Page 36: of Maritime Reporter Magazine (December 1994)

Hanne Knutsen (Continued from page 32) as well as for the main alternators, auxiliary systems and electric mo- tors of the thrusters. Sea water cooling circuit pipes are made of copper-nickel.

The loading System

In addition to the conventional loading systems, the vessel is equipped with two "offshore" load- ing systems: one for articulated load- ing turrets (APC) and buoys (OLS); and a submerged turret loading sys- tem (STL). The Hanne Knutsen is reportedly the first newbuilding in- corporating both systems.

The loading systems and tank arrangements are designed to handle crude oils with low vapor tensions in two segregations.

Four transversal collectors have been installed in the cargo manifold for crude oil and two others to send the cargo vapors to shore. Inert gas is generated and purified in a

Flexinert plant with the vapors com- ing from the main diesel genera- tors.

The ship features a sophisticated integrated control system redun- dantly computerized with process stations and a local area network (LAN) with control stations in the engine room, cargo control and wheelhouse.

The automation system in the engine room is designed to be oper- ated without personnel, and the automation in the wheelhouse is designed to be operated by one per- son.

Hanne Knutsen Equipment List

Main generators driving engines Sulzer

Auxiliary generator engine Bergen

Main propulsion electric motor ABB

Electric generators AB

Sterntube bearing Rolla

Propeller NavaLips

Emergency generating set Caterpillar

F.W. generating plant Alfa Laval

Coolers Alfa Laval

Centrifugal pumps Kvaerner Eureka

Screw pumps Kvaerner Eureka

F.O. & L.O. Purifiers Alfa Laval

Foam F.F. system Unitor

Air compressors Roweco

Sewage treatment plant Aries

Steering gear Porsgrunn

Transverse bow & stern thrusters Ulstein

Active rudder Willi Becker

Steel pipes Almesa/Cunado

GRP pipes Sarplast

Main switchboard & Cycloconverters ABB

Electric cables (automation) Ericsson

Fire detection Salwico

DPS Simrad

Radio communications S.R.M.

Radars Atlas-Krupp

Gyropilots Anschutz

Doppler log Atlas-Krupp

Echosounding Simrad

Satellite navigator Saturn-ABB

Bridge integration Kvaerner Eureka

Integrated control system Simrad

Deck machinery Ulstein

Service crane Navacel

Access hatches Faro

Doors & Windows Aux. Naval

Coatings Sigma

Lifeboats & Davits Harding

Modular cabins A.E.S.A.

Air conditioning Novenco

Pumps Kvaerner Eureka

Oil monitoring system Seres

Tank cleaning equipment Consilium

Inert gas generating plant Maritime Protection

Pressure & Vacuum valves Pres-Vac

Cargo valves & Control system.... Kvaerner Eureka

Cargo tanks level indicators Saab

Gas detection equipment Omicron

Yard: Chantiers de I'Atlantique

Ship: Petronas Tanker

Type: LNG Tanker

Owner: Petronas Marine

Length: 889 ft. (271.1 m)

Breadth: 142 ft. (43.3 m)

Depth (to upper deck): 103 ft. (31.4 m)

Draft: 36 ft. (11 m)

Total cargo volume: 130,300-cu.-m.

Speed: 21 knots

For more information on Chantiers de I'Atlantique

Circle 49 on Reader Service Card

Chantiers de I'Atlantique, a sub- sidiary of GEC Alsthom, delivered in July the first of five methane carriers for Petronas Marine of

Malaysia. The keel for the first vessel was laid in September 1992, and the production schedule for the series of five will run through July of 1997. The 130,000-cu.-m. lique- fied natural gas (LNG) carriers have been constructed using automated manufacturing and assembly pro- cesses. Each ship has four tanks which are incorporated in the ship's metal structure.

Liquefied natural gas is stored in four tanks, and the Petronas vessel is the first which combines the Gaz

Transport Membrane system with a reduction in the number of tanks: four-cargo-tank design, as opposed to a design incorporating five or six cargo tanks, which was previously associated with the system.

Thermal insulation for the liquid methane cargo is provided by a double layer of plywood boxes filled with perlite, an insulating powder made of volcanic materials.

Gastightness is ensured by a ,7-mm thick membrane made of Invar, a steel and nickel alloy which has an extremely low coefficient of thermal expansion. For safety reasons, a second, identical membrane is placed between the two layers of boxes to ensure tightness in the event of a leak in the first mem- brane. To minimize the cost of as- sembly operation aboard the ships, components have been extensively standardized and widespread use has been made of prefabrication techniques. The construction of a carrier requires 50,000 plywood boxes, each measuring 3.3 ft. (1 m) by 3.9 ft. (1.2 m), which are pro- duced in a fully automated, pur- pose-built workshop on site. In ad- dition, the special Invar parts form- ing the tank corner structures are made in completely pre-fabricated 10-ft. (3-m) long elements.

Special attention has been given to optimizing the supply of the many components installed aboard the ship. Materials are delivered by the erectors themselves using the just- in-time method with the aid of a computer system.

One of the first operations car- ried out inside the tanks is to weld metal elements called coupler studs to the ship's double hull, working from data provided by a precision topographical survey. The studs anchor the first layer of boxes.

Chantiers de I'Atlantique has devel- oped a special device for this pur- pose.

The Dromadec system comprises a viewing unit, an on-board com- puter, a stud positioning arm and a welding torch. Using the topographi- cal data provided by a laser and a distance measuring device, the com- puter places each coupler at the desired position before welding it automatically to the double hull.

Dromadec reportedly makes it pos- sible to achieve the precision speci- fications set for assembling the tank's insulation elements, namely a +/- .9-mm positioning accuracy for the studs relative to the topographi- cal data. Chantiers de I'Atlantique and a number of specialist firms worked to develop machines to au- tomate the welding of the mem- branes and achieve maximum qual- ity. A single ship requires 90,000 m ; of resistance seam welding and r 21,000 m of TIG welding. The ship is powered to a speed of 21 knots at 100 percent MCR (26,720 kW) at 93 ; rpm. The ship is designed to be 3 operated with the LR mark Unat- tended Machinery Space (UMS). 26D Maritime Reporter/Engineering News