• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Table of Contents
 Foreword
 Introduction
 Early developments: Aluminum beam...
 Steel beam trawls (2nd generat...
 Steel beam trawls (3rd generat...
 Conclusion
 Acknowledgement
 Photos of experimental beam trawls:...
 Construction plans of 3rd generation...
 Construction plans of 1st generation...
 Construction plans of 2nd generation...






Group Title: Technical paper - Florida Sea Grant Program ;, no. 6
Title: Shrimp beam trawls
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00072257/00001
 Material Information
Title: Shrimp beam trawls design, construction and operation
Series Title: Technical paper - Florida Sea Grant College Program no. 6
Physical Description: i, 42 p. : ill. ; 28 cm.
Language: English
Creator: Christensen, Bent A
Publisher: State University System of Florida, Sea Grant Program
Place of Publication: Gainesville
Publication Date: 1978
 Subjects
Subject: Trawls and trawling   ( lcsh )
Shrimp fisheries   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by Bent A. Christensen and John Dorman.
General Note: "August 1978."
Funding: Technical paper (Florida Sea Grant College) ;
 Record Information
Bibliographic ID: UF00072257
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: aleph - 000990236
oclc - 04741060
notis - AEW7148

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page 1
        Title Page 2
    Table of Contents
        Table of Contents
    Foreword
        Page i
    Introduction
        Page 1
    Early developments: Aluminum beam trawls (1st generation)
        Page 2
        Page 3
        Page 4
    Steel beam trawls (2nd generation)
        Page 5
        Page 6
    Steel beam trawls (3rd generation)
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Conclusion
        Page 12
    Acknowledgement
        Page 13
    Photos of experimental beam trawls: Figures 1-20
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
    Construction plans of 3rd generation beam trawl: Figures 21-26
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
    Construction plans of 1st generation beam trawl: Figures 27-28
        Page 40
        Page 41
    Construction plans of 2nd generation beam trawl: Figure 29
        Page 42
Full Text



/562G


SHRIMP BEAM TRAWLS
DESIGN, CONSTRUCTION AND OPERATION
by
Bent A. Christensen, Professor
and
John Dorman, Research Assistant
Department of Civil Engineering
University of Florida


TECHNICAL PAPER NO. 6
August 1978


Florida Sea Grant

















SHRIMP BEAM TRAWLS
DESIGN, CONSTRUCTION AND OPERATION

by
Bent A. Christensen, Professor
and
John Dorman, Research Assistant
Department of Civil Engineering
University of Florida

TECHNICAL PAPER NO. 6
August 1978









The information contained in this paper was
developed under the auspices of the Florida Sea Grant
College Program, with support from the NOAA Office of
Sea Grant, U. S. Department of Commerce, grant number
04-8-M01-76; and the Coastal Plains Regional Commission
of Charleston, S.C. This document is a Technical Paper
of the State University System of Florida Sea Grant
College Program, 2001 McCarty Hall, University of
Florida, Gainesville, FL 32611. Technical Papers are
duplicated in limited quantities for specialized
audiences requiring rapid access to information which
may be unedited.











SHRIMP BEAM TRAWLS
Design, Construction and Operation



A Preliminary Report
Report No. 7804


Hydraulic Laboratory
Department of Civil Engineering
University of Florida
Gainesville, Floirda 32611












TABLE OF CONTENT


FORWARD . . . . .

1 INTRODUCTION . . . .

2 EARLY DEVELOPMENTS. ALUMINUM BEAM TRAWLS
(1st Generation) . . .

3 STEEL BEAM TRAWLS (2nd Generation) .


4 STEEL BEAM TRAWLS (3rd Generation) .

5 CONCLUSIONS. . . . ..

6 ACKNOWLEDGEMENTS . . .


Photos of Experimental Beam Trawls. Figures 1 -

Construction Plans of 3rd Generation Beam Trawl.

Construction Plans of 1st Generation Beam Trawl.

Construction Plans of 2nd Generation Beam Trawl.


20 . .

Figures 21 26

Figures 27 28

Figure 29 .


Page
i


. 2

S 5


S 6

. 12

S 13


. 14-33

S34-39

. 40-41

S. 42














FOREWORD


This preliminary report is being written and distributed in response

to numerous inquiries concerning the beam trawl recently developed by the

University of Florida's Hydraulic Laboratory. Although testing of the trawl

is not complete at the present time (August, 1978) it is hoped that this

information adequately answers at least some of the questions presented.

