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KNUD E. HANSEN A/S

Design of Wind Turbine Installation Vessel Pacific Orca for Swire Blue Ocean

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KNUD E. HANSEN A/S

Design of Wind Turbine Installation Vessel Pacific Orca for Swire Blue Ocean

An introduction to the technical aspects of the design of the Wind Turbine Installation Vessels Pacific Orca & Pacific Osprey by Senior Naval Architect Jesper Kanstrup, Knud E. Hansen A/S • • • • • • • •

Owner’s design requirements The development of Knud E. Hansen’s designs Legs, spud cans and jacking system Cranes Thrusters Engine arrangement Cargo deck and sea fastening Accommodation

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The Starting Point KNUD E. HANSEN A/S

The starting point was the world’s first purpose-built wind turbine installation vessel “Resolution”, a 130 m long and 38 m wide vessel with 6 square plate legs, which KEH had developed for “Marine Projects International” in 2001 and was delivered in 2003

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Owner’s Design Requirements KNUD E. HANSEN A/S

Owner’s initial design requirement: Water depth for jacking: Cargo deck space: Crane capacity: Speed: Dynamic positioning: Jacking conditions: Storm survival conditions: Complement:

45 m @ 10 m air gab, 5 m sea bed penetration sufficient for ten 2.2 MW wind turbines 1200 t for handling jackets and tripods >14 knots in calm water at design draught DP-2 @ 2 knots of current and 22 m/s head wind Hs = 1.6 m, Beaufort 6 Hs = 5.4 m, Beaufort 12 (36 m/s) 60 – 70 persons

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Design Development KNUD E. HANSEN A/S

One of the first designs: 6-legged 155.5 m long and 40.6 m wide vessel with 85 m square plate legs and engine room/casing forward

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Owner’s Increased Design Requirements KNUD E. HANSEN A/S

Relatively early in the design process the design requirements were increased for deeper water and larger wind turbines: Water depth for jacking: Cargo deck space: Significant wave height for jacking: Complement:

55 m @ 10 m air gab, 5 m sea bed penetration sufficient for twelve 3.6 MW wind turbines Hs = 2 m (depending on swell) 110 persons

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Design Development KNUD E. HANSEN A/S

6-legged 42 m wide vessel with 96 m truss legs and engine room/casing fwd

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Owner’s Increased Design Requirements KNUD E. HANSEN A/S

Later in the design process the requirements were further increased for even deeper water and support in the offshore oil & gas sector: Water depth for jacking: Storm survival as a wind turbine installation vessel with deck load of twelve 3.6 MW turbines (vertically stored towers): Storm survival as offshore support vessel without deck load of wind turbines: Significant wave height for jacking:

70 m @ 22 m air gab, 3 m sea bed penetration

100 years storm (70 m/s) on 60 m water depth @ 17 m air gab

100 years storm (70 m/s) on 70 m water depth @ 22 m air gab Hs = 2 – 2.5 m (depending on swell)

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Final KEH Design KNUD E. HANSEN A/S

6-legged 49 m wide vessel with 120 m truss legs and engine room/casing amidships

Principal particulars: Length over all: 161.0 m Breadth: 49.0 m Depth: 10.4 m Draught, design: 5.5 m Draught, summer max. 6.0 m Speed, design draught 90% MCR: calm water: 14.5 kn 15 % s.m.: 13.5 kn Deadweight for jacking: 8,400 t Complement: 110 pers.

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Pacific Orca – As-built KNUD E. HANSEN A/S

Principal particulars Length oa. excl. helicopter deck: 161.3 m Length oa. incl. helicopter deck: 164.9 m Length bp: 155.6 m Breadth, mld: 49.0 m Depth to main deck, mld: 10.4 m Draught, mld, design: 5.5 m Draught, max. summer: 6.0 m Gross tonnage: 14,000 t Lightweight incl. 105 m legs: 24,400 t Lightweight excl. legs: 18,400 t Deadweight, design draught: 9,900 t Deadweight, max. summer draught: 13,155 t Deadweight, max. for jacking: 8,400 t Speed, 90% MCR, 15% s.m.: 13.0 knots Tank capacities: Marine gas oil: Lube oil: Fresh water - potable: Water ballast: Treated sewage:

4,285 44 1,533 11,905 634

m3 m3 m3 m3 m3

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Number of legs KNUD E. HANSEN A/S

