Delivery of the CSO Deep Blue in March 2001.
Deep Blue's sailing bridge.
Deep Blue's operations bridge.
CSO Deep Blue towed in Ulsan Harbour, Korea, August 2000.
CSO Deep Blue before the installation of her pipelay system, March 2001.
Artists impression of the CSO Deep Blue.

The CSO Deep Blue is the world’s largest purpose-built ultra deepwater pipelay and subsea construction vessel. It can lay flowlines and umbilicals, and support developments in water depths ranging from 75m to 2,500m. The vessel is owned and operated by Technip Marine.

The CSO Deep Blue has an overall length of 206.5m and a moulded breadth of 32m. It has a moulded depth of 17.8m and an operating draught of from 7.5-8.95m, with a 10m maximum of draught. It has a 55,234t displacement and is 33,791gt. The upper deck aft of moonpool can withstand loading of 14lb/in². Loading for the moonpool covers is 4lb/in² and the rest of the upper deck is 7lb/in². It has a free deck area (aft of the moonpool) of approximately 7,400ft².


It can carry out rigid pipelay (reeling) of up to 5,500t of 4in to 18in pipe or 4,000t of 4in to 26in rigid pipelay (J-Lay). Alternatively, it can lay up to 5,764t of 2in to 16in flexible pipe. Its maximum payload of 11,023t can consist of either two rigid reels (5,511t), flexible lines in two carousels (2,000t and 1,500t), eight portable 300t reels, 4,000t rigid pipe strings or 3,000t of subsea structures.

Three cranes assist operations:

  • Crane 1 is a telescopic box boom, ram-luffing type located between main reels on centreline forward; it has a 12t capacity at 15m
  • Crane 2 is a telescopic box boom, ram-luffing type on the starboard side aft of main reels; it has a 30t capacity at 32.75m
  • Crane 3 is a lattice boom, rope-luffing type with a 15m flying jib and anti heave compensation; it can lift 400t at 18m

The CSO Deep Blue has a total installed normal power of 33.6MW at 6.6kV (45,000hp) and 1MW at 440V emergency power. It has a transit thrust power of 14MW (three thrusters in use) or 25.6MW (eight thrusters in use) for DP.

“The CSO Deep Blue is the world’s largest purpose-built ultra deepwater pipelay and subsea construction vessel.”

The vessel is equipped with eight thrusters:

  • Two 5.5MW (7,000hp) KaMeWa type UUC 7001 non-retracting azimuthing thrusters aft for propulsion and DP
  • One 3MW (4,000hp) KaMeWa type UL 4001 retractable azimuthing thruster aft for propulsion and DP
  • Three 3MW (4,000hp) KaMeWa type UL 4001 retractable azimuthing thrusters forward below keel for DP
  • Two 1.3MW (1,740hp) KaMeWa type TT2200-BMS-CP tunnel thrusters in the bow used for DP and manoeuvring

All azimuthing thrusters have fixed pitch propellers at variable speed. The tunnel thrusters have a controllable pitch propeller and fixed speed.

The machinery for power generation and propulsion is controlled by a fully integrated Kongsberg system. Integral with this is a Kongsberg Simrad SDP-22 Dual redundant dynamic positioning system. Reference systems provided include three Robertson RGC11 gyrocompasses, one MRU 5 vertical reference unit, two MRU 2 vertical reference units, three DEIF879 wind sensors and two Sercel DGP systems.

There is also a hydro-acoustic system (HIPAP), a KS mark 8 lightweight taut wire and an Artemis Mk lV.

The vessel has a 29,606bbl fuel capacity, giving it a transit period of 50 days (90 days standby conditions). It can also store 377bbl of hydraulic oil, 5,629bbl of fresh water and 9,082bbl of technical water. It has 121,695bbl of ballast and a 10,409bbl flume tank.

Hotel accommodation is provided for a total complement of 120 persons, comprising four executive single-occupancy cabins, 18 single-person cabins and 49 two-person cabins.

Lifesaving appliances include four 60-man TEMPSC, located two port and two starboard of accommodation. Inflatable life rafts are installed on the upper deck with 100% POB capacity port and starboard.

Sikorsky S61 N type helicopters can also be accommodated on the helideck.