Additional information and test results will be provided when they become

available. The following discussion is devoted primarily to those persons

who wish to build and operate this type of trawling system.

The development and testing of this trawl was made possible by a

grant from:

The Coastal Plains Regional Commission
1725 K Street NW
Washington, D.C. 20006


The Hydraulic Laboratory will be grateful for any data generated by

the use of this type of gear. Such information may be mailed to:


Hydraulic Laboratory
Department of Civil Engineering
University of Florida
Gainesville, FL 32611








1. INTRODUCTION

The idea of the beam trawl, namely keeping a trawl or net open by means
of a structural member, i.e. the beam, functioning structurally as a column,

is in no way new. As a matter of fact, a crude version of the beam trawl was

the forerunner of the otter door trawl that is so widely used by the fishing

industry today. The modern otter door trawl was easier to use and manipulate

than the old clumpsy beam trawls. It required less manpower but more fuel

since it applies a hydrodynamic force to keep the net open, a hydrodynamic

force which must be generated by the powerplant on board the trawler.

In the days when fossil fuel was plentiful and cheap the switch to the

otter door trawl seemed logical. However, today with fuel shortages and in-

creasing fuel prices it does not seem rational to use scarce and expensive

fossil fuel to provide the force that keeps the net open when this force may

be provided free of charge so to speak by a beam. In other words the time

has come when reconsidering the beam trawl and redesigning and modernizing

it for improved ease of handling and fishing efficiency may prove an answer

to some of the fishing industry's present economical problems.

The beam trawl discussed in this report is now in its third generation.

Improvements have been made such that each generation was supposedly better

than earlier models, but this does not imply that further improvements are

not possible. Each fisherman should be able to make changes that will fully

adapt its use to his particular situation. The modifications that have been

made, as well as potential modification, will be discussed herein. Photos

are provided of the three generations of beam trawls, and drawings with the

specifications necessary for their construction are included. Unless otherwise

noted, the dimensions given on the drawings are the same as those of the ex-

perimental beam trawls shown in the photos.








2. EARLY DEVELOPMENTS. ALUMINUM BEAM TRAWLS. (1st Generation)

Figures through 6 are photos of the first generation of the beam trawl

developed by this laboratory. The corresponding dimensions are shown in

Figures 27 and 28. The beam with end frames is 3 feet high, 31 feet long

and,except shoes and some hardware, is all heli-arc welded aluminum. This beam

was built earlier in conjunction with tests being made on door trawls and the

development of model laws for trawls. Laboratory and ocean tests revealed

that the webbing itself was only responsible for about half of the towing

force being used and the remaining force was required to pull the doors. At-

tempts to devise a system that would perform the same function as the doors,

but be cheaper fuel-wise to pull, led to the construction and testing of the

beam trawl. Those first tests revealed that the beam was indeed easier to pull,

requiring about 25% less total force than the doors to fish a bottom strip of

the same width as the one fished by a conventional otter door trawl. Since

development of the beam was not the main objective at that time, only little

information was recorded concerning its performance. However, work done

during the past nine months has been directly oriented toward the evaluation

and development of a fuel efficient beam trawl.

The following comments are made in reference to the aluminum beam. The

net used was made especially for the beam and is basically a modified flat

net less wings. It has 2 inch webbing of #15 twine and a foot rope length of

approximately 45 feet. Although the middle of the head rope is shown connected

to the pipe, this is not necessary unless it is desired to limit the fishing

height. Also, the length of the head rope is not critical to the performance

of the beam and may be longer if consistent with the rest of the net. Most

of the-tests done recently have used longer head ropes attached only to the

ends of the pipe. Connecting the head ropeto the pipe at its center makes
*All figures appear at the end of text.







the net slightly easier to pull, but the savings will probably not offset the

loss in area fished. The length of the foot rope is about right. It should be

from 1 1/2 to 2 times the length of the beam. Shorter lengths tend to put too

much bending and compression in the pipe. Longer lengths may cause the net to

wind up, pick up too much trash, or not fish properly.

It should be noted that the net has no leg lines, although leg lines of
1 or 2 feet are suggested. The shoes on the beam slide straight forward along

the bottom and do not kick up as much trash and mud as a set of doors. The

long leg lines normally used to clear trash are therefore not needed. Note

also that the net has a loop chain along the full length of the foot rope as well

as a tickler chain stretched between the two end frames. No information con-

cerning this setup was recorded, but tests made on the second and third gener-

ation beams indicate that the tickler chain helps increase the catch.

