Concept
The Saipem 7000, originally named the Micoperi 7000, was conceived in the mid-1980s by its original owners Micoperi as a multipurpose offshore oil platform installation vessel that would be able to install very large oil production platform decks (known as integrated decks) as well as the decks' supporting structures (known as jackets) using its two very large fully revolving cranes. It would also be able to support the offshore completion of the platform by providing hotel and workshop facilities for large construction crews. Saturation diving facilities would support subsea connection work. The vessel's size and semi-submersible form would allow it to operate in worse weather conditions than smaller and conventionally shaped vessels.
The huge cost of a vessel of this size would be offset by the cost and time savings made by the oil company as the large integrated decks could be completed, tested and commissioned onshore. Prior to the introduction of the large crane vessels, offshore oil platforms were made up of 1000 - 2000 tonne modules which were lifted into place individually by smaller SSCVs or monohull crane vessels and then connected together offshore, tested and then commissioned; this often took over a year. Other savings in the installation of the jackets could also be made.
Original specification
Heavy lift
The Saipem 7000 has two NOV Lifting and Handling AmClyde model Saipem 7000 fully revolving cranes. Each has a 140-metre-long boom fitted with 4 hooks. Each crane is capable of lifting up to 7,000 tonnes at 40 m lift radius using the main hook. The auxiliary hook capacities are 1st Auxiliary 2,500 tonnes at 75 m radius and 2nd Auxiliary 900 tonnes at 115 m. The whip hook has a capacity of 120 tonnes at 150 m. The 2nd Auxiliary hook can be deployed to a water depth of 450 m. The two cranes are capable of a tandem lift of 14,000 tonnes.
Each crane was fitted with 15600 hp engines to power the boom and load hoists, 9 tugger lines and the crane slewing system. The cranes use 48 mi of wire rope of various diameters.
Ballast system
The Saipem 7000 was fitted with two ballast systems: a conventional pumped system which could transfer up to 24,000 tonnes of water per hour using 4 pumps and a free flooding system. The free flooding system used 2 m diameter valves to open certain compartments to the sea thus trimming or heeling the vessel. This allows the vessel to lift cargoes from barges much faster than if just the crane hoists are used.
Power system
The vessel's main power is provided by eight 12-cylinder 8400 hp diesel engines built by Grandi Motori Trieste, a former Fincantieri company. Later Grandi Motori was purchased by the Finnish Wärtsilä. They provide up to 47,000 kW of electric power at 10,000 V 60 Hz for propulsion and positioning. Auxiliary power is provided by two 6-cylinder 4200 hp GMT diesel engines. There is also an emergency generator.
Total power that can be supplied is 57000 kW.
Mooring system
The vessel was supplied with 16 anchor lines, 4 at each corner. Each line consists of 3350 m of 96 mm wire rope, 50 m of 92 mm chain and a 40-tonne Norshore Mark 3 anchor. Each line has its own 1350 kW single drum winch. The mooring system can be used in water depths of up to 450 m.
The Saipem 7000 is also equipped with two anchor windlasses equipped with 550m of 130mm chain and 35 tonne anchor.
Thrusters
The vessel was fitted with 12 thrusters—6 on each hull. They are, per hull:
- 1 No. 2500 kW bow thrusters in athwartship tunnels
- 2 No. 3500 kW azimuthing retractable thrusters under the hull
- 2 No. 4500 kW azimuthing thrusters at the stern—these are used when transiting
- 1 No. 5500 kW azimuthing retractable thrusters under the hull (added during 1999 refit)
Dynamic positioning system
The vessel is equipped with a dynamic positioning system which uses either the thrusters or the mooring system or a combination of both, controlled by a number of computers, to hold the vessel in a predefined location.
- Two Menck MHU 3000 hydraulic hammers capable of 3000 kJ impact energy.
- Two Menck MHU 1700 hydraulic hammers.
- Two Menck MHU 1000 hydraulic hammers.
- Two Menck MHU 600 hydraulic hammers.
- One Menck MHU 220 hydraulic hammer.
- One Menck MHU 195 hydraulic hammer.
- Two underwater power packs.
- One hydraulic hammer compensator.
- Various Menck steam hammers and their associated boilers
- Sixteen 35 cm diameter 60 m long cable laid slings
- A containerized 14-man saturation diving system which can be moved to any of the vessel's three moon pools
- Two leveling systems, range 66" - 72" diameter; 900 tonne capacity each.
- Two external levelling systems; 1000 tonnes each.
Handling deck equipment
- One Kobelco Crawler Crane 70 tonnes capacity
- One Hydraulic Tyred Crane 35 tonnes capacity
- Two Fork Lifts 5 tonnes capacity each
Accommodation
The accommodation designed for 800 people contains 30 triple cabins, 335 double cabins, 35 singles and 5 suites. The accommodation also contains a large galley and mess rooms, a hospital, cinema and lounges.
