Repsol YPF


Alba-North Sea (Chevron U.K. Ltd.)

Main dimensions

  • Length overall: 248.20 m
  • Length between perpendicular: 237.20 m
  • Moulded beam: 42.00 m
  • Moulded depth: 23.00 m

Main capacities

  • Displacement: 162,000 ton
  • Crude Storage: 890,000 bbls
  • Segregated water ballast: 53,500 m³

Crude Oil storage and offloading

7 cargo tanks plus 2 slop tanks operated by hydraulic submerged pumps

  • Crude storage: 890,000 bbls
  • Offloading rate: 35,000 bbls/h

Station keeping system

The vessel rotates around a Bottom Mounted Internal Turret located forward, just aft of the collision bulkhead. Twelve mooring lines, each with 6’’ diam., at the upper end. Remaining configuration will be dictated by site specific conditions
A 19 tons azimuth thruster is installed to improve heading and manoeuvrability

Subsea interface

4 risers up to 12 inch. are handled through the turret upgranding of number an size of risers is feasible
The turret system includes a pig-trap device

Turret Transfer system

Transfer or fluids between turret and vessel is made through a multichamber swivel installed above deck
Control and electrical power lines are handle through the swivel

Power generation and utilities

  • Diesel generator: 4×1,700 kW
  • Emergency diesel generator: 1×750 kW
  • UPS
  • Fire and Gas detection
  • Fire pumps: 3×560 m³/h, 3×100% independently fed
  • Offshore crane de 20 ton a 20 m

Main control offices and quarters

Fully enclosed H-120 accommodation module located aft

  • Complements for 56 people
  • Central control room
  • Muster area
  • Helicopter deck (S-61) and reception

Structural design

The structure is designed for the 100 year storm and fatigue criteria to operate 20 years in the North Sea
The unit has double side shell




  • UK certificate of Fitness (S.I 289 and its Guidance)
  • Statement of Compliance with:
  •       • S.I. 611 (Fire Fighting)
          • S.I. 486 (Life Saving)
          • S.I. 1019 (Operational Safety health and welfare)
          • S.I. 1029 (Emergency pipeline valves)
          • S.I. 1542 (Emergency procedures)


Safety Features

Accommodation surrounded by H-120 bulkheads, with fore and aft bulkheads extending to sides to project the life-boat areas
Fire main of the ring type around the desck. Three independently driven fire pumps providing 2×100% even when the third is in maintenance. Deck monitors fed from both sides of the ring
Diesel generators installed in two separate compartments of the engine room
Double skin in side shell (with segregated ballast) to sustain collision and pollution hazard