Hull lines and breadth of vessel with 4 or 6 legs If the width of the critical slot between the crane and the leg in the opposite side shall be maintained, a 4-legged vessel will be approximately 2.8 m wider than a 6-legged, because the spud cans have to be approx. 45 % larger With wider, but shorter hull and blunter bow a 4-legged vessel will have higher propulsion resistance and less directional stability

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Number of legs KNUD E. HANSEN A/S

Deck layout and loading flexibility with 4 or 6 legs 12 wind turbines or tripods/jackets

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Number of legs KNUD E. HANSEN A/S

Buoyancy distribution, LCG/LCB and leg loading with 4 or 6 legs Ideal situation:

Even trim and equal load on all legs Only possible with 5 or 6 legs or with 4 legs and a very blunt nose

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Number of legs KNUD E. HANSEN A/S

Safety against failure of jacking system or sea-bed punch-through

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Number of legs KNUD E. HANSEN A/S

Safety against sea-bed punch-through in sand overlying clay Phases of the development of the characteristic bearing resistance: a. initial bearing resistance when the widest cross-sectional area of the spudcan is in contact with the sand surface b. maximum bearing resistance in the upper sand layer c. interface bearing resistance when the spudcan penetrates into the underlying clay

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Number of legs KNUD E. HANSEN A/S

Number of recorded incidents according to “Guidelines for jack-up rigs with particular reference to foundation integrity – Research report 289 – 2004” Topic Area 

Before 1980 

1981‐ 1990 

1991‐ 2000 

2001‐ 2004 

Total 

Spudcan / Pile Interaction 

0 

8 

8 

7 

23 

Punch‐Through

0 

15 

13 

11 

39 

Settlement 

1 

4 

14 

10 

29 

Sliding

1 

3 

13 

6 

23 

Scour

0 

3 

2 

6 

11 

Instability of Seafloor 

0 

3 

2 

2 

7 

Shallow Gas

0 

0 

4 

1 

5 

Debris

0 

1 

1 

1 

3 

Rack Phase Difference 

0 

5 

1 

7 

13 

Footprints

0 

3 

2 

10 

15 

Layered Soils

1 

6 

3 

3 

13 

Cyclic Loading 

0 

7 

20 

8 

35 

Liquefaction / Pore‐Pressure 

1 

1 

9 

2 

13 

Fixity

2 

17 

54 

23 

96 

Fatigue

0 

0 

1 

4 

5 

Risk of Impact with Jacket 

0 

0 

4 

4 

8 

Case History 

0 

10 

13 

10 

33 

Unclassified

3 

2 

13 

9 

27 

Total No. of Documents 

7 

44 

108 

71 

230 

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Number of legs KNUD E. HANSEN A/S

Consequence of punch-through with 4 or 6 legs (Assuming all legs have been pre-loaded by +50 %)

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Number of legs KNUD E. HANSEN A/S

The choice between 4, 5 or 6 legs 4 legs + + -

Optimal loading flexibility Cheapest Critical in case of leg failure or punch-through Difficult to obtain an even load balance between the legs Higher water resistance and less directional stability because of wider/shorter hull

6 legs + + + -

Optimal safety against leg failure or punch-through Optimal load balance between the legs Lower resistance and better directional stability because of longer/slimmer hull Restrictions in loading flexibility Expensive

5 legs + -

Compromise between loading flexibility, safety and load distribution Restricts the vision from the bridge, Restricts the boom resting position Does not provide symmetrical pre-loading of the legs 18

Type of Legs KNUD E. HANSEN A/S

Two types of legs – plate legs (square or tubular) or truss legs Plate legs + + + -

Cheap and with good shear strength Compact design takes little space on deck Jacking systems are simple and relatively cheap Considerably heavier than truss legs Only suitable for water depths up to approximately 45 m because of the weight

Truss legs + + + -

Suitable for water depths of more than 100 m Much lighter than plate legs Less wave impact loads Very expensive Jacking systems for truss legs are much more expensive than for plate legs

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Spudcans KNUD E. HANSEN A/S

Types of spudcans

Spudcan with rim skirt Very skid resistant, but very high water resistance because of the recess Conical spudcan Standard solution, but if the spudcan is not circular the rim will not at all points be in level with the bottom of the ship, which will increase the water resistance Spudcan with flat bottom and center cone Low water resistance as the rim is in level with the bottom of the ship, but not as self-centering as a conical spudcan Spudcan designed for easy assembly Easy assembly in dry dock, but high water resistance because of slots between spudcan and leg well and the design limits the area 20