As evident from the photos, short bridle cables were used on the aluminum

beam. The beam could be lifted high enough to clear the water when the junc-

tion point of the bridles was pulled to the towing block. One bad effect of

short bridle cables is that they cause large bending and compressive forces in

the pipe. The aluminum pipes were strong enough to withstand these forces

with no ill effects. The second and third generation beams use long bridle

cables and smaller pipes. These beams can also be lifted out of the water by

pinching the cables together as they are pulled through the block. It is ob-

vious that the cables can only be pulled so far for fear of buckling the pipe.

Several different arrangements of long bridle cables have been tested. Some

of them performed very well and others were very poor.

Different holes were provided in the end frames of the aluminum beam for

connection of the outside bridle cables. Although the cables are shown con-

nected to the center holes, the bottom holes should probably have been used.








Connecting the cables too high on the frames causes the beam to rotate forward

and lifts the rear of the frame and shoe. This may or may not be desirable.

If the beam rotates too much, the center cable will go slack and the beam will

rock.

The photos indicate some of the procedure used to load the beam. It ap-

pears that most of the lifting was done by the net. Depending on the equipment

available on the trawler and its arrangement, there are any number of ways to

handle the beam. One particularly good method will be explained when the

second generation beam is discussed. Since trawlers are not set up to handle

beams, putting it on board may be difficult in some cases. The development of

new methods for storing the beam is one area of potential improvement. At-

taching the beam to the outrigger or providing rail mounted storage racks are

good possibilities.

Figures 5 and 6 show more of the details of how the beam is assembled

than any of the other photos. The end frames have a short section of pipe

which slides over the long pipes, and they are secured by putting a bolt in

holes bored through the pipes. The center section of pipe is larger than the

two outside sections. The pipes used for the aluminum beam were selected such

that the outside pipes would telescope into the center section for easier

handling, however, this was not done on any of the newer beams simply because

handling the fully extended beam did not seem to createany problems for the

crews during the actual ocean testing of the trawls.

The pipes for the newer beams were selected for a close fit and not to

telescope. Although some changes were made, the same general relationship

between pieces of the beam was used for all three generations of beam trawl.

They each have three sections of pipe and two end frames. These five pieces

are completely separable.







3. STEEL BEAM TRAWLS (2nd Generation)

The following comments concern the second generation beam trawl shown

in Figures 7 through 16 with dimensions indicated in Figure 29. Two of these

beams were tested in February, 1978, and primary consideration was given to

their performance. Reproduction of this beam is not suggested since it was

designed for test purposes and not for routine fishing. The third generation

beam, to be discussed later, is designed for routine fishing and incorporates

all of the improvements found to be necessary from tests of the second gener-

ation beam. Both the second and third generation beams are 30 feet long and

3 feet high. They are made of steel and not aluminum.

Two different nets were used on the second generation beams. One was

a conventional two seam balloon net; and the other was a new beam net, dif-

ferent from the net used on the aluminum beam. Hanging to hanging, the

balloon net was 50 feet long on the head rope and 60 feet long on the foot

rope. The beam net was 34 feet long on the head rope and 41 feet long on

the foot rope. The leg lines on both head ropes were adjusted to make the

nets pull properly from the beams. Both nets used 2 inch webbing and #15

twine. Fishing side by side for two days, the balloon net caught twice as

many shrimp as the beam net.

During these tests both beams used a 5/16 inch tickler chain stretched

between the two end frames. They were set to pull about 2 feet forward of

the foot rope. Figures 7 through 10 show the second generation beam in its

original form. The pipes used were the smallest size considered adequate.

Figures 9 and 10 show that they were not adequate since both beams bent their

center section of pipe due to unexpected problems. Both of these sections

were replaced with larger pipes, and the beams performed satisfactorily for

the remaining three days of testing. The beams bent partly because of the








bridle cable system that was used and partly because the pipe was too small

to start with. The beam with the short net was bent considerably more than

the other beam, indicating an increase in the forces acting on the pipe

because of the short foot rope. Figures 11 and 12 show the beam after being

repaired.

