Page 4: of Maritime Reporter Magazine (April 15, 1971)

Two Records Set By Kockums;

The Largest Ship Built In Sweden

The Largest Ship In French Merchant Fleet

The 255,374-Dwt Tanker Jade

The recent delivery by Kockums Mekaniska

Verkstads AB of Malmo, Sweden, of the 255,- 374-dwt tanker Jade to her owners, Cie Fran- caise des Petroles of France, has set two rec- ords. First, the ship is the largest vessel built in Sweden; and secondly, the Jade is the larg- est ship in the French merchant fleet. Further, the Jade is the first of 17 similar tankers which

Kockums will build at a rate of five per year.

This new 255,000-dwt tanker series resembles in major features the seven 210,000-dwt tank- ers which were commissioned at Kockums dur- ing the last 19 months, commencing with the

Chevron tanker John A. McCone. These sig- nificant features are: cylindrical bow, raised forecastle deck, deck house with navigating bridge and accommodations erected on a cof- ferdam placed on the main deck aft, separate engine-room casing with one or two funnels, and cruiser stern. The Jade has, however, an extra accommodation deck (a total of seven) owing to a roomy dining and smoking salon and an owner's suite, which are not included in the standard six-deck arrangement. The standard cruiser stern has been slightly short- ened by means of a small triangular transom stern.

The Jade was built under the special survey of the Bureau Veritas and fitted out in ac- cordance with French regulations but with sev- eral extra features for safety and comfort.

The hull design for this class of ship was prepared by Kockums after careful analysis which employed the latest concepts in strength calculations. The concept has been checked and approved by Bureau Veritas, Lloyd's Reg- ister, American Bureau of Shipping and Det

Norske Veritas, and also by Chevron and Tex- aco who both have ordered ships of this type.

During sea trials, the Jade was instrumented for measuring static strain conditions—150 strain gauges were combined into 360 measur- ing circuits. During the maiden voyage to the

Persian Gulf, the ship will have a 40-circuit instrumentation program for measuring dy- namic stresses. The static measurements were made by the shipyard, while the dynamic measurements will be made by the Bureau

Veritas.

The longitudinally framed hull has several structural changes from the usual tanker de- sign which the yard feels reduced the hull weight and building costs. For example, the deep longitudinal bottom and deck stringers, except for the centerline docking stringer, have been eliminated. The functions of these deep stringers have been compensated for by strengthening the transverse frames and bo- using high-tensile steel in the center-tank bot- tom transverses. Previously, such steel was used mainly in the longitudinal strength mem- bers for the deck and bottom. All transverse tank bulkheads are stiffened by horizontal stringers and secondary webs. This feature aids in preventing hull vibrations.

Length overall

Length bet. perp.

Breadth, mid.

Depth, mid.

Draft, summer

Cargo capacity

Ballast capacity

Shaft horsepower

Trial speed

Gross tonnage

Prinicipal Characteristics 1,117 ft. 2 in. 1,080 ft. 0 in. 170 ft. 0 in. 84 ft. 0 in. 65 ft. 9VA in. 2,130,680 bbls. 7,980 tons 32,000 16.24 knots 126,370 tons

The cargo-oil space is divided into three sets of five tanks each. Clean ballast spaces are ar- ranged only in the fore and aft peak tanks and in wing tanks along the engine room. Fuel oil is carried in the forward deep tank and in a center tank and two wing tanks adjacent to the engine room.

Each group of cargo tanks are connected by a free-flow system. Normally loading will be done through the number 4 tanks and dis- charge from the number 5 tanks. An additional pipeline on deck may be used to load through the number 1 tanks. Oil interflow is regulated by rectangular port valves in the tank bulk- heads. Most of the cargo-oil valves are remote- ly operated from a cargo-control room on C- deck. Aft of the number 5 wing tanks there is a load-on-top slop-tank system, having a ca- pacity of 47,500 barrels.

The pump room, just forward of the engine room, is provided with two turbine-driven

Laval/JMV cargo-oil pumps, each capable of discharging at a rate of 27,518 gpm, one Laval/

JMV stripping pump of 8,000 gpm capacity,

Stern view of the largest tanker constructed in Sweden. one reciprocating Gothia stripping pump with a capacity of 1,233 gpm, and one electric bal- last pump of 17,600 gpm.

Due to the high capacity of the cargo pumps, the cargo-oil piping has the unusually large diameter of 31 inches. All cargo tanks are provided with venting devices for oils of grade

B and level indicators recording in the cargo- control room. The venting-relief valves at the tank hatches have the same diameter as the piping and are provided with waterlocks. In parallel with these there is a conventional venting system with Pres-Vac valves. The tanks are fitted with high-pressure cleaning machines of the Hydro-Synge type. The cargo piping is of spun nodular iron throughout.

Heating coils are installed only in the bunker tanks and in the starboard slop tank.

Propulsion Machinery

During the fully loaded sea trials, the Jade attained an average speed of 16.24 knots. The contract called for a speed of 15.7 knots.

Propulsion is by a regular set of cross-com- pound triple-reduction geared Kockum-Stal-

Laval AP 32 type turbines developing 32,000 shp at 85 rpm. The propulsion plant is re- motely operated from the bridge by a Kock- um-ASEA automation system. Otherwise, the automation and alarm system is arranged for continuous operation with a one-man engine- room watch. (Continued on page 8)

The chart room, which is part of the wheelhouse, has its own radar and can be closed off by curtains at night. 6

The large wheelhouse has navigating, steering and ma- chinery controls in one console along forward bulkhead.

Vast expanse of main deck can be seen from wheel- house. Note men on deck amidships on starboard side.

Maritime Reporter/Engineering News