Spudcans KNUD E. HANSEN A/S

Assembly of leg-well section and leg/spud can Assembly procedure if the spudcan is too large for the leg including the spudcan to be lowered into the leg-well Keel blocks need to be relatively high

Assembly procedure if the spudcan is designed so that the assembled leg including the spudcan can be lowered into the leg-well

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Spudcans KNUD E. HANSEN A/S

Example of spudcan, which is designed so that the assembled leg including the spudcan can be lowered into the leg well

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Jacking System KNUD E. HANSEN A/S

GustoMSC hydraulic hand-over-hand systems for square plate legs with long lifting cylinders and short holding cylinders – Interrupted motion Left – System on MPI Resolution with lifting collars Right – High performance system with lifting yokes

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Jacking System KNUD E. HANSEN A/S

GustoMSC hydraulic guided-yoke type for tubular plate legs Continuous motion

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Jacking System KNUD E. HANSEN A/S

Knud E. Hansen A/S compact hydraulic hand-over-hand system with lifting collars for 3-chorded truss legs Continuous motion

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Jacking System KNUD E. HANSEN A/S

Friede & Goldman electrical rack-and-pinion Continuous motion

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Jacking System KNUD E. HANSEN A/S

Hydraulic systems: + + + + -

Limited wear and tear Shock tolerant Low price Compact design Long-term maintenance issues because of complicated design with many valves, hoses, electrical switches and problematic hydraulic seals - Risk of spillage of hydraulic oil

Electrical rack-and-pinion: + Limited long-term maintenance + High-speed continuous jacking + High redundancy (jacking / lowering is still possible even if one or two units per leg are out of service) - Expensive - Not very shock tolerant - Must be heavily over-dimensioned (+50%) to deal with wear and tear - Need biodegradable rack greasing oil

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Legs & Jacking System – Final KEH Design KNUD E. HANSEN A/S

Legs & jacking system • • • • • • • • • • • • • • • • •

Number of legs: Length of legs: Leg protrusion below BL of ship: Number of chords per leg: Chord distance: Chord type: Jacking system maker/type: Jacking units: Jacking unit motors: Number of jacking units per leg: Jacking speed, raising/lowering legs: Jacking speed, raising/lowering hull: Rated normal jacking capacity per leg: Pre-loading capacity per leg: Max. soil penetration capacity per leg: Static holding capacity per leg: Rack chock system for static holding:

6 120 m (fitted 105 m) 80 m @ 105 m legs / 95 m @ 120 m legs 3 9.7 m Split-pipe, 6” rack BLM electrical rack-and-pinion Double-pinion D110 V units 690 V, 70/90 kW, 1800/3600 RPM 3x6 2.4 m/min 1.2 m/min 4,500 t 6,750 t (+50%) 8,820 t 10,650 t No

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Legs & Jacking System – Final KEH Design KNUD E. HANSEN A/S

Legs & jacking system – Fatigue life / wear and tear Jacking system and leg racks is over-dimensioned by 50 % to reach a theoretical fatigue life, which is defined as at least 5000 cycles (e.g. 200 cycles per year during 25 years) of each of the following operations: Leg lowering: Leg pre-loading / soil penetration:

25 m 8m

Leg load: 750 t Leg load: 6,600 t

Hull lifting: Hull lowering:

15 m 15 m

Leg load: 3,700 t (2,500 cycles) Leg load: 3,700 t (2,500 cycles)

Hull lifting: Hull lowering:

15 m 15 m

Leg load: 4,400 t (2,500 cycles) Leg load: 4,400 t (2,500 cycles)

Leg soil extraction: Leg lifting:

8m 25 m

Leg load: 6,600 t Leg load: 750 t

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Leg Configuration – Final KEH Design KNUD E. HANSEN A/S

Longitudinal position and turn of legs Aft • optimization of width of slot between crane and jacking frame • optimization of lines in way of spudcans Midship • optimization of horizontal operational sector of aux crane • Longitudinal position optimized for even load balance between legs Forward • retracted for refined lines in shoulder region and reduced buoyancy forward • optimization of space for MOB and life boats • optimization of lines in way of spud cans