Figures 13 and 14 show part of the sequence of steps used to load the

beams. Figures 9 and 10 both indicate clearly the two handling lines which

were attached to each beam. Using the line on the end of the beam and

nearest to the boat, one end of the beam was raised as shown in Figure 13.

The block used for this was located above the winch. By easing off on the

towing cable the beam was allowed to move toward the boat. When the beam was

in far enough, the lifting line was let off and the end of the beam was set

on deck as shown in Figure 14. Although it was not done at the time, it is

best to make the end of the beam fast after this step. Using the line at the

one-third point of the beam and farthest from the boat, the other end of the

beam was simultaneously swung and lifted as the towing cable was eased out.

The block used for this was located in the rigging at the stern of the boat.

When the beam had swung parallel to the boat, the lifting line was let off and

the pipe was set on the stern rail and made fast. The end of the beam was

allowed to protrude over the stern. This particular loading procedure is

safe and efficient. It was devised and implemented by Captain Jimmy Moore,

whose trawler pulled the beams.

The last day of testing for the second generation beam was devoted to

direct comparison of the beam with conventional doors. The beam with the 50

foot two seam balloon net was pulled from one side of the trawler, and nine

by forty doors with a 60 foot four seam flat net was pulled from the other

side. Three drags were made. On the first drag the beam caught 2 2/3 pounds







of shrimp for each pound caught by the doors. On the second drag the beam

caught 2 pounds ofshrimp for each pound caught by the doors. The

last drag was started by a sharp 1800 turn at full throttle which unfortu-

nately-was enough to flip the beam upside down as shown in Figure 15. The

beam caught 3/4 pound of shrimp for each pound caught by the doors. 1This is

the extent of direct comparison of the two systems in shallow water. Addi-

tional testing is planned for shallow water to better verify the performance

of the two systems. The results will be released when available.

Figure 16shows a net that has caught itself. The trawler was stopped

quickly from full throttle. The beam also stopped. The bag, however,did not

stop because of inertia of the water moving with it. It came far enough

forward to cross over the head rope. When the trawl was pulled again, the

head rope crossed over the bag. This is not normal for the beam but has been

included here because it did happen. It should also be noted that flipping

the beam is not normal, but it may happen. The beam can be flipped back up-

right with the lazy line. A better method is to drop it back down in the

water and turn the boat through 1800 in a circle with the beam at the center

of the circle.

It took about twice as much total force to pull the doors as it did the

beam. This ratio would change if the beam was compared with smaller doors.

4. STEEL BEAM TRAWLS (3rd Generation)

Figures 17 through 20 show the third generation beam. Its dimensions
are given in Figures 21 through 26. It is very similar to the second gener-

ation beam but has many improvements. It is lighter, stronger, easier to

pull, easier to handle because of the improved bridle cables, and fishes a

larger area.








The steel used to build the end frames of the third beam was not as

thick as that used in the second. Also, the unnecessary parts used only for

testing were omitted and the shoes were shortened. The center section of

pipe is the same size as the replacement pipe used on the second beam, but

the outside pipes are larger. The distance between the pipe and the bottom

of the shoe is also larger. It is not obvious from the pictures, but the

pipes have small steel rods welded to them along their top and bottom about

1 inch forward of the center line of the pipe. These small rods change the

character of the flow of water around the pipes and are expected to reduce

drag thereby making them easier to pull.

The third generation beam was tested out of Key West during May, 1978,

to check its performance in deep water. The beam was pulled from one side

of the trawler and seven by thirty-four doors were pulled from the other.

Four different nets were used with the beam. The doors pulled a 39 foot

flat net with 5 foot leg lines. This net was never changed and was used as

a standard for comparison with the beam and its nets. The depth of water

fished in ranged from 200 to 245 fathoms, but most of the drags were made at

about 230 fathoms (1380 feet). Twenty-four drags of approximately 4 hours

duration each were made in 6 days. The following table gives the description

of the nets used on the beam and the total catch comparisons.










