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DESIGN OF A YOKE SYSTEM FOR A CLOSE-COUPLED SPAR/FpSO FLOATING PRODUCTION

SYSTEM FOR THE GULF OF MEXICO

International Student Offshore Design Competition

Yoke System Final Report

By: Michelle Arango, Jamie Armstrong, Donald Burris,

Christopher Ordonez, Birgitte Rossabo, Jefferson Stanford.Faculty Advisor: Dr. Robert Randall

OCEAN ENGINEERING PROGRAMCIVIL ENGINEERING DEPARTMENTTEXAS A&M UNIVERSITY

COLLEGE STATION, TEXAS 77843-3136June 28, 2002

Spar

FpSO

Crew Transfer

Yoke

Crew

Quarters


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Table of Contents

CHAPTER 1 Introduction...........................................................................................................................................1-1Background................................................................................................................................................................1-1Location......................................................................................................................................................................1-1Environmental Conditions ......................................................................................................................................1-2

Organization ..............................................................................................................................................................1-3CHAPTER 2 Yoke System Design ...........................................................................................................................2-1Yoke System Overview ...........................................................................................................................................2-1Force Transfer ...........................................................................................................................................................2-2

Structure ................................................................................................................................................................2-2Force Transfer Connection to Spar: Large Diameter Bearing .....................................................................2-4Force Transfer Connection to FpSO: Rigid Connection...............................................................................2-6Structural Analysis Results ................................................................................................................................2-7Physical Model.....................................................................................................................................................2-8

Fluid Transfer..........................................................................................................................................................2-12Wrapping Hose Fluid Transfer........................................................................................................................2-13Oil Transfer Ring ...............................................................................................................................................2-15Flow Assurance..................................................................................................................................................2-17

Crew Transfer..........................................................................................................................................................2-17Master Equipment List ..........................................................................................................................................2-20Environmental Loading .........................................................................................................................................2-20Yoke System Cost..................................................................................................................................................2-21Design Conclusions and Recommendations......................................................................................................2-22

CHAPTER 3 Executive Summary .............................................................................................................................3-1CHAPTER 4 References .............................................................................................................................................4-1Appendix A Calculations and Example StruCAD Analysis ................................................................................A-1


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List of Figures

Figure 1-1. Design Location of Conocos Prospective Field in the Gulf of Mexico (NOAA, 2002). ..........1-2Figure 1-2. Illustration of Multi-Directional Wind Patterns (Conoco, 2002a). ................................................1-3

Figure 2-1. Overall General Arrangement. .............................................................................................................2-1

Figure 2-2. Force Transfer Yoke. ..............................................................................................................................2-2Figure 2-3. General Layout, Force Transfer (units in m). ....................................................................................2-4

Figure 2-4. Machining of the Barracuda P-34 FPSO Internal Turret Bearing (Courtesy FMC SOFEC).........2-5Figure 2-5. Detail View of Force Transfer Bearing...............................................................................................2-5Figure 2-6. Yoke Connection to FpSO. ...................................................................................................................2-6

Figure 2-7. Torsion Hinge In Yoke System (Photo Courtesy of FMC SOFEC). .............................................2-7Figure 2-8. StruCAD Unity Check. ..........................................................................................................................2-8Figure 2-9. Force Transfer Model Overview. .........................................................................................................2-9

Figure 2-10. Force Transfer Model in Heave. ........................................................................................................2-9Figure 2-11. Force Transfer Model in Roll. ..........................................................................................................2-10Figure 2-12. Force Transfer Model of Torsion Joint in Equilibrium................................................................2-11

Figure 2-13. Force Transfer Model of Torsion Joint in Roll. ............................................................................2-11Figure 2-14. FMC SOFECs Soft Yoke Mooring Tower in Bohai Bay, China. .............................................2-12

Figure 2-15. Conceptual Drawing of Overhead Oil Track. ................................................................................2-13Figure 2-16. Wrapping Hose Oil Transfer. ...........................................................................................................2-14Figure 2-17. Close-up of Wrap Hose Support......................................................................................................2-14Figure 2-18. Overview of Fluid Transfer System. ...............................................................................................2-15

Figure 2-19. Cross Section of Oil Transfer Ring. ................................................................................................2-16Figure 2-20. Oil Transfer Ring Dimensions (units in m)....................................................................................2-17Figure 2-21. Crew Transfer Deck Dimensions (units in m). ..............................................................................2-18

Figure 2-22. Crew Transfer Ramp Connection. ...................................................................................................2-19Figure 3-1. Overall Close-Coupled Floating Production System. .......................................................................3-1Figure 3-2. Yoke Components ..................................................................................................................................3-2


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List of Tables

Table 1-1. Overall Design Criteria for Close-Coupled System (Conoco, 2002a). ...........................................1-1Table 1-2. Characteristics of Gulf of Mexico 100 Year Hurricane Conditions (Conoco, 2002b).................1-2

Table 2-1. HSS 20X 0.75 Member Properties........................................................................................................2-3Table 2-2. Force Transfer Weights...........................................................................................................................2-3

Table 2-3. Force Transfer Bearing Weights............................................................................................................2-6Table 2-4. Weight of Oil Transfer Ring. ...............................................................................................................2-16Table 2-5. Weight of Crew Transfer System. .......................................................................................................2-19Table 2-6. Environmental Loading On the Yoke System. ..................................................................................2-21

Table 2-7. Cost Breakdown for Yoke Components.............................................................................................2-21Table 3-1. Summary of Overall Design Criteria for Close-Coupled System. ...................................................3-1Table 3-2. Gulf of Mexico 100-Year Hurricane Design Environment...............................................................3-1

Table 3-3. Estimated Total Project Cost..................................................................................................................3-3Table 3-4. Cost Comparison of Existing Mid-Water Flowline System and New Close-Coupled System. .3-3Table A-1. StruCAD Program Specifics. ...............................................................................................................A-4Table A-2. StruCAD Input File. ...............................................................................................................................A-6

Table A-3. StruCAD Output File.............................................................................................................................A-9


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Abstract

The Ocean Engineering Senior Design Class at Texas A&M University was commissioned todesign a close-coupled Spar/FpSO system for use in the Gulf of Mexico. A small p is used in the FPSO

to indicate that only part of production will be conducted upon it. The idea is that the combined structurewill rely on one mooring system, which reduces cost, and allows medium and small yield oil fields from

100 to 300 million barrels to be produced economically. The overall project was divided into three designteams, Spar, Yoke, and FpSO. The groups collaborated amongst each other to form the complete solution,similar to a real world situation where several design teams are working on different aspects of the sameproject.

The emphasis of the yoke team was to design a yoke to connect the FpSO to the spar system. Theyoke team will concentrate on general arrangement/system design, weight, global loading, general strengthand structural design, environmental loading, and a structural analysis. As with any projects, all relevant

regulatory guidelines were followed while attempting to ultimately find a cost effective solution. Safetywas integrated into every aspect of design to minimize hazards. Efforts were made to protect the crew, theenvironment, and the structures themselves.

The design objectives stated by Conoco, the project sponsor, indicated that the system must haveonly one mooring system, facilitated by the connection of the FpSO to the spar through the yoke. Thehigher-risk first stage oil production was located on the spar platform. Further production, crew quarters,

and oil storage were placed on the FpSO. The yoke design had to accommodate crew movement betweenthe spar and FpSO. The FpSO had to retain a weathervane capability so it could face bow intoenvironmental forces and minimize loading. The Spar was chosen to provide a dry-tree system in a design

water depth of 4700 feet. StruCAD was used to conduct structural analysis of the yoke. The specific goalsof the yoke design will include the transfer of forces, partially processed drill fluids, and crew betweenstructures while maximizing safety.

A bearing around the spar was designed to allow for the transfer of forces from the FpSO to thespar. An oil ring system fitted about the spar hull allows for continuous fluid transfer while the FpSOweathervanes. A special crew transfer deck was added to the spar so that a track mounted ramp couldallow the crew to walk from the spar to the crew quarters on the FpSO bow. The yoke design team

combined students of varying strengths and backgrounds in an effort to create a diverse design teamcapable of accomplishing a successful yoke design for a close-couple Spar/FpSO system in the Gulf ofMexico.


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Acknowledgements

The Ocean Engineering Senior design class would like to thank many people and

companies for all their help, support, and guidance. They are Peter Noble, Matthew

Pritchard, and Chuck Steube of Conoco; Sean Barr, Tom Bauer, Chris Broussard, andKent Longridge of Halliburton KBR; Alp Kocaman of J. Ray McDermott; Scott McClure

of Allen C. McClure Associates, Inc.; TerryBoatman, Marty Krafft, and Allen Liu ofFMC-SOFEC; Det Norkse Veritas (DNV) for their Mimosa software; and Zentech for

their StabCAD and StruCAD software.


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CHAPTER 1 Introduction

Background

Senior Ocean Engineering students at Texas A & M University are required to complete a seniordesign course before graduation. The spring 2002 senior design class is to design a close-coupledspar/FpSO floating production system for deepwater Gulf of Mexico locations. The objective of the designis to create a cost effective solution for producing small to medium offshore oil fields, containing 100 to

300 million barrels of oil equivalent (MMBOE). A spar platform was chosen to support dry trees andconduct first stage production. Gas removed during this production process is re-injected into the well.From there, the partially produced oil is to be transferred to the FpSO for further production and storage.

The lower case p in FpSO is to indicate that only partial production is completed on the FpSO. Crewquarters are to be placed upon the FpSO away from the dangers of high-pressure first stage production.The entire system is to rely on one mooring system, on the spar platform, facilitated through a yoke

connection between the spar and FpSO. The yoke system must account for mooring load transfer, crew

transfer, and fluid transfer. The yoke also allows the FpSO to weathervane 360? about the spar in order toreduce the loads on the mooring system by station keeping to bow seas. Since no oil or gas pipelines

currently exist in deepwater, shuttle tankers are used to take the oil into port off the FpSO and the high-pressure gas is reinjected into the well. The other well byproducts, such as water and sediment, are alsoreinjected into the well. The use of shuttle tankers allows the oil to enter the mainland United States at a

variety of ports. The overall design criteria for our project is outlined in Table 1-1 below. The yoke teamwill concentrate on general arrangement/system design, weight, global loading, general strength andstructural design, cost, regulatory compliance, environmental loading, and a structural analysis.

Table 1-1. Overall Design Criteria for Close-Coupled System (Conoco, 2002a).

Approximate Field Capacity 150 MMBOE

Estimated Production Rate 55,000 BOPD

Water Depth 1433 m (4700 ft)

Number of Risers 8 ( 9 riser wells )

Type of well tree Dry

Offtake System Shuttle Tanker ( No existing pipelines )

Production on Spar 1st Stage Only

Production on FpSO All Post 1st Stage

Location of Crew Quarters FpSO ( Away from high pressure gas separation )

YokeWeathervane 360?