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Spudcans – Final KEH Design KNUD E. HANSEN A/S

Design of spudcans optimized for: • • •

adapting to hull lines and minimum water resistance (necessary because of the required service speed) maximum area (125 m2) minimal bending moment in legs considering the large area

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Legs & Jacking System – Pacific Orca KNUD E. HANSEN A/S

120 m truss legs with rack-and-pinion jacking system and 6 BLM D110 V (double-pinion) units per leg chord – Identical to final KEH design

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Spudcans – Pacific Orca KNUD E. HANSEN A/S

Spudcans are designed so that the legs can be lowered into the leg wells (jacking frames and upper leg guides not fitted during this procedure)

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Spudcans – Pacific Orca KNUD E. HANSEN A/S

Spudcans: Area:

Conical, buoyant 95.4 m2

Optimal height of legs for minimum water resistance is 500 mm below bottom of ship

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Crane Configuration KNUD E. HANSEN A/S

Initial KEH proposal for work-around-leg cranes for truss legs Main crane: Aux crane:

Asymmetrical, 1200 t, rope luffing Asymmetrical, 300 t, hydraulic luffing with telescopic boom, which can cover most of the main deck and work below the main crane while this is resting in the boom rest cradle

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Crane Configuration KNUD E. HANSEN A/S

KEH design with Huisman cranes Main crane: Aux crane:

1200 t 300 t

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Crane Configuration – Final KEH Design KNUD E. HANSEN A/S

Main crane: Aux crane:

NOV work-around-leg w. 2 x 600 t main hoists for 1200 t in tandem Huisman 300 t rope luffing, mounted on cantilever on jacking frame

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Crane Configuration – Pacific Orca KNUD E. HANSEN A/S

Main crane

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Crane Configuration – Pacific Orca KNUD E. HANSEN A/S

Main crane Make: Type:

NOV Amclyde Rope luffing, “work-around-leg”

Main hoists: Load: Max load radius:

2 x 600 t side by side for 1200 t in tandem 1200 t @ (14) 18 - 31 m 600 t @ 50 m 91 m

Aux hoist: Max load radius:

500 t @ 20 – 60 m 107 m

Whip hoist:

50 t @ 23 – 113 m, approved for man riding

Tuggers:

7 x 5 t SWL

Max. wind speed:

20 m/s

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Crane Configuration – Pacific Orca KNUD E. HANSEN A/S

Auxiliary crane Make: Type: Main hoist: Aux hoist:

NOV Amclyde Hydraulic 35 t @ 6.5 to 35 m 25 t @ 6.5 to 40 m approved for man-riding

Knuckle-boom crane Make: Type:

NOV Amclyde Hydraulic with telescopic jib Hoist: 2 t @ 25 m, 4 t @ 14 m Man-riding radius: 30 m by operating telescopic jib

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Stern Thrusters KNUD E. HANSEN A/S

ABB’s gearless Compact Azipod right Schottel geared azimuth thruster below

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Stern Thrusters KNUD E. HANSEN A/S

Voith Schneider

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Stern Thrusters KNUD E. HANSEN A/S

Geared azimuth thrusters + Cheap and well proven solution - Sensitive to ventilation shocks because of the gears - Must be turned 180 degrees to reverse thrust

Gearless Compact Azipods + + + -

Very robust and insensitive to ventilation shocks because of the lack of gears Simple installation High efficiency because of permanent magnet motor and no gear losses Not as well proven as standard geared azimuth thrusters More expensive than geared azimuth thrusters Must be turned 180 degrees to reverse thrust

Voith Schneider thrusters + + + + -

Very quick steering reaction – excellent for DP and course keeping Do not have to be turned 180 degrees to reverse thrust Slow turning with low vibrations Insensitive to ventilation shocks because of the slow turning motion Very expensive Very heavy Not suitable for higher speeds 43

Bow Thrusters KNUD E. HANSEN A/S

Left: Middle: Right:

Schottel tunnel thruster Shottel & Rolls Royce retractable azimuth thrusters Brunvoll retractable combi azimuth/tunnel thruster

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Bow Thrusters KNUD E. HANSEN A/S

Standard tunnel thrusters + Cheap and well proven solution + Works on shallow water - Low efficiency at speeds above 4 knots