Catch Catch
Beam Doors Ratio

Beam Net 1.27
2 inch mesh, #15 Twine 79/lb 100/lb to
Foot Rope 54 ft pounds 1


Beam Net 1.77
2 inch mesh, #18 Twine 163/lb 288/1b to
Foot Rope 48 ft 1


Two Seam Balloon Net 1.36
2 inch mesh, #15 Twine 234/1b 319/1b to
Foot Rope 60 ft 1
Head Rope 50 ft


39 Foot Flat Net 2.28
2 inch mesh, #15 Twine 159/lb 363/1b to
Same net as on doors 1




In every case the doors did better than the beam in deep water. Both

drums had 700 fathoms of towing cable, giving a cable length-to-depth

ratio of about 3 to 1. This is apparently not sufficient for the beam to

make good bottom contact. Although the beam got to the bottom, it pro-

bably never had both ends touching at the same time. The force measure-

ments made indicated that the beam drag was below normal and in the same

range as measurements made earlier when the beam was pulled without

bottom contact. The doors have one advantage in that the force of the

water also takes them to the bottom. The beam has only its weight to take

it down. This advantage may be reversed for shallow water. Figure 20








shows the shine on the bottom of the shoe which indicates that the beam

was at least touching bottom part of the time. This picture was taken at

the end of the 14th drag on the fourth day of testing. When the picture

was taken, the beam was upside down as shown in Figure 19. The beam is

very stable and has flipped only twice. The first time it flipped was

mentioned earlier. This time the two rigs caught together. The beam came

up upside down, and one of the chains was pulled out of a door.

If the beam was practically flying, as suggested earlier, it should be

reflected in the catch made by each net. The beam net with #15 twine and

the balloon net both have a long foot rope. When pulled without interfer-

ence from the bottom, these nets should expand more in the vertical direc-

tion. If one end of the beam is allowed to touch bottom, then the net that

expanded the most should have more of its net touch bottom. The short flat

net probably had the least vertical expansion. As reflected in the catch

comparison, the beams catchseems proportional to its nets ability to expand

vertically. This effect is also shown from the fact that the catch in-

creased when Texas dropdown was used instead of a tickler stretched between

the end frames. The dropdown helped hold down the bottom of the net. This

tendency of the beam to fly is not normal but is the result of insufficient

towing cable length.

Figures 17 and 25 show the arrangement of the bridle cables for the

third generation beam. Please refer to Figure 25 for the following discus-

sion. The four cables connected to the pipe are arranged such that they all

come tight at the same time. This helps equalize the forces acting on the

pipe. The longer outside bridle cables reduce the bending and compression

of the pipe that would be present if short bridles were used. The beam is

weakest when the two outside bridle cables are pinched together as it is







pulled close to the towing block. It is designed to be pulled to within

8 or 9 feet from the block but not much closer. This bridle system was ar-

ranged such that the forward ends of the two outside cables could be dis-

connected from their normal position and reconnected to the center cable at

about 48 feet from the pipe. By doing this the beam could be suspended by

the center cable which is connected to the four short cables. The junction

point of these four lines may be moved closer to the pipe if necessary;

say to within 7 feet. The length of 60 feet was chosen so that when the

beam was pulled up, the junction point of the longer cables would be at the

winch. If the two outside cables are made fast at this point, the winch

can be let out and these two cables disconnected. When the winch is brought

in again, the center cable will support the beam. This was done several

times during testing and went smoothly. A piece of chain looped around the

winch frame was used to make the outside cables fast. The chain held a

small shackle which the cable thimbles would not slide through. By ar-

ranging the cables so that they can be disconnected, the length of the lines

can be changed by adding a short piece of chain or a shackle. When the beam

is let out again, it can be made to drag heel heavy, toe heavy or whatever

is desired. The position the beam takes while being pulled is defined by

the length of the bridle cables and the angle of the towing cable.

Figure 17 shows that there are several different places to attach the

outside bridle cables to the end frames. The higher the cables are con-

nected, the smaller the forces in the pipe. Since different types of nets

pull differently, it is suggested that the cables be attached as high as

possible and still have the beam function properly. If it is desired to

increase the fishing height, extensions can be welded or bolted to the end

frame to attach the head rope to. The bridle cables may be connected in a









higher position if this is done. Extensions of more than 2 1/2 feet are

not suggested since they would make the beam tend to tip over backwards.

Extensions should be positioned to lean forward.


