NKK delivers VLCC with double-hull

PUBLISHED : Monday, 29 March, 1993, 12:00am
UPDATED : Monday, 29 March, 1993, 12:00am

NKK Corporation has delivered the world's largest double-hull very large crude carrier (VLCC) to Bergesen of Norway.

Named the Berge Sigval, the tanker is only the third double-hull VLCC in the world.

It is the first of two such VLCCs ordered from NKK by Bergesen, and the fifth vessel NKK has built for the world's leading ship owner-operator.

The previous four - the last of which was delivered in November last year - were LPG-ammonia carriers.

The second double-hull tanker is now under construction for scheduled delivery in October this year.

The features of the Berge Sigval include that it has a double-hull structure in anticipation of a revision in the IMO's Marine Ocean Pollution Control (MARPOL) Convention to be applied to all tankers contracted from July 6 this year to prevent oil spillsfollowing accidents.

Compared with conventional single-hull tankers, in which cargo oil and ballast tanks are alternately arranged, the double-hull tanker's oil and sea water tanks are completely separated.

This even includes piping systems to ensure maximum protection against ocean pollution.

The double-hull along the tanker's sides and bottom surrounds the oil tanks with sufficient breadth and depth for safety.

It has a service speed of about 16 knots, making it among the world's fastest for tankers.

Its ballast tanks have tarepoxy coatings and glass-fibre-reinforced plastic (GRP) pipes are employed in ballast piping inside the tanks to ensure perfect corrosion prevention.

Cargo oil and residual oil pipes are made of highly corrosion-resistant chromium-containing cast iron.

A number of ladders, passageways and other inspection corridors have been installed to facilitate strict inside-tank inspections.

The oil unloading system as an automatic stripping system and a special bell mouth to considerably improve oil unloading performance.

The generator, auxiliary main engine and unloading-related equipment can be monitored and remotely controlled from CRT displays and keyboards in the engine control and cargo control rooms.

A wide variety of energy conservation equipment, including an economical and reliable exhaust eco-turbo power generation system, supplies in-house electricity needs during voyages.

To realise thorough automation/manpower savings without sacrificing reliability and safety, the tanker employs the following equipment: Automated EO-code approved by NV (Classification Society Det Norske Veritas).

Worldwide GMDSS shipwreck/safety system.

Highly accurate radar-type oil-level indicator in cargo tanks.

Emergency towing equipment expected to be required by the US LOOP (Louisiana Offshore Oil Loading Pie).

Electro-hydraulic hose handling crane.

Remote-controlled electro-hydraulic mooring winches.