FR2669723A1 - Device for tearing the hull of ships - Google Patents

Abstract

The subject of the invention is a device for tearing the hulls of ships. The device according to the invention, in its preferred form, is particularly characterised in that it includes a casing (1) comprising, in particular, the members for firing, retarding, and booby-trapping, and strips (2) of slight thickness consisting of a flexible explosive adjoining the casing (1) and having the faculty of being capable of being rolled or unrolled on themselves. The device, with these strips deployed, is fixed against the hull and inflicts on it extremely harmful tears. The device, with the strips rolled up, is very lightweight and has very small bulk. The device according to the invention in effective equipment for attacking ships of all tonnages. It can also be used in underwater and land-based salvage and rescue operations for cutting armoured panels.

Description

 The present invention relates to devices for tearing the hulls of ships.

 A large number of explosive devices are known which, placed under the waterline of ships, make it possible to damage the hull in order to immobilize or sink them. These devices are generally routed and placed on a sensitive point of the hull by combat swimmers. Improvements in current detection means make this type of mission very delicate, so it is very desirable that the swimmer has, in addition to good training, great freedom of movement.

In addition, the generally unique nature of this type of mission requires that the device has a high reliability and that each charge causes the greatest possible damage.

 The devices known to date are generally bulky and heavy and cause damage which is not always sufficient to knock the target ship out of action. Indeed, these devices, which very often use the hollow charge effect, mainly comprise heavy metal parts so as to concentrate and transmit the effects of the explosion. The opening made using such devices is generally roughly circular so that the water only invades one or at best two of the sealed partitioned chambers with which warships are provided.

 The purpose of the device according to the invention is to remedy all the drawbacks which have just been mentioned and to further bring a certain number of appreciable advantages to its user.

The device according to the invention combines both a greatly reduced weight and a minimum size and is capable of causing an extremely pernicious tear in the hull of the building to be fought. The device according to the invention is characterized in that it comprises a box comprising the firing, delay and trapping members and one or more thin elements made of flexible explosive, said elements adjoining said box and having the possibility of being able to be rolled up or folded up on themselves so that the device takes up little space during transport or storage. According to a preferred version of the invention, the elements are cut in the form of ribbons which are rolled up during storage and transport to the places of the mission, then unrolled and plated on the hull by the swimmer once the goal has been achieved. compactness, ease of implementation and particularly pernicious nature, the device according to the invention has other advantages which will be highlighted in the following more complete description where reference may be made to Figures 1 to 4
FIG. 1 represents a perspective view of an embodiment
preferred device according to the invention, as it appears
during storage or during transport to the places of use,
elements cut from a flexible explosive sheet each having
the shape of a strip wound on itself.

Figure 2 shows the previous device applied to the
shell to be torn, the flexible explosive strips being deployed
on each side of a central resistant box with
ignition, trapping, timer and fixing devices
the shell, so as to form a cross of which one of the cross-pieces
is longer than the other.

Figures 3a, 3b, 4a and 4b show other embodiments.
tion of the device according to the invention respectively in the wound state
(for storage and transport) and in the deployed state (ready for
employment).

The device according to the invention is characterized in that it comprises, in addition to an ignition box, one or more elements of small thickness made up of flexible explosive, said elements having the ability to be rolled up or folded in on themselves. so that the device is compact.

 The thin elements made of flexible explosive which characterize the invention are preferably strips whose arms may or may not be parallel. It is advantageous to cut such strips from a sheet of flexible explosive. The strips can have any shape although the ribbon shape is preferred. You can also use triangular or trapezoid bands.

 The elements of flexible explosive must have a thickness sufficiently small for it to be possible to roll them or to fold them back on themselves, but sufficiently large however so that the element does not tear at the slightest external constraint. In addition below a certain thickness, the detonation wave no longer propagates or in an unreliable manner. Depending on the nature and flexibility of the explosive used, the thickness of each element can be between 2 and 15 mm and can vary within the same element. The choice of thickness depends naturally on the thickness of shielding that one wants to pierce and increases as a function of the latter.

 The attachment to the hull of the combat ship of flexible elements of thin explosive, according to the invention, can be done in a large number of equally satisfactory ways. In general the hull of buildings is made of steel so that the use of magnetic fastening means is most often possible. One can use magnetic pads included in the explosive element, a magnetic powder embedded in the explosive sheet during manufacture, or a rubber sheet loaded with a magnetic substance bonded to the surface of the element explosive. Magnetic fastening bridges can also be advantageously used, it is also possible to use suction cups or coat the faces to be bonded with an adhesive substance which is insensitive to water and capable of adhering to metallic parts but not to rubbery surfaces in such a way. to allow the transport of the device, the elements of flexible explosive of small thickness being in wound form. In the case of fixing by magnetic means and in particular in the case of bridges, a film of damping material will advantageously be interposed between the magnets and the shell, so as to foil the sound detection means which certain buildings are provided with.

 Any kind of flexible sheet explosive can be used that can withstand the action of water for at least a few minutes.