5. CONCLUSIONS

At the present time, before the final modification of the third gen-

eration beam trawl for more efficient deep water shrimping, the following

conclusions may be drawn:

a. The beam trawl is substantially easier to pull and will under

all circumstances save fuel when compared to a conventional

otter door trawl of same size.

b. The newly designed beam trawls are easy to handle. They do

not create more handling problems to a two man crew than the

otter door trawl.

c. Once in the water the beam trawl seems to be more stable than

the otter door trawl. This is true not only on its way to the

bottom but also after bottom contact has been established.

d. In shallow water the beam trawl has been demonstrated to fish

cleaner and catch substantially more shrimp per unit time

trawling than a conventional otter door trawl of the same

size.

e. In deep water the experimental beam trawl was surpassed in

catch by the otter door trawl. Dynamometer readings show

that this was due to lack of weight that prevented proper

bottom contact. Improvements are possible by increasing the

beam weight without increasing drag.








f. It is reasonable to expect that the beam trawl will be

equally successful for other bottom fish.

6. ACKNOWLEDGEMENTS

The development of the beam trawl has required a great deal of cooper-

ation from many individuals and organizations. Although recognition of

everyone involved is not possible, we at the Hydraulic Laboratory would like

to express our sincere appreciation and gratitude for the many contributions

that have been made and give formal recognition to those individuals whose

dedicated effort and talents have been key elements in this research.

Without the cooperaLion we have received, little of our accomplishments

would have been possible.

Captains David Cook, Jimmy Moore, Gene Lewis, and their crews have

provided the trawlers and manpower necessary for field testing of the three

generations of beam trawl. The many contributions and suggestions made by

these men have been invaluable and have provided guidelines for many im-

provements.

Standard Hardware, Inc. in Fernandina Beach, Florida, and its employees

have provided many courteous services. Our special appreciation is extended

to W. H. "Billy" Burbank, Jr. and his crew in the net shop. They made all

of the nets that have been used on the beams and door trawls.

Mr. William F. Feger, Jr., owner and operator of "Feger Seafood" in

New Smyrna Beach, Florida, has provided a great deal of assistance through-

out the duration of this project. We are grateful to have his continued

support.

We would also like to extend our appreciation to the agents of the

Florida Marine Advisory Program, who have been a valuable link between our

laboratory in Gainesville and the fishermen throughout the state.















































Figure 1 1st Generation Beam.
















































Figure 2 1st Generation Beam.













15


































-.


Figure 3 1st Generation Beam.



















































Figure 4 1st Generation Beam.









17


















































































Figure 5 1st Generation Beam.


.-r~
~hir;..
:I~~rr
:; e
'i'i



:;~ ~:
'~' LA~''~
I i. I
















































Figure 6 1st Generation Beam.












19
















































Figure 7 Original 2nd Generation Beam. Two Seam Net.













20

















































Figure 8 Original 2nd Generation.


Beam Net.



































, i


Figure 9 Original 2nd Generation Beam. Two Seam Net.

























Figure 10 Original 2nd Generation Beam. Beam Net.


I















































Figure 11 Modified 2nd Generation Beam. Two Seam Net.













24















































Figure 12 Modified 2nd Generation Beam. Beam Net.













25















































Figure 13 2nd Generation Beam During Loading.













26










































--L-C~.
ryr~

u L-~~_ ---~-
'- `--c---
~1--rrr
E`~-~,f~-~p~
s
4rs~C~1~L~r,
~2~: 5---~ U lr~f~52


Figure 14 2nd Generation Beam During Loading.




















27















































Figure 15 2nd Generation Beam.













28





























~aw-




ZCr -*~
5-. vP~ ~r -
- 1;93~ -Bi- r
ma.U7. ,a b,-


- -r ~ -z..r"-
~I,-- *PI."l. A-


Figure 16 2nd Generation Beam.


Two Seam Balloon Net.

















































Figure 17 3rd Generation Beam.











30















































Figure 18 3rd Generation Beam.













31





















































Figure 19 3rd Generation Beam.


E~'S~c"~ar~~
~pLcrr75;r+T~-~LP3














































Figure 20 3rd Generation Beam Underside of Shoe.













33







THiR GENERATE ION AM


End Frame


Channel
Cross Section


7T-
=LL


American


Standard


Channel C 3 x 4.1


(3in wide- x 4.1 Ib/ft)


Total Le.ngth


o1 ft


(2 stock length of 2o ft)


Fij re-


BEAM (STEEL)


~I HIRD


G ENER AT \ON


k







THI~D ENEAT ONBEAM (5TEEiL')


End Fromere- Outside. View


-H


Pltte on Both


5ide5 ~P Frome.


Angle. 3"x Z"x




/
I
I
!


