US3038406A

US3038406A - Mooring device

Info

Publication number: US3038406A
Application number: US615175A
Authority: US
Inventors: William B Elmer
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-09-08
Filing date: 1945-09-08
Publication date: 1962-06-12
Anticipated expiration: 1979-06-12

Description

June 12, 1962 w. B. ELMER 3,038,406

- MOORING DEVICE 4 Filed Sept. 8, 1945 v 3 Sheets-Sheet 1 Ms M}? 4/ M7 ME. 6

ev WITNESSES: I INVENTOR W/l/faw .6. [/men w. am 59 4 BY ATTORNEY June 12, 1962 w. B. ELMER 3,033,406

MOORING DEVICE Filed Sept. 8, 1945 3 Sheets-Shee't' 2 WITNESSES: 1 INVENTOR www. twp/77,5 7,778

ATTORN EY W. B. ELMER MOORING DEVICE June 12, 1962 5 Sheets-Sheet 3 Filed Sept. 8, 1945 Ka i I lNVENTOR [MW/0m 5 70791.

WITNESSES:

ATTORNEY United States Patent 3,038,406 MOORING DEVICE William B. Elmer, Lakewood, Ohio, assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Sept. 8, 1945, Ser. No. 615,175 17 Claims. (Cl. 102-13) My invention relates to mines and more particularly to the mooring of torpedoes or similar shaped bodies used as mines or moored for other purposes.

In using a torpedo as a mine, it is the practice to moor the torpedo at a specified depth in regions of the sea where enemy merchant ships, or enemy war ships, or both are likely to pass. It is thus important that the torpedo stay at the moored position at the proper depth until the torpedo, through its acoustic or other type of control, is released from the mooring cable and set in operation to attack the target. Tidal currents and currents from other causes may produce forces which move the torpedo. But it is extremely important that the torpedo remain moored in a stable position to avoid excessive displacing forces. Tests with actual conventional shaped torpedoes in ocean currents of the velocity usually encountered have shown that the conventional shaped torpedo is very unstable.

One broad object'of my invention is to produce a stable mooring condition for a body generally of the shape of a torpedo or blimp moored in a medium flowing with reference to the moored body.

Another object of my invention is the provision of stabilizing forces on the elevator rudders and steering rudders to counteract the hydrodynamic forces of the ocean currents acting on a torpedo to thus effect stable mooring of a torpedo.

It is also an object of my invention to produce a substantially constant deflecting force on the elevators and the steering rudders of a body moored in a flowing me dium to produce a desired action on a moored body.

These few objects recited are merely illustrative. Other objects and advantages of my invention will become more apparent from a study of the following specification and the accompanying drawings, in which:

FIGURE 1 is a schematic showing of a torpedo moored in still water;

FIGS. 2 and 3 are schematic showings of the action on a moored torpedo of a current flowing past the torpedo;

FIGS. 4,5, and 6 show diagrams facilitating the explanation of the theory of action involved;

FIGS. 7 is a longitudinal sectional view on a vertical plane of the tailcone of a torpedo provided with my invention; and

FIG. 8 is a view on a transverse section, on section lines VHIVIII of the tailcone shown in FIG. 7.

In FIGS. 7 and 8, 1 designates the tailcone of a torpedo provided with the stabilizing fins 2 and 3 disposed in the same generally vertical plane of the steering rudders R. These steering rudders are preferably airfoil in section, and during operation of the torpedo toward the target, are in a vertical plane. The steering rudders are mounted in suitable bearings and the rudder actuating studs projecting into the tailcone are secured to a yoke 4. The yoke 4 is, by means of suitable pull rods 5 and 6, secured to the armatures of solenoids 7 and 8 which are operated by the steering control of the torpedo.

The yoke 4 is provided with a tiller, or stud, 9 disposed substantially in a plane radially of the bearing axis of the steering rudders and in a plane substantially perpendicular to the longitudinal axis of the torpedo. In a small hole in the free end of the tiller 9, I hook the aft end of a relatively long spring 10. The forward end of the spring 10 is hooked in the eye of the bracket 11 welded to the bulkhead 12. The spring 10 is under tension and is chosen relatively long and designed to produce a substantially constant deflecting force on the rudders. The purpose of this constant deflecting force will become clearer from a study of the theory of operation hereinafter discussed.

