US3004488A

US3004488A - Moored mine

Info

Publication number: US3004488A
Application number: US778265A
Authority: US
Inventors: Jr Daniel T Wieland
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-12-04
Filing date: 1958-12-04
Publication date: 1961-10-17
Anticipated expiration: 1978-10-17

Description

Oct. 17, 1961 D. T. WIELAND, JR

MOORED MINE 2 Sheets-Sheet 1 Filed Dec. 4, 1958 INVENTOR.

DANIEL T. W|ELAND,JR.

Oct. 17, 1961 D. T. WIELAND, JR 3,004,488

MOORED MINE Filed Dec. 4, 1958 2 Sheets-Sheet 2 FIG.2.

SENSITROL RELAY STERILIZER BATTERY INVENTOR.

DANIEL T. W|ELAND,JR.

3,004,488 MOORED Daniel T. Wieland, Jr., 1216 Jarrett Road, Norfolk 2, Va. Filed Dec. 4, 1958, Ser. No. 778,265 2 Claims. (Cl. 102--13) (Granted under Title 35, US. Code (1952), see. 266) 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.

This invention relates to a contact mine having an improved anti-sweep device for use in and around friendly harbors. More specifically, this invention provides a mine arming system whereby the mine is maintained in the passive condition until an attempt is made to sweep it.

Prior to this invention, devices employed to protect a moored mine against sweeping were designed to damage the sweep gear. While such devices prolong the time re quired to sweep an area they are not very effective in destroying or damaging desirable targets because all the moored mines are eventually swept and the enemy is not mislead into thinking a mined harbor has been swept.

In the present invention the mine is secured to the anchor so that it sinks with the anchor and rests upon the harbor floor. The electromagnetic field set up by an impulse of strong current applied to the sweep wire of a mine sweeper moving through the water releases the mine and allows it to float up to a selected depth where it is in position to sink or damage any ships passing over the supposedly swept area.

One object of the present invention is to provide a moored contact mine which operates against a magnetic sweeper.

Another object is the provision of a contact mine ineluding a magnetic search coil which moors the mine in the shipping lanes only after an attempt has been made to magnetically sweep the mine.

A further object is to provide a contact mine for use in a friendly harbor which normally lies on the harbor floor to permit free passage of shipping in the harbor but is moored when an attempt is made to magnetically sweep the harbor by an enemy.

These and many other objects, and advantages of this invention will become apparent when the following specification is read and considered in conjunction with the accompanying drawings wherein like numerals designate like or similar parts throughout the drawings in which:

FIG. 1 indicates the sequence of operation of the mine;

FIG. 2 is a perspective view of the mine before release of the mine casing from the mine anchor; and

FIG. 3 is a sectional view of the mine mooring mechamsm.

Referring now with greater particularity to the drawings, the mine, comprising a mine casing 11 supported upon a mine anchor 12 by a plurality of brackets 13 fixed to anchor 12, is launched into a body of water 14 and commences to sink to the floor 16 thereof.

Although mine casing '11 is positively buoyant it does not separate from the anchor 12 because it is secured by a rod or piece of stout cable 17 connected between lugs and 20 on the casing and the anchor respectively. A mooring cable bail 21 is fixed to the mine between two eyes 18 and is connected to one end of mooring cable 22. The other end of cable 22 is secured to a freely rotatable drum (not shown) within the mine anchor. After launching, the mine sinks to the floor of the harbor so that it does not present a hazard to friendly ships in the harbor.

Attached to the mine anchor is a housing 36 and a coarse search coil 23. In the event that the harbor is taken over by an enemy, and an attempt is made to sweep the harbor, search coil 23 actuates a sensitrol relay 24 encased in a foam rubber cushion 19 and disposed within the coil form to complete the circuit across the igniter wire 26 disposed within a container 27 fixed by bracket 28 to the mine anchor 12. Container 27 has a C shaped'portion 29 at one end to receive the cable 17. Upon completion of the igniter wire circuit current from a battery 31 in housing 36 flows through igniter 26 to initiate a detonator 32 which in turn ignites booster 33 to detonate the shaped charge 34 thereby severing cable :17. The mine case 11, thus freed, floats upward and is moved just below the surface so that it is detonated when a ship contacts one of the horns 39. This may be accomplished by hydrostat bight releasing means or since the depth of the harbor is known, by employing a mooring cable cut to the desired length.

Search coil 23 must be rather coarse and insensitive since it should be actuated only when the mine is attempted to be swept by the strong magnetic impulses generated by a magnetic sweep wire.

A sterilizer 37 may be inserted in the firing circuit to disarm the mine after a selected period of time. A delay circuit 38 preferably is included in the firing circuit to allow a time lag between the sweep and time the mine is moored so that the mine will not sink the mine sweeper but will destroy the more desirable targets that follow it.

While the invention has been described with reference to one specific example, it will be understood by those skilled in the art, after understanding this invention, that it is susceptible of many alterations and modifications without departing from the spirit and scope of the inven tion. Accordingly the invention is to be limited only by the scope of the appended claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A moored contact mine adapted to be sown in a friendly harbor comprising; a mine casing having an explosive charge therein, a mine anchor, frangible means securing said mine casing to said anchor whereby said mine casing sinks to the floor of said harbor with said anchor when the mine is launched, a slack cable connected between said anchor and said casing, a coarse search coil disposed on the mine anchor adapted to generate an electrical pulse only when it is subject to a strong electromagnetic field of an enemy magnetic mine sweeper, and means operatively connected to said search coil and disposed adjacent to said frangible means to fracture said frangible means upon receipt of an electrical pulse from said coarse coil to release said mine casing and permit it to float upward a predetermined distance and lie in the path of travel of ships in the harbor.

2. The contact mine of claim 1 wherein said means operatively connected to the search coil comprises; a container having an opening disposed about said frangible means, a shaped explosive charge disposed within said container adjacent said opening and adapted to fracture said frangible means upon initiation, and an igniter wire electrically connected to said search coil and adapted to detonate said shaped charge upon receipt of a pulse from the coil.

Johnson Feb. 15, 1955 Turlay Apr. 26, 1955 ratented Oct. 17, 1961