US3643365A

US3643365A - Mounting mechanism for a seine-hauling power block

Info

Publication number: US3643365A
Application number: US701A
Authority: US
Inventors: Lawrence E Demmert
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-01-05
Filing date: 1970-01-05
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A trolley carrying the seine-hauling power block can be driven along an elongated track having its length extending athwartships of a boat. A carriage supporting such athwartships track can be driven along a fore-and-aft boom and the block trolley can be driven along the athwartships track so as to lay the seine back and forth in a pile below the block as it is hauled in. The athwartships track may include two quadrants having inboard ends parallel to each other and to the boom or such track may be straight. If the athwartships track includes two quadrants, the boom carriage carries a transfer track section which can be placed in registry with the inboard end of either arcuate track section by shifting such arcuate track sections transversely of the boom. Rollers mounted for engagement by a seine being hauled by the power block can guide and deter billowing of the seine.

Description

Waited States Patent Uemrnert [54] MUUNTIING MIEQHANHSM IFQR A SEllNlE-HAHJLHNG lPUWl/Elli RILUCM [72] inventor: Lawrence 1E. lliemmert, 3408 Redwood Avenue, Bellingham, Wash. 98225 [22] Filed: Jim. 5, 1197 0 [21] Appl.No.: 71111 llielated US. Application Data [63] Continuation-impart of Ser. No. 759,693, Sept. 13,

1968, Pat. No. 3,535,811.

[52] US. (ll... 43/8 [51] int. Cl. .Atlllir 73/12 [58] lFielldoiSearch 43/8, 14; 254/137, 138

[56] References Cited UNITED STATES PATENTS 2,810,979 10/1957 Puretic ..43/8 2,859,882 11/1958 Puretic ..43/8 X 2,875,547 3/1959 Puretic ..43/8

[ liebfl, 11972 FOREIGN PATENTS OR APPLlCATlONS 1,357,963 3/1964 France ..43/8

Primary Examiner-Warner H. Camp Attorney-Robert W. Beach [5 7] ABSTMQT A trolley carrying the seine-hauling power block can be driven along an elongated track having its length extending athwartships of a boat. A carriage supporting such athwartships track can be driven along a fore-and-aft boom and the block trolley can be driven along the athwartships track so as to lay the seine back and forth in a pile below the block as it is hauled in.

. The athwartships track may include two quadrants having inboard ends parallel to each other and to the boom or such track may be straight. If the athwartships track includes two quadrants, the boom carriage carries a transfer track section which can be placed in registry with the inboard end of either arcuate track section by shifting such arcuate track sections transversely of the boom. Rollers mounted for engagement by a seine being hauled by the power block can guide and deter billowing of the seine.

9 Claims, 13 Drawing Figures MOUNTING MECHANISM FOR A SlEllNE-IHIAULING POWER BLOCK This application is a continuation-in-part of my copending application Ser. No. 759,693, now U.S. Pat. No. 3,535,811, for Mounting Mechanism for a Seine-Hauling Power Block, filed Sept. 13, 1968, which was a continuation-in-part of my application Ser. No. 757,199, for Mounting Mechanism for a SeineI-Iauling Power Block, filed Aug. 12, 1968, now abandoned, which was a continuation of application Ser. No. 465,391, filed June 21, 1965, now abandoned. It is a principal object of the present invention to effect power-driven movement of a power block into various locations above the deck of a purse seiner by remote control so that the seine can be stowed effectively by piling it on the purse seiner deck with minimum handling.

More specifically it is an object to shift such a power block back and forth generally athwartships of the purse seiner for laying the seine in elongated piles, the lengths of which extend athwartships of the purse seiner. Alternatively, it is an object to effect movement of the power block fore and aft while the seine is being hauled in so that it will be stowed in elongated piles having their lengths running fore and aft in each instance. When a pile is completed the location of the path along which the power block moves can be shifted so that the next pile will be laid alongside the one last completed.

It is also an object to provide power block mounting mechanism which will guide movement of such a power block along paths located above either side of the purse seiner deck, depending upon the side of the purse seiner over which the net is being hauled.

An additional object is to provide such power block mounting mechanism which can be supported effectively for location ofthe power block in any ofits possible positions.

In providing such power block mounting mechanism, it is an object to maintain the deck space clear so as not to interfere with piling ofthe seine gear.

Another object is to provide mechanism which can be used to effect movement of the block mounting mechanism quickly and easily.