Oil Transfer (55,000 BOPD)

Crew Transfer

Location

The floating production system is being designed for production in the Gulf of Mexico. Conocosprospective field is located on the edge of the continental shelf in 1433 m (4700 feet) of water as shown in

Figure 1-1. The field is a medium yield field of 150 MMBOE, with an expected 55,000 barrels of oil perday (BOPD).


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Figure 1-1. Design Location of Conocos Prospective Field in the Gulf of Mexico (NOAA, 2002).

Environmental Conditions

Conoco supplied environmental condition specifications for this design. A single environmentalsurvival condition is being used for the design. Since this is a production facility, it has a required design

life of 15 to 20 years. For this reason, the 100-year Gulf of Mexico hurricane conditions have been chosen.Table 1-2 contains a list of wind, wave, and current data that must be considered in the design.

Table 1-2. Characteristics of Gulf of Mexico 100 Year Hurricane Conditions (Conoco, 2002b).

100 year Hurricane Wind 46.8 m/s ( 1 min. speed at 10 m ) 90.9 kts

100 year Current

-Surface to 100 m depth 1.1 m/s 2.1 kts

-Below 100 m depth 0.2 m/s 0.4 kts

100 year Significant Wave

-Significant Wave Height 12.3 m 40.1 ft

-Significant Wave Period 12 s 12 s

The data shown in the above table was obtained from Met-Ocean data, which was provided by

Conoco. Met-Ocean criteria also required this data to be applicable to the 360? weathervaning capabilities

of the FpSO. The full weathervaning of the FpSO about the spar is necessary because of the lack of apredominant wind direction for this location in the Gulf of Mexico. Figure 1-2 illustrates the speed,direction, and percentage of occurrence of the substantial winds that have occurred at this location. Since

the dominant environmental force is the wind load, all forces are assumed to ac in the same direction.


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Figure 1-2. Illustration of Multi-Directional Wind Patterns (Conoco, 2002a).

OrganizationThe senior design class is made up of 18 students. The class was broken into three groups of six.

Each group has performed the design on a different portion of the system. The spar group is made up ofAaron Horine, Gennine Krautkremer, Scott Murrah, Chad Petrash, Wes Rains, and Clay Thompson. The

FpSO design group is Robert Adair, David Batcheler, Adam Dushinske, Jacqueline Gutierrez, GuadalupeReachi, and Matt White. Finally, the yoke groups members are Michelle Arango-Martinez, JamieArmstrong, Donald Burris, Christopher Ordonez, Birgitte Rossabo, and Jefferson Stanford. The three

groups have been in constant communication to ensure the best possible total system design. A furtherbreakdown of the responsibilities of each member in the groups is discussed in the respective sections ofthis report. The yoke group had to coordinate a flow of information from the other two teams.

Environmental forces had to be constantly updated from FpSO calculations to ensure the yoke could handlethe load. The yoke also had to adapt to size changes of the spar and FpSO. Information was also given bythe yoke team, such as weight and attachment requirements.


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CHAPTER 2 Yoke System Design

Yoke System Overview

The yoke design group has strived to engineer solutions to closely connect or couple aweathervaning FpSO and a moored spar platform. Challenges that must be overcome in designing thissystem include force transfer, fluid transfer, as well as crew transfer between the two vessels. Figure 2-1

gives a general arrangement of the overall final yoke design system. The following paragraphs detail eachportion of the yoke design.

Figure 2-1. Overall General Arrangement.

The yoke group began the project by identifying major design areas in the project. Afterwards,work was divided between the various members to ensure an efficient design process. Jamie Armstrong

and Jefferson Stanford took on the task of creating a force transfer design, using StruCAD to complete thestructural analysis. Donald Burris and Chris Ordonez developed initial concepts of fluid transfer, and

proceeded to fully design the concepts to meet pertinent regulations such as API RP 14E (API 2000).Donald Burris used the same standards to calculate flow assurance and transfer hose design. Chris Ordonezalso aided Michelle Arango in design specifications for crew transfer. To round out the design, BirgitteRossabo tracked project cost and environmental loading.

FpSO Spar


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Force Transfer

Structure

Force transfer components of the yoke are constructed of structural steel in accordance withregulations set fourth by the American Institute of Steel Construction in the Load and Resistance FactoredDesign (LRFD) (AISC 2000). The American Petroleum Institute in API RP 2A-LRFD (API 1996) calls for

these structural specifications. The yoke acts as both a tension and compression structure whiletransferring load from the floating FpSO to the moored spar, and is designed using the LRFD regulationsgoverning such structural members.

The FpSO design team has calculated that an inline bow environmental live load of 226 tonnes(500 kips) act on the FpSO during a 100-year hurricane event. This environmental force considers noshielding from the spar. LRFD regulations state that 1.6 times the live load must be used as the minimum

design load in a steel structure to account for fatigue loading. Therefore, based on the LRFD standards, aminimum design load of 362 tonnes (800 kips) must be used for member size determination. Due to thepossibility of catastrophic environmental consequences in the event of failure of the close-coupled system,

a factored design load of 725 tonnes (1600 kips) was used in member design for added safety.The design load is assumed to act through one side of the force transfer yoke to adequately design

for the worst-case condition of fish tailing by the FpSO. Figure 2-2 shows a layout of the structural

members of the force transfer system.

Figure 2-2. Force Transfer Yoke.

Cylindrical HSS (Hollow Structural Section) 20 X 0.75 members have been chosen to carry the

load through the force transfer yoke from one vessel to the other. Members were chosen based oncalculations performed using procedures and techniques outlined in the LRFD manual for design of tension

and compression members. Structural analysis was also performed on several different designs using thecomputer program StruCAD, a structural analysis software package. HSS 20 X 0.75 members have designtension rupture strength of 468 tonnes (1032 kips). Using the double member construction shown in Figure

2-2, a factor of safety of 1.55 per member in the damaged, or worse case condition, and an overall safetyfactor of 2.58 in the fully functional intact condition. HSS 20 X 0.75 member properties are given in Table2-1. The total yoke is comprised of 250 m (821 ft) of total steel, yielding a total weight of 58 tonnes (130

kips), as shown in Table 2-2.


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Table 2-1. HSS 20X 0.75 Member Properties.

HSS 20 X 0.75 (LRFD Third Edition)

Diameter 0.508 m 20 in

Thickness 0.019 m 0.75 inGross Area: 0.0184 m 28.5 in

Weight / unit length 0.235 tonnes/m 158 lb/ft

Design Strength: Tension Yielding 435 tonnes 960 Kips

Design Strength: Tension Rupture 468 tonnes 1032 Kips

Design Compression Limit 570 tonnes 1260 Kips

Table 2-2. Force Transfer Weights.

Total MemberLengths (m)

Weight (tonnes/m) Total Weight(tonnes)

Total Weight(Kips)

250 0.235 58.75 130

This design enables the yoke to withstand an angle of inclination of 34o, at which point a

transverse brace located 8.7 m (24.6 ft) from the spar hull will contact the crew transfer ramp above. Thelayout and transverse brace are shown in Figure 2-3. In order for the yoke to achieve such a large angle ofinclination, the FpSO would have to heave 89 feet from its equilibrium position. Such a large heave

motion will not occur in the Gulf of Mexico during a 100-year hurricane. The estimated maximumfreeboard change plus heave motions of the FpSO are estimated to be 9 m (29-ft) in amplitude. This

motion only permits a maximum angle of inclination of 17.2?; therefore the yoke will not impact the crew

transfer ramp attached to the deck above. The yoke can with stand a maximum roll angle of 26o. Down

flooding of the FpSO begins at an angle of 18o. After an 18? roll, water begins to flood the FpSO. Sincethe FpSO is designed to never reach this point, the yoke allows for more than enough roll.


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Figure 2-3. General Layout, Force Transfer (units in m).

Force Transfer Connection to Spar: Large Diameter Bearing

The yoke arm connects to a 30.67 m (100 ft) diameter bearing, similar to the one shown in Figure2-4. Large diameter bearings such as these have been proven effective in the field in the form of internalturret mooring bearings on FPSOs. The Barracuda P-34 FPSO is currently under construction with a 100-

foot diameter internal turret, as shown in Figure 2-4. These bearings have proven to provide efficient forcedistribution as well as smooth weathervane ability. The bearing assembly is mounted a distance of 0.91 m(3 ft) from the spar hull to allow mooring lines to pass up the spar hull from the fairleads to the chain

winches. A layout can be seen in Figure 2-5.


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Figure 2-4. Machining of the Barracuda P-34 FPSO Internal Turret Bearing (Courtesy FMC SOFEC).

Figure 2-5. Detail View of Force Transfer Bearing.

The large diameter bearing allows the FpSO to weathervane 360o around the spar, keeping theFpSO bow into environmental forces. This assumes a collinear environment in which current, wind, andwave forces all act in the same direction. The pin connections to the high load bearing transfers load from

the FpSO through the yoke to the spar, allows for heave motions of both vessels simultaneously, and allowsfor changes in FpSO freeboard due to the loading/offloading of oil and supplies. As shown in Table 2-3,the bearing has a total weight of 100 tonnes (220 kips).


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Table 2-3. Force Transfer Bearing Weights.

Volume (m^3) Weight (tonnes)

Bearing Top 0.8 6

Bearing Bottom 0.8 6

Bearing Sides 4.97 38

Rollers 19 50

Total 25.57 100

Force Transfer Connection to FpSO: Rigid Connection

The force transfer yoke is pin connected to large gusset plates rigidly attached to the FpSO bow.These pin connections, along with the pin connected transverse brace, allow opposite sides of the yoke tomove counter to each other in a scissor type motion, allowing the FpSO to roll in the environment. It was

first believed that universal joints must be used in place of pin connections on the bow to accommodateFpSO roll, however a physical model was built to view and better understand the hydrodynamic motionsthe yoke must undergo relative to the spar, and it was found that connections that rotate only in a vertical

plane will be sufficient. Universal joints capable of the large loads that this system must endure are verylarge and costly to manufacture. One-dimensional rotating hinges dramatically cut down on cost andmaintenance. Rotating connections must be located in the vicinity of the pin connection to relieve torsion

in the yoke when one side moves counter to the other during FpSO roll. Otherwise, fatigue loading due toroll-induced torsion could be a mode of failure. FMC SOFEC has used torsion connections in yokesystems in the field with great success, such as in their tower yoke system used in Bohai Bay, China, shown

in Figure 2-7. This system takes flow from multiple production units in the bay and transfers oil to an FSO.The sphere between the gusset plates shown in Figure 2-6 represents the pin and torsion connection.Rotator joints found in the market could be readily adapted to this application.

Figure 2-6. Yoke Connection to FpSO.

FpSO Bow


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Hinge

Universal Joints

Torsion Hinges

Figure 2-7. Torsion Hinge In Yoke System (Photo Courtesy of FMC SOFEC).