Indeed, the device according to the invention can be transported to the places of use in a sealed container, so that the duration of the exposure to water of the elements of flexible explosive does not exceed the time necessary the installation of the device and the ignition delay. Explosives with a high detonation speed in sheets are advantageously used, of the type described in French patents Nos. 1321237, 1334741 and 1398664, consisting for example of crystals of hexogen or penthrite embedded in a rubbery binder. The FORMEX sheet sold by SNPE is particularly recommended. If desired, one can also use sheets of multi-layer or composite explosives such as those described in French patent 2,199,859 and French patent application No. 73.3 6840, in the name of the plaintiff.

 The length of the thin elements made of flexible explosive according to the invention is limited only by considerations of size and weight. In general, when strips with parallel edges are used, the notch of the shell caused by the explosion has approximately the same length as that of the strip. Depending on the thickness of the shell to be torn, the length of the tear that can be caused by the device according to the invention is from 1 to 6 m, which allows, depending on the case, to puncture one or more sealing partitions, warships are provided.

 The device according to the invention also comprises a box containing the usual means or organs for ignition, delay, ignition and trapping. Other organs can be added to the previous ones, especially if one wishes to make the device even more perfected. These means are preferably assembled in a rigid case to which the elements made of flexible explosive of small thickness are connected by one of their ends.

In addition to the aforementioned functions, this rigid case makes the device particularly space-saving, the elements made of flexible explosive folded or rolled up being able to be firmly compressed against said case which also plays a protective role with respect to these elements. The rigid case is of any material but preferably of low density. It is possible, for example, to use both a light alloy based on aluminum and a rigid syntactic foam combining both great lightness and very low water uptake. Means for fixing the rigid case to the shell can also be provided, such as those mentioned above (magnets, suction cups, adhesive, etc.). The detonators used in the context of the present invention are conventional detonators and are chosen according to the nature of the sheet explosive used and the conformation of the thin elements made of a flexible explosive.

 The following example is given by way of illustration of the device according to the invention and does not in any way limit the scope of the latter.

Example: In a flexible sheet explosive plate of the FORMEX type
based on penthrite and natural rubber 10 mm thick,
we cut a straight cross, one of the crosses having a length
208 cm, the other, perpendicular to the first in the middle, having
a length of 108 cm.

In the center of the cross, a light syntactic foam box is placed
low water uptake, shaped like a 8 cm hollow dube
from the side and comprising: a detonator no. 8, a timer, a system
trapping making it impossible to defuse and, on the edges
lower, four magnetic bars helping to maintain the
device against the wall of a 16 mm thick steel box,
submerged in 2 m of water and in which atmospheric pressure prevails.

The cross pieces, 10 cm wide, are kept on the box thanks to
to magnetic jumpers, the magnetic part of which is coated with a
2 mm thick shock-absorbing resin film, so as to make the fixing operation on the box of said bridges perfectly silent.

The device has a total weight of 8 kg for a size of around 6 dm3 and can be transported without hindrance by a swimmer, in the prone position. After the explosion, the steel sheet is cut into a straight cross of 1.90 m by 95 cm, the average width of the tear being approximately 50 mm.

The device according to the invention is a particularly formidable underwater attack material because, under a low volume and a low weight, it makes it possible to inflict pernicious and hardly reducible tears on the selected targets. By its very design, it can cause tears of extremely varied shapes, regardless of the radius of curvature of the shell. Other applications of the device according to the invention are possible, in particular in rescue missions, bailout or ground missions, such as cutting armored panels.

Claims (10)

1. Explosive device for tearing the hulls of ships, characterized in  what it includes a box comprising the firing organs,  delay and trapping and one or more thin elements  made of flexible explosive, said elements adjoining said case  and having the ability to be rolled up or folded in on themselves  so that the device takes up little space during transport  or storage. 2. Explosive device according to claim 1, characterized in that the element  or thin elements made of flexible explosive have the  form of a ribbon. 3. Explosive device according to claim 1, characterized in that the element  or thin elements made of flexible explosive have the  shape of a triangle or a trapezoid. 4. Explosive device according to any one of the preceding claims,  characterized in that the thickness of the flexible explosive elements is  between 2 and 15 mm. 5. Explosive device according to any one of the preceding claims,  characterized in that the element or elements of small thickness  made of flexible explosive have means of attachment to the shell  ships. 6. Explosive device according to claim 4, characterized in that the  fastening means are magnetic and included in the explosive element  flexible. 7. Explosive device according to claim 4, characterized in that the  fastening means are rubber sheets loaded with substances  magnetic and are stuck on the elements of flexible explosive. 8. Explosive device according to claim 4, characterized in that the  fixing means are magnetic bridges.  cushioning.  place a film of material on the magnetic parts of the bridges -9. Explosive device according to claim 7, characterized in that 10. Explosive device according to any one of the preceding claims,  characterized in that the element or the elements of small thickness are  made of a flexible multi-layer explosive.