A further object is to provide mechanism for controlling the seine as it is being hauled in, more specifically by providing guide rollers having various functions including preventing the seine from billowing, wrapping the seine closely around the spool of the block, and supporting the seine so that it can be hauled in readily.

FIG. I is a top perspective of the aft portion of a purse seiner showing the power block mounting of the present invention in use.

FIG. 2 is a plan of the aft portion ofthe purse seiner showing the mounting mechanism and FIG. 3 is a side elevation of the aft portion ofa purse seiner showing such mounting.

FIG. 4 is an enlarged detail plan ofa portion of the generally transverse track elements and an adjacent portion of the boom, parts being broken away.

FIG. 5 is a port side elevation having parts broken away, and

FIG. 6 is an elevation of such forward, from which parts have FIG. 7 is a top perspective seiner showing a modified type cording to the present invention.

FIG. 8 is a plan and FIG. 9 is a side elevation of this type of power block mounting installation on a reduced scale.

FIG. 10 is a detail section through a portion of the modified power block mounting taken on line 10-10 of FIG. 7, parts being broken away.

FIG. 11 is a horizontal section of the block portion of the mechanism on line ll-ll of FIG. 10 and FIG. 12 is a vertical section through the block on line l2-l2 of FIG. 11.

FIG. 13 is a top perspective of the aft portion of a purse seiner showing a power block mounting generally of the type shown in FIG. 7 in combination with a different type of seineguiding roller mechanism.

of the mounting mechanism,

mounting mechanism looking been broken away.

of the aft portion of a purse of power block mounting ac- The boat ll shown in FIG. I is a typical purse seiner, on the afterdeck 2 of which the purse seine is stowed. In recent years such purse seines including the corkline 3, the web t and the leadline 5 have been hauled by being passed over a powerdriven block 6. Customarily such a power block has been suspended from the tip of an upwardly inclined boom which has been held stationary during hauling of the seine. In order to stow the seine as it is hauled in, four men have been required. The first man has piled the leadline on the bottom of the seine, two men have piled the web of the net, which may be as wide as feet, and the fourth man has piled the corkline secured to the upper edge ofthe web.

By use of the present invention, the seine can be laid back and forth by moving the block bodily athwartships and fore and aft as the seine is hauled in so that only two men are required for the operation. One man slides the purse rings on a ring bar and coils the leadline, and the other man operates the controls to effect reeling in of the seine and the athwartship movement and the fore-and-aft movement of the block for piling the seine. The seine is laid on the deck in folds by shifting the power block as the seine is hauled in. Thus the power block will be moved bodily progressively over locations where it is desired to have the seine piled. For this purpose the power block is supported on traveling mounting means which are located relatively close to the deck of the purse seiner and substantially in a horizontal plane.

The mounting mechanism for the power block 6 thus includes the trolley 7 from which the power block is suspended by a swivel 8. Such trolley runs along track means extending generally athwartships which are illustrated in FIGS. 1 to 6 as two arcuate sections 9 of a channel track which opens downward. As shown best in FIG. 6, such channel sections have inturned flanges 10 along their edges which form between them and the sidewalls of the channel section track grooves 11. Movement of the trolley along the tracks of the sections 9 is effected by rotation of the pinion I2 shown in FIGS. 4, 5 and 6, which meshes with the rack 13 extending along one ofthe channel flanges 10 of each channel section-9.

The track means elements 9 constitute principal components of a carriage supported by and movable fore and aft along the horizontal boom 14 which projects aft from the mast l5. Such carriage further includes the sleeve l6 encircling the boom and carrying a post 17 projecting upward from it and an athwartships tie bar 18 engaged in the lower portion of the sleeve and connecting the outboard ends of the track sections 9. Such outboard ends of the track sections are further supported by the cable 19 connected to such track section ends and passing over a pulley 20 on the upper end of the post 17. The outboard ends of these track sections are stabilized by guy lines 21 extending from them down to anchor blocks 22 which are received in and movable along guide channels 23 extending fore and aft along the inner sides of the rails 24.

The inboard ends of the arcuate track members 9 preferably lie alongside each other, as shown best in FIG. 4. To enable the inboard track ends to be disposed in such relationship, it is preferred that each track section be substantially a quadrant in extent, as indicated in FIGS. 1 and 2. Such inboard ends of the track sections can be received in a channel 25 attached to an aft sleeve 26 of the carriage which also encircles the horizontal boom 14. This sleeve can be supported from the boom for easy movement along it by rollers 27 which are journaled in the sleeve. The carriage can be moved fore and aft along the boom by rotation of a pinion 28 driven by a hydraulic motor 29 and engaged with a rack 28 provided on and extending along the boom, as illustrated particularly in FIG. 5.

