Phase 0: Design report
- Producing design report
- Planning OTAO® activities
- Producing engineering plans
Phase 1: Design and engineering
- Determining loads involved in transport and immersion
- Processing salt/fresh water quality data
- Design of temporary bearings (tiles and pins)
- Dimensioning and detailed specification of transport and immersion
- Prestress Dimensioning of ballast tanks
- Dimensioning of OTAO® suspension points
- Determining deck layout
- Determining transport and immersion loads
- Dimensioning mooring system
- Dimensioning dock winch system
- Dimensioning immersion site winch system
- Design of closure joint frame
- Recommendation on choice of 'Gina' gasket profile
- Dimensioning closure joint wedges
- Dimensioning bulkheads
- Dimensioning underflow system
- Processing of as-built dimensional data
- Dimensioning of the Jacking System for horizontal positioning
- Outline dimensional characteristics during immersion
Phase 2: Preparation
- Drafting scenarios and activity plans
- OTAO® coordination during casting of tunnel elements
- Producing dimensional plan for sinking
- Positioning and dimensioning foundation tiles
- Dimensioning tunnel elements for sinking
- Dimensioning immersion trench (third parties)
- Dredging immersion trench (third parties)
Phase 3A: Construction of casting basin and temporary mooring location
- Floating and shifting TE
- Winching out TE
- Transporting TE to temporary mooring site
- Preparing temporary mooring site (excl. buoys, lighting etc.)
- Making TE ready for immersion
- Installing shaft and survey tower
- Filling ballast tanks and checking for leaks
- Emptying TE ballast tanks
- Installing winches on anchors and working platforms developed by us and made available by you
- Preparing immersion pontoons
- Securing immersion pontoons to TE
- Attaching fenders to TE
- Checking navigation depth of access channel for keel clearance
- Attaching winch lines to TE by divers
Phase 3B: Work at the immersion site
- Setting out anchors and installing winch pontoons
- Installing anchor points on shore for forward lines
- Transporting TE to immersion site
- Making immersion trench ready (survey/ /anchor points etc.)
- Installing anchors
- Installing winches
- Attaching winch lines to TE by divers
- Securing TE in winch lines
- Seeking sheltered site in fast current conditions
- Attaching forward lines
- Miscellaneous diving work
- Loading TE with ballast to immersion weight
- Immersing TE
- Dimensioning during immersion
- Diver check of 'Gina' gasket
- Positioning of jacks on foundation tiles, check by divers
- Attaching horizontal pulling cylinders (by divers)
- Fastening TE
- Emptying immersion joint
- Check of TE position
- Jack corrections of TE position
- Check of immersion trench
- Under flowing TE
- Check measurements of under flowing reaction forces
- Removing towers and jacks
- Backfilling and covering immersion trench
- Diving work for the immersion operation
Possible supplies (temporary nature)
- Deck layout
- Bulkheads
- Ballast water system
- Pontoons
- Winches and fastenings
- Ducts
- Bulkhead doors
- Access shafts
- Measurement masts
- Tugs
- Sheer legs and pontoons
- Under flowing sand
- Sand injection installation
- Support vessels
- Jacks
Outside standard Mergor scope;
- Permits
- Accommodation on site
- Communication facilities including telephone, fax and internet connections
- Consequences of wind on the immersion operation
- CAR insurance
- etc. (more details to follow)