preferred embodiments given solely by way of non-limiting example. In this description, reference will be made to the accompanying drawings, in which:
In the description which follows, for reasons of simplification and clarity and because it refers here to a most particularly interesting application of the arrangements of the invention, reference will be more particularly made, as a life-saving means, to a container containing an uninflated and folded inflatable life raft, it being understood that the invention relates more generally to any rigid life-saving means (lifeboat, rescue boat, etc.) or inflatable life-saving means (raft, rescue platform, etc.) suitable for being put into the water by launching from a launch site (deck of a ship, offshore platform, etc.).
By referring now firstly to
The stowage point of the container 1 is located at a height H above the water 5, whilst the container is mechanically designed and approved to be able to be launched into the water from a maximum height or nominal height hmax which is lower than the stowage height H.
According to the invention, at least one halyard 4 is provided, fixedly hooked at one of its ends to the container 1 or to the launch site of the container 1.
Moreover, the halyard 4 functionally cooperates (at 7) respectively with the launch site or the container 1 so that the container 1 falling by gravity under the action of its own weight (several hundred kilos, or even in the order of a tonne) is braked on and/or by the halyard 4 over at least one part (H-hmax) of its drop height.
Due to these arrangements according to the invention, by regulating the braking effect due to the functional cooperation of the halyard with the launch site or the container, it is possible that the container 1 falling from the height H in a braked manner over at least one part (H-hmax) of this height, hits the surface of the water 5 with a kinetic energy not exceeding that which it would have at the end of a non-braked free fall, from at most the height hmax.
These arrangements may be implemented in various ways.
In the embodiment illustrated schematically in
In the variant of
In the variant of
In these conditions, once released, the container 1 starts by falling by gravity along the halyard 4 with the braking effect produced by the functional cooperation means 7 to which the container 1 is hooked by means of slings 6; then, once the container has reached the free end 8 of the halyard, it finishes by falling in free fall as far as the water from a height which does not exceed hmax.
This preferred variant is particularly interesting as it allows the fall characteristics normally anticipated for the container (drop height hmax) to be exploited, whilst providing the halyard 4 only with the length L necessary to move the container in a braked manner to the position where it may be released. This results in a saving in the cost of the halyard.
A second embodiment of the arrangements of the invention is illustrated in
If the length of the halyard 4 is at least equal to the height H, it will unwind through the means 7 and accompany the container 1 over its entire drop height and the container 1 will be braked over the entire length of its fall until its contact with the surface of the water 5 in the same conditions as have been illustrated in
If the length L of the halyard 4 is less than the height H but greater than the height hmax, the container 1 will firstly fall whilst being braked by the halyard 4, then will finish in free fall, in the same conditions as those which have been illustrated in
Due to the arrangements according to the invention, it is possible to standardize the life raft containers with which the whole ship or a fixed installation is equipped. More specifically, all the containers may therefore be selected of the type intended to be arranged in the lower part of the installation or the lower deck of the ship, namely of the type having the lowest mechanical resistance. Regarding containers which have to be installed on the decks or intermediate or upper areas, they are selected from the same type as the aforementioned containers and a halyard having the required length is functionally associated therewith which makes it possible to ensure that they are put into the water from the nominal height for which they have been designed and approved. Due to this standardization, it therefore becomes possible to reduce the overall cost of equipping the ship or fixed installation with life-saving equipment.
To provide the functional cooperation means 7 with a braking effect, a plurality of practical solutions are conceivable.
A first solution consists in generating a braking or deceleration effect by successive ruptures of a multiplicity of rupturable members designed to this effect.
An embodiment illustrated in
The braking of the container is directly associated with the weight thereof: the greater the weight to be braked, the higher the resistance to splitting the strap 9 has to have. This resistance to splitting may be increased:
A further conceivable solution consists in generating the desired braking effect by the friction produced by the sliding of the halyard 4 through a member fixed to the container 1. For example, the halyard 4 may be slid in a system of staggered passages provided on the container 1. To this end, as illustrated in
A further embodiment, which in practice is easier to control and which currently appears to constitute the preferred embodiment of the invention, refers to a process of tearing a halyard 4 in the form of a double strap 19 which, as illustrated in
In this case, the container 1 may be fitted out in a preferred manner as shown in
It will be noted that it would be possible to adopt the reverse solution, with the ends of the straps separated from one another attached to the container and the chain plates arranged on the cradle, the pocket containing the halyard being associated therewith. Nevertheless, the solution disclosed above regarding
In a possible variant illustrated in
The resistance of the stitching of the double strap 19 is selected according to the weight of the container to be braked and the speed to be attained upon impact of the container with the surface of the water. The resistance of the stitching depends on the resistance of the thread used, the number of stitching points per surface unit of the straps 20, the geometry of the stitching lines and the frequency of the stop points. So as not to increase the number of drawings,
By way of example, two straps available commercially may be used with the reference PY L22 undyed, having a nominal width of 22 mm, a nominal thickness of 1.5 mm and a nominal resistance of 1000 daN and which are sewn to one another with the polyester thread Saphyr ER 16/3 of 190 tex, having a diameter of 0.49 mm and a resistance of 9.8N. The two straps are connected by 6 lines of parallel stitching, with 4 stitching points per 12 mm. A braking halyard constituted by a strap produced in this manner is capable of braking a container of a weight in the order of 130 to 170 kg, in the targeted conditions within the scope of the invention.
If it is necessary, in particular, to handle a greater weight than that allowable for an individual halyard, the appropriate braking force may be obtained by using a plurality of halyards in parallel. It is also possible to combine a plurality of means explained above, when such a combination is technically possible. Furthermore, on the launch site, it is possible to position the aforementioned braking means on the container or in association therewith, and vice versa.
Number | Date | Country | Kind |
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05 07212 | Jul 2005 | FR | national |