A purse seine can be hauled onto a purse seiner over one rail by the apparatus described above, as illustrated, for example, in FIG. I. The seine will be passed over the power block 6 from which it will fall onto the deck 2 of the purse seiner. When the seine is hauled in over the starboard rail, as illustrated, it will be desirable for the power block to be located at the portside of the boom 14. As the seine is hauled in by power rotation of the block effected by the hydraulic motor 30 the lead-piling man will pull the leadline over to the starboard rail and pile it just inside the rail. A stretch of web will extend from the leadline to the bulk of the seine which falls directly down from the block 6.

With the carriage maintained at one location along the boom 14, the hydraulic motor 31 can be energized to drive the trolley 7 slowly along a track section 9 as the pinion 12 turns in driving engagement with the rack 13. The speed at which the trolley is propelled along the track section will be coordinated with the speed of rotation of the power block 6 so that most of the web and the corkline will be laid properly on the deck. Such operation of the trolley-driving motor 31 and the power block motor 30 can be effected by remote control by an operator standing near or on the deckhouse 32, for example. When the power block has been shifted to complete a desired pile of corkline and web, as shown in FIG. 1, extending athwartships from the port rail, the motor 29 will be energized to shift the carriage along boom 14 forward through an increment equal to the width of one pile of gear. As more of the seine is hauled in, the trolley motor 31 will then be energized again to lay net in the next pile.

Alternatively, the seine can be laid in piles extending fore and aft by locating the trolley 7 in a particular athwartships position and then progressively traversing the carriage fore or aft along boom 14 to produce such a longitudinal pile of gear. When one elongated pile has thus been laid, the trolley motor 31 will be energized to shift the trolley through an increment athwartships of the purse seiner so that the next pile of gear can be laid alongside the first pile by again traversing the carriage along the boom 14 as the seine is hauled in. Such operations may be performed successively to deposit the seine in successive layers of crossing piles.

Guy lines 33 are arranged to interconnect the trailing end of the boom and opposite sides of the purse seiner to secure such boom end against swinging. The aft end of the boom is supported by a line 34 extending upward to the top of the mast 15. The desired elevation of the boom 14 can be established by sliding collar 36 supporting the forward end of the boom upward or downward along the mast 15. Such vertical adjustment can be accomplished by actuating hydraulic jacks 37 located alongside the mast which support the collar.

As has been mentioned above, when a seine is being hauled aboard the purse seiner, it is desirable for the power block to be supported at the side of the boom 14 opposite the rail over which the seine is being hauled. Consequently, if the seine is to be hauled over the port rail, instead of the starboard rail as illustrated in FIG. I, the power block 6 should be located on the starboard side of the boom 14. For this type of operation it will, therefore, be necessary to shift the trolley 7 from the port track section 9 to the starboard track section. Such shifting of the trolley can be accomplished by mounting the two track sections 9 for athwartships movement relative to a transfer track section 38, shown best in FIGS. 4, and 6. Such transfer track section cannot be moved athwartships, but the composite athwartships track sections 9 can be moved as indicated in FIG. 4 so as to shift the aft end of either of the track sections 9 into registry with the track section 38.

The transfer track section has in it a rack stub 39 which will extend in continuation of the rack section 13 of the port track section 9 when such track section and the transfer track section 38 are in registry, as shown in FIG. 4. Consequently, the hydraulic motor 31 can drive the pinion 12 in mesh with the rack section 39 to move the trolley 7 into the transfer track section 38. When the two track sections have been moved to port so that the rack 13 of the starboard track section is in registry with the rack section 39, the hydraulic motor 31 can be operated in the opposite direction to drive the trolley 7 forward into the starboard track section 9. The track sections may then be left in such position as long as the power block is being used to haul the seine in over the port rail.

Athwartships movement of the two track sections 9 can be accomplished by actuation of the hydraulic jack 40. The track sections are guided for such movement by the aft ends of such track sections being slidable in the supporting channel 25 and by the tie bar 18 being slidable through sleeve 16. During such movement the forward supporting line 19 can be shifted lengthwise relative to the post 17 by rolling on the roller 20 mounted on post 17. The jack 40 is double acting so that the track sections can be locked in either extreme position by hydraulic fluid trapped in one end or the other of the jack.