Retractable azimuth thrusters + Much more efficient on deep water than tunnel thrusters - Not suitable on shallow water where they cannot be lowered

Retractable combi azimuth/tunnel thrusters + + -

Much more efficient on deep water than tunnel thrusters Works both as tunnel thrusters and retractable azimuth thrusters Nozzle not quite as efficient as on normal retractable thrusters More expensive than normal retractable thrusters

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Thruster Configuration – Final KEH Design KNUD E. HANSEN A/S

Thruster configuration Stern thrusters: Under consideration: Final choice: Reason for decision:

4 x 3.4 MW Voith Schneider (36R6/265-2) 4 x 3.4 MW ABB Compact Azipods Price and weight

Bow thrusters: Under consideration: Final choice: Reason for decision:

2 x 2.2 MW Brunvoll combi + 1 x 2.2 MW tunnel 2 x 2.2 MW retractable + 2 x 2.2 MW tunnel Better power balance between stern and bow for DP

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Thruster Configuration – Final KEH Design KNUD E. HANSEN A/S

Dynamic positioning Upper view: all thrusters operating Lower view: one thruster lost Note that in both cases DP can be performed by adjusting the power balance without turning the thrusters

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Thruster Configuration – Pacific Orca KNUD E. HANSEN A/S

Thruster Configuration Bow tunnel thrusters: Bow retractable azimuth thrusters: Stern azimuth thrusters:

2 x Brunvoll FU100LTC2750, 2.2 MW 2 x Brunvoll AR100LNA2600, 2.2 MW 4 x ABB Compact Azipod, 3.4 MW

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Cargo Deck – Final KEH Design KNUD E. HANSEN A/S

Structural design of cargo deck Grid system of transverse girders with a spacing of 1.4 m and longitudinal girders or reinforced longitudinals (HP 300x11) also with a spacing of 1.4 m creates a grid system of strong points in a mesh of 1.4 x 1.4 m Max. load in strong points: Uniformly distributed load: Aft and amidships: Forward: Wear & tear allowance: Aft & amidships: Forward:

250 t down / 200 t up (pull) @ 4.2 m transverse distance between two loads on same transverse girder 20 t/m2 15 t/m2 3 mm 2 mm

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Cargo Deck – Final KEH Design KNUD E. HANSEN A/S

Structural design of cargo deck

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Cargo Deck – Pacific Orca KNUD E. HANSEN A/S

Cargo deck area: 4300 m2 Grid system of strong points aft and amidships (mesh 1.4 x 1.4 m) Max. load in strong points: Downwards: 250 t Pull: 200 t Uniformly distributed load: 15 t/m2 Wear & tear allowance: Aft & amidships: 3 mm Forward: 1 mm

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Engine Arrangement – Final KEH Design KNUD E. HANSEN A/S

Engine room arrangement Under consideration:

Engine room and casing forward for optimal deck space for cargo in way of the midship legs

Final choice:

Engine room and casing amidships

Reason for decision:

Wider stern-facing bridge and less noise and vibrations in the accommodation

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Engine Arrangement – Final KEH Design KNUD E. HANSEN A/S

Engine room arrangement

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Engine Arrangement – Pacific Orca KNUD E. HANSEN A/S

Engine arrangement

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Engine Arrangement – Pacific Orca KNUD E. HANSEN A/S

Diesel generators Make and type: Type of fuel: Rated electrical power:

8 x MAN 9L27/38, 750 RPM Marine gas oil 3024 kW

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Engine Cooling while Jacked-up KNUD E. HANSEN A/S

Engine cooling: • •

Sea water cooling by submersible pumps Air cooling

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KNUD E. HANSEN A/S

Engine Cooling while Jacked-up Pacific Orca

Sea water pumps arranged in SB just aft of the forward leg Pumps will have to be lowered over the side whenever the vessel is jacked

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Accommodation – Final KEH Design KNUD E. HANSEN A/S

Accommodation block

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Accommodation – Pacific Orca KNUD E. HANSEN A/S

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Accommodation – Pacific Orca KNUD E. HANSEN A/S

Accommodation Number of single cabins:

111, all with bath room

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Helicopter Deck – Pacific Orca KNUD E. HANSEN A/S

Helicopter deck D-diameter: 22 m, Load-bearing capacity: 12.8 t (medium size helicopters)

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Questions? KNUD E. HANSEN A/S

? Thanks for your attention

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