JACKET TOPSIDE TRANSPORTATION SEA FASTENING AND INSTALLATION
We provide stability analysis and planning for heel and trim balance by ballasting and deballasting sequence and loading / off loading, and the up-ending of heavy structures by heavy lifting crane / ballasting.
A transportation structural analysis shall be performed on the deck subjected to barge motions associated with towing. Seafastening and grillages shall be modeled explicitly as structural elements.
Load cases based on conservative combinations of motions are developed using barge motion data determined by a hydrodynamic analysis for the transportation barge.
The scope of work for the transportation normally includes
A transportation structural analysis shall be performed on the deck subjected to barge motions associated with towing. Seafastening and grillages shall be modeled explicitly as structural elements.
Load cases based on conservative combinations of motions are developed using barge motion data determined by a hydrodynamic analysis for the transportation barge.
The scope of work for the transportation normally includes
- Calculation of Maximum motions and accelerations of the barge
- Resistance force during tow calculation
- Sea-fastening Design
- Stability analysis
OFFSHORE LOADOUT, TRANSPORTATION AND INSTALLATION ANALYSIS
We provide coordination and supervision of structure load out, transportation and installation.
transportation analysis of the topside or heavy modules during wet tow from the sheltered area to the final installation site requires following checks
- Transportation ballast plan
- Stability analysis (Intact and Damaged)
- Barge longitudinal strength check
- Motion and acceleration response analysis
- Bollard pull calculation (for Towing Tug Selection)
- Calculations and sketches of barge ballast plans.
- Description of manoeuvring plans to clear harbor.
- Description of instructions to tow master, if any, regarding headings, or speeds which, if Encountered, would exceed stability or strength limitations assumed or determined by analysis.
- Contingency plans for Avoidance of adverse weather
- Transit schedule.
- Communication plans, including methods of communicating with Company.
- Documented description of the wind and sea conditions expected during the tow.
- Weather forecasting services which Transportation Contractor will provide to tug captain(s) prior to and during tow.
- Planned inspection of cargoes during tow.
- Tow resistance/propulsion calculations.
- Interactions and responsibilities of tow personnel and vessels during installation.
- Safety plan and evacuation plan of personnel during tow.
- Stowage plan for transportation
- Transportation rigging
- Lifting rigging arrangement during transportation
- Transportation barge towing
- FPSO transportation manual
- Deck strength check for transportation
- Seafastening design and check: stanchion check, stacking check, overturning check, longitudinal sliding check, lashing design or turnbuckle check, and padeye check.
- Basis of Design for Structures Transportation and Installation
- Piles Driveability Report
- Conductors Driveability Report
- Transportation Analysis Marine Spread
- Transportation Analysis Grillage and Seafastening Design
- Lifting Analysis (Rigging Design)
- Upending Analysis (Rigging Design)
- Conductors Rigging and Upending Design
- Barge Loadout Stern Wedges Design
- Barge Local Strength Check during Loadout
- Derrick Barge Mooring Analysis During Installation
- Transportation General Arrangement
- Transportation Barge Towing Arrangement
- Grillage and Seafastening Details
- Lifting - Rigging General Arrangement
- Lifting - Rigging Details
- Lifting and Upending - Rigging Arrangement During Transportation
- Rigging Platform for Upending Slings
- Upending Sequence
- Derrick Barge Anchor Pattern During Installation
- Arrangement for Levelling of
- Pile Upending and Installation Sequence
- Conductor Upending and Installation Sequence
- Installation Sequence
- Upending-Rigging Details
- Loadout Configuration
- Barge Loadout Stern design
- Operating Manual - Derrick Lay Barge (Structural - Transportation and Installation)
- Operating Manual - CPP Topside Barge
- Transportation Manual - Jacket
- Transportation Manual - Jacket Piles,Conductors & Boatlanding
- Transportation Manual - Topside
JACKET UNPILED ("ON-BOTTOM") STABILITY
The jackets are designed to be placed on the seabed without undue risk of being overturned, or moved, by the action of wave and current prior to establishment of the piled foundation.
FLOTATION/UPENDING ANALYSIS
We Perform three dimensional linear analysis of the jacket during flotation and upending.
Buoyant members are designed for their respective submerged depths using appropriate safety factors. The reserve buoyancy after jacket launch will follow Noble Denton criteria. During upending by crane assistance with controlled ballasting, sufficient bottom clearance is provided.
Jacket flotation and upending stability, and jacket member stresses are determined by using a three dimensional computer simulation.
The stability of the jacket during upending are assessed for roll and pitch movement.
During upend by controlled ballasting, the minimum bottom clearance for the substructure will follow Noble Denton rules.
Buoyant members are designed for their respective submerged depths using appropriate safety factors. The reserve buoyancy after jacket launch will follow Noble Denton criteria. During upending by crane assistance with controlled ballasting, sufficient bottom clearance is provided.
Jacket flotation and upending stability, and jacket member stresses are determined by using a three dimensional computer simulation.
The stability of the jacket during upending are assessed for roll and pitch movement.
During upend by controlled ballasting, the minimum bottom clearance for the substructure will follow Noble Denton rules.
JACKET MUDMAT DESIGN
Mudmats are designed for the on-bottom weight of the jacket and the additional loads generated by wind, waves and current prior to installing the piled foundation. The weight of any piles hanging from the jacket prior to pile driving operations are included.
The mudmats and their supports shall be designed in accordance with the provisions of API RP 2A.