When the power block is shifted into a position near the outboard end of an athwartships rail section 9, a strong wind will tend to blow the web over the rail. To limit such billowing of the web, a barrier member in the form ofa roller 41 may be mounted on the carriage by jacks 42 connected to its opposite ends. Such jacks can maintain the roller in a position with its length extending fore and aft substantially parallel to the boom 14. Such roller can be supported by a link 43 connecting the outboard end of a track section 9 and the forward end of the roller. By contracting the jacks 42, the roller can be shifted from the operative position shown at the portside of FIG. 1 inboard into the retracted position shown at the starboard side of FIG. 1. While retraction of the roller may not be necessary, it is preferred that such roller be capable of being retracted at the side of the carriage corresponding to the rail of the purse seiner over which the seine is being hauled.

In the modified type of installation shown in FIGS. 7 to 10, inclusive, and 13 the forward end of the horizontal boom 44 again is supported on a collar 36 slidable elevationally along the mast 15. The carriage 45 movable along such boom carries a straight track 46, thelength of which extends athwartships of the boat 1. A swivel 47 supported from such track constitutes the mounting for the power-driven seine-hauling block 48. The outboard ends of the athwartships track 46 carry sleeves 49, each of which embraces a guiding and supporting rail 50 mounted on fore-and-aft posts 50 at a side of the boat.

The carriage 45 with the athwartships track 46 can be shifted fore and aft along the boom 44 by an endless line including a forward portion 51 having its end 52 connected to the forward portion of the carriage 45 and an aft portion 53 having its end 54 connected to the aft portion of the carriage. An intermediate portion of the

line

51, 53 is wound around the drum of a small winch motor 55, which can be either hydraulic or electric. Rotation of the motor in one direction will reel in the forward line portion 51 and pay out the aft line portion 53 correspondingly to shift the carriage 45 forward. Alternatively, the motor 55 can be driven in the reverse direction to haul in the aft line portion 53 and correspondingly pay out the forward line portion 51 to shift the carriage 45 rearwardly. I I

The carriage 45 is supported for movement fore and aft along the boom 44 by rollers 56 journaled in the upper portion of the carriage fore and aft of the athwartships track 46, respectively. The outboard sleeves 49 have corresponding rollers 57 journaled in their upper portions fore and aft of the athwartships track 46 for the purpose of supporting such sleeves on one or the other of the side rails 50. It is desirable for each track 50 to be anchored to withstand both upward and downward loads transmitted to it from the adjacent end of track 46. Consequently, as shown in FIG. 10, it is desirable to provide guide rollers 57 both above and below the side rail 50v In order to enable either one of the guide sleeves 49 to be disconnected readily from its rail 50, each sleeve can be split longitudinally to form an upper section 58:: and a lower section 58b as shown in FIG. 10. The upper section is formed or secured integrally with its end of the athwartships track 46. The upper and lower arcuate sections of the sleeve 49 are connected together at one side of the rail 50 by a hinge 59 and at the other side of the rail by eyebolts 60 connecting slotted ears of the sleeve sections.

The lower ends of the guide rails 50 can be anchored to the deck of the boat 1 by flanged deck plates 61 connected tothe lower ends of the U-shaped guide rail. In order to avoid chafing of the seine by being drawn across the aft leg of a guide rail 50, such leg may be fitted loosely within a tube 62 rotatable relative to such leg to constitute a roller. The junctions of the upright legs with the horizontal stretches of the guide rails 50 can be braced relative to the boom 44 by struts variable in ef fective length. Each strut may be of telescoping construction including an inner section 63 having one end detachably connected to a collar 64 secured to the boom MI and having its opposite end received within an outer tubular portion 65. The outboard end of each outer section is detachably connected to a collar 66 embracing the guide rail 50 and the opposite end of such outer section is connected to the end of the inner strut section 63 by one or more pins 67 extending through one or more of the apertures 68 in the overlapping strut ends. Thus one end of a strut can be disconnected or the entire strut can be removed.

