US2758542A - Ahead-thrown weapon for submarine warfare - Google Patents

Description

Aug. 14, 1956 s. BURG AHEAD-THROWN WEAPON FOR SUBMARINE WARFARE Filed Sept. 7, 1950 ATTORNEY}? AHEAD-THROWN,

This invention "relates to improvements in naval ordnance, and its underlying purpose is to provide a weapon to be used in submarine warfare- Since the weapon is launched in air and is contrived not to explode until it goes a prescribed distance underwater, the weapon is said to embody the factor of discrimination which makes it remain inert while traversing a light medium and become activated only after entering and traversing a denser medium. 'The principle of operation of the weaponis,

the building up'o'f internal hydrostatic pressure in-the depth charge-containing cavity of an explosively inert rocket case or equivalent carrier when the water is struck,

thereby'to eject the depth charge. The primary development was that of a practice weapon to be used to simulate a depth charge attack from the underwater explosion of which the accuracy of aim with respect to the target submarine vessel could be determined. This use, however, is not a limitation upon the invention because the I 7 identical principle would be operative with full-scale components and in actual warfare.

The weapon comprises a carrier and a core. The carrier may consist of the appropriately modified rocket case shown herein or any similarly constituted case which is adapted to be projected through the air. The core consists of the depth charge. When this combination is assumed, in other words the depth charge is fitted inside of the rocket case, it is called an ahead-thrown Weapon and is adapted to be projected from a rocket launcher, or it can merely be dropped from an aircraft.

From the foregoing brief outline it will be understood that one of the objects of the invention is to provide an explosive weapon capable of discriminating between air and water as the medium in which to explode.

Another object of the invention is to provide a weapon, intended herein for submarine warfare practice purposes but manifestly not so confined, wherein a depth charge is combined with an explosively inert rocket case for trans? portation over an air trajectory to the surface of the water, separation occurring at water entry by the building up of internal hydrostatic pressure.

Another object of the invention is to provide for the building up of the hydrostatic pressure behind the depth charge, thereby to disconnect it from its superficial mooring and thereupon to eject the depth charge clear of the rocket case.

Another object of the invention is to utilize the dissimilarity in frontal shapes of the depth charge and rocket case as an aid in producing the separation of the depth charge from the rocket case.

Another object ofthe invention is to modify a known type of rocket case by removing the fuze well and substituting a bottomed sleeve to form the well, thereby to provide a cavity for the depth charge and so adapt the .rocket case as a carrier for the depth charge.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following United M States Patent detailed description when considered connection with the accompanying drawings wherein: p

Fig. 1 is a combined sectional and elevational view of the ahead-thrown weapon;

Fig. 2 is a detail sectional view illustrating the detent and spacing means;

Fig. 3 is a cross section on the line 3-3 of Fig. 2, and

Fig. 4 is a cross section on the line 4-4 of Fig. 1.

In the drawings, the explosively inert rocket case 10 has combined with it an explosive depth charge 11. The rocket case has a sleeve well 12 which is screwed in place in the thread course 13 in lieu of the fuze well which otherwise could occupy this position. The well thus becomes an adapter sleeve, defining a cavity, open at the front and modifying the rocket case to support the depth charge along the longitudinal center of the case.

The inner end of the sleeve is bottomed at 14. The neck 15 into which the rocket motor .tube 16 is screwed is a seal-off. The compartment thus defined in the case 10 is filled with water 17 or an equivalent explosively inert material, to give the weapon the weight that it would have were the filling 17 composed of an explosive substance. Three rods 18 or their equivalent are welded to the inside of the sleeve well 120 apart. They form a kept from sliding out of the sleeve well during air transit of the weapon by a snap fastener 19.

The snap fastener as shown consists of a ring 21 from which the spring fingers 23 which constitute the detent means extend. The spring fingers grip the walls of a groove 22 in spacer means 24 to support the depth charge clear of the bottom 14 so that the fins 26 will be saved from damage either upon inserting the depth charge or from the setback action in projecting the weapon from a rocket launcher. The spacer means is a steel or equivalent piece, long enough to stand the fins clear of the bottom.

Spacing of the depth charge 11 from the internal walls of the sleeve well by the guide rods 18 and the means 24 produces an annular orifice. The front opening, now designated 28, provides Water access'to this orifice. The spherical nose piece 29 of the depth charge protrudes at this opening. The amount of protrusion beyond the ad j acent blunt face 30 of the case 10 is from 1 /2" to 2%", depending on the length of the spacer means 24.

In practice the drag of the nose piece is much less per unit area than that of the orifice 27. As the result the pressure built up in the orifice and therefore on the interior of the sleeve well and behind the depth charge is greater than the pressure on the nose piece. It is this pressure difference, due to the fact that rounded objects have less drag than fiattobjects when pushed or pulled through water, which produces the positive force that ejects the depth charge from the rocket case. Since the drag varies with the square of the velocity it follows that the separation force varies by the same factor. Therefore, the greater the air height drop or water entry ve locity, the greater the separation force upon the depth charge.

The operation is reviewed briefly. The rocket case 10 is loaded by inserting the depth charge 11 into the sleeve well cavity tail first. The spacer means 24 supports the fins 26 clear of the bottom 14. Ample room is thus as-' trajectory. It is here that the factor of discrimination enters. The depth charge is disconnected from its mooring and ejected, as has been pointed out. Another factor assists in this separation. The mere impact of the blunt is put on the automatic hydrostatic thrust build-up behind the depth charge.

The latter'will explode according to its setting. The

sound of the explosion can be detected underwater over a distance of several miles. The sound detection is made by the target submarine vessel, and it is by the latter that the accuracy of the simulated attack is evaluated. 7

Obviously modifications and variations of the present invention are possible in thelight of the above teach-' ings. It is therefore to be understood that within the scope of the appended claim the invention may be practiced otherwise than'as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

An item of ordnance comprising the combination of an elongated finned type carrier missile having a cavity open only at the front end thereof and a bottom internally of the carrier, said carrier being configured to pass head-on through a body of Water, a detachably mounted core missile normally disposed'in the cavity of said carrier missile having a rounded nose portion exposed only at the open end of the cavity and a finned tail section disposed adjacent the bottom of said cavity, means for releasably latching the core missile in said cavity, said last named means having spring portions for frictionally engaging a mating portion of said core missile when it is bottomed, guide rod means for spacing the core from the inside wall of the cavity and coact-ing with the fins of said core missile to provide for Water access and the building up of hydrostatic pressure between the cavity bottom and I the tail section of thecore missile in excess of the pressure on 'therounded nose portion, thereby to cause separation of the core from the carrier only upon entry of the said item into abody of water following launching thereof. 1 ,6

References Cited in the file of this patent UNITED STATES PATENTS 36,686 Callender 061. 14, 1862 1,184,699 Kenney May 23, 1916 1,275,686 Hill Aug. 13, 1918 1,303,499 Romain May 13, 1919 1,409,409 Rist Mar. 14, 1922 I 1 FOREIGN PATENTS 75,404 Austria Feb. 10, 1919 406,574 Great Britain Mar. 1, 1934 539,699 Great Britain Sept. 22, 1941

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