The elevator E, or depth control rudders, are disposed on bearings having the axis 13 disposed at right angles to the plane including the longitudinal axis of the torpedo and the bearing axis of the steering rudders. The elevators fall in the plane of the normally horizontal stabilizing fins, not shown.

The inner or operative ends of the elevators project into the tailcone 1 and are secured to a yoke 14. The yoke 14 is substantially of the same structure as yoke 4 and is, by links 15 and 16, secured to the

armatures

17 and 18 operated by the control of the depth and tilt responsive devices of the torpedo.

A stud, or tiller, 19 is secured to the yoke 14. This stud 19 is disposed with reference to yoke 14 inthe same manner as stud 9W1 th reference to yoke 4.

In a suitable hole in the free end of the tiller 19, I hook the forward end of a relatively long spring 20. The aft end of spring 20 is hooked in the eye of the bracket 21 rigidly secured to the tailcone.

The spring 20 is under suitable tension and is so designed and proportioned that the elevators are dey fiected hard-0ver to one side with a predetermined substantially constant force. The purpose of this will become more apparent from the discussions to follow presently.

If a positively buoyant tor-pedo or torpedo-shaped body is moored in still water or any flowing medium, it is apparent that the mooring line can be attached at such a point that the body will take a position in the water such that its longitudinal axis is horizontal, but the longi tudinal axis may take any direction in azimuth. This is illustrated in FIG. 1 of the drawings.

Let D=the displacement force; Let W=torpedo weight; and Let T: mooring cable tension.

Since the body, the torpedo, is as assumed, buoyant and at rest, then 1) D W, (2) D=T+W, and (3) Dx=Ty+ Wz From these relations it can readily be shown that the distance of the point of attachment of the mooring cable from the nose of the torpedo is given by Dx-Wz 4) T W If the center of displacement and the center of gravity are equidistant from the nose, as is the case in torpedoes actually in use, then x=z, and the point of cable attachment is seen from Equation 4 to be such that ing fins and to some extent also the rudders, are adequate 8,038,406 I I I a a. U b brother type'o'ffiofwgbe natirrally unstable:in thc posh :over sothat tlne,centerofgravityisno,longerin the I 3 centralplane The words bod y moments 17 l I I I I arily used to designate the horizontal steering forces I I I I 'pr'oducedby: the rudders and fins. I .Pnll around" is not I I I I I I I .tion shown in FIG. 2; 1 This instabiiity will res'ult in 3 j I f I I f angular oscillations of. the longitudinal axis :of the tor- I I 1 1 pedo nnit about a line parallel to'the'flow of; wate1' and I I I I I I I I I I I has the effect' of moving the noseIin Iany direction such genenallymsecl to apply to such body momenta Let, the, I I I I I I 1 I i I I :as 11, 15,11; or d; or inany: intermediate direction, as indi-: 1 i stable moored position. be representedby FIG; 5;.; The I I I I I eaten at FIGJS; I Thisins't-ahility is caused; by the hy r I I I tensi n T in. t e moo ng cable l ex t a lins we I I I I I I i dynamic moment which appearson the body in accord- I I nien tTe upon theI bodnIwhich will-he lt e b dy around I I I I I I i I i I I ancel withf Bernohllis= thelorermj when the water is in i to an angle a; from vertical; This :means force T diS I I I I I I i i motion; I I I I I I I I I I I I I i 3 I '10 tance Ie-=moment Te. Inspection ofFIGi 5 will show I I I I I The hydrodynamic moment can bescgregated into two- I i the following relationship for, the stable condition; I I I I I I I I icomponentgoneindireotiomaorcintheplaneotthe I mooring cable; :and other :at right angles thereto, in di- I I I I I I I ,M-i -n M W I i rection b or d. e i l I I I I I I II I I I Tests with actual torpedoes indicated: that the body. 6) I I I I I I I I I I 5 5 =7; II I I I I i quickly'reachesa stable condition in the t'a*c. direction: I I I I I I I I I I as follows. If the body is initially paralleltotheflow', I I I I I I I in IIIII III I I 'thetension:in thernooringcable exerts anose-lifti-ng. I