The swivel 47 on which the block 48 is mounted is suspended from a trolley 69 received in the channel-shaped track 46, as shown best in FIG. 10. The downwardly extending flanges of such channel have inturned edges 7t) constituting tracks along which the trolley 69 can travel lengthwise of the athwartships track. Such trolley can be moved along the track by a line loop 711 received within the track channel and having its opposite ends connected to opposite sides of the trolley, as shown in FIG. It). One end portion of the loop extends around an idler guide pulley 72 located adjacent to one outboard end of the track and the other end of the line loop extends over another idler guide pulley 73 adjacent to the opposite outboard end of the track 49 and around the drum of a small winch 74 which can be driven either by a hydraulic motor or an electric motor.

The pulley of the power block 48 is mounted on a hanger 75 which is supported for swinging relative to the mounting 47 by a pivot pin 76 extending through the eye 76. Such eye carries a shank '77 upon which a collar 77' of the hanger 75' is swiveled. Consequently, the power block can swing athwartships and can be swiveled freely while it is hauling in the seine.

The power block sheave is mounted on a shaft 78 turned by a motor 79 to haul the seine. The seine is kept wrapped reasonably closely around the core of the power block sheave by passing the seine between opposite idler guide rollers 80 journaled on cantilever shafts bl, each of which has one end secured in a plate 82 which is swingably mounted on the sup porting shaft 78 for the sheave.

The installation shown in FIGS. 7 to 13 can be operated to haul and stow a seine in a manner similar to that described in connection with the apparatus shown in FIGS. 1 to n, inclusive. Thus, by operation of the winch 74, the trolley 69 can be shifted athwartships back and forth along the track 46 as the seine is being hauled in. Periodically the carriage 45 supporting the track 46 from the boom 44 can be shifted forward or rearward along such boom by operation of the winch 55. By such combination of athwartships movement of the trolley 69 and longitudinal shifting of track 46, the seine can be laid in neat convolutions on the deck of the purse seiner, as shown in FIG. 1, by one man with comparatively little effort, instead of such stowing of the seine requiring hard work ofseveral men.

In FIG. 13 the installation of the seine-hauling power block described is modified by bracing the boom 44- more effectively and providing an arrangement of guide rollers to support the seine for facilitating the hauling operation. Struts d3 connect opposite sides of collar 64 on the boom 44- to the forward ends of side rails 50. Preferably both ends of these struts are detachably connected by pins to the collars so that either end of a strut can be disconnected or a strut can be removed completely. Diagonal struts 84 extend between collars 85 on the forward posts 50 supporting the side rails 50 and a deck plate as. Such struts b3 and M cooperate to support the posts 50', the forward ends of the side rails 50 and the boom 414i quite rigidly.

The aft ends of the side rails 50 are connected to an aft collar 64 by oppositely directed struts 83. The opposite ends of such struts also should be detachably connected to their collars. In addition, the forward and aft posts 50 are connected at a location a substantial distance below the side rails 50 by horizontal struts 87 which are attached to the posts by collars M forming T-fittings with the respective ends of the struts 84.

Such struts extend through tubes 89 mounted loosely on them to function as rollers for supporting the seine 4 passing over such a roller and beneath the guide rail 50 above it.

As has been explained previously, the aft rail-supporting posts 5U extend through rollers 62 which may be engaged by a seine to reduce resistance to movement of the seine past such posts. It is desirable to have guide rollers serving the same purpose located in registry with the upper portions of the posts 50. Rollers 9f) rotatable about upright axes are shown supported by upper brackets 91 and lower brackets 92 attached to the upper portions of the forward posts d0. Such rollers extend lengthwise from locations below the horizon tal rollers 89 to locations a substantial distance above such horizontal rollers to be engaged by a seine sliding forward along a horizontal roller 89.

Correspondingly, rollers 93 are supported for rotation about upright axes by upper brackets 9d and lower brackets 95 attached to the aft rail-supporting post 50'. Again, these rollers extend from locations below the horizontal rollers 89 to locations a substantial distance above such rollers. A roller 93 might therefore be contacted by a seine being hauled in over the aft portion of the corresponding horizontal roller 89.

The power block did of the installation shown in FIG. 13 may have guide rollers mounted adjacent to it like the guide rollers 80 shown in H65. 7, Ill and 12 to increase the angle of contact between the seine and the block sheave. Alternatively, the sheave may have a single guide roller 96 beneath the power block sheave which may be engaged by the seine.