Heavy lift
The Saipem 7000 has two NOV Lifting and Handling AmClyde model Saipem 7000 fully revolving cranes. Each has a 140-metre-long boom fitted with 4 hooks. Each crane is capable of lifting up to 7,000 tonnes at 40 m lift radius using the main hook. The auxiliary hook capacities are 1st Auxiliary 2,500 tonnes at 75 m radius and 2nd Auxiliary 900 tonnes at 115 m. The whip hook has a capacity of 120 tonnes at 150 m. The 2nd Auxiliary hook can be deployed to a water depth of 450 m. The two cranes are capable of a tandem lift of 14,000 tonnes.
Each crane was fitted with 15600 hp engines to power the boom and load hoists, 9 tugger lines and the crane slewing system. The cranes use 48 mi of wire rope of various diameters.
Ballast system
The Saipem 7000 was fitted with two ballast systems: a conventional pumped system which could transfer up to 24,000 tonnes of water per hour using 4 pumps and a free flooding system. The free flooding system used 2 m diameter valves to open certain compartments to the sea thus trimming or heeling the vessel. This allows the vessel to lift cargoes from barges much faster than if just the crane hoists are used.
Power system
The vessel's main power is provided by eight 12-cylinder 8400 hp diesel engines built by Grandi Motori Trieste, a former Fincantieri company. Later Grandi Motori was purchased by the Finnish Wärtsilä. They provide up to 47,000 kW of electric power at 10,000 V 60 Hz for propulsion and positioning. Auxiliary power is provided by two 6-cylinder 4200 hp GMT diesel engines. There is also an emergency generator.
Total power that can be supplied is 57000 kW.
Mooring system
The vessel was supplied with 16 anchor lines, 4 at each corner. Each line consists of 3350 m of 96 mm wire rope, 50 m of 92 mm chain and a 40-tonne Norshore Mark 3 anchor. Each line has its own 1350 kW single drum winch. The mooring system can be used in water depths of up to 450 m.
The Saipem 7000 is also equipped with two anchor windlasses equipped with 550m of 130mm chain and 35 tonne anchor.
Thrusters
The vessel was fitted with 12 thrusters—6 on each hull. They are, per hull:
- 1 No. 2500 kW bow thrusters in athwartship tunnels
- 2 No. 3500 kW azimuthing retractable thrusters under the hull
- 2 No. 4500 kW azimuthing thrusters at the stern—these are used when transiting
- 1 No. 5500 kW azimuthing retractable thrusters under the hull (added during 1999 refit)
Dynamic positioning system
The vessel is equipped with a dynamic positioning system which uses either the thrusters or the mooring system or a combination of both, controlled by a number of computers, to hold the vessel in a predefined location.
- Two Menck MHU 3000 hydraulic hammers capable of 3000 kJ impact energy.
- Two Menck MHU 1700 hydraulic hammers.
- Two Menck MHU 1000 hydraulic hammers.
- Two Menck MHU 600 hydraulic hammers.
- One Menck MHU 220 hydraulic hammer.
- One Menck MHU 195 hydraulic hammer.
- Two underwater power packs.
- One hydraulic hammer compensator.
- Various Menck steam hammers and their associated boilers
- Sixteen 35 cm diameter 60 m long cable laid slings
- A containerized 14-man saturation diving system which can be moved to any of the vessel's three moon pools
- Two leveling systems, range 66" - 72" diameter; 900 tonne capacity each.
- Two external levelling systems; 1000 tonnes each.
Handling deck equipment
- One Kobelco Crawler Crane 70 tonnes capacity
- One Hydraulic Tyred Crane 35 tonnes capacity
- Two Fork Lifts 5 tonnes capacity each
Accommodation
The accommodation designed for 800 people contains 30 triple cabins, 335 double cabins, 35 singles and 5 suites. The accommodation also contains a large galley and mess rooms, a hospital, cinema and lounges.
1999 vessel re-fit
During the winter of 1999/2000 the Saipem 7000 underwent a refit to enhance its positioning and power systems and add a J-lay system.
The power system was upgraded to provide up to 70,000 kW using 12 diesel generators. To improve the vessel's resilience the generators are distributed between four separate engine rooms.
Two 5,500 kW retractable azimuthing thrusters were added, one below the forward part of each hull. The DP system control computers were also replaced.
The hull, deck and deck structures were modified to accept the Gusto designed J-lay tower and its support equipment. The J-lay tower can lay pipe from 4" to 32" diameter with a tension of up to 525 tonnes (5.15 MN) using the tensioners and up to 2,000 tonnes (20 MN) when using friction clamps. The deck can be used to store up to 10,000 tonnes of pipe.
To allow space for the increased equipment some items from the original specification were removed, including 2 anchor winches from the bow, all the moon pools, and the boilers used to provide steam for the steam hammers.