Structural Analysis Results

A structural analysis was performed on the force transfer yoke components using the

environmental forces the FpSO receives in a collinear 100-year hurricane event. StruCAD uses finiteelement analysis to analyze forces and reactions on a model specified by the user. This program was usedto optimize the yoke design, shape, and placement of truss type supports within the structure. Several

design iterations of the yoke were used in a trial and error fashion before an optimal shape was achieved.This optimal design uses straight cylindrical members to minimize deflections and transfer load. Completeoutput from the analysis is contained in the appendix for member reactions, forces, moments, and shear

forces developed due to the application of the 725 tonnes (1600 kips) FpSO load. A maximum memberunity check of 0.823 occurs due to induced moments and shear stresses on various members. The unitycheck is used as a maximum check of yielding. Values greater than one should be interpreted as a structure

failure. A member-by-member unity check is shown in Figure 2-8.


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Figure 2-8. StruCAD Unity Check.

Physical Model

A physical model of the original yoke design was constructed in order to view the hydrodynamicmotions the yoke had to withstand. Figure 2-9 through Figure 2-13 show the motions at different stages.

The model contained in the figures is an early design. It was later found that the yoke could be bestdesigned with straight members. Figure 2-9 shows the yoke in the equilibrium position. The bar at the

right of the figure represents the rigid FpSO bow. The large diameter bearing mounted on the spar isrepresented in our physical model on the left by the bicycle wheel labeled spar bearing. This bearingallows the FpSO to weathervane in any environment. Hinges located at various points in the yoke allowthe structure to flex and allow the FpSO and spar to heave, pitch, yaw and roll relative to each other.


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FpSOBow

Hinge

Spar Bearing

Figure 2-9. Force Transfer Model Overview.

Figure 2-10 shows the motions of the yoke in heave. The FpSO bow at the right moves upwardwhile the spar with its relatively low heave motions is assumed to s tay essentially in one position. Hinges at

the connection to the spar allow the yoke to rotate and maintain the connection between the two vessels.Hinges located at the FpSO bow allow the vessel to pitch about its center of gravity as the heave motiontakes place.

FpSOBow

Spar Bearing

Connection

Hinge

Figure 2-10. Force Transfer Model in Heave.


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Figure 2-11 shows the yoke motions as the FpSO rolls in waves. The member at the upper edge ofFigure 2-11 has the ability to move relative to the lower member, allowing the scissor motion of the yoke

and allowing roll of the vessels relative to one another. The cross member acts as a brace support againstbuckling when axially loading the yoke. The hinge attachment of the cross member allows movementwhile preserving its bracing ability.

FpSO Bow inroll motion

Spar Bearing Connection

Cross Member Support

Torsion Connection

Figure 2-11. Force Transfer Model in Roll.

In the equilibrium position with no vessel roll, the torsion hinge within the member is shown inFigure 2-12. Figure 2-13 shows the torsion hinge in position as the ship undergoes roll motions, as

evidenced by the offset line. This line is the product of a paint scratch made over both sides of the torsionhinge in equilibrium position. This hinge is needed to relieve torsion within the yoke and avoid failure dueto repeated loading of the yoke in the offshore environment as the vessels roll. Torsion hinges such as

these have been used in many yoke systems in the offshore industry for years. Figure 2-14 shows a close-up of the torsion hinge used in the soft yoke designed by FMC SOFEC for Chinas Bohai Bay.


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Torsion Hinge within member:Equilibrium State

Figure 2-12. Force Transfer Model of Torsion Joint in Equilibrium

Torsion Hinge within member:Torsion State with ship roll

Figure 2-13. Force Transfer Model of Torsion Joint in Roll.

Paint Scratch

Paint Scratch


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Figure 2-14. FMC SOFECs Soft Yoke Mooring Tower in Bohai Bay, China.

This solution of force transfer satisfies the need for a 360o weathervane capability while allowing

for full hydrodynamic motions between the two vessels. This system is adequate to maintain a coupling

system between the two vessels, and successfully maintain this linkage during a 100-year hurricane event.It is our recommendation that a full hydrodynamic motions and model test be completed to get a complete

overview of the full design requirements for a site-specific system. This may also allow for reductions inFpSO loading due to environmental shielding.

Fluid Transfer

The two main concepts investigated for fluid transfer were an oil transfer ring and a wrapping hosesystem. The wrapping hose system involves the use of flexible hoses for oil transfer, requiring manual

connection and disconnection. The oil ring transfer system involves a new idea in fluid transfer. Bothconcepts have their own merits and are discussed in the following paragraphs. A third concept was calledthe overhead oil track, that is based on an adaptation of proven swivel technology for use in transferring oil,

but it was not pursued due to several problems. First, the swivel stack and transfer lines had to be high

enough to clear every item on the spar deck. It must be suspended above the work over rig, flare tower,and cranes. Also, a secondary ring had to be sufficiently large in diameter to encircle a lower topside spar

deck to allow for the rotating pipe to freely rotate about the decks, and go around the cranes. If no addedsupport at a lower elevation had been provided, the flow line would tend to take a catenary shape, allowingfor possible crane contact. Figure 2-15 provides a conceptual drawing of this concept.


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Figure 2-15. Conceptual Drawing of Overhead Oil Track.

As evidenced in Figure 2-15, the flare tower was also an issue, since it could burn the track if it

was activated. Upper deck reconfiguration of the spar would have been necessary and would have created

a large weight high in the air. Since wind speed increases with height, a large moment would be generatedby the placement of equipment at this height, causing potential problems in equilibrium and stability.

Therefore, this concept development was halted and more focus was given to the wrapping hose and oiltransfer ring systems.

Wrapping Hose Fluid Transfer

The wrapping hose oil transfer concept, Figure 2-16, consists of two dual-hose systems onopposite sides of the spar platform that can alternately be connected to the FpSO given the vessels

orientation. Each set of flexible hoses is supported by swinging W14 x 38 horizontal beams, extending27.4 m (90 ft) from the spar hull. The double-hose feature allows for a contingency if one hose can nolonger operate. At the end of the beam, the hoses hang from a small vertically adjustable crane hook and

connect to the bow of the FpSO. A lazy W type device is at the edge of the beam to ease transition of the

flow line from horizontal to vertical. The crane hook also attaches to the bow to act as a tension cable inorder to limit the stresses on the flexible pipe. The hoses are 129 m (425 ft) long, the circumference of the

spar hull with additional length for transport across the gap to the connections on the FpSO, allowing forexcessive rotation before connection of the opposite hose set must be made.

The hoses require a crewmember to connect and disconnect them from the FpSO at all times.

Also, a crewmember must lower and raise the hoses with the crane hook during the hose switch, and mustreel the hoses back onto their spools. Two connection sets on the bow of the FpSO allows for continualflow as one set is disconnected only after the other is connected and flowing. This is a standard procedure

used by industry for a number of years and is similar to operations required for FPSO offloading. A closeup view of the crane hook and tension cable system can be seen in Figure 2-17.


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Figure 2-16. Wrapping Hose Oil Transfer.

Figure 2-17. Close-up of Wrap Hose Support.


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Each supporting arm consists of the above horizontal I-beam holding the hoses at top deck level,and an angle brace, made from a W10 x 33 beam 23.5m (67 ft) long, and a support column mounted to the

sides of the three decks of the spar. The flexible hoses are fed through a reel system located on the deck.Again, this is similar to FPSO offload systems.

Given that this oil transfer concept does not rotate about the central axis of the spar hull, it requires

continuous attention for hose changes and it cannot provide unmanned operation. This is a systemlimitation, since shut-in of the wells and hose disconnection must occur before the crew can leave in asevere weather event.

Oil Transfer Ring

The second developed concept of fluid transfer is an oil transfer ring. This ring is around the spar

in a collar fashion, similar to the bearing discussed above in the force transfer design. It also has a 0.914-m(3 ft) gap from the spar hull to allow for mooring lines. The ring is 0.305 m (1 ft) deep, with an additional0.305 m (1 ft) gap to the outer hull. The ring is 0.305 m (1 ft) wide, with the same gap to the outer hull.

The tank will hold 43 barrels of oil at a time. This size was selected to ensure continuous oil transfer atmaximum production of 60,000 barrels of oil per day. This air gap contains oil sensors to protect againstleakage situations. All parts are made of 12.7 mm (0.5 in) steel. Figure 2-18 details the general layout of

the concept.

Figure 2-18. Overview of Fluid Transfer System.

Since first-stage production is completed on the spar, the fluid can be piped down the side of thespar and into the tank through a hard connection at atmospheric pressure. The lid of the tank rests upon

bearings, so that it can rotate as a ring around the spar as the FPSO weathervanes. A pump is on top of the

rotating lid above the tangential connection of the force transfer arm. A backup pump is located on theopposite side of the lid in order to have redundancy. This second pump would be used to maintain

production if the primary pump fails. A dip tube running below the pump taps into the oil reserve topump it out of the tank and into a hard pipe connection over to the FpSO. Figure 2-19 provides a crosssection of the tank.

FpSO

Spar


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2-16

Figure 2-19. Cross Section of Oil Transfer Ring.

Hard pipes transfer oil down 0.610 m (2 ft) from the oil transfer tank to the force transfer

connections. Flexible hoses transfer fluid along the force transfer yoke arms to the FpSO deck. Weightcalculations are in Table 2-4, with a total concept weight of 38.79 tonnes (87 kips). The oil ring holds 43barrels of oil. Figure 2-20 shows the dimensions of the oil transfer ring.

Table 2-4. Weight of Oil Transfer Ring.

Volume (m3) Weight (tonnes)

Transfer Ring Body 3.23 24.81

Transfer Ring Lid 0.71 5.36

Oil Entrained 9.51 8.62Total 13.45 38.79


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2-17

Figure 2-20. Oil Transfer Ring Dimensions (units in m).

Flow Assurance

In either fluid transfer concept, a 21.6 cm (8.5 in) outside diameter flexible hose with 0.64 cm

(0.25 in) thick walls was selected to meet API RP 14E codes. A spreadsheet courtesy of FMC SOFEC(Boatmen 2002) was used to aid in hose design. The spreadsheet is based on API RP 14E (API 2000) codeand facilitates a rapid design and check process. At 55,000 barrels of oil per day, the pipe has a flow

velocity of 3.4 m/s (11.2 ft/s), resulting in 4.7 m3/min (166 ft3 /min) of oil transfer. The 3E-143J Type BIMO Pump can deliver the required flow rate. It is an electric driven, single stage, screw pump capable ofcontinuous operation. It was chosen over other pumps for its compact size, continuous operation, and low

maintenance requirements. In hard piping areas, steel pipes with dimensions identical to the flexible hosesare used. By using the same dimensions, coupling of the hoses is easier than if a size conversion coupling

had to be used. The hoses and pumps specified can accommodate a maximum of 65,000 BOPD. If higherflow rate is desired, larger hoses must be used. The oil transfer ring would also need to increase in size toaccommodate a larger capacity.

Crew Transfer

The purpose of the crew transfer system is to move personnel continuously between the FpSO andthe spar using a suspended ramp. The ramp is connected to the front of the FpSOs crew quarters on a

stationary platform. Figure 2-21 shows the placement of the crew transfer ramp. The FpSO platform has alength of 4.4 m (14.5 ft) and 3 m (9.8 ft) wide. The crew can access this platform by a door located directlyin front of the ramp leading into the crew quarters. The ramp spans 47.3 m (155 ft) from the FpSO to the

spar with a width of 2.13 m (7 ft) and a thickness of 1.26 cm (0.5 in). The ramp then is connected to theother end into another stationary platform mounted to the bottom of the spars lowest deck or bottom deck.


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2-18

Figure 2-21. Crew Transfer Deck Dimensions (units in m).

The ramp has a fixed pin connection on the spar side and a tracked pin connection on the FpSO

side to allow for hydrodynamic motions. This pinned connection is linked to a rotating track. The spar endof the ramp rotates about the stationary platform with the FpSO. The spar stationary platform is circular,and it is suspended from the bottom of the first deck. It has an inner diameter of 30.5 m (100 ft) and an

outer diameter of 34.5 m (113 ft). The circular platform is 1.98 m (6.5 ft) wide and 0.64 cm (.25 in) thick.This circular platform surrounds the spar deck legs and also leaves sufficient space for the mooring systemand any other objects that may be coming from top decks to lower decks. 12-vertical I-beams (each welded

to supporting horizontal I-beams and to the bottom of the lowest deck) hold the platform 3 m (10 ft) belowthe deck and 21.3 m (70 ft) above the waterline.

At the FpSO connection, the ramp is pinned to a track that allows horizontal movement. This

negates compressive loads on the ramp due to surge and heave of the FpSO. The track is mounted to theoutside of a small platform attach to the crew quarters which is 15.5 m (51 ft) above the deck and 22 m

(72.2 ft) above the waterline. Given the freeboard variation of 4.6 m (15 ft), an estimated FpSO heave of3.6 m (11.8 ft), and the bow moving 0.05 m (0.2 ft) closer to the spar during heave, the ramp only moves0.04 m (0.15 ft) horizontally, but the track allows 0.5 m (1.6 ft) of motion. This allows for more thanadequate compensation.

The estimated maximum ramp inclination when the FpSO is in operation is ?3.6?. When it goes

through a 100-year hurricane condition the expected angle of inclination is ?24.7?. This would cause thebow to move 3.6 m (11.8 ft) closer to the spar and the ramp would move 0.74 m (2.5 ft). To accommodate

roll, the ramp has a torsion relief joint and a horizontal hinge that rotates in the horizontal plane, both nearthe FpSO connection. A close up of these connections can be seen in Figure 2-22. The torsion relief jointconsists of a rotating axle parallel to the ramp that connects ramp sections and allows the structure to twist

with minor roll motions of the FpSO. Flexible covers to ensure the safety of the personnel cover theconnections between the FpSO platform and the ramp, the spar platform and ramp, and the torsion relief

joint and horizontal hinge.


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2-19

Figure 2-22. Crew Transfer Ramp Connection.

A chain-link fence encloses the ramp on all sides for safety. It prevents crewmembers from falling

off the ramp and it prevent falling objects from contacting crew members. Also, a stationary chain-linkfence on the interior of the platform and a rotating chain-link fence (moving with the ramp and FpSO) onthe exterior, each 3 m (10 ft) tall, hold the crew safely. In compliance with the Occupational Safety and

Health Administration (OSHA 1998) a safety railing system of more than 1.07 m (3.5 ft) in height had to be

placed along the walkway. The railing also rotates with the exterior fence and has adequate lighting. Allthe fences are corrosion resistant. Four ladders, spaced around the platform, provide access to the working

decks. OSHA 1998 requirements were investigated in depth for guidelines with respect to walkwaysbetween two structures over water. It specifies that there may be no suspended load over the ramp whilepeople are on it. The crew transfer system weighs 41 tonnes (87 kips), and the individual components are

tabulated in Table 2-5.

Table 2-5. Weight of Crew Transfer System.

Component

Weight(tonnes)

Weight(kips)

Ramp 10.0 22.2

Spar Crew Transfer Deck 10.1 22.2

FpSO Platform 6.3 14.0

FpSO Connection Track 4.2 9.3

Crew 4.1 6.0

Fence 5.9 13.0

TOTAL 40.6 86.7


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2-20

Master Equipment List

Following is a listing of major system components. They are broken down into three main

categories: force transfer, fluid transfer, and crew transfer. This listing includes only major components ofeach.

?? Force Transfer:

o Bearing around spar

o 2 HSS 20 X 0.75 main yoke armso HSS 20 X 0.75 cross support

o 2 Torsion Relief Jointso 2 Hinge connections (To bearing)o 2 Gusset plates (for mounting to FpSO)

?? Fluid Transfer:o Oil Transfer Ring:

?? Circular tank around spar

?? 2 pumps

?? 2 Flexible flow lines across yoke arms

?? Floating Sealso Wrapping Hose System:

?? 2 Support arms

?? 4 flexible flow lines?? 2 winches

?? 2 Tension cables

?? 2 Tension connectors

?? 6 Storage reels (4 for flow lines, 2 for tension cables)

?? Crew Transfer:o Crew transfer deck around sparo Circular track connected to spar

o Ramp

o Connection track into FpSO crew quarterso Torsion Relief Joint in rampo Safety Fences, railings

Environmental Loading

Environmental loading typically includes wind, wave, and current forces. In Chapter 1, Table 1-1details the 100-year storm data. However, this yoke system is high enough above the water level to avoid

effects due to waves and current. Even though the yoke is theoretically always bow into the wind, andreceive shielding from the spar, both bow and beam forces were calculated for design considering noshielding. Calculations of wind force effect on each portion of the yoke system can be seen in Table 2-6.

The yoke system receives a total force 172 kN (39 kips) in the beam, and 61 kN (14kips) in bow direction.These force values are valid for the system when the oil transfer ring is used. If the wrapping hose is usedinstead, the force values change to 168 kN (38 kips) in beam, and 61 kN (14 kips) in bow. Loads were

provided o the spar group to be included in mooring system design.

.


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2-21

Table 2-6. Environmental Loading On the Yoke System.

Wind Force Vw= 46.8 m/s

Section Cs Ch A (Beam m^2) AChCs

Parallel stiffening beam 0.50 0.0 0.0

Beams on the s ides 0.50 1.00 914.0 457.0

Beam from FPSO 0.50 1.00 108.0 54.0

Beam parallel to FPSO 0.50 1.00 0.0 0.0

Oil transfer 0.50 1.00 120.0 60.0

Floor, crew transfer 1 1.23 0.0 0.0

Rails, crew transfer 0.60 1.23 930.0 686.3

Supporting beams 1 1.23 96.0 118.1

Sum (AChCs) 1375.4

F 172.1 kN

Yoke System Cost

Minimizing cost has been an overall objective for the entire project. A design currently exists inwhich a 2 km distance separates the spar and FpSO. To transfer oil between structures, a mid-water

insulated flow line had to be designed, at a cost of $15 million (Conoco 2002) that has been itemized inTable 2-7. Flow line cost is based on length required in each design, and information was obtained throughpersonal communications (Mekha 2002). Cost of safety railings, fences, and gates were obtained from the

Derenzo Fence Company website (DFC 2002). The total material and construction cost of the yoke systemusing the oil ring is $10.4 million. The total cost using the wrapping hose concept is $13.6 million. Thissystem is $20 million less than a traditional mid-water flow line.

Table 2-7. Cost Breakdown for Yoke Components.

Component Unit Cost Amount Cost ($)

Force TransferBearing $7,700,000 1 7,700,000

Structure $12,000 /MT 38.7 464,400

Connections $50,000 ea. 6 300,000

Total 8,464,400

Crew TransferConnections $50,000 ea 4 200,000

Materials $12,000 /MT 24 290,765

Gates, Fence 94,893

Total 585,658

Oil Transfer RingPumps $150,000 ea 2 300,000

Ring $15,000 / MT 29 435,000Flow lines $300,000 ea 2 600,000

Total 1,335,000

Wrapping Hose Fluid TransferStructure (Steel) $12,000 /MT 56 669,720

Pumps $150,000 ea 2 300,000

Flow Lines $825,000 ea 4 3,300,000

Total 4,564,483


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2-22

Design Conclusions and Recommendations

The largest variable in the yoke system is how to transfer fluid. The oil ring provides the greatestbenefit to the overall system. It moves the weight of oil transfer to a lower area of the spar, having lessnegative effects on ship motions, and allows for continuous unmanned operation. The seals required by the

tank are a limit, but it is highly feasible that they can be made. Industry has provided indication that a sealsimilar to an API floating roof on an oil storage tank could be adapted for this use. The use of the wrappinghose oil transfer requires the system to be manned at all times, thereby limiting the system. However, the

wrapping hose system does use proven technology. The yoke system with oil transfer conducted throughthe transfer ring still has a greater overall benefit than the wrapping hose oil transfer system. It isrecommended that a full hydrodynamic motions study and a model test of the coupled system be completed

for site specific conditions to get a complete picture of the behavior of the system. Costs could possibly bereduced by getting more accurate environmental force numbers for the coupled system. Regardless of whatfluid transfer system is used, this design provides a viable solution to creating a close-coupled spar and

FpSO system. The concept is economically feasible, as well as technically viable. Further work shouldinclude an investigation of having all hinges in the system, located on both the crew transfer ramp and theforce transfer yoke, parallel in the vertical plane. This alignment may lead to more favorable motion in the

yoke, with movement of all parts at the same time. A total yoke system, that provides transfer of force,

crew, and oil using the oil ring, can be built for a cost of only $10.4 million, saving $22 million over a mid-water flow line.


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3-1

CHAPTER 3 Executive Summary

The eighteen Ocean Engineering students of the Texas A&M University 2002 Ocean Engineeringsenior design class feel that the close-coupled Spar/FpSO floating production system shown in Figure 3-1 isa technically viable solution for offshore oil production of intermediate size fields. A summary of design

criteria is outlined in Table 3-1. Table 3-2 details the 100-year hurricane design environment conditions.Conoco volunteered to sponsor the class to help design a system with a 20-year design life, operating at55,000 BOPD in 1433 m (4700 ft) of water in the Gulf of Mexico.

Figure 3-1. Overall Close-Coupled Floating Production System.

Table 3-1. Summary of Overall Design Criteria for Close-Coupled System.

Approximate Field Capacity 150 MMBOE

Estimated Production Rate 55,000 BOPD

Water Depth 1433 m (4700 ft)

Design Location Gulf of Mexico

Design Environment 100-year Hurricane

Table 3-2. Gulf of Mexico 100-Year Hurricane Design Environment.

100 year Hurricane Wind 46.8 m/s ( 1 min. speed at 10 m ) 90.9 kts100 year Current

-Surface to 100 m depth 1.1 m/s 2.1 kts

-Below 100 m depth 0.2 m/s 0.4 kts

100 year Significant Wave

-Significant Wave Height 12.3 m 40.1 ft

-Significant Wave Period 12 s 12 s


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3-2

A critical component of this floating production system is the yoke coupling that brings it alltogether. Yoke componets can be seen in Figure 3-2. Oil transfer from the spar to the FpSO is the most

difficult design aspect. The oil ring provides the greatest benefit to the overall system and is therecommended concept. It moves the weight of oil transfer to a low area of the spar, having little negativeeffects on hydrodynamic motions, and allows for continuous unmanned operation. The seals required by

the tank are a limit, but it is believed that they can be manufactured. Industry has provided indication that aseal similar to an API floating roof on an oil storage tank could be adapted for this use. The use of thewrapping hose oil transfer requires the system to be manned at all times, thereby limiting the system.

However, the wrapping hose system does use proven technology. It is recommended that a fullhydrodynamic motion study and a model test of the coupled system be conducted for site-specificconditions to get a complete picture of the behavior of the system.

Figure 3-2. Yoke Components

Crew members are able to traverse between the two vessels. The crew transfer ramp is connected

into the side of the crew quarters on the FpSO bow so that the crew does not have to move about the FpSOin order to go to the spar. If the cranes have any suspended load over the crew ramp, the ramp must beclosed. The only other limitation to when the ramp can be used is during severe weather. While it has been

designed to withstand a 100-year hurricane, it is impractical for the human body to make the crossing

during those conditions. Regardless of what fluid transfer system is used, this design provides a viablesolution to creating a close-coupled spar and FpSO system. The concept is economically feasible, as well

as technically viable. Further work should include an investigation of having all hinges in the systemlocated on both the crew transfer ramp and the force transfer yoke, parallel in the vertical plane. Thisalignment may lead to more favorable motion in the yoke, with movement of all parts at the same time. A

total yoke system, that provides transfer of force, crew, and oil using the oil ring, can be built for anestimated cost of $10 million.

This system satisfies the design objective of coupling a spar and FpSO in a joint floating

production system that relies on one mooring system, while preserving the FpSO ability to weathervane. Itis designed to meet ABS and API guidelines. Coast Guard regulations, OSHA standards, and OPA 90 have

FpSO

Spar


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3-3

all been followed to ensure safety. Table 3-3 shows the cost of each portion of the system, and the totalproject cost has been estimated at $392 million.

Table 3-3. Estimated Total Project Cost.

System Cost (M$)

Spar 212FpSO System 170

Yoke Connection 10

Total 392

A cost comparison of the close-coupled Spar/FpSO system with an existing system is illustrated inTable 3-4. The existing system consisted of a full production spar with light/medium workload, a FloatingStorage and Offloading vessel (FSO), with a mid-water flow line transporting the produced fluid between

the two vessels. There is an approximate separation of 2 km between the Spar and FSO. Table 3-2 shows acost savings of approximately $65,000,000 for the close-coupled system compared to a typical system inuse today.

Table 3-4. Cost Comparison of Existing Mid-Water Flowline System and New Close-CoupledSystem.

System ComponentExisting/ New

Mid-Water Flowline System(M$)

Close-Coupled System(M$)

Spar / Spar 250 212

FSO / FpSO 174 170

MW Flowline / Yoke 33 10

Total Cost (M$) 457 392

One difficulty encountered during the project was design integration. This project is the firstexposure to working on a project so large, where different groups are each designing components of the

same system. However, the completion of this project has provided a rewarding experience, and many

lessons have been learned. Learning how important communication is throughout the design spiral is quitepossibly the most important lesson learned. All students involved have gained an understanding of a large-

scale real world engineering design process.The entire design team recommends that model testing be conducted to prove the viability of the

design described in this report. A clear understanding of force and structure interaction may allow for

smaller, less costly design modifications. It is hard to account for environmental shielding effects, and anycurrent anomalies that may result from wave passing the spar. There are also other uses of the system yetto be explored. Since part of production and the crew quarters have been removed from the spar, it may be

possible to have more extensive drilling equipment on the spar. The work over rig used in this designcould potentially be replaced with a fully functional derrick allowing for extensive drilling capabilities.This could alleviate the need for the use of a separate drilling vessel to drill extra wells. It has been proven

technically viable that the close coupling of a spar and FpSO can provide a cost effective dry tree solutionthat supports deep and ultra-deep water oil and gas production at a cost benefit over existing systems .


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4-1

CHAPTER 4 References

American Institute of Steel Construction (AISC). Load Resistance Factored Design (LRFD) Manual ofSteel Construction - Third Edition; American Institute of Steel Construction; 2001.

American Petroleum Institute (API), API RP -14E, Design and Installation of Offshore Production PlatformPiping Systems, Fifth Edition. Washington, D.C., October 1, 1991, Reaffirmed, June 2000.

American Petroleum Institute (API), API RP-2SK, Design and Analysis of Station keeping Systems forFloating Structures, Second Edition, December 1996. Washington, D.C., 1996.

American Petroleum Institute (API), API RP 2A-LRFD, Planning, Designing And Constructing FixedOffshore Platforms -- Load And Resistance Factor Design, Washington, D.C., 1996.

Boatman, Terry, FMC SOFEC, Personal Communications, 2002.

Conoco, Met-Ocean Environmental Criteria, 2002a.

Conoco, Personal Communication, 2002b.

Derenzo Fence Company (DFC), http://www.derenzofence.com/. Wire Fence Cost. April 4, 2002.

Mekha, Basim, Intec Engineering, Personal Communications, March 2002.

NOAA, http://www.ngdc.noaa.gov/mgg/ibcca/images/1234sh.jpg, 2002.

Occupation Safety Health Administration (OSHA) Codes, Federal Register, 1998.


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A-1

Appendix A Calculations and Example StruCAD Analysis

Design of tension members

Assume: round HSS 20 X 0.5 for a required factored design strength of 1600 kips transferredfrom FpSO to spar through the yoke connection.

Assume: end connection to gusset plate has a length = 68 inches and is a fillet-welded inthick. (Connection length = width of gusset plate)

From Table 3-5 of LRFD Steel Design Manual, HSS 20 X 0.5 properties:Ag = gross area = 28.5 in2Tdesign = design thickness = 0.465 in

R = radius of gyration = 6.91 in

Fy = yield strendth = 42 ksiFu = ultimate strength = 58 ksiX = dist to axis

Design Strength of HSS 20 X 0.5 is tabulated to be 1080 kipsFactored design load through a double member construction = 800 kips < 1080 o.k.

For tension rupture, the HSS 20 X 0.5 design strength with Ae= 0.75Ag is tabulated as 931 kips.From HSS Specification Section 2.1,

20

6.366

Dx?

?

?

?

?

1 0.9x

Ul

? ? ?

6.366168

? ?

0.906?


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A-2

Allowing for a 116

inch gap in fit-up between the HSS and the gusset plate,

2

12( )16

128.5 2(3 )0.46516

25.65

n g gusset HSSA A t in t

in

? ? ?

? ? ?

?

0.9(25.65)

23.08

e nA UA?

?

?

9310.75

23.08931

0.75(28.5)

1005

et n

g

AP

A

kips

?? ?

? ? ?

? ?? ?

? ?? ? ?

? ?

?

Rupture Strength o.k.

max

max

300

6.91300

12

172 max_ _ _

L r

inL

inft

ft braced member length

?

? ?

? ??

? ?? ?? ?

? ?

Slenderness o.k.

Conclusion: HSS 20 X 0.5 member is adequate to take the 1600 kip design load.


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A-3

Design of Compression Members

K= reduction factor based on end restraints of member

L= effective length of member in controlling axis

KL=0.65*30ft=19.5

From Table 4-7 of LRFD for HSS 20 X 0.5 compression members gives a design compressionstrength of 950 kips.

Compression o.k.


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A-4

Example StruCAD Structural Analysis

Structural Analysis using Computer Program StruCAD led to the use of HSS 20 X 0.75 members due to unity

checks. Included are StruCAD input (Appendix Table A-1) and output files (Appendix Table A -2).

Table A-1. StruCAD Program Specifics.

* * * Units Definition * * *

* Description * * Input Units * * Output Units *

A. Joint Information

1. Joint Coordinates ............. . Ft Ft2. Joint Settlements .......... .... In In

Joint Translations

B. Structure Description

3. All Lengths, Heights & Depths .. Ft Ft

Joint Thickness, Area Centroids4. Projected Areas ......... ....... Ft^2 Ft^25. Volumes ........ ......... ....... Ft^3 Ft^3

C. Element Properties

6. Element Offsets ................ In In7. Element Dimensions ............. In In

Rebar Area and SpacingMarine Growth Thickness

8. Element Cross Section Areas .... In^2 In^29. Element Moment of Inertia ...... In^4 In^4

D. Material Properties & Stresses

10. Steel E & G Modulus ............ 1000KSI 1000KSI

11. All Stresses ................ ... KSI KSISteel And Concrete Strength12. Material Density ........... .... PCF PCF

E. Spring Constants

13. Rotational Spring Constant ..... In-Kips/Rad In-Kips/Rad14. Translational Spring Constant .. Kips/In Kips/In

F. Load Data

15. Concentrated Loads & Weights ... Kips Kips16. Uniform Loads & Weights ........ Kips/Ft Kips/Ft17. Concentrated Moments ......... .. In-Kips In-Kips18. Uniform Moments ................ In-Kips/Ft In-Kips/Ft19. Weight Moment of Inertia ....... Kips-Ft^2 Kips-Ft^220. Load Distances .......... ....... Ft Ft

21. Pressures .......... .......... .. PSF PSF22. Wind & Current Velocity ........ Knots Knots23. Wave Velocity ............ ...... Ft/Sec Ft/Sec24. Wave Acceleration .............. Ft/Sec^2 Ft/Sec^225. Kinematic Viscosity ............ Ft^2/Sec Ft^2/Sec26. Response Curve Acceleration .... G's G's27. Response Curve Velocities ...... In/Sec In/Sec28. Response Curve Displacements ... In In

G. Soil Data And Pile Forces

29. Soil Friction, Soil Force ...... Kips/In Kips/In


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A-5

30. Soil Moments ......... ......... . In-Kips/In In-Kips/In31. Undrained Shear Strength ....... KSF KSF

* * * Load Generation Options * * *

Density of Seawater ( PCF ) .......... ....... 64.20

Density of Structural Steel ( PCF ) ......... 490.00

Density of Structural Concrete ( PCF ) ...... 150.00

Density of Enclosed Material ( PCF ) ........ 0.00

Density of Encasing Material ( PCF ) ........ 0.00

Density of Grout ( PCF ) ........... ......... 150.00

Density of Marine Growth ( PCF ) .......... .. 0.00


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A-6

Table A-2. StruCAD Input File.

ALPID 3D View 0.707 0.707 -0.424 0.424 0.800 1ALPID Global XY Pl 10.000 10.000ALPID Global YZ Pl 10.000 10.000

ALPID Global XZ Pl 10.000 10.000ALEAT TRS 11 111ALEAT JEF 1000 1000ALJAT FIX 111111ALJAT PIN 111000ALJAT RFX 000111ALJAT TRS 111111ALJAT FX1 111100ALPREF 3D View 0.0 0.0 0.75 G 107TITLEOPTIONS SA9 2 PTPTPT PT PT PTLDOPTUNITI UGRUP YOK 20.0 .750 50. 104.MEMBER 15 16 YOK .7501.001.00MEMBER 2 1 YOK .7501.001.00

MEMBER 5 22 YOK .7501.001.00MEMBER 22 2 YOK .7501.001.00MEMBER 1 21 YOK .7501.001.00MEMBER 21 6 YOK .7501.001.00MEMBER 16 23 YOK .7501.001.00MEMBER 24 11 YOK .7501.001.00MEMBER 12 23 YOK .7501.001.00MEMBER 15 24 YOK .7501.001.00MEMBER 11 3 YOK .7501.001.00MEMBER 3 8 YOK .7501.001.00MEMBER 8 9 YOK .7501.001.00MEMBER 9 14 YOK .7501.001.00MEMBER 14 17 YOK .7501.001.00MEMBER 17 18 YOK .7501.001.00MEMBER 18 13 YOK .7501.001.00MEMBER 13 10 YOK .7501.001.00MEMBER 10 7 YOK .7501.001.00

MEMBER 7 4 YOK .7501.001.00MEMBER 4 12 YOK .7501.001.00MEMBER 4 3 YOK .7501.001.00MEMBER 6 19 YOK .7501.001.00MEMBER 19 26 YOK .7501.001.00MEMBER 26 27 YOK .7501.001.00MEMBER 27 30 YOK .7501.001.00MEMBER 30 31 YOK .7501.001.00MEMBER 31 32 YOK .7501.001.00MEMBER 32 29 YOK .7501.001.00MEMBER 29 28 YOK .7501.001.00MEMBER 28 25 YOK .7501.001.00MEMBER 25 20 YOK .7501.001.00MEMBER 20 5 YOK .7501.001.00MEMBER 20 19 YOK .7501.001.00MEMBER 19 33 YOK .7501.001.00MEMBER 33 3 YOK .7501.001.00MEMBER 20 34 YOK .7501.001.00MEMBER 34 4 YOK .7501.001.00MEMBER 33 34 YOK .7501.001.00MEMBER 31 17 YOK .7501.001.00MEMBER 32 18 YOK .7501.001.00MEMBER 22 21 YOK .7501.001.00MEMBER 23 24 YOK .7501.001.00MEMBER 28 27 YOK .7501.001.00MEMBER 10 9 YOK .7501.001.00MEMBER 26 35 YOK .7501.001.00MEMBER 35 8 YOK .7501.001.00


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A-7

MEMBER 25 36 YOK .7501.001.00MEMBER 36 7 YOK .7501.001.00MEMBER 36 35 YOK .7501.001.00MEMBER 6 5 YOK .7501.001.00MEMBER 29 30 YOK .7501.001.00MEMBER 25 26 YOK .7501.001.00MEMBER 13 14 YOK .7501.001.00MEMBER 7 8 YOK .7501.001.00

MEMBER 12 11 YOK .7501.001.00MEMBER 30 28 YOK .7501.001.00MEMBER 28 26 YOK .7501.001.00MEMBER 26 20 YOK .7501.001.00MEMBER 20 6 YOK .7501.001.00MEMBER 14 10 YOK .7501.001.00MEMBER 10 8 YOK .7501.001.00MEMBER 8 4 YOK .7501.001.00MEMBER 4 11 YOK .7501.001.00MEMBER 32 30 YOK .7501.001.00MEMBER 18 14 YOK .7501.001.00MEMBER 21 2 YOK .7501.001.00MEMBER 24 16 YOK .7501.001.00MEMBER 35 33 YOK .7501.001.00MEMBER 36 34 YOK .7501.001.00MEMBER 6 22 YOK .7501.001.00MEMBER 11 23 YOK .7501.001.00

JOINT 1 105.000169.000 0.000 0.912 5.844 111111JOINT 2 105.000169.000 2.000 0.912 5.844 8.004 111111JOINT 5 105.000129.000 2.000 0.912 5.844 8.004JOINT 6 105.000129.000 0.000 0.912 5.844JOINT 11 220.000129.000 0.000 11.004 5.844JOINT 12 220.000129.000 2.000 11.004 5.844 8.004JOINT 15 220.000169.000 0.000 11.004 5.844 111111JOINT 16 220.000169.000 2.000 11.004 5.844 8.004 111111JOINT 21 105.000149.000 0.000 0.912 5.844JOINT 22 105.000149.000 2.000 0.912 5.844 8.004JOINT 23 220.000149.000 2.000 11.004 5.844 8.004JOINT 24 220.000149.000 0.000 11.004 5.844JOINT 3 220.000109.000 0.000 11.004 5.844JOINT 4 220.000109.000 2.000 11.004 5.844 8.004JOINT 7 220.000 89.000 2.000 11.004 5.844 8.004JOINT 8 220.000 89.000 0.000 11.004 5.844JOINT 9 220.000 69.000 0.000 11.004 5.844JOINT 10 220.000 69.000 2.000 11.004 5.844 8.004JOINT 13 220.000 49.000 2.000 11.004 5.844 8.004JOINT 14 220.000 49.000 0.000 11.004 5.844JOINT 17 220.000 29.000 0.000 11.004 5.844JOINT 18 220.000 29.000 2.000 11.004 5.844 8.004JOINT 19 105.000109.000 0.000 0.912 5.844JOINT 20 105.000109.000 2.000 0.912 5.844 8.004JOINT 25 105.000 89.000 2.000 0.912 5.844 8.004JOINT 26 105.000 89.000 0.000 0.912 5.844JOINT 27 105.000 69.000 0.000 0.912 5.844JOINT 28 105.000 69.000 2.000 0.912 5.844 8.004JOINT 29 105.000 49.000 2.000 0.912 5.844 8.004JOINT 30 105.000 49.000 0.000 0.912 5.844JOINT 31 105.000 29.000 0.000 0.912 5.844JOINT 32 105.000 29.000 2.000 0.912 5.844 8.004JOINT 33 162.000109.000 0.000 11.964 5.844

JOINT 34 162.000109.000 2.000 11.964 5.844 8.004JOINT 35 162.000 89.000 0.000 11.964 5.844JOINT 36 162.000 89.000 2.000 11.964 5.844 8.004WGHTCN 1LOADCN 1LOAD 17 0.000-800.00 0.000 0.000 0.000 0.000 GLOB JOINLOAD 18 0.000-800.00 0.000 0.000 0.000 0.000 GLOB JOINLOAD 31 0.000-800.00 0.000 0.000 0.000 0.000 GLOB JOINLOAD 32 0.000-800.00 0.000 0.000 0.000 0.000 GLOB JOINLOAD Z 5 22 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 5 22 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 22 2 -0.0400 -0.0400 GLOB UNIF OIL LOAD


43/60

A-8

LOAD Z 22 2 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 16 23 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 16 23 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 12 23 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 12 23 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 18 13 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 13 10 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 10 7 -0.0400 -0.0400 GLOB UNIF OIL LOAD

LOAD Z 7 4 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 4 12 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 32 29 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 29 28 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 28 25 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 25 20 -0.0400 -0.0400 GLOB UNIF OIL LOADLOAD Z 20 5 -0.0400 -0.0400 GLOB UNIF OIL LOADEND


44/60

A-9

Table A-3. StruCAD Output File.

* * * Joint Deflection Report * * *

Joint Load /------------- Deflections (In) ------------/ /------------- Rotations (Rad) -------------/ID Case X Y Z X Y Z

1 1 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000

2 1 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000

3 1 -0.0007839 -0.2958739 -0.7905315 0.0025803 0.0000550 0.0000307

4 1 0.0008237 -0.3783063 -0.7913431 0.0026009 0.0000499 0.0000241

5 1 0.0022289 -0.2569396 0.0936406 0.0020313 -0.0000353 -0.0000011

6 1 0.0033628 -0.1920655 0.0944513 0.0020625 -0.0000355 0.0000003

7 1 -0.0008198 -0.4945064 -1.1531875 0.0029046 -0.0000563 -0.0000327

8 1 0.0008276 -0.4016070 -1.1523636 0.0029207 -0.0000513 -0.0000247

9 1 -0.0029273 -0.5110606 -2.1931254 0.0030761 -0.0000391 -0.0000049

10 1 -0.0041825 -0.6094384 -2.1939360 0.0030865 -0.0000393 -0.0000035

11 1 -0.0033627 -0.1920654 0.0944513 0.0020625 0.0000355 -0.0000003

12 1 -0.0022288 -0.2569396 0.0936405 0.0020313 0.0000353 0.0000011

13 1 -0.0030995 -0.7218783 -2.6333563 0.0031285 -0.0000239 0.0000098

14 1 -0.0023370 -0.6214728 -2.6325674 0.0031513 -0.0000238 0.0000089

15 1 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000

16 1 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000

17 1 0.0001230 -0.7353315 -3.7204742 0.0031444 -0.0000082 0.0000111

18 1 -0.0001407 -0.8339724 -3.7209027 0.0035123 -0.0000089 0.0000119

19 1 0.0007841 -0.2958739 -0.7905314 0.0025803 -0.0000550 -0.0000307

20 1 -0.0008234 -0.3783063 -0.7913429 0.0026009 -0.0000499 -0.0000241

21 1 0.0017048 -0.0913837 0.1676469 0.0008171 -0.0000167 0.0000093

22 1 0.0011452 -0.1329831 0.1667877 0.0008891 -0.0000183 0.0000082

23 1 -0.0011452 -0.1329831 0.1667877 0.0008891 0.0000183 -0.0000082

24 1 -0.0017048 -0.0913837 0.1676469 0.0008171 0.0000167 -0.0000093

25 1 0.0008201 -0.4945064 -1.1531872 0.0029046 0.0000563 0.0000327

26 1 -0.0008273 -0.4016070 -1.1523633 0.0029207 0.0000512 0.0000247

27 1 0.0029274 -0.5110606 -2.1931250 0.0030761 0.0000391 0.0000049

28 1 0.0041826 -0.6094384 -2.1939357 0.0030865 0.0000393 0.0000035

29 1 0.0030995 -0.7218783 -2.6333559 0.0031285 0.0000238 -0.0000098


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A-10

30 1 0.0023370 -0.6214728 -2.6325670 0.0031513 0.0000238 -0.0000089

31 1 -0.0001231 -0.7353315 -3.7204737 0.0031444 0.0000082 -0.0000111

32 1 0.0001406 -0.8339724 -3.7209021 0.0035123 0.0000089 -0.0000119

33 1 0.0000001 -0.3536060 -0.6846610 0.0024172 0.0000000 0.0000000

34 1 0.0000002 -0.4310276 -0.6846612 0.0024179 0.0000000 0.0000000

35 1 0.0000002 -0.3534406 -1.2595078 0.0024335 0.0000000 0.0000000

36 1 0.0000001 -0.4312657 -1.2595080 0.0024330 0.0000000 0.0000000

Max. Def. 0.0041826 -0.8339724 -3.7209027 0.0035123 -0.0000563 -0.0000327Joint No. 28 18 18 18 7 7Load Case 1 1 1 1 1 1

* * * Member Detail Report * * *

Dist MaxMember GRP Load From Force *Bending Moment* *Shear Force* Torsion Axial Bending Stress Comb. Shear Comb.JA- JB ID Case End Fx My Mz Fy Fz Mx Stress Y Z Stress Stress Unity

(Ft) (Kips ) /-- (In-Kips) --/ /-- (Kips ) -/ (In-Kips) /------------ ( KSI ) -----------/ Check

15- 16 YOK 1 0.0 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.0001 1.3 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.000 S1 2.7 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.000

2- 1 YOK 1 0.0 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.0001 1.3 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.000 S1 2.7 0.00 0.0 0.0 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 0.000

5- 22 YOK 1 0.0 679.36 -2085.0 3.8 -0.01 15.49 3.5 14.98 9.91 0.02 24.89 0.69 0.8001 10.0 679.36 -274.4 2.4 -0.01 14.69 3.5 14.98 1.30 0.01 16.28 0.66 0.5391 20.0 679.36 1440.2 0.9 -0.01 13.89 3.5 14.98 -6.84 0.00 21.82 0.62 0.707

22- 2 YOK 1 0.0 728.83 -1996.3 -1.1 -0.01 15.29 3.7 16.07 9.49 -0.01 25.56 0.68 0.8231 10.0 728.83 -210.0 -2.1 -0.01 14.49 3.7 16.07 1.00 -0.01 17.07 0.65 0.5661 20.0 728.83 1480.2 -3.1 -0.01 13.69 3.7 16.07 -7.03 -0.01 23.10 0.61 0.749

1- 21 YOK 1 0.0 500.84 1481.1 6.1 -0.03 -14.07 3.4 11.04 -7.04 0.03 18.08 0.63 0.5811 10.0 500.84 -207.7 2.4 -0.03 -14.07 3.4 11.04 0.99 0.01 12.03 0.63 0.3981 20.0 500.84 -1896.6 -1.3 -0.03 -14.07 3.4 11.04 9.01 -0.01 20.06 0.63 0.641

21- 6 YOK 1 0.0 551.80 1414.5 0.9 -0.03 -14.43 3.8 12.17 -6.72 0.00 18.89 0.65 0.6091 10.0 551.80 -316.6 -2.3 -0.03 -14.43 3.8 12.17 1.50 -0.01 13.67 0.65 0.4511 20.0 551.80 -2047.8 -5.5 -0.03 -14.43 3.8 12.17 9.73 -0.03 21.90 0.65 0.700

16- 23 YOK 1 0.0 728.83 1480.2 -3.1 0.01 -13.69 -3.7 16.07 -7.03 -0.01 23.10 0.61 0.7491 10.0 728.83 -210.0 -2.1 0.01 -14.49 -3.7 16.07 1.00 -0.01 17.07 0.65 0.5661 20.0 728.83 -1996.3 -1.1 0.01 -15.29 -3.7 16.07 9.49 -0.01 25.56 0.68 0.823

24- 11 YOK 1 0.0 551.80 1414.5 -0.9 0.03 -14.43 -3.8 12.17 -6.72 0.00 18.89 0.65 0.6091 10.0 551.80 -316.6 2.3 0.03 -14.43 -3.8 12.17 1.50 0.01 13.67 0.65 0.4511 20.0 551.80 -2047.8 5.5 0.03 -14.43 -3.8 12.17 9.73 0.03 21.90 0.65 0.700

12- 23 YOK 1 0.0 679.36 -2085.0 -3.8 0.01 15.49 -3.5 14.98 9.91 -0.02 24.89 0.69 0.8001 10.0 679.36 -274.4 -2.4 0.01 14.69 -3.5 14.98 1.30 -0.01 16.28 0.66 0.5391 20.0 679.36 1440.2 -0.9 0.01 13.89 -3.5 14.98 -6.84 0.00 21.82 0.62 0.707

15- 24 YOK 1 0.0 500.84 1481.1 -6.1 0.03 -14.07 -3.4 11.04 -7.04 -0.03 18.08 0.63 0.5811 10.0 500.84 -207.7 -2.4 0.03 -14.07 -3.4 11.04 0.99 -0.01 12.03 0.63 0.3981 20.0 500.84 -1896.6 1.3 0.03 -14.07 -3.4 11.04 9.01 0.01 20.06 0.63 0.641


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A-11



11- 3 YOK 1 0.0 568.93 -2215.5 1.1 0.06 17.37 -4.0 12.54 10.53 0.01 23.07 0.78 0.7371 10.0 568.93 -131.7 7.9 0.06 17.37 -4.0 12.54 0.63 0.04 13.17 0.78 0.4371 20.0 568.93 1952.2 14.6 0.06 17.37 -4.0 12.54 -9.28 0.07 21.82 0.78 0.699

3- 8 YOK 1 0.0 579.48 1809.5 -8.3 -0.05 -15.80 21.6 12.78 -8.60 -0.04 21.38 0.75 0.6861 10.0 579.48 -86.5 -14.1 -0.05 -15.80 21.6 12.78 0.41 -0.07 13.19 0.75 0.4381 20.0 579.48 -1982.5 -19.8 -0.05 -15.80 21.6 12.78 9.42 -0.09 22.20 0.75 0.711

8- 9 YOK 1 0.0 599.87 -2080.8 3.8 0.01 17.01 -2.5 13.23 9.89 0.02 23.11 0.76 0.7411 10.0 599.87 -39.5 5.0 0.01 17.01 -2.5 13.23 0.19 0.02 13.41 0.76 0.4471 20.0 599.87 2001.8 6.3 0.01 17.01 -2.5 13.23 -9.51 0.03 22.74 0.76 0.729

9- 14 YOK 1 0.0 605.13 1937.6 4.2 -0.01 -16.31 -3.1 13.34 -9.21 0.02 22.55 0.73 0.7241 10.0 605.13 -19.1 3.5 -0.01 -16.31 -3.1 13.34 0.09 0.02 13.43 0.73 0.4481 20.0 605.13 -1975.9 2.8 -0.01 -16.31 -3.1 13.34 9.39 0.01 22.73 0.73 0.729

14- 17 YOK 1 0.0 624.01 -2111.2 0.9 0.00 17.61 -3.2 13.76 10.03 0.00 23.79 0.78 0.7631 10.0 624.01 1.8 0.6 0.00 17.61 -3.2 13.76 -0.01 0.00 13.77 0.78 0.4591 20.0 624.01 2114.7 0.2 0.00 17.61 -3.2 13.76 -10.05 0.00 23.81 0.78 0.763

17- 18 YOK 1 0.0 -17.61 2114.7 2.4 -0.24 -175.99 1.2 -0.39 -10.05 0.01 -10.44 7.76 0.388 S1 1.3 -17.61 -701.4 -1.3 -0.24 -175.99 1.2 -0.39 3.33 -0.01 -3.72 7.76 0.388 S1 2.7 -17.61 -3517.5 -5.1 -0.24 -175.99 1.2 -0.39 16.72 -0.02 -17.11 7.76 0.520

18- 13 YOK 1 0.0 614.34 1733.9 1.7 -0.02 -15.00 -3.0 13.54 -8.24 0.01 21.79 0.67 0.7011 10.0 614.34 -89.6 -0.5 -0.02 -15.40 -3.0 13.54 0.43 0.00 13.97 0.69 0.4641 20.0 614.34 -1961.0 -2.8 -0.02 -15.80 -3.0 13.54 9.3 2 -0.01 22.86 0.70 0.734

13- 10 YOK 1 0.0 616.24 -1974.1 -1.3 -0.02 16.63 -3.1 13.59 9.38 -0.01 22.97 0.74 0.7371 10.0 616.24 -2.7 -3.4 -0.02 16.23 -3.1 13.59 0.01 -0.02 13.61 0.72 0.4541 20.0 616.24 1920.7 -5.5 -0.02 15.83 -3.1 13.59 -9.13 -0.03 22.71 0.71 0.730

10- 7 YOK 1 0.0 629.90 1983.3 -1.1 -0.05 -16.65 -3.5 13.89 -9.43 -0.01 23.31 0.74 0.7491 10.0 629.90 -38.3 -7.4 -0.05 -17.05 -3.5 13.89 0.18 -0.04 14.07 0.76 0.4691 20.0 629.90 -2107.8 -13.7 -0.05 -17.45 -3.5 13.89 10.02 -0.07 23.91 0.78 0.766

7- 4 YOK 1 0.0 636.85 -1992.5 10.6 0.03 16.23 21.6 14.04 9.47 0.05 23.51 0.77 0.7551 10.0 636.85 -69.2 14.4 0.03 15.83 21.6 14.04 0.33 0.07 14.38 0.75 0.4781 20.0 636.85 1806.1 18.3 0.03 15.43 21.6 14.04 -8.58 0.09 22.62 0.73 0.728




4- 12 YOK 1 0.0 665.16 1931.2 -5.6 0.00 -17.03 -3.0 14.67 -9.18 -0.03 23.84 0.76 0.7671 10.0 665.16 -136.8 -5.8 0.00 -17.43 -3.0 14.67 0.65 -0.03 15.32 0.78 0.5091 20.0 665.16 -2252.8 -6.0 0.00 -17.83 -3.0 14.67 10.71 -0.03 25.37 0.79 0.813

4- 3 YOK 1 0.0 -33.35 -209.6 -15.5 1.59 10.65 -10.0 -0.74 1.00 -0.07 -1.73 0.50 0.0551 1.3 -33.35 -39.2 9.9 1.59 10.65 -10.0 -0.74 0.19 0.05 -0.93 0.50 0.0311 2.7 -33.35 131.3 35.3 1.59 10.65 -10.0 -0.74 -0.62 0.17 -1.38 0.50 0.044

6- 19 YOK 1 0.0 568.93 -2215.5 -1.1 -0.06 17.37 4.0 12.54 10.53 -0.01 23.07 0.78 0.7371 10.0 568.93 -131.7 -7.9 -0.06 17.37 4.0 12.54 0.63 -0.04 13.17 0.78 0.4371 20.0 568.93 1952.2 -14.6 -0.06 17.37 4.0 12.54 -9.28 -0.07 21.82 0.78 0.699

19- 26 YOK 1 0.0 579.48 1809.5 8.3 0.05 -15.80 -21.6 12.78 -8.60 0.04 21.38 0.75 0.6861 10.0 579.48 -86.5 14.1 0.05 -15.80 -21.6 12.78 0.41 0.07 13.19 0.75 0.4381 20.0 579.48 -1982.5 19.8 0.05 -15.80 -21.6 12.78 9.42 0.09 22.20 0.75 0.711


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A-12

26- 27 YOK 1 0.0 599.87 -2080.8 -3.8 -0.01 17.01 2.5 13.23 9.89 -0.02 23.11 0.76 0.741

1 10.0 599.87 -39.5 -5.0 -0.01 17.01 2.5 13.23 0.19 -0.02 13.41 0.76 0.4471 20.0 599.87 2001.8 -6.3 -0.01 17.01 2.5 13.23 -9.51 -0.03 22.74 0.76 0.729

27- 30 YOK 1 0.0 605.13 1937.6 -4.2 0.01 -16.31 3.1 13.34 -9.21 -0.02 22.55 0.73 0.7241 10.0 605.13 -19.1 -3.5 0.01 -16.31 3.1 13.34 0.09 -0.02 13.43 0.73 0.4481 20.0 605.13 -1975.9 -2.8 0.01 -16.31 3.1 13.34 9.39 -0.01 22.73 0.73 0.729

30- 31 YOK 1 0.0 624.01 -2111.2 -0.9 0.00 17.61 3.2 13.76 10.03 0.00 23.79 0.78 0.7631 10.0 624.01 1.8 -0.6 0.00 17.61 3.2 13.76 -0.01 0.00 13.77 0.78 0.4591 20.0 624.01 2114.7 -0.2 0.00 17.61 3.2 13.76 -10.05 0.00 23.81 0.78 0.763

31- 32 YOK 1 0.0 -17.61 2114.7 -2.4 0.24 -175.99 -1.2 -0.39 -10.05 -0.01 -10.44 7.76 0.388 S1 1.3 -17.61 -701.4 1.3 0.24 -175.99 -1.2 -0.39 3.33 0.01 -3.72 7.76 0.388 S1 2.7 -17.61 -3517.5 5.1 0.24 -175.99 -1.2 -0.39 16.72 0.02 -17.11 7.76 0.520

32- 29 YOK 1 0.0 614.34 1733.9 -1.7 0.02 -15.00 3.0 13.54 -8.24 -0.01 21.79 0.67 0.7011 10.0 614.34 -89.6 0.5 0.02 -15.40 3.0 13.54 0.43 0.00 13.97 0.69 0.4641 20.0 614.34 -1961.0 2.8 0.02 -15.80 3.0 13.54 9.32 0.01 22.86 0.70 0.734

29- 28 YOK 1 0.0 616.24 -1974.1 1.3 0.02 16.63 3.1 13.59 9.38 0.01 22.97 0.74 0.7371 10.0 616.24 -2.7 3.4 0.02 16.23 3.1 13.59 0.01 0.02 13.61 0.72 0.4541 20.0 616.24 1920.7 5.5 0.02 15.83 3.1 13.59 -9.13 0.03 22.71 0.71 0.730




28- 25 YOK 1 0.0 629.90 1983.3 1.1 0.05 -16.65 3.5 13.89 -9.43 0.01 23.31 0.74 0.7491 10.0 629.90 -38.3 7.4 0.05 -17.05 3.5 13.89 0.18 0.04 14.07 0.76 0.4691 20.0 629.90 -2107.8 13.7 0.05 -17.45 3.5 13.89 10.02 0.07 23.91 0.78 0.766

25- 20 YOK 1 0.0 636.85 -1992.5 -10.6 -0.03 16.23 -21.6 14.04 9.47 -0.05 23.51 0.77 0.7551 10.0 636.85 -69.2 -14.4 -0.03 15.83 -21.6 14.04 0.33 -0.07 14.38 0.75 0.4781 20.0 636.85 1806.1 -18.3 -0.03 15.43 -21.6 14.04 -8.58 -0.09 22.62 0.73 0.728

20- 5 YOK 1 0.0 665.16 1931.2 5.6 0.00 -17.03 3.0 14.67 -9.18 0.03 23.84 0.76 0.7671 10.0 665.16 -136.8 5.8 0.00 -17.43 3.0 14.67 0.65 0.03 15.32 0.78 0.5091 20.0 665.16 -2252.8 6.0 0.00 -17.83 3.0 14.67 10.71 0.03 25.37 0.79 0.813

20- 19 YOK 1 0.0 -33.35 -209.6 15.5 -1.59 10.65 10.0 -0.74 1.00 0.07 -1.73 0.50 0.0551 1.3 -33.35 -39.2 -9.9 -1.59 10.65 10.0 -0.74 0.19 -0.05 -0.93 0.50 0.0311 2.7 -33.35 131.3 -35.3 -1.59 10.65 10.0 -0.74 -0.62 -0.17 -1.38 0.50 0.044

19- 33 YOK 1 0.0 -1.48 60.9 -33.0 0.10 -0.19 -11.5 -0.03 -0.29 -0.16 -0.36 0.04 0.0121 29.0 -1.48 -4.8 2.7 0.10 -0.19 -11.5 -0.03 0.02 0.01 -0.06 0.04 0.0031 57.9 -1.48 -70.6 38.4 0.10 -0.19 -11.5 -0.03 0.34 0.18 -0.41 0.04 0.014

33- 3 YOK 1 0.0 -1.48 -70.6 38.4 -0.10 0.19 11.5 -0.03 0.34 0.18 -0.41 0.04 0.0141 29.0 -1.48 -4.8 2.7 -0.10 0.19 11.5 -0.03 0.02 0.01 -0.06 0.04 0.0031 57.9 -1.48 60.9 -33.0 -0.10 0.19 11.5 -0.03 -0.29 -0.16 -0.36 0.04 0.012

20- 34 YOK 1 0.0 1.56 63.3 -31.5 0.10 -0.19 -12.9 0.03 -0.30 -0.15 0.37 0.04 0.0111 29.0 1.56 -4.4 2.1 0.10 -0.19 -12.9 0.03 0.02 0.01 0.06 0.04 0.002 S1 57.9 1.56 -72.1 35.7 0.10 -0.19 -12.9 0.03 0.34 0.17 0.42 0.04 0.013

34- 4 YOK 1 0.0 1.56 -72.1 35.7 -0.10 0.19 12.9 0.03 0.34 0.17 0.42 0.04 0.0131 29.0 1.56 -4.4 2.1 -0.10 0.19 12.9 0.03 0.02 0.01 0.06 0.04 0.002 S1 57.9 1.56 63.3 -31.5 -0.10 0.19 12.9 0.03 -0.30 -0.15 0.37 0.04 0.011

33- 34 YOK 1 0.0 -0.01 -19.0 0.0 0.00 1.11 0.0 0.00 0.09 0.00 -0.09 0.05 0.0031 1.3 -0.01 -1.2 0.0 0.00 1.11 0.0 0.00 0.01 0.00 -0.01 0.05 0.002 S1 2.7 -0.01 16.6 0.0 0.00 1.11 0.0 0.00 -0.08 0.00 -0.08 0.05 0.002 S


48/60

A-13

31- 17 YOK 1 0.0 0.23 0.7 1.0 0.00 0.00 0.0 0.01 0.00 0.00 0.01 0.00 0.0001 57.9 0.23 0.7 1.0 0.00 0.00 0.0 0.01 0.00 0.00 0.01 0.00 0.0001 115.8 0.23 0.7 1.0 0.00 0.00 0.0 0.01 0.00 0.00 0.01 0.00 0.000


Dist Max

Member GRP Load From Force *Bending Moment* *Shear Force* Torsion Axial Bending Stress Comb. Shear Comb.JA- JB ID Case End Fx My Mz Fy Fz Mx Stress Y Z Stress Stress Unity(Ft) (Kips ) /-- (In-Kips) --/ /-- (Kips ) -/ (In-Kips) /------------ ( KSI ) -----------/ Check

32- 18 YOK 1 0.0 -0.27 0.8 1.0 0.00 0.00 0.0 -0.01 0.00 0.00 -0.01 0.00 0.0021 57.9 -0.27 0.8 1.0 0.00 0.00 0.0 -0.01 0.00 0.00 -0.01 0.00 0.0021 115.8 -0.27 0.8 1.0 0.00 0.00 0.0 -0.01 0.00 0.00 -0.01 0.00 0.002

22- 21 YOK 1 0.0 -35.31 4973.3 3.4 -0.02 -319.37 -1.7 -0.78 -23.64 0.02 -24.41 14.09 0.7421 1.3 -35.31 -137.3 3.1 -0.02 -319.37 -1.7 -0.78 0.65 0.01 -1.43 14.09 0.704 S1 2.7 -35.31 -5247.9 2.8 -0.02 -319.37 -1.7 -0.78 24.94 0.01 -25.72 14.09 0.782

23- 24 YOK 1 0.0 -35.31 4973.3 -3.4 0.02 -319.37 1.7 -0.78 -23.64 -0.02 -24.41 14.09 0.7421 1.3 -35.31 -137.3 -3.1 0.02 -319.37 1.7 -0.78 0.65 -0.01 -1.43 14.09 0.704 S1 2.7 -35.31 -5247.9 -2.8 0.02 -319.37 1.7 -0.78 24.94 -0.01 -25.72 14.09 0.782

28- 27 YOK 1 0.0 -33.32 -103.9 -0.1 -0.02 5.25 -2.1 -0.73 0.49 0.00 -1.23 0.24 0.040

1 1.3 -33.32 -19.9 -0.4 -0.02 5.25 -2.1 -0.73 0.09 0.00 -0.83 0.24 0.0281 2.7 -33.32 64.2 -0.6 -0.02 5.25 -2.1 -0.73 -0.31 0.00 -1.04 0.24 0.034

10- 9 YOK 1 0.0 -33.32 -103.9 0.1 0.02 5.25 2.1 -0.73 0.49 0.00 -1.23 0.24 0.0401 1.3 -33.32 -19.9 0.4 0.02 5.25 2.1 -0.73 0.09 0.00 -0.83 0.24 0.0281 2.7 -33.32 64.2 0.6 0.02 5.25 2.1 -0.73 -0.31 0.00 -1.04 0.24 0.034

26- 35 YOK 1 0.0 1.57 -63.2 27.8 -0.09 0.19 -34.2 0.03 0.30 0.13 0.36 0.09 0.0111 29.0 1.57 4.5 -2.2 -0.09 0.19 -34.2 0.03 -0.02 -0.01 0.06 0.09 0.005 S1 57.9 1.57 72.2 -32.2 -0.09 0.19 -34.2 0.03 -0.34 -0.15 0.41 0.09 0.013

35- 8 YOK 1 0.0 1.57 72.2 -32.2 0.09 -0.19 34.2 0.03 -0.34 -0.15 0.41 0.09 0.0131 29.0 1.57 4.5 -2.2 0.09 -0.19 34.2 0.03 -0.02 -0.01 0.06 0.09 0.005 S1 57.9 1.57 -63.2 27.8 0.09 -0.19 34.2 0.03 0.30 0.13 0.36 0.09 0.011

25- 36 YOK 1 0.0 -1.55 -60.8 36.4 -0.11 0.19 -33.1 -0.03 0.29 0.17 -0.37 0.09 0.0131 29.0 -1.55 4.9 -2.9 -0.11 0.19 -33.1 -0.03 -0.02 -0.01 -0.06 0.09 0.004 S1 57.9 -1.55 70.7 -42.2 -0.11 0.19 -33.1 -0.03 -0.34 -0.20 -0.43 0.09 0.014

36- 7 YOK 1 0.0 -1.55 70.7 -42.2 0.11 -0.19 33.1 -0.03 -0.34 -0.20 -0.43 0.09 0.0141 29.0 -1.55 4.9 -2.9 0.11 -0.1

good yoke design

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