Page 12: of Maritime Reporter Magazine (December 1986)

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in construction method, with cabin wall elements completely fabricated at the factory. The units were fitted with all needed details, including furniture fastenings, plumbing, and electrical wiring. The partