This document discusses DNV Marine Operations' rules for subsea lifting. It provides an overview of relevant DNV publications and describes the capacity checks outlined in the 1996 rules for lifting operations. The document then introduces a new simplified method for calculating hydrodynamic forces during subsea lifts, which will be included in an upcoming DNV recommended practice. This method makes simplifying assumptions and provides equations to estimate forces like slamming impacts and varying buoyancy in a conservative manner.
This document provides a summary and disclaimer for Noble Denton Marine Services. It states that Noble Denton provides marine warranty survey services to evaluate marine operations for insurance purposes. It should be read together with other DNVGL standards that describe Noble Denton's marine warranty survey process. The document disclaims any liability if the client's project scope does not encompass needs or fit for purpose. It also states that industry knowledge and experience must be applied throughout marine operations in addition to using DNVGL standards.
This document provides an overview of load modeling for an offshore platform, including self-weight, live loads, equipment loads, crane loads, wave loads, current loads, wind loads, and environmental load factors and combinations. It discusses determining member properties, offsets, load details, and references for weight, dimensions, and assumptions. Load inputs from a previous model are also addressed.
Basic load out methodologies introductionBruce nguyen
The document provides details on the load out plan using skidding and strand jacks. It assigns responsibilities to various managers for the safe execution of the load out. The key steps include pre-ballasting the barge, installing strand jacks and anchor blocks, pre-tensioning strands, breaking out the structure, and pulling it onto the barge while coordinating with ballasting operations. Safety is the top priority, and specific responsibilities are defined for project management, supervisors, and subcontractors to ensure a safe load out.
This document provides design details and checks for a lifting shackle, sling, and padeye assembly. Key points include:
1. The sling and shackle are selected to have sufficient minimum breaking load capacity to safely lift the design load of 8417 kN, with safety factors applied according to standards.
2. The padeye dimensions are checked against criteria for the pin hole diameter, thickness, radii, and plate sizes. Stress checks are performed at critical locations like the pin hole.
3. Forces acting on the assembly are calculated based on the design load and orientation. Stresses are analyzed at points on the padeye to ensure values are below allowable limits.
The document provides guidelines for padeye design and calculations for lifting attachments. It states that padeyes shall be designed for at least 5% of the design load applied laterally and that permissible stresses shall follow AISC standards with additional requirements limiting through-thickness stresses to 0.2 times the yield strength if the material does not have through-thickness properties. It then provides examples of calculations for padeye design including shear stress, tension stress, weld shear stress, and dimensional requirements.
Badaruddin provides his credentials and experience in engineering and rigging. He outlines key considerations for rigging plans including defining the lifting method, estimating the lifted load, selecting rigging and a crane. As an example, he summarizes installing a gas cooler using a 180-ton crane. Key steps are setting the crane configuration, defining the 34.5-ton lifted weight and center of gravity, verifying the crane capacity of 42.3 tons is not exceeded, selecting wire rope slings rated for 28 and 16 tons, and checking ground bearing pressure does not exceed capacity.
Bentley Systems is a global leader in engineering software for infrastructure modeling and analysis. It offers SACS, a software for designing and analyzing offshore structures from conceptual design through installation, operation, and decommissioning. SACS can model various offshore structure types and perform analyses like structural analysis, fatigue analysis, earthquake analysis, and dropped object analysis.
This document summarizes the steps for performing an offshore platform analysis using analysis generator software. It reviews loading and parameters, covers the options available for analysis type, load combination factors, and allowable stresses. The document also highlights important points for configuring the analysis, including specifying the working directory, input and output files, and solution options. Students are then instructed to run an analysis on their model, ensuring the load combination is included, and upload the results to an FTP site using a specified naming convention.
This document provides a summary and disclaimer for Noble Denton Marine Services. It states that Noble Denton provides marine warranty survey services to evaluate marine operations for insurance purposes. It should be read together with other DNVGL standards that describe Noble Denton's marine warranty survey process. The document disclaims any liability if the client's project scope does not encompass needs or fit for purpose. It also states that industry knowledge and experience must be applied throughout marine operations in addition to using DNVGL standards.
This document provides an overview of load modeling for an offshore platform, including self-weight, live loads, equipment loads, crane loads, wave loads, current loads, wind loads, and environmental load factors and combinations. It discusses determining member properties, offsets, load details, and references for weight, dimensions, and assumptions. Load inputs from a previous model are also addressed.
Basic load out methodologies introductionBruce nguyen
The document provides details on the load out plan using skidding and strand jacks. It assigns responsibilities to various managers for the safe execution of the load out. The key steps include pre-ballasting the barge, installing strand jacks and anchor blocks, pre-tensioning strands, breaking out the structure, and pulling it onto the barge while coordinating with ballasting operations. Safety is the top priority, and specific responsibilities are defined for project management, supervisors, and subcontractors to ensure a safe load out.
This document provides design details and checks for a lifting shackle, sling, and padeye assembly. Key points include:
1. The sling and shackle are selected to have sufficient minimum breaking load capacity to safely lift the design load of 8417 kN, with safety factors applied according to standards.
2. The padeye dimensions are checked against criteria for the pin hole diameter, thickness, radii, and plate sizes. Stress checks are performed at critical locations like the pin hole.
3. Forces acting on the assembly are calculated based on the design load and orientation. Stresses are analyzed at points on the padeye to ensure values are below allowable limits.
The document provides guidelines for padeye design and calculations for lifting attachments. It states that padeyes shall be designed for at least 5% of the design load applied laterally and that permissible stresses shall follow AISC standards with additional requirements limiting through-thickness stresses to 0.2 times the yield strength if the material does not have through-thickness properties. It then provides examples of calculations for padeye design including shear stress, tension stress, weld shear stress, and dimensional requirements.
Badaruddin provides his credentials and experience in engineering and rigging. He outlines key considerations for rigging plans including defining the lifting method, estimating the lifted load, selecting rigging and a crane. As an example, he summarizes installing a gas cooler using a 180-ton crane. Key steps are setting the crane configuration, defining the 34.5-ton lifted weight and center of gravity, verifying the crane capacity of 42.3 tons is not exceeded, selecting wire rope slings rated for 28 and 16 tons, and checking ground bearing pressure does not exceed capacity.
Bentley Systems is a global leader in engineering software for infrastructure modeling and analysis. It offers SACS, a software for designing and analyzing offshore structures from conceptual design through installation, operation, and decommissioning. SACS can model various offshore structure types and perform analyses like structural analysis, fatigue analysis, earthquake analysis, and dropped object analysis.
This document summarizes the steps for performing an offshore platform analysis using analysis generator software. It reviews loading and parameters, covers the options available for analysis type, load combination factors, and allowable stresses. The document also highlights important points for configuring the analysis, including specifying the working directory, input and output files, and solution options. Students are then instructed to run an analysis on their model, ensuring the load combination is included, and upload the results to an FTP site using a specified naming convention.
1. This document provides guidelines for conducting marine lifting operations, including calculations for load and safety factors.
2. It describes the approval process for operations requiring Noble Denton approval. An operator must provide documentation and plans demonstrating the lifting operation has been properly designed.
3. The guidelines cover factors of safety for structural members, lift points, rigging, and environmental conditions. They aim to ensure lifting operations are conducted safely according to industry standards.
The document outlines the process for designing vertical vessel foundations, including determining the vessel type, design considerations, calculation criteria, and steps. The key steps are: (1) sketching the vessel and foundation, (2) determining equipment and load data, (3) calculating gravity, wind, and seismic loads, (4) checking soil bearing capacity, sliding, and overturning, (5) structurally designing the pedestal with vertical bars, horizontal ties, and top face bars, and (6) calculating anchor forces. The purpose is to ensure the foundation can safely support the vertical vessel according to Saudi Aramco standards.
DESIGN OF A MODEL HAULAGE TECHNIQUE FOR WATER FLOODING CAISSON ASSEMBLY.Emeka Ngwobia
Presented in this study is the engineering solution to the movement of a 63m, 45tons Caisson from a fabrication yard to a field location in the Gulf of guinea. This was achieved by dividing the whole process into three stages; firstly by using excel sheets with relevant design formulas to design the spreader bar configuration to lift the caisson from the quayside to a crane barge conveniently, showing the necessary lifting sequence employed to complete this process, also designing the lifting accessories needed which includes pad eyes, shackles, wire rope and spreader bars according to relevant codes and standards The first spreader Is an I beam of length of 25m and section with dimension 533mm by 229mm weighing 129kg/m, the second beam and the third beam are designed similarly as an I beam of length 9m and section 533mm by 229mm weighing 129kg/m. The choice of pad eye to be welded on the spreader beam was based on the working limit of the pad eye, which was analytically designed using spread sheet, performing necessary checks to make sure it will not break off during the lifting operations. It is reinforced with cheek plates at the pin hole to reduce the stresses at the pin hole. The total pad eye used for this operation is 16. The choice of shackle attached to each of the pad eye was based on the total self weight of all the lifting materials(55tons), according to the Crosby group catalogue it is an S2130 bow shackle of Nominal size 50.8mm, Stock no 1019659 and weight 23.7002kg, also the wire rope configuration chosen to based on the safe working load limit according to the Bethlehem wire rope general purpose catalogue ASME B30.5- 1995 the wire rope has nominal strength of 53.1tons, sling class 19x7 IWRC(Purple or extra improved ploy (EIP Steel).
. Secondly, by providing solutions to sea fastening for the caisson on the deck of the crane barge, which was modeled using STAADPRO, which involved support designs and loss of support designs, so as to accommodate for the hydrodynamic effect while the caisson is being transported by the crane barge, having in mind that the crane barge chosen will adequately accommodate the caisson because of the deck space required to fit the 63m long caisson, from the analysis the Caisson is supported by steel beams spaced at 10 m interval which is fastened with the aid of a clamp as seen in the detailed drawings, this caisson and beam supports are modeled with staadpro software and support reactions obtained. These supports are now spaced at 20 m intervals and analyzed to simulate a situation where there is a loss of support reaction during transportation of the caisson. A saddle clamp is to joined to a H beam for support to hold it to the deck at varying length and at the starting point a pivot made from a pad eye joined with a pin to connect the saddle clamp to allow for easy lifting of the caisson when it is at 25m to the FPSO.
The centre of gravity (CG) is the point where the entire weight of a body or system of bodies is concentrated so that if supported at this point the body or system would remain in static equilibrium in any position. It is important to position the crane hook directly over the CG of a load for stability during lifting operations. Lifting a load with an offset CG can cause the load to shift until balance is restored with the CG below the hook. When lifting loads with an offset CG, one sling leg will take more of the load weight than the other, so the sling SWL should be based on the full load weight on one leg. Careful lifting is required as loads with an offset CG could kick in an unexpected manner once lifted
This document describes the process for creating and running a pushover analysis to investigate the collapse behavior of an offshore structure. It involves:
1) Modifying input files to include additional load cases and define member behavior.
2) Creating a collapse input file to define analysis options, load sequences, and output selections.
3) Generating a run file and running the analysis.
4) Reviewing results in the collapse view program, including pile capacity reports and structural damage displays.
This document provides an overview of the SACS software, which is used for analyzing offshore structures. It discusses the history and capabilities of SACS, including that it can perform various types of analyses like pre-service, service, and incident analyses. It also outlines the process for setting up and performing an analysis in SACS, including defining the structure, running the analysis, and checking the results. The final section provides instructions for an assignment to build a jacket structure in SACS based on specific criteria.
This document discusses the influence of wind on lifting operations. It notes that wind is often an underrated hazard that can cause crane accidents. Statistics show that several crane accidents in recent years were caused by high winds, sometimes resulting in fatalities and injuries. The document explores the basics of wind and gusts, and how wind force can overload cranes and suspended loads from various directions. It provides guidance on assessing wind speed and sail areas to determine the actual permissible wind speed for safe lifting operations according to the crane's load chart. Managing wind risks is important for safely conducting lifts.
The document summarizes various types of offshore drilling structures used in oil and gas exploration and production. It describes the key design features and operating parameters of jack-up drilling rigs, semisubmersibles, floating production systems, drill ships, tension leg platforms, fixed jacketed structures, gravity structures, guyed towers, and articulated tower and single anchor leg mooring systems. It compares the advantages and disadvantages of each type of structure in terms of operating depth, stability, mobility, load capacity, costs, and suitability for different applications.
The document provides guidance on safe lifting practices for engineering students. It discusses duties and responsibilities of riggers which include observing safety precautions, checking the load and work area, inspecting equipment, communicating with crane operators, and reporting issues. The document also covers safety awareness, with sections on general safety, safety systems, personal protective equipment, lifting hazards, electrocution hazards, and overload/maintenance hazards. It describes the importance of using standardized hand signals or radios to properly communicate with crane operators during lifting operations.
This document summarizes the topics that will be covered in Tutorial #2 on modeling an offshore platform. It includes reviewing structure definition, adding and modifying joints and members, creating member groups and properties, and laying out the deck design. The instructor asks if there are any questions and provides example member group types. Students will be guided to add member properties to their jacket model from Assignment #1 and lay out the deck beams by using example drawings available on an online FTP site.
This document provides an overview of the analysis and design of offshore structures. It discusses various types of offshore structures including fixed platforms, compliant structures, and floating structures. It then covers the design methodology, loads assessment, materials selection, corrosion protection, structural simulation, and structural analysis techniques for offshore structures. The document is intended as a reference for the analysis and design of offshore oil and gas platforms.
International convention on load lines 1968 group 2jabbar2002pk200
The document discusses the history and provisions of the International Convention on Load Lines from 1930 to 2003. Some key points:
- The 1930 Load Line Convention was the first international agreement to apply load line regulations universally based on reserve buoyancy and stability.
- Revisions were needed as ship designs evolved, leading to the 1968 Load Lines Convention which updated rules on structural strength, reserve buoyancy, crew protection and limiting deck cargo.
- The 1968 Convention set out rules for calculating and assigning freeboard based on a ship's zone, season, and cargo. It ensured watertight integrity and proper load line markings.
- Further amendments in 1971, 1975, 1979, 1983, 1995, and 2003 aimed to
Bs 7121 2º INSPECTION, TESTING AND EXAMINATION-CRANESANA ISABEL R.R.
This document provides guidelines for inspection, testing and examination of cranes according to BS 7121-2 Code of Practice for Safe Use of Cranes Part 2. It outlines requirements for pre-use checks, in-service inspections, and thorough examinations to be carried out by competent personnel. Thorough examinations must follow a written examination scheme and are required at least every 6 months for cranes that lift persons and every 12 months for other cranes. The document specifies inspection and testing procedures, responsibilities of different parties, and record keeping requirements.
This document discusses importing a structural model from the Sacs software into the GeniE software. It describes how the import process automatically brings in the structure, wave loads, and load combinations. It also notes what may need manual modification after import and how to verify the imported GeniE model matches the original Sacs model. The purposes of the imported model in GeniE include performing linear analyses, evaluating results, and using the model over the entire lifecycle of the structure.
The document provides an overview of key considerations for rigging jobs, including the load's weight, center of gravity, attachment points, required rigging hardware, lift equipment, and personnel. It discusses determining a load's center of gravity and how rigging to the center of gravity helps control the load. Various factors that affect sling capacities are covered, such as end attachments, splicing efficiency, hitch types, D/d ratios, number of legs used, and load angles. Methods for calculating load sharing and tensions in multi-leg rigging configurations are also presented.
introduction, drawing, calculation for winch designAman Huri
The document provides information about designing a winch that can withstand a maximum load of 15kN and uses a cable with a diameter of 14mm.
It begins with an introduction to winches, their components, and operation systems. It then discusses the problem statement of designing a winch for pulling up boat anchors. The key design requirements are that it withstands 15kN of load and uses 14mm diameter cable.
The summary discusses the components that will be included in the design - the wire rope, drum, gears, and other parts. It provides calculations for selecting the appropriate wire rope and determining the drum dimensions based on withstanding the load requirement. Gears are also designed with calculations of number of teeth
The document describes a spreadsheet program called "LIFTING_LUG" that analyzes lifting lugs used in rigging operations. The program allows the user to input parameters of a lifting lug and determines its ultimate strength based on several checks. It then applies a desired factor of safety to calculate allowable loads for the lifting lug. The program consists of two worksheets - one for documentation and one for performing the lifting lug analysis calculations according to industry standards.
This document provides guidance on assessing the strength of members and connections for lattice towers and masts. It defines key terms and describes common structural configurations for lattice towers and masts. It also provides methods for determining the effective length and slenderness of members based on their end conditions and bracing patterns. Design strengths are determined using characteristic strengths and appropriate partial safety factors.
This document discusses procedures for mooring and anchoring a ship. It describes various deck fittings and equipment used such as cleats, bitts, bollards, chocks and mooring lines. It outlines the steps for mooring to a pier, including leading lines through chocks and securing them to bollards. Safety precautions and standard commands for line handlers are provided. The document also describes procedures for anchoring such as readying the anchor and windlass and letting go the anchor. Key terms related to anchoring such as hawsepipe, chain pipe and flukes are defined.
Guidelines for marine lifting operation noble dentonOFFSHORE VN
1. This document provides guidelines for approving marine lifting operations using floating crane vessels or land-based cranes.
2. It describes Noble Denton's approval process and guidelines for load and safety factors to apply at the design stage.
3. The report also offers comments on practical considerations for managing lifting operations and the information required for approval.
This document outlines standards and certification procedures for offshore containers from Det Norske Veritas (DNV). It includes sections on materials, design, production, marking, lifting sets, periodic examination and testing. The key changes in the 2006 edition include more detailed requirements for lifting sets, new material standards for temperate climate use, and alignment with international standard EN 12079. Containers certified under this standard meet requirements of the IMO and EN 12079, and existing containers certified to previous versions generally comply with the new standard as well.
IRJET- Study on Different Estimation Methods of Propulsion Power for 60 Mts O...IRJET Journal
This document studies different methods to estimate the propulsion power required for a 60-meter offshore supply vessel, including resistance calculation using Guldhammer & Harvald, Holtrop, and Oortmerssen methods. It analyzes the vessel's hull geometry and calculates parameters like resistance, effective power, and total resistance at ship speeds of 10-19 knots using each method. The results are compared to determine the most accurate way to obtain hull resistance and powering requirements for propelling the vessel.
1. This document provides guidelines for conducting marine lifting operations, including calculations for load and safety factors.
2. It describes the approval process for operations requiring Noble Denton approval. An operator must provide documentation and plans demonstrating the lifting operation has been properly designed.
3. The guidelines cover factors of safety for structural members, lift points, rigging, and environmental conditions. They aim to ensure lifting operations are conducted safely according to industry standards.
The document outlines the process for designing vertical vessel foundations, including determining the vessel type, design considerations, calculation criteria, and steps. The key steps are: (1) sketching the vessel and foundation, (2) determining equipment and load data, (3) calculating gravity, wind, and seismic loads, (4) checking soil bearing capacity, sliding, and overturning, (5) structurally designing the pedestal with vertical bars, horizontal ties, and top face bars, and (6) calculating anchor forces. The purpose is to ensure the foundation can safely support the vertical vessel according to Saudi Aramco standards.
DESIGN OF A MODEL HAULAGE TECHNIQUE FOR WATER FLOODING CAISSON ASSEMBLY.Emeka Ngwobia
Presented in this study is the engineering solution to the movement of a 63m, 45tons Caisson from a fabrication yard to a field location in the Gulf of guinea. This was achieved by dividing the whole process into three stages; firstly by using excel sheets with relevant design formulas to design the spreader bar configuration to lift the caisson from the quayside to a crane barge conveniently, showing the necessary lifting sequence employed to complete this process, also designing the lifting accessories needed which includes pad eyes, shackles, wire rope and spreader bars according to relevant codes and standards The first spreader Is an I beam of length of 25m and section with dimension 533mm by 229mm weighing 129kg/m, the second beam and the third beam are designed similarly as an I beam of length 9m and section 533mm by 229mm weighing 129kg/m. The choice of pad eye to be welded on the spreader beam was based on the working limit of the pad eye, which was analytically designed using spread sheet, performing necessary checks to make sure it will not break off during the lifting operations. It is reinforced with cheek plates at the pin hole to reduce the stresses at the pin hole. The total pad eye used for this operation is 16. The choice of shackle attached to each of the pad eye was based on the total self weight of all the lifting materials(55tons), according to the Crosby group catalogue it is an S2130 bow shackle of Nominal size 50.8mm, Stock no 1019659 and weight 23.7002kg, also the wire rope configuration chosen to based on the safe working load limit according to the Bethlehem wire rope general purpose catalogue ASME B30.5- 1995 the wire rope has nominal strength of 53.1tons, sling class 19x7 IWRC(Purple or extra improved ploy (EIP Steel).
. Secondly, by providing solutions to sea fastening for the caisson on the deck of the crane barge, which was modeled using STAADPRO, which involved support designs and loss of support designs, so as to accommodate for the hydrodynamic effect while the caisson is being transported by the crane barge, having in mind that the crane barge chosen will adequately accommodate the caisson because of the deck space required to fit the 63m long caisson, from the analysis the Caisson is supported by steel beams spaced at 10 m interval which is fastened with the aid of a clamp as seen in the detailed drawings, this caisson and beam supports are modeled with staadpro software and support reactions obtained. These supports are now spaced at 20 m intervals and analyzed to simulate a situation where there is a loss of support reaction during transportation of the caisson. A saddle clamp is to joined to a H beam for support to hold it to the deck at varying length and at the starting point a pivot made from a pad eye joined with a pin to connect the saddle clamp to allow for easy lifting of the caisson when it is at 25m to the FPSO.
The centre of gravity (CG) is the point where the entire weight of a body or system of bodies is concentrated so that if supported at this point the body or system would remain in static equilibrium in any position. It is important to position the crane hook directly over the CG of a load for stability during lifting operations. Lifting a load with an offset CG can cause the load to shift until balance is restored with the CG below the hook. When lifting loads with an offset CG, one sling leg will take more of the load weight than the other, so the sling SWL should be based on the full load weight on one leg. Careful lifting is required as loads with an offset CG could kick in an unexpected manner once lifted
This document describes the process for creating and running a pushover analysis to investigate the collapse behavior of an offshore structure. It involves:
1) Modifying input files to include additional load cases and define member behavior.
2) Creating a collapse input file to define analysis options, load sequences, and output selections.
3) Generating a run file and running the analysis.
4) Reviewing results in the collapse view program, including pile capacity reports and structural damage displays.
This document provides an overview of the SACS software, which is used for analyzing offshore structures. It discusses the history and capabilities of SACS, including that it can perform various types of analyses like pre-service, service, and incident analyses. It also outlines the process for setting up and performing an analysis in SACS, including defining the structure, running the analysis, and checking the results. The final section provides instructions for an assignment to build a jacket structure in SACS based on specific criteria.
This document discusses the influence of wind on lifting operations. It notes that wind is often an underrated hazard that can cause crane accidents. Statistics show that several crane accidents in recent years were caused by high winds, sometimes resulting in fatalities and injuries. The document explores the basics of wind and gusts, and how wind force can overload cranes and suspended loads from various directions. It provides guidance on assessing wind speed and sail areas to determine the actual permissible wind speed for safe lifting operations according to the crane's load chart. Managing wind risks is important for safely conducting lifts.
The document summarizes various types of offshore drilling structures used in oil and gas exploration and production. It describes the key design features and operating parameters of jack-up drilling rigs, semisubmersibles, floating production systems, drill ships, tension leg platforms, fixed jacketed structures, gravity structures, guyed towers, and articulated tower and single anchor leg mooring systems. It compares the advantages and disadvantages of each type of structure in terms of operating depth, stability, mobility, load capacity, costs, and suitability for different applications.
The document provides guidance on safe lifting practices for engineering students. It discusses duties and responsibilities of riggers which include observing safety precautions, checking the load and work area, inspecting equipment, communicating with crane operators, and reporting issues. The document also covers safety awareness, with sections on general safety, safety systems, personal protective equipment, lifting hazards, electrocution hazards, and overload/maintenance hazards. It describes the importance of using standardized hand signals or radios to properly communicate with crane operators during lifting operations.
This document summarizes the topics that will be covered in Tutorial #2 on modeling an offshore platform. It includes reviewing structure definition, adding and modifying joints and members, creating member groups and properties, and laying out the deck design. The instructor asks if there are any questions and provides example member group types. Students will be guided to add member properties to their jacket model from Assignment #1 and lay out the deck beams by using example drawings available on an online FTP site.
This document provides an overview of the analysis and design of offshore structures. It discusses various types of offshore structures including fixed platforms, compliant structures, and floating structures. It then covers the design methodology, loads assessment, materials selection, corrosion protection, structural simulation, and structural analysis techniques for offshore structures. The document is intended as a reference for the analysis and design of offshore oil and gas platforms.
International convention on load lines 1968 group 2jabbar2002pk200
The document discusses the history and provisions of the International Convention on Load Lines from 1930 to 2003. Some key points:
- The 1930 Load Line Convention was the first international agreement to apply load line regulations universally based on reserve buoyancy and stability.
- Revisions were needed as ship designs evolved, leading to the 1968 Load Lines Convention which updated rules on structural strength, reserve buoyancy, crew protection and limiting deck cargo.
- The 1968 Convention set out rules for calculating and assigning freeboard based on a ship's zone, season, and cargo. It ensured watertight integrity and proper load line markings.
- Further amendments in 1971, 1975, 1979, 1983, 1995, and 2003 aimed to
Bs 7121 2º INSPECTION, TESTING AND EXAMINATION-CRANESANA ISABEL R.R.
This document provides guidelines for inspection, testing and examination of cranes according to BS 7121-2 Code of Practice for Safe Use of Cranes Part 2. It outlines requirements for pre-use checks, in-service inspections, and thorough examinations to be carried out by competent personnel. Thorough examinations must follow a written examination scheme and are required at least every 6 months for cranes that lift persons and every 12 months for other cranes. The document specifies inspection and testing procedures, responsibilities of different parties, and record keeping requirements.
This document discusses importing a structural model from the Sacs software into the GeniE software. It describes how the import process automatically brings in the structure, wave loads, and load combinations. It also notes what may need manual modification after import and how to verify the imported GeniE model matches the original Sacs model. The purposes of the imported model in GeniE include performing linear analyses, evaluating results, and using the model over the entire lifecycle of the structure.
The document provides an overview of key considerations for rigging jobs, including the load's weight, center of gravity, attachment points, required rigging hardware, lift equipment, and personnel. It discusses determining a load's center of gravity and how rigging to the center of gravity helps control the load. Various factors that affect sling capacities are covered, such as end attachments, splicing efficiency, hitch types, D/d ratios, number of legs used, and load angles. Methods for calculating load sharing and tensions in multi-leg rigging configurations are also presented.
introduction, drawing, calculation for winch designAman Huri
The document provides information about designing a winch that can withstand a maximum load of 15kN and uses a cable with a diameter of 14mm.
It begins with an introduction to winches, their components, and operation systems. It then discusses the problem statement of designing a winch for pulling up boat anchors. The key design requirements are that it withstands 15kN of load and uses 14mm diameter cable.
The summary discusses the components that will be included in the design - the wire rope, drum, gears, and other parts. It provides calculations for selecting the appropriate wire rope and determining the drum dimensions based on withstanding the load requirement. Gears are also designed with calculations of number of teeth
The document describes a spreadsheet program called "LIFTING_LUG" that analyzes lifting lugs used in rigging operations. The program allows the user to input parameters of a lifting lug and determines its ultimate strength based on several checks. It then applies a desired factor of safety to calculate allowable loads for the lifting lug. The program consists of two worksheets - one for documentation and one for performing the lifting lug analysis calculations according to industry standards.
This document provides guidance on assessing the strength of members and connections for lattice towers and masts. It defines key terms and describes common structural configurations for lattice towers and masts. It also provides methods for determining the effective length and slenderness of members based on their end conditions and bracing patterns. Design strengths are determined using characteristic strengths and appropriate partial safety factors.
This document discusses procedures for mooring and anchoring a ship. It describes various deck fittings and equipment used such as cleats, bitts, bollards, chocks and mooring lines. It outlines the steps for mooring to a pier, including leading lines through chocks and securing them to bollards. Safety precautions and standard commands for line handlers are provided. The document also describes procedures for anchoring such as readying the anchor and windlass and letting go the anchor. Key terms related to anchoring such as hawsepipe, chain pipe and flukes are defined.
Guidelines for marine lifting operation noble dentonOFFSHORE VN
1. This document provides guidelines for approving marine lifting operations using floating crane vessels or land-based cranes.
2. It describes Noble Denton's approval process and guidelines for load and safety factors to apply at the design stage.
3. The report also offers comments on practical considerations for managing lifting operations and the information required for approval.
This document outlines standards and certification procedures for offshore containers from Det Norske Veritas (DNV). It includes sections on materials, design, production, marking, lifting sets, periodic examination and testing. The key changes in the 2006 edition include more detailed requirements for lifting sets, new material standards for temperate climate use, and alignment with international standard EN 12079. Containers certified under this standard meet requirements of the IMO and EN 12079, and existing containers certified to previous versions generally comply with the new standard as well.
IRJET- Study on Different Estimation Methods of Propulsion Power for 60 Mts O...IRJET Journal
This document studies different methods to estimate the propulsion power required for a 60-meter offshore supply vessel, including resistance calculation using Guldhammer & Harvald, Holtrop, and Oortmerssen methods. It analyzes the vessel's hull geometry and calculates parameters like resistance, effective power, and total resistance at ship speeds of 10-19 knots using each method. The results are compared to determine the most accurate way to obtain hull resistance and powering requirements for propelling the vessel.
QinetiQ Australia's Stability Program is designed to manage the compliance and validation process and the interaction between three major components: Stability, Weight Management and Safety During Docking.
IRJET- Planning and Design of Container TerminalIRJET Journal
This document discusses the planning and design of a container terminal including a breakwater, jetties, and wharf. It aims to satisfy prompt accommodation of ships with minimum wait times while maximizing berth usage. The design approach considers loads like dead load, live load, mooring forces, berthing forces, wind, and seismic loads. The breakwater, jetties, and wharf are designed to withstand these loads through their structural components. Analysis of the designs is conducted using software to compare with manual calculations. The terminal is planned in phases to ultimately reach a capacity of 127 million metric tons per annum.
1) There are currently no internationally agreed upon stability requirements specifically for anchor handling tug supply (AHTS) vessels.
2) After the 2007 accident of the AHTS Bourbon Dolphin, initiatives were taken to improve design, operations, and stability requirements for AHTS vessels, including guidelines from the Norwegian Maritime Directorate.
3) The guidelines from the Norwegian Maritime Directorate propose criteria for limiting the heeling moment on AHTS vessels during anchor handling operations based on the angle of heel equivalent to 50% of the maximum GZ, the angle of flooding of the work deck, or 15 degrees, whichever is smallest.
Research Project Presentation_Michael LiMichael Li
This document summarizes an investigation into the drag and added mass properties of mid-water arch structures for riser design. Hydrodynamic force analysis was conducted using Morison's equation and existing codes. Added mass coefficients were analyzed using panel methods and CFD simulations, finding panel methods provided better predictions than codes. Drag coefficients were found to vary with structure design and Reynolds number. CFD simulations matched published cylinder results and provided better coefficient predictions than codes.
LPG Go Dau - LPG tank supported column structural calculationHenry Hoang
The document discusses the design of the foundation for an LPG storage tank. It includes information on the structure, materials, design standards, software, and load cases considered. A STAAD Pro model of the foundation is presented, showing the element types and node numbering. Design loads include self-weight, internal LPG pressure, hydrostatic pressure, and wind loads according to Vietnamese standards. Results of the STAAD analysis are presented, including member forces and displacements.
This document provides change pages for EM 1110-2-1601, the US Army Corps of Engineers manual on hydraulic design of flood control channels. Specifically, it:
1) Updates chapters 2, 3, and 5 of the manual, adding new content on predicting Manning's n values.
2) Adds a new Chapter 5 that describes methods for predicting n values for the Manning equation.
3) Updates appendices and inserts omitted pages to reflect the changes made to chapters 2, 3, and 5.
Critical levels for monitoring ground anchor systems provide essential safety checks during deep excavation projects. They define an alert level and work suspension level to monitor anchor loads. Exceeding the alert level requires close monitoring, while exceeding the work suspension level stops work. This case study of a large excavation project in Singapore demonstrates how critical level monitoring, conservative design parameters, and controlled pre-loading of anchors ensures the safety and performance of complex temporary earth retaining systems.
Ukrainian Catholic University
Faculty of Applied Sciences
Data Science Master Program
January 21st
Abstract. The maritime industry is huge and consists of a lot of complex processes. It is a consequence of the fact that the maritime industry provides most of the goods transportation. During transportation, people serve the vessel. And here the problem is raised of the optimal distribution of crew on vessels. This problem can be solved by formalizing the integer programming problem. In practice, we saw that solving this problem is time-consuming since there are a large number of free variables. This makes the solution inapplicable to the end-user. In this work, we describe the approach to speed up a solution of crew optimization for the maritime industry using the Rolling Time Horizon technique. Our approach is 3.5 times faster than the benchmark and deviates from the optimal solution by less than 1%.
This document outlines methods for assessing the efficiency of securing arrangements for non-standardized cargo. It describes:
1) Determining the strength of securing equipment using maximum securing load values.
2) Applying a safety factor of 1.5 to account for uneven force distribution.
3) A basic "rule of thumb" method requiring total securing device strength equal cargo weight.
4) A more advanced calculation method involving balancing external forces from acceleration with friction and securing device strength. Transverse sliding, tipping and longitudinal sliding are evaluated.
offshore structural design description, starts from codes and standards, data requirements, plate form data, extreme storm parameters, operational parameters and installation parameters
This document provides a diagnostic test report of a 22kV/0.4kV transformer. It includes the results of various tests performed on the transformer such as insulation resistance, magnetic balance, vector group, impedance, winding resistance, and SFRA tests. The document finds that the transformer is in critical condition based on dissolved gas, moisture content, and partial discharge analysis. It recommends taking the transformer out of service, performing oil filtration and retrofitting with new protections before putting it back in service.
Design by Analysis - A general guideline for pressure vesselAnalyzeForSafety
This presentation file is provided by Mr. Ghanbari and published under permission.
The presentation gives an introduction and general guideline for pressure vessel design by analysis.
The “design by analysis” procedures are intended to guard against eight possible pressure vessel failure modes by performing a detailed stress analysis of the vessel with the sufficient design factors. The failure modes are:
1.excessive elastic deformation, including elastic instability,
2.excessive plastic deformation,
3.brittle fracture,
4.stress rupture/creep deformation (inelastic),
5.plastic instability - incremental collapse,
6.high strain - low cycle fatigue,
7.stress corrosion, and
8.corrosion fatigue
Most of the “design by analysis” procedures that are given in ASME BPVC relate to designs based on “elastic analysis.”
The design-by-analysis requirements are organized based on protection against the failure modes listed below. The component shall be evaluated for each applicable failure mode. If multiple assessment procedures are provided for a failure mode, only one of these procedures must be satisfied to qualify the design of a component.
a)All pressure vessels within the scope of this Division, irrespective of size or pressure, shall be provided with protection against overpressure in accordance with the requirements of this Part.
b)Protection Against Plastic Collapse – these requirements apply to all components where the thickness and configuration of the component is established using design-by-analysis rules.
c)Protection Against Local Failure – these requirements apply to all components where the thickness and configuration of the component is established using design-by-analysis rules. It is not necessary to evaluate the local strain limit criterion if the component design is in accordance with Part 4 (i.e. component wall thickness and weld detail per paragraph 4.2).
d)Protection Against Collapse From Buckling – these requirements apply to all components where the thickness and configuration of the component is established using design-by-analysis rules and the applied loads result in a compressive stress field.
e)Protection Against Failure From Cyclic Loading – these requirements apply to all components where the thickness and configuration of the component is established using design-by-analysis rules and the applied loads are cyclic. In addition, these requirements can also be used to qualify a component for cyclic loading where the thickness and size of the component are established using the design-by-rule requirements of Part 4.
This document provides an equipment breakdown and analysis of critical systems on HAL's Vista class vessels. It identifies single points of failure that could impact propulsion and maneuverability. The goals are to evaluate redundancy, identify high-risk areas, and modify systems to improve reliability. Several cooling water systems are identified as critical, as a single failure could disable multiple diesel generators. Modifications are recommended, such as adding a second high temperature cooler. Proper crew training and maintenance are also emphasized to minimize risks from the vessels' integrated systems.
The document presents a method for calculating the residual lifetime of lifting equipment using non-destructive testing methods. It involves inspecting the equipment to analyze its condition and operation history. Finite element analysis is used to determine stress levels in areas like welds. Non-destructive tests like ultrasound and liquid penetrant testing are conducted on high-stress areas found by analysis. Loads are calculated considering fatigue damage. The number of operating cycles is estimated based on the equipment's operation over its lifetime. This information is used to calculate the residual lifetime and determine if the equipment can continue operating at a reduced capacity for an extended period.
This document summarizes a thesis presentation on the Energy Efficiency Design Index (EEDI) and minimum propulsion power requirements for ships. It discusses how the EEDI measures a ship's carbon emissions based on its transportation work. Ships built after 2013 must meet increasingly stringent EEDI reference lines that are reduced by 10% every 5 years. To comply, ships can utilize technologies like slow steaming or alternative fuels. However, slow steaming may negatively impact maneuverability, especially in adverse weather. International guidelines were developed to determine the minimum power needed to maintain maneuverability in waves and wind at a speed of 4 knots or while keeping course.
This document describes the 1978 ITTC Performance Prediction Method for predicting the delivered power and revolutions of single and twin screw ships based on model test results. It defines variables used and outlines the process of analyzing model test data, applying scale corrections to predict full-scale ship performance, and determining a model-ship correlation factor based on validation with full-scale trials.
This document is a reference manual on hydrometry that contains information on various topics related to hydrology and hydraulic measurements. It begins with an introduction to hydraulics, covering the classification of flows, properties of water, velocity profiles in laminar and turbulent flow, hydrodynamic equations, and backwater curves. Subsequent sections provide information on measurement structures, instrumentation, errors, and quality assurance plans. The manual contains detailed technical content intended to serve as a reference for professionals performing hydrologic monitoring and discharge measurements.
This document discusses Float Inc.'s Pneumatically Stabilized Platform (PSP) technology for use as a deep ocean offshore floating platform. The PSP technology was validated through testing by the Defense Advanced Research Projects Agency and Office of Naval Research in the 1990s and 1990s. The PSP uses air buoyancy within cylinders to stabilize the platform and reduce wave motion by 50-94%, even with 20 meter incident waves. The modular PSP design allows for extension and reconfiguration. Float Inc. proposes an Offshore Ocean Energy System placed on a PSP that would incorporate offshore wind, wave, and current energy generation as well as potential energy storage and other applications like aquaculture. Preliminary estimates for a site off
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
1. DNV Marine Operations’ Rules
for Subsea Lifting
New Simplified Method for Prediction of Hydrodynamic Forces
Tormod Bøe
DNV Marine Operations
2nd December 2008
2. DNV Marine Operations' Rules for Subsea Lifting Slide 2
2 December 2008
Content
„ Brief overview of relevant DNV publications
„ DNV Rules for Marine Operations, 1996,
Pt.2 Ch.5 Lifting – Capacity Checks
„ New Simplified Method for calculation of
hydrodynamic forces
„ CFD Analyses – Test Cases
3. DNV Marine Operations' Rules for Subsea Lifting Slide 3
2 December 2008
Relevant DNV Publications
Lifting- and subsea operations :
DNV-OS-E402
Offshore Standard for Diving
Systems January 2004
(Amendments October 2008)
DNV Rules for Planning and Execution of
Marine Operations – 1996
’Special planned, non-routine operations of
limited durations, at sea. Marine operations are
normally related to temporary phases as e.g.
load transfer, transportation and installation.’
DNV Standard for Certification
No.2.22 Lifting Appliances
October 2008
DNV Standard for Certification
No. 2.7-1 Offshore Containers
April 2006
Special planned non-routine operations Routine operations
4. DNV Marine Operations' Rules for Subsea Lifting Slide 4
2 December 2008
Relevant DNV Publications - Other
„ DNV-RP-C205 Environmental Conditions
and Environmental Loads April 2007
(replacing Classification Notes No 30.5)
„ DNV-RP-H101 Risk Management in Marine
and Subsea Operations, January 2003
„ DNV-RP-H102 Marine Operations during
Removal of Offshore Installations, April
2004
„ Standard for Certification No. 2.7-3
Portable Offshore Units, June 2006
(a new revision is planned which will include subsea
units)
5. DNV Marine Operations' Rules for Subsea Lifting Slide 5
2 December 2008
Relevant DNV Publications - Purchase
DNV publications can be purchased at:
http://webshop.dnv.com/global/
„ The new DNV-RP-H103 (December draft version) will be
made available together with the presentation material
from this Subsea Lifting Operations seminar.
„ DNV accept use of the December draft version until
the official release is issued in April 2009.
6. DNV Marine Operations' Rules for Subsea Lifting Slide 6
2 December 2008
Content
„ Brief overview of relevant DNV
publications
„ DNV Rules for Marine Operations, 1996,
Lifting – Capacity Checks
„ New Simplified Method for calculation of
hydrodynamic forces
„ CFD Analyses – Test Cases
7. DNV Marine Operations' Rules for Subsea Lifting Slide 7
2 December 2008
Capacity Checks - DNV 1996 Rules
Rules for Planning and Execution of Marine Operations, 1996
Part 1 - General
Pt.1 Ch.1 - Warranty Surveys
Pt.1 Ch.2 - Planning of
Operations
Pt.1 Ch.3 - Design Loads
Pt.1 Ch.4 - Structural Design
Part 2 - Operation Specific Requirements
Pt.2 Ch.1 - Load Transfer Operations
Pt.2 Ch.2 - Towing
Pt.2 Ch.3 - Special Sea Transports
Pt.2 Ch.4 - Offshore Installation
Pt.2 Ch.5 - Lifting
Pt.2 Ch.6 - Sub Sea Operations
Pt.2 Ch.7 - Transit and Positioning
of Mobile Offshore Units
8. DNV Marine Operations' Rules for Subsea Lifting Slide 8
2 December 2008
Capacity Checks - DNV 1996 Rules
Part 2 Chapter 5
„ Dynamic loads, lift in air
„ Crane capacity
„ Rigging capacity,
(slings, shackles, etc.)
„ Structural steel capacity
(lifted object, lifting points,
spreader bars, etc.)
Part 2 Chapter 6
„ Dynamic loads, subsea lifts
(capacity checks as in Chapter 5 applying dynamic loads from Chapter 6)
9. DNV Marine Operations' Rules for Subsea Lifting Slide 9
2 December 2008
Capacity Checks – DAF for Lift in Air
„ Dynamic loads are accounted for by
using a Dynamic Amplification Factor
(DAF).
„ DAF in air may be caused by e.g.
variation in hoisting speeds or motions
of crane vessel and lifted object.
„ The given table is applicable for
offshore lift in air in minor sea states,
typically Hs < 2-2.5m.
„ DAF must be estimated separately for
lifts in air at higher seastates and for
subsea lifts !
Table 2.1 Pt.2 Ch.5 Sec.2.2.4.4
10. DNV Marine Operations' Rules for Subsea Lifting Slide 10
2 December 2008
Capacity Checks - Crane Capacity
The dynamic hook load, DHL, is
given by:
DHL = DAF*(W+Wrig) + F(SPL)
ref. Pt.2 Ch.5 Sec.2.4.2.1
„ W is the weight of the structure,
including a weight inaccuracy factor
„ The DHL should be checked against
available crane capacity
„ The crane capacity decrease when
the lifting radius increase.
11. DNV Marine Operations' Rules for Subsea Lifting Slide 11
2 December 2008
Capacity Checks - Sling Loads
The maximum dynamic sling load, Fsling,
can be calculated by:
Fsling = DHL·SKL·kCoG·DW / sin φ
ref. Pt.2 Ch.5 Sec.2.4.2.3-6
where:
„ SKL = Skew load factor → extra loading
caused by equipment and fabrication tolerances.
„ kCoG = CoG factor → inaccuracies in estimated
position of centre of gravity.
„ DW = vertical weight distribution → e.g.
DWA = (8/15)·(7/13) in sling A.
„ φ = sling angle from the horizontal plane.
Example :
12. DNV Marine Operations' Rules for Subsea Lifting Slide 12
2 December 2008
Capacity Checks - Slings and Shackles
The sling capacity ”Minimum breaking load”,
MBL, is checked by:
The safety factor is minimum γsf ≥ 3.0.
(Pt.2 Ch.5 Sec.3.1.2)
sf
sling
sling
γ
MBL
F <
”Safe working load”, SWL, and ” MBL, of the
shackle are checked by :
a) Fsling < SWL· DAF
and b) Fsling < MBL / 3.3
Both criteria shall be fulfilled (Pt.2 Ch.5 Sec.3.2.1.2)
13. DNV Marine Operations' Rules for Subsea Lifting Slide 13
2 December 2008
Capacity Checks – Structural Steel
Other lifting equipment:
A consequence factor of γC = 1.3
should be applied on lifting yokes,
spreader bars, plateshackles, etc.
Lifting points:
The load factor γf = 1.3, is increased by a
consequence factor, γC = 1.3, so that total
design faktor, γdesign , becomes:
γdesign = γc· γf = 1.3 · 1.3 = 1.7
The design load acting on the lift point becomes:
Fdesign = γdesign· Fsling = 1.7· Fsling
Structural strength of Lifted Object:
The following consequence factors
should be applied :
A lateral load of
minimum 3% of the
design load shall be
included. This load
acts in the shackle
bow !
(ref. Pt.2.Ch.5 Sec.2.4.3.4)
Table 4.1 Pt.2 Ch.5 Sec.4.1.2
14. DNV Marine Operations' Rules for Subsea Lifting Slide 14
2 December 2008
Content
„ Brief overview of relevant DNV
publications
„ DNV Rules for Marine Operations, 1996,
Lifting – Capacity Checks
„ New Simplified Method for calculation of
hydrodynamic forces
„ CFD Analyses – Test Cases
15. DNV Marine Operations' Rules for Subsea Lifting Slide 15
2 December 2008
New Simplified Method - DNV-RP-H103
„ A new Recommended Practice; ”DNV-RP-
H103 Modelling and Analysis of Marine
Operations” will be issued.
„ A new Simplified Method for calculating
hydrodynamic forces on objects lifted
through wave zone is included in chapter 4.
„ This new Simplified Method will supersede
the calculation guidelines in DNV Rules for
Marine Operations, 1996, Pt.2 Ch.6.
„ The DNV 1996 Rules will be replaced by a
set of New Offshore Standards on Marine
Operations.
16. DNV Marine Operations' Rules for Subsea Lifting Slide 16
2 December 2008
New Simplified Method - Assumptions
The Simplified Method is based upon the
following main assumptions:
„ the horizontal extent of the lifted object is
small compared to the wave length
„ the vertical motion of the object is equal the
vertical crane tip motion
„ vertical motion of object and water dominates
→ other motions can be disregarded
The intention of the Simplified Method is to
give simple conservative estimates of the
forces acting on the object.
17. DNV Marine Operations' Rules for Subsea Lifting Slide 17
2 December 2008
New Simplified Method - Assumptions
18. DNV Marine Operations' Rules for Subsea Lifting Slide 18
2 December 2008
New Simplified Method – Crane Tip Motions
„ The Simplified Method is unapplicable if the crane tip
oscillation period or the wave period is close to the
resonance period, Tn , of the hoisting system
K
A
M
Tn
33
2
+
= π
„ Heave, pitch and roll RAOs for
the vessel should be combined
with crane tip position to find
the vertical motion of the crane tip
„ If operation reference period is
within 30 minutes, the most
probable largest responses may
be taken as 1.80 times the
significant responses
„ If the vessel heading is not fixed,
vessel response should be
analysed for wave directions at
least ±15° off the applied vessel
heading
19. DNV Marine Operations' Rules for Subsea Lifting Slide 19
2 December 2008
New Simplified Method – Wave Periods
There are two alternative approaches:
13
9
.
8 ≤
≤
⋅ z
T
g
Hs
A lower limit of Hmax=1.8·Hs=λ/7 with
wavelength λ=g·Tz
2
/2π is here used.
Alt-1) Wave periods are included:
Analyses should cover the following zero-
crossing wave period range:
g
H
z
T
S
⋅
≥ 6
.
10
A lower limit of Hmax=1.8·Hs=λ/10 with wavelength
λ=g·Tz
2
/2π is here used.
Alt-2) Wave periods are disregarded:
Operation procedures should in this case reflect that the calculations are only valid for
waves longer than:
20. DNV Marine Operations' Rules for Subsea Lifting Slide 20
2 December 2008
New Simplified Method – Wave Kinematics
Alt-1) Wave periods are included:
The wave amplitude, wave particle
velocity and acceleration can be taken as:
„
„
„
S
a H
⋅
= 9
.
0
ζ
g
T
z
a
w
z
d
e
T
v
2
2
4
2
π
π
ζ
−
⋅
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
⋅
=
g
T
z
a
w
z
d
e
T
a
2
2
4
2
2
π
π
ζ
−
⋅
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
⋅
=
s
H
d
35
.
0
v e
s
H
g
30
.
0
w
−
⋅
= π
s
H
d
35
.
0
a e
g
10
.
0
w
−
⋅
= π
Alt-2) Wave periods are disregarded:
The wave particle velocity and acceleration can
be taken as:
„ d : distance from water plane to CoG of
submerged part of object
„
„
21. DNV Marine Operations' Rules for Subsea Lifting Slide 21
2 December 2008
New Simplified Method – Hydrodynamic Forces
Slamming impact force
Slamming forces are short-term impulse
forces that acts when the structure hits the
water surface.
AS is the relevant slamming area on the
exposed structure part. Cs is slamming coeff.
The slamming velocity, vs, is :
2
2
w
ct
c
s v
v
v
v +
+
=
„ vc = lowering speed
„ vct = vertical crane tip velocity
„ vw = vertical water particle velocity
at water surface
g
V
F ⋅
⋅
= δ
ρ
ρ
Varying buoyancy force
Varying buoyancy, Fρ , is the change in
buoyancy due to the water surface elevation.
δV is the change in volume of displaced
water from still water surface to wave
crest or wave trough.
2
2
~
ct
a
w
A
V η
ζ
δ +
⋅
=
g
V
F ⋅
⋅
= δ
ρ
ρ
„ ζa = wave amplitude
„ ηct = crane tip motion amplitude
„ Ãw = mean water line area in the
wave surface zone
22. DNV Marine Operations' Rules for Subsea Lifting Slide 22
2 December 2008
New Simplified Method – Hydrodynamic Forces
Drag force
Drag forces are flow resistance on
submerged part of the structure. The drag
forces are related to relative velocity between
object and water particles.
The drag coefficient, CD, in oscillatory flow for
complex subsea structures may typically be
CD ≥ 2.5.
Relative velocity are found by :
2
2
w
ct
c
r v
v
v
v +
+
=
„ vc = lowering/hoisting speed
„ vct = vertical crane tip velocity
„ vw = vertical water particle velocity
at water depth , d
„ Ap = horizontal projected area
Mass force
“Mass force” is here a combination of inertia
force, Froude-Kriloff force and diffraction
force.
Crane tip acceleration and water particle
acceleration are assumed statistically
independent.
( )
[ ] ( )
[ ]2
33
2
33 w
ct
M a
A
V
a
A
M
F ⋅
+
+
⋅
+
= ρ
„ M = mass of object in air
„ A33 = heave added mass of object
„ act = vertical crane tip acceleration
„ V = volume of displaced water relative to
the still water level
„ aw = vertical water particle acceleration
at water depth, d
23. DNV Marine Operations' Rules for Subsea Lifting Slide 23
2 December 2008
New Simplified Method – Hydrodynamic Force
The hydrodynamic force is a time dependent function of slamming impact
force, varying buoyancy, hydrodynamic mass forces and drag forces. In the
Simplified Method the forces may be combined as follows:
2
2
slam
hyd )
F
F
(
)
F
F
(
F M
D ρ
−
+
+
=
„ The structure may be divided into
main items and surfaces contributing
to the hydrodynamic force
„ Water particle velocity and
acceleration are related to the
vertical centre of gravity for each
main item. Mass and drag forces
contributions are then summarized :
∑
=
i
i
M
M F
F ∑
=
i
i
D
D F
F
FMi and FDi are the individual
force contributions from each
main item
24. DNV Marine Operations' Rules for Subsea Lifting Slide 24
2 December 2008
New Simplified Method – Load Cases Example
Load Case 1
Still water level beneath top of ventilated buckets
„ Slamming impact force, Fslam, acts on top of
buckets.
„ Varying buoyancy force, Fρ , drag force, FD
and mass force, FM are negligible.
The static and hydrodynamic force should be calculated for different stages. Relevant
load cases for deployment of a protection structure could be:
Load Case 2
Still water level above top of buckets
„ Slamming impact force, Fslam, is zero
„ Varying buoyancy, Fρ , drag force, FD and
mass force, FM, are calculated. Velocity and
acceleration are related to CoG of submerged
part of structure.
25. DNV Marine Operations' Rules for Subsea Lifting Slide 25
2 December 2008
New Simplified Method – Load Cases Example
Load Case 3
Still water level beneath roof cover.
„ Slamming impact force, Fslam, acts on the roof
cover.
„ Varying buoyancy, Fρ , drag force, FD and mass
force, FM are calculated on the rest of the
structure. Drag- and mass forces acts mainly on
the buckets and is related to a depth, d, down to
CoG of submerged part of the structure.
Load Case 4
Still water level above roof cover.
„ Slamming impact force, Fslam, and varying
buoyancy, Fρ, is zero.
„ Drag force, FD and mass force, FM are calculated
individually. The total mass and drag force is the
sum of the individual load components, e.g. :
FD= FDroof + FDlegs+ FDbuckets applying correct CoGs
26. DNV Marine Operations' Rules for Subsea Lifting Slide 26
2 December 2008
New Simplified Method – Load Cases Example
27. DNV Marine Operations' Rules for Subsea Lifting Slide 27
2 December 2008
New Simplified Method – Static Weight
„ In addition, the weight inaccuracy factor should be applied
28. DNV Marine Operations' Rules for Subsea Lifting Slide 28
2 December 2008
New Simplified Method - DAF
Capacity Checks
The capacities of crane, lifting equipment and
lifted object are checked as for lift in air. The
following relation should be applied:
where
Mg : weight of object in air [N]
Ftotal : is the characteristic total force on the
(partly or fully) submerged object. Taken as the
largest of;
Ftotal = Fstatic-max + Fhyd or
Ftotal = Fstatic-max + Fsnap
„ Fstatic-max is the maximum static
weight of the submerged object
including flooding and weight
inaccuracy factor
„ Fhyd is the hydrodynamic force
„ Fsnap is the snap load (normally
to be avoided)
Mg
F
DAF total
=
29. DNV Marine Operations' Rules for Subsea Lifting Slide 29
2 December 2008
New Simplified Method – Slack Slings
The Slack Sling Criterion.
„ Snap forces shall as far as possible
be avoided. Weather crietria should
be adjusted to ensure this.
„ The following criterion should be
fulfilled in order to ensure that snap
loads are avoided:
min
static
hyd F
9
.
0
F −
⋅
≤
„ Fstatic-min = weight before flooding,
including a weight reduction implied
by the weight inaccuracy factor.
30. DNV Marine Operations' Rules for Subsea Lifting Slide 30
2 December 2008
New Simplified Method – Added Mass
Hydrodynamic added mass for flat plates
b
a
4
76
.
0
A 2
33 ⋅
⋅
⋅
⋅
=
π
ρ
Example:
Flat plate where
length, b, above
breadth, a, is
b/a = 2.0 :
31. DNV Marine Operations' Rules for Subsea Lifting Slide 31
2 December 2008
New Simplified Method – Added Mass
Added Mass Increase due to Body Height
The following simplified approximation of the
added mass in heave for a three-dimensional
body with vertical sides may be applied :
o
33
2
2
33 A
)
1
(
2
1
1
A ⋅
⎥
⎥
⎥
⎦
⎤
⎢
⎢
⎢
⎣
⎡
+
−
+
≈
λ
λ
p
p
A
h
A
+
=
λ
Added Mass Increase due to Body Height
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
0 0.5 1 1.5 2 2.5
ln [ 1+ (h/sqrt(A)) ]
A33/A33o
1+SQRT((1-lambda^2)/(2*(1+lambda^2)))
and
where
„ A33o = added mass for a flat plate with a
shape equal to the horizontal projected
area of the object
„ h = height of the object
„ Ap = horizontal projected area of the object
32. DNV Marine Operations' Rules for Subsea Lifting Slide 32
2 December 2008
New Simplified Method – Added Mass
Added Mass from Partly Enclosed Volume
A volume of water partly
enlosed within large plated
surfaces will also contribute
to the added mass, e.g.:
„ The volume of water
inside suction anchors
or foundation buckets.
„ The volume of water
between large plated
mudmat surfaces and
roof structures.
33. DNV Marine Operations' Rules for Subsea Lifting Slide 33
2 December 2008
New Simplified Method – Added Mass
Added Mass Reduction due to Perforation
.
Effect of perforation on added mass
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 10 20 30 40 50
Perforation
Added
Mass
Reduction
Factor
e^-P/28
BucketKC0.1-H4D-NiMo
BucketKC0.6-H4D-NiMo
BucketKC1.2-H4D-NiMo
BucketKC0.5-H0.5D-NiMo
BucketKC1.5-H0.5D-NiMo
BucketKC2.5-H0.5D-NiMo
BucketKC3.5-H0.5D-NiMo
PLET-KC1-4
Roof-A0.5-2.5+
Hatch20-KCp0.5-1.8
Hatch18-KCp0.3-0.8
BucketKC0.1
BucketKC0.6
BucketKC1.2
RoofKCp0.1-0.27
RoofKCp0.1-0.37
DNV-Curve
Mudmat CFD
0
.
1
A
A
S
33
33
=
[ ]
34
/
)
5
p
(
cos
3
.
0
7
.
0
A
A
S
33
33
−
+
= π
28
p
10
S
33
33
e
A
A
−
=
if p< 5
if 5 < p < 34
if 34 < p < 50
Recommended reduction:
A33S = added mass for a non-
perforated structure.
„ No reduction applied in added mass when perforation is small. A significant drop in the
added mass for larger perforation rates. Reduction factor applicable for p<50.
34. DNV Marine Operations' Rules for Subsea Lifting Slide 34
2 December 2008
New Simplified Method – Example Case
Example: Submerged Foundation Bucket
kg
21867
0
.
2
3
4
2
A 3
o
33 =
⋅
⋅
⋅
⋅
= π
π
ρ
( )
s
33
2
2
2
s
33
o
33
2
2
'
s
33
2
2
3
o
33
A
8
4
0
.
2
4
.
0
100
P
61546
25
.
3
75
.
1
29496
A
29496
A
78
.
0
1
2
78
.
0
1
1
A
78
.
0
0
.
2
1
0
.
2
21867
0
.
2
3
4
2
A
of
reduction
No
:
n
Perforatio
kg
:
volume
inside
Incl.
kg
:
increase
Height
:
factor
Height
kg
:
plate
Flat
⇒
<
=
⋅
⋅
⋅
=
=
⋅
⋅
⋅
+
=
=
⋅
⎥
⎥
⎥
⎦
⎤
⎢
⎢
⎢
⎣
⎡
+
⋅
−
+
=
=
⋅
+
⋅
=
=
⋅
⋅
⋅
⋅
=
π
π
ρ
π
π
π
λ
π
π
ρ
„ Added mass for a thin circular disc:
„ Added mass increase due to body height:
( ) kg
33803
A
50
.
0
1
2
50
.
0
1
1
A
50
.
0
0
.
2
5
.
3
0
.
2
o
33
2
2
'
s
33
2
2
=
⋅
⎥
⎥
⎦
⎤
⎢
⎢
⎣
⎡
+
⋅
−
+
=
⇒
=
⋅
+
⋅
=
π
π
λ
„ Added mass including partly enclosed volume:
kg
65854
25
.
3
75
.
1
33803
A 2
s
33 =
⋅
⋅
⋅
+
= ρ
π
„ Added mass reduction due to perforation:
s
33
2
2
A
4
0
.
2
4
.
0
100
P of
reduction
No
SMALL ⇒
≈
=
⋅
⋅
⋅
=
π
π
Bucket Dimensions:
„ Height = 3.5m
„ Diameter = 4.0m
„ Plate thickness = 0.25m
„ Ventilation hole diameter = 0.8m
35. DNV Marine Operations' Rules for Subsea Lifting Slide 35
2 December 2008
New Simplified Method – Example Case
Example: Submerged Foundation Bucket
( ) N
5
2
2
2
r
P
D
D 10
37
.
0
48
.
1
25
.
0
0
.
2
96
.
0
0
.
2
5
.
0
v
A
C
5
.
0
F ⋅
=
+
⋅
⋅
⋅
⋅
=
⋅
⋅
⋅
⋅
= π
ρ
ρ
( )
[ ] ( )
[ ] ( ) N
5
2
w
33
2
ct
33
M 10
33
.
1
69
.
1
65854
13031
a
A
V
a
A
M
F ⋅
=
⋅
+
=
⋅
+
+
⋅
+
= ρ
2
m/s
and
m/s 69
.
1
v
5
.
5
2
a
48
.
1
e
5
.
5
2
75
.
1
v w
w
81
.
9
5
.
5
)
25
.
1
1
(
4
w
2
2
=
⋅
⎟
⎠
⎞
⎜
⎝
⎛
=
=
⋅
⎟
⎠
⎞
⎜
⎝
⎛
⋅
= ⋅
+
⋅
− π
π
π
Regular Wave Data:
„ Wave Height, Hmax = 3.5m
„ Wave Period, Tz = 5.5s
„ Water particle velocity and acceleration:
„ Drag force:
„ Mass force:
„ Hydrodynamic force:
1.0m
1.25m
CoG
Other Data
„ Buoyancy, ρV = 13031kg
„ Negligible crane tip motions
„ Lowering speed = 0.25m/s
( ) ( ) ( ) ( ) N
5
2
5
2
5
2
M
2
slam
D
hyd 10
4
.
1
10
33
.
1
10
37
.
0
F
F
F
F
F ⋅
=
⋅
+
⋅
=
−
+
+
= ρ
36. DNV Marine Operations' Rules for Subsea Lifting Slide 36
2 December 2008
Content
„ Brief overview of relevant DNV
publications
„ DNV Rules for Marine Operations, 1996,
Lifting – Capacity Checks
„ New Simplified Method for calculation of
hydrodynamic forces
„ CFD Analyses – Test Cases
37. DNV Marine Operations' Rules for Subsea Lifting Slide 37
2 December 2008
CFD Analyses – Test Cases
„ Computational Fluid Dynamics
(CFD) is a numerical method for
computing fluid flows based on
the Navier Stokes equations.
„ The CFD-program COMFLOW is
able to study complex free
surface problems applying the
Volume of Fluid method.
„ The fluid domain consists of a
cartesian grid where the fluid
cells are defined either as
boundary cells, empty cells,
surface cells or fluid cells.
„ Pressure forces are calculated
as the integral of the pressure
along the boundary of an object.
„ Motion responses are not
included, but the object can be
given a prescribed motion.
Structure
Fluid
domain
Inflow boundary,
Airy or Stokes
5th wave
Numerical
beach at
aft end
38. DNV Marine Operations' Rules for Subsea Lifting Slide 38
2 December 2008
CFD Analyses – Protection Structure
CFD analysis:
Regular Stokes 5th
wave: H=3.5m T=5.5s
Domain 95x30x37m
4.4 million fluid cells
Minimum grid size
0.18m near object,
stretched elsewhere
8.5x8.5m solid roof
and 10x10xØ1.0m top
frame
Ø1.0m legs, height 8m
and hollow
3.5xØ4.0m buckets at
x,y=±8.5m
ventilation holes
Ø0.8m
Wall thickness 0.25m
half model
60s simulation time
computer time 6weeks
39. DNV Marine Operations' Rules for Subsea Lifting Slide 39
2 December 2008
CFD Analyses – Protection Structure
Highest upwards
hydrodynamic force
when bucket is fully
submerged occurs
at time t=21s where
the object is located
in a wave trough.
Fhyd ≈ 1.1·105N
Buoyancy, ρVg
40. DNV Marine Operations' Rules for Subsea Lifting Slide 40
2 December 2008
CFD Analyses – Protection Structure
Half wave length
is ~23.5m and
the distance
between buckets
are 17m.
Hence, there is a
large phase
difference
between the
hydrodynamic
forces on forward
and aft bucket.
41. DNV Marine Operations' Rules for Subsea Lifting Slide 41
2 December 2008
CFD Analyses – Protection Structure
ComFlow results
show very high
slamming loads
on bucket top
and the solid roof
structure.
These values are
most likely too
high as
compressibility
and formation/
collapse of air
cushions are not
included in the
simulation.
Slamming load
on aft bucket
Slamming load
on roof structure
42. DNV Marine Operations' Rules for Subsea Lifting Slide 42
2 December 2008
CFD Analyses – Spool Piece
CFD analysis:
Regular Stokes 5th
wave: H=3.5m
T=5.5s
The wave length is
~equal spool length
Domain
130x30x31m
2.2 million fluid cells
Minimum grid size
0.25m near object,
stretched elsewhere
50m long closed
pipe with diameter
Ø1.0m
Two simulations;
1) half submerged
2) 2m below surface
22s simulation time
computer time 13-
18hrs
43. DNV Marine Operations' Rules for Subsea Lifting Slide 43
2 December 2008
CFD Analyses – Spool Piece Half Submerged
N
N 5
5
2
m
vertical
5
2
2
w
add
m 10
4
.
1
10
6
.
0
81
.
9
25
4
0
.
1
F
Vg
F
10
6
.
0
2
5
.
3
5
.
5
2
2
25
4
0
.
1
0
.
2
a
)
m
V
(
F ⋅
=
⋅
−
⋅
⋅
⋅
⋅
=
+
=
⇒
⋅
−
=
⋅
⎟
⎠
⎞
⎜
⎝
⎛
⋅
⋅
⋅
⋅
⋅
⋅
−
≈
⋅
+
= π
ρ
ρ
π
π
π
ρ
ρ
The wave length is equal
the spool piece length
Vertical force on aft half at time t=5s :
Half of the spool piece is
always out of the water.
The total force on each
half vary between zero
and buoyancy+Fhyd
44. DNV Marine Operations' Rules for Subsea Lifting Slide 44
2 December 2008
CFD Analyses – Spool Piece 2m Submerged
Total vertical force
Vertical force,
fwd half
Vertical force,
aft half
N
5
2
2
w
add
m 10
45
.
0
2
5
.
3
5
.
5
2
77
.
0
2
25
4
0
.
1
1025
0
.
2
a
)
m
V
(
F ⋅
=
⋅
⎟
⎠
⎞
⎜
⎝
⎛
⋅
⋅
⋅
⋅
⋅
⋅
≈
⋅
+
=
π
π
π
ρ
Brief approximation of mass force:
Dynamic force amplitude (mainly mass forces)
≈ 0.55·105 kN
45. DNV Marine Operations' Rules for Subsea Lifting Slide 45
2 December 2008
And then – One Final Comment:
When planning
Marine Operations,
remember to take
into account ....
46. DNV Marine Operations' Rules for Subsea Lifting Slide 46
2 December 2008
Easy Handling ..
47. DNV Marine Operations' Rules for Subsea Lifting Slide 47
2 December 2008
.. and Survey Access !!