moment in direction "an": 'Asthc bodyincrc sesitsannle I From: a I I I II I I I I I I I II II I. above thehorizontal; the horizontalfinsuand elevators zo 1.131 11 i I tIiI' I I I I I I counteract this motionand. a condition of stability I (3) I I I I I I at cos 9 I I I I soon established, still assuming that the tail; structure, is: I from (7) I I I I I I I I I I I I I I I I I I I I I II.adequateforstablerunningu I I I II 11785111, I I II I I I Thereisnoanalogousstabilizingefiectinthehorizontal I I I I I I I I I a??? direction, and the body tales n; turn and movje away: I :B b titu in and in I 9/ 'I -I- I I I from vertical: along path b 0rd; I 'As thebody departs I :0 i I t i g (g+ ;w iga: i

iiorn'apositiondirectly-abovetheanchonaweakre- I I I I i I I I I storing effect is provided by the positive Ib'uoyan'cy; or: I I II I I l t er l' m I I I i I I I I I "the body. Tests haveshownthata bodywith; tail struc- I T;=ableI t ngi0n, I I I i I I i I I I j I I I II I I I I I I I I I iture adequate for stable I running and balanced to float; I m y f. ble i pmdufing, Im I level in still water-will oscillate back and: forth slowly I I I I I I I I I I along the path h--d. with a wide amplitudeat moderate pg z I I I I I I I I I I I I I I I I currents. I ISuch oscillations I are objectionable since the I f :h -i m l di l m; gfcemgf gf' gravityy I I I I I I I :body may oe-carried to excessive depths:periodio llyflflhc a I 9- izanglejof Ieablsmakgswith I h m g, f I I I Imooring cablemaybe subjecttoexcessive wear, andex i gza iglegf hegiIdue wiaablelension; I i I I I I I II I I I IIIIIIIII I I I Icessive cable'tensions mayI develop atcertain points of, I =1;:orpedo radius, and I I I I 1: I I I I I I I i i e sy oscillations, -ns k ne of h n ha f I g zdista nce :mm :the center of gravity to the geometric I I I I 'Inorder to:correct-thisinstability,itisnecess-aryto I ;II.:I:: ;.;II.; I I I I I I I II I I I I I I I I I I I providearestoringmornentsomebodywhichisalways. II I I I. II I I I 'inIsuch a vectorial irelation as toI direct the body; toward Q E I I B9 1 1 mow s I i I i j I 1 I I I I the vertically moored position. (11) Tr[cos 6 cos a-sin 6 sin a]=Wg sin a Such a restoring moment can be obtained as shown in FIG. 4, by a combination of trim unbalance and an (12) cos a: cos 6 +tan 0 off-neutral positioning of the rudders and elevators. In Tr-eos 6 this FIG. 4 a shift of weight aft will produce a constant and nose lifting moment M which is always in the vertical direction. If the elevators (and rudders also if the cable (13) tan 01: cos 6 does not attach on the vertical centerline of the body Q 0 as is actually the case in a certain torpedo model) be Tr I fixed in a hard-over position, a moment will be exerted on the body tending to force the nose toward the anchor as shown by M This moment M is the resultant of M exerted by the rudders and M exerted by the elevators. If the magnitudes of M and M be approximately equal, their resultant can be represented by a vector M which is always directed toward the desired mooring location. The magnitude of M increases in proportion to the distance from this desired mooring location, as shown by the various positions of the torpedo While the relation shown in (13) is perfectly general for the type of body under consideration, and any actual values herein given are not to be taken in a limiting sense, it might be noted that the typical conditions for an actual torpedo were,

g=1.25 inches, r=20.5 inches, W=2450 pounds, and T=l50 pounds.

shown in FIG. 4. Th l Tests have shown that sufficiently powerful moments Elmore can be developed in this manner to counterbalance the (14) t cos 6 hydrodynamic body moment, and thereby insure stable an 1 945+ i 0 running of conventional torpedo bodies in currents up to 5 knots or over. During such stable running the body For example, If fi 15"- FIG. 6 has been drawn to represent the conditions for a particular model of torpedo used as a moored mine. It will be noted that the point of mooring cable emergence from the present torpedo is located at an angle of 23 around the body from the vertical centerline.

From an inspection of the B position of the torpedo, it will be apparent that Substituting in (13) n COS (16) M W.q

+sin 0 Also from FIG. 6 it is apparent that %=cos or (approximately) But M =w/M, +M,

2 (19) M W B 2 (-TT-PSID. 6)

2 1 COS 0 o Wg 2 TT+S1I1 0

Equations

16 and 20 provide means for computing the required angular shift of the center of gravity with reference to the plane defined by the vertical stabilizing fins and steering rudders and the radial shift of the center of gravity with reference to the geometric longitudinal centerline, namely, longitudinal axis of the torpedo, and provide means for computing the corresponding rudder and elevator forces in order to obtain any desired stabilizing moment.

In these relations M =the moment clue to unbalance trim,

M =the resultant moment produced by M and M M =the moment of the elevators E,

M =the moment of the steering rudders R, and

M =the stabilizing moment, namely the resultant of M and MT- The required rudder and elevator moments M and M I obtain by the use of mooring springs, which are designed to apply a nearly constant torque to the rudder and elevator stocks, respectively. These springs are designed to apply moments to the stocks which are just equal and opposite to the hydrodynamic moments appearing on the stocks while the rudders and elevators are at such angles as to produce the desired values or" torpedo moment M and M respectively.

The springs are designed to develop the desired rudder and elevator moments in a three knot current. Higher velocities of flow are rarely encountered in the sea. With more rapid currents, yielding of the springs will permit the rudder and elevator angles to decrease but will maintain substantially constant lift it the springs are long, and consequently a constant stabilizing moment, in both magnitude and direction. In order to obtain constant lift, it is also necessary that the rudders and elevators be streamlined (airfoil section).

If the water attains a velocity such that the hydrodynamic body moment exceeds the stabilizing moment, the body will lose stability.

When the torpedo starts its run of some thirty to forty knots per hour, the mooring spring tensions are insignificant with respect to the control and hydrodynamic forces then present, and the torpedo will then perform as though the springs were non-existent.

From inspection of FIG. 5 and Equation 13 above, it can be seen that if the pullaround of the unit is decreased, the body will heel over more nearly toward the angle of the mooring cable. As the heel angle approaches the cable angle, the stabilizing moment increases. Thus, low pullaround is evidently a condition favoring mooring stability.

By a proper selection of the spring strength and the spring length of each of the springs and and a proper radial disposition of the center of gravity from the geometric centerline and a proper angular relation chosen for the planes including respectively, the axis of the steering rudder bearings and the longitudinal axis of the torpedo, and the center of gravity and the longitudinal aXis of the torpedo, the torpedo may be caused to take a stable moored position, some position intermediate the position A and the position B, as shown in FIG. 6. The force of deflection of the rudders and elevators will be such as to produce the desired stable mooring of the torpedo.

While I have shown but one embodiment, I do not wish to be limited to the single embodiment shown but Wish to be limited only by the scope of the claims hereto appended.

I claim as my invention:

1. In a torpedo mine, having steering rudders and elevators, moored by a mooring cable the combination of means for deflecting the steering rudders hard-over by a predetermined substantially constant force, and means for deflecting the elevators downwardly with a substantially constant predetermined force.

2. In a mooring control for a torpedo type mine having the shape of a torpedo and having conventional vertical stabilizing fins and conventional horizontal stabilizing fins, and having substantially conventional rudders and elevators coupled for operation to yokes disposed in the tailcone of the torpedo, an actuating arm coupled to the yoke of the rudders, a bracket secured to the tailcone, a relatively long spring under a predetermined tension having one end hooked to the bracket and theother end to the actuating arm to thus actuate the rudders hardover to one side by a force determined by the spring action, an actuating arm coupled to the yoke of the elevators, a bracket fixed to the tailcone, and a relatively long spring under a predetermined tension at one end hooked to the last named bracket and at the other end hooked to the actuating arm for the elevators to thus force the elevators to a hard-over position by a predetermined force.

3. In a mooring control for a torpedo mine having the conventional shape and external surface tailcone of construction including rudders and elevators, in combination, a mooring anchor and cable attached to the torpedo at the transverse plane including the center of buoyancy and center of gravity, elastic means for deflecting the elevators and rudders hard-over by substantially constant forces acting on the elevators and rudders, respectively.

4. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as steering rudders at the tailcone, in combination, an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams flowing past the moored torpedo will produce body moments on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the steering rudders to a hardover position by a substantially constant predetermined force.

5. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as steering rudders and elevators at the tailcone, in combination, an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams, flowing past the moored torpedo will produce body moments on the torpedo so as to cause the torpedo to head into the stream, means for biasing the steering rudders to a hard-over position by a substantially constant predetermined force, and means for biasing the elevators to a hardover position by a substantially constant predetermined force.

6. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as elevators at the tailcone, in combination, an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams flowing past the moored torpedo will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force.

7. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as steering rudders, at the tailcone, in combination, an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams flowing past the moored torpedo will produce body moments on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the steering rudders to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value sufiicient to produce stable mooring conditions for the torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable effect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with conventional torpedoes.

8. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as steering rudders and elevators, at the tailcone, in combination, an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams flowing past the moored torpedo will produce forces on the torpedo so as to cause the torpedo to head into the stream, means for biasing the steering rudders to a hardover position by a substantially constant predetermined force, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value suflicient to produce stable mooring conditions for the torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable effect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with conventional torpedoes.

9. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements, as elevators, at the tailcone, in combination,an anchor, a mooring cable, said mooring cable being attached to the anchor and being attached to and emerging from the cylindrical torpedo housing at a point near the center of gravity and center of buoyancy in the mid-region of the cylindrical torpedo housing, whereby ocean streams flowing past the moored torpedo will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value suflicient to produce stable mooring conditions for the torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable effect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with conventional torpedoes.

10. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including steering rudders, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length suificient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the position of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the steering rudders to a hard-over position by a substantially constant predetermined force.

11. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including elevators, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length sufiicient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the position of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force.

12. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including steering rudders and elevators, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length sufficient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the position of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, means for biasing the steering rudder-s to a hard-over position by a substantially constant predetermined force, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force.

13. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including steering rudders, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length suificient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the posi tion of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the steering rudders to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value suflicient to produce stable mooring conditions for the moored torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable effect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with torpedoes.

14. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including elevators, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length suflicient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the position of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value suificient to produce stable mooring conditions for the moored torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable effect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with torpedoes.

15. In a mooring control for a torpedo mine comprising a torpedo having substantially conventional stabilizing and directional control elements disposed within and on the outside of the tailcone, said directional control elements including steering rudders and elevators, in combination, an anchor, a mooring cable having one end secured to the anchor and the other end, by a length sufficient to moor the torpedo at a given depth, secured to the torpedo, said cable emerging from the cylindrical torpedo housing at a point falling in a line including the center of gravity and center of buoyancy and the line falling in a plane normal to the longitudinal axis of the torpedo, the position of the center of gravity being so chosen that the said line is disposed at a selected angle with reference to a plane including the longitudinal axis of the torpedo and the axis of the steering rudders, whereby tidal currents, or currents from other causes flowing in the sea will produce forces on the torpedo so as to cause the torpedo to head into the stream, means for biasing the steering rudders to a hard-over position by a substantially constant predetermined force, and means for biasing the elevators to a hard-over position by a substantially constant predetermined force, said biasing force being selected to have a value suflicient to produce stable mooring conditions for the moored torpedo for the usual relatively slow ocean currents encountered but being too small to produce any noticeable eifect on the operation of the torpedo when being propelled toward the target at the relatively high torpedo speeds being used in connection with torpedoes.

16. In combination with a body to be moored in a flowing medium, said body having a streamline shape and being buoyant with reference to the medium, and having steering rudders and stabilizing fins disposed substantially in the plane including the axis of the steering rudders, both the steering rudders and stabilizing fins being disposed at the aft end of the body, said steering rudders being secured to a stern post, a tiller secured to the stern post for actuating the rudders, a mooring cable having one end anchored and the other end secured to the body intermediate the ends of the body, and a relatively long spring, at one end secured to the free end of the tiller and at the other end and under a selected tension secured to the body, for deflecting the steering rudders hard-over with a predetermined substantially constant force.

17. In combination with a body to be moored in a flowing medium, said body having a streamline shape and being buoyant with reference to the medium, and having elevating rudders and stabilizing fins disposed substantially in the plane including the axis of the elevating rudders, said rudders and fins being disposed at the aft end of the body, said elevators being secured to a stern post, a tiller secured to the stern post for actuating the elevators, a mooring cable having one end anchored and the other end secured to the body intermediate the ends of the body, and a relatively long spring, at one end secured to the free end of the tiller and at the other end and under a selected tension secured to the body, for deflecting the elevating rudders hard-over with a substantially constant force.

References Cited in the file of this patent UNITED STATES PATENTS 1,465,232 Pape Aug. 14, 1923 FOREIGN PATENTS 273,126 Germany Apr. 20, 1914 328,970 Germany Nov. 12, 1920