With the installation shown in FIG. T3 the seine can be pulled in directly over a side of the boat 1, but usually it will be preferable to lead the seine between a roller 89 and the guide rail 50 above it as shown in FIG. 13, for example. The power block can then be shifted athwartships along the track 46 while such track is shifted progressively forward or rearward along the boom 44 as described previously. The seine will pass over the roller 89 progressively from one end to the other as the seine is piled on the boat deck as indicated in FIGS. l and 2.

I claim:

ll. Mounting mechanism for mounting a seine-hauling power block on a fishing boat, comprising elongated athwartships track means including a substantially straight track having its length extending generally perpendicular to and crossing the longitudinal central plane of the boat, supporting means for the power block supported by said track means and guided thereby for bodily movement therealong, and power drive means moving said supporting means along said track means while a seine is being hauled in by the power block to shift the power block bodily athwartships. of the boat at a speed corresponding to the speed at which the seine is being hauled in by rotation ofthe power block.

2. Mounting mechanism for mounting a seine-hauling power block on a fishing boat comprising elongated athwartships track means, supporting means for the power block supported by said track means and guided thereby for bodily movement therealong, a substantially horizontal boom extending fore and aft of the boat and having track means therealong, a carriage supported on said boom track means and in turn supporting said athwartships track means for foreand-aft movement along said boom track means, a substantially horizontal rail disposed substantially parallel to said boom and spaced outboard therefrom, guide means engaged between said rail and said athwartships track means for supporting and guiding movement of said track means along said rail, and power drive means moving said supporting means along one of said track means while a seine is being hauled in by the power block to shift the power block bodily relative to the boat deck at a speed corresponding to the speed at which the seine is being hauled in by rotation of the power block.

3. The mounting mechanism defined in claim 1, in which the supporting means for the power block includes a hanger carrying the power block, and two spaced seine-guiding members located below the power block and spaced apart a distance less than the width of the power block for receiving therebetween portions of a seine wrapped around the power block.

4. The mounting mechanism defined in claim 3, in which the spaced guide members are cantilever rollers having corresponding ends mounted on the hanger.

5. The mounting mechanism defined in claim 4, in which the spacing between the rollers is substantially equal to the minimum diameter of the power block.

6. The mounting mechanism defined in claim 2, stantially horizontal roller disposed substantially and spaced below the substantially horizontal rail ofa seine thereover to the power block.

7. The mounting mechanism defined in claim 6, and a roller and a subparallel to for passage disposed with its axis upright and extending upward from the substantially horizontal roller for limiting movement of a seine longitudinally of the substantially horizontal roller.

8. The mounting mechanism defined in claim 6, and two rollers disposed with their axes upright and extending upward from the substantially horizontal roller spaced lengthwise thereof for passage of a seine over the substantially horizontal roller and between said upright rollers to the power block.

9. The mounting mechanism defined in claim 2, an upright post engaged with the substantially horizontal rail, and roller means disposed with its axis upright adjacent to said post for engagement by a seine being hauled by the power block.

Claims

1. Mounting mechanism for mounting a seine-hauling power block on a fishing boat, comprising elongated athwartships track means including a substantially straight track having its length extending generally perpendicular to and crossing the longitudinal central plane of the boat, supporting means for the power block supported by said track means and guided thereby for bodily movement therealong, and power drive means moving said supporting means along said track means while a seine is being hauled in by the power block to shift the power block bodily athwartships of the boat at a speed corresponding to the speed at which the seine is being hauled in by rotation of the power block.

2. Mounting mechanism for mounting a seine-hauling power block on a fishing boat comprising elongated athwartships track means, supporting means for the power block supported by said track means and guided thereby for bodily movement therealong, a substantially horizontal boom extending fore and aft of the boat and having track means therealong, a carriage supported on said boom track means and in turn supporting said athwartships track means for fore-and-aft movement along said boom track means, a substantially horizontal rail disposed substantially parallel to said boom and spaced outboard therefrom, guide means engaged between said rail and said athwartships track means for supporting and guiding movement of said track means along said rail, and power drive means moving said supporting means along one of said track means while a seine is being hauled in by the power block to shift the power block bodily relative to the boat deck at a speed corresponding to the speed at which the seine is being hauled in by rotation of the power block.

6. The mounting mechanism defined in claim 2, and a substantially horizontal roller disposed substantially parallel to and spaced below the substantially horizontal rail for passage of a seine thereover to the power block.

7. The mounting mechanism defined in claim 6, and a roLler disposed with its axis upright and extending upward from the substantially horizontal roller for limiting movement of a seine longitudinally of the substantially horizontal roller.