Insert x 2?- x 3"


H*- 2-2


Pipe
4" Standard /Weight
Length 18"
0. D. -4.500"; D.- 4.02.("


C~1
-I


Figure. 22


I ,


(STEEL~


GENERATION


BEAM


3j"


5ides of Frome


-L ''
4


THIRD







THIRO G~N~RAT~ON BEA~I (S,-~E2


-- *'3 Eye Nut




\\ End Frame

\ I-nside Vie-w


' Nu%


o" -- 7 -


Shoe- "T Fcat Bar 45 Long -
Drilled and tapped for -" bolts on 10" c.nte.rs .
Eye Nuts: /Welded in p\ac.e as shown. Siz.e. optional.

Note: The. s.hacpe. o-f the curve-d portion o the. shoe.
is not c-ri-it.\. It may be a smooth curve or
a series of bends as asNo\n.

Figure- 23
36


j


BEAM


STEELE)


THIRD GENERATION







THIRD GENERATION BEAI (STEEL')

Pipes (for30 ft Beam)
-- 1"--1 lt2'0"
22"- -t12. 12"--

0o 0
I


0 0

F-\o" ,o "-9-


3 dimee.
All koles are. T diomeae.r.


Not to Sc.le

2I 1BI
20
o


So o

H- -1 1o0


Use. x "

30


--- 8'l
8F


e.ye oolt to conne..-c.


8 10o"


SI Larger Pipes
SSmaller Pipes

Note: T)he- 3 pipe- Is
will u.)Ql y not- do so.
of the- 5mc\cle.r pipes5


4" Standard W eight O.D. 4.5-00' I.D.

3 StandQrd Weight O.D. 4.000"; I.D.

supposed to -ft inside tihe- 4" pipe.)
It- ius aljy necersscrj +to tur-

unti\ they fit.

Figure.. 24


4.02>" r

3.5-s" 4

how vever it
doAJrn the ends






T7HRD GENE.RATION BEAM STEEL.)


Bridle Cable. System

iew All Ccb,\e.s ore. '


-F-


(0'


60'


I I
C"T


Top

V ITndicates 5Shckcle.


C MQin Towing Cable

Shacle- t Top Line. to t'llt beam bock.
Shockle to Bottom Line_ to ~ilt be-am orward.


Figure- 25
38


Add
Add


C


Top V


391


i'* c





TIIRD GENERATION BEAM (STEEL)
Pipes (for 25 ft Beamr)


O O
---------" 'o" I
So12
0 0


'ih 6 '"(22


G"7t


Not to 5ccile

2--L"

r 10 ......


0 0

9 .-9


r-89


o o

- -a9r


257A "
71011


Lctv-9er FPipes5 3- Stctriord Vveqj+ht O.D. 4.00" I.D. 3.548&
5rlle. Pipels 3"5tar'dQv-d We'ht O.D. 3.500"; T.D. 3.068's
U5Pe TVjrd G-rnerv-citton Encl Frcme- with 32j Pipe.
Use. Third Garer-tion Br-idle- Ccb1b. Syrem.


,irre. 26


-~- If"


----


I___pi [ _o~ r-


8 9


A


W"


6









FIRST


GENERATION BEAM


(ALUMrINUM)


JL, i 4xs c4
T YP'c~

c ~14


All pie-ces are .lded
the shvoe, whichh is


together.- e-xe-pt
boltte'a in p\ac-e.


36" ------)


3


---P =- = --- = -=E~E~~








FIRST GENERATION BEAM (ALUMINUM)


PiLps and Bridle CaLles


Not to scale
---------- ^


S4 16'6 4

-- --12" 12"--I --
Io_ o- o I o o _o _
7 -_1--" 81~ 3 ,-
^ ------ c( '3"---- -- --- >---


Top View


All cables Y 4'


Not. to scale


Lorer Pipes 5" Extra Stronr,
Smaller Pipes 4" Stand~ard


OD. 5.5s3"; I.D. 4.813"
O.D. 4.500"; I.D. 4.026"


Figure_
41







GENERATION BEAM MoDIVIED (ST-EEL)


It ~
' I


Shown for compare son only. See third gene.rction beam.
Bridle connector and insert omitted.
All pipes tor modified second g~ner-cion bec~a are.
the .ame as those. or the. ir-d enero ion beam.


r1 8 ~


I


4 x33


L2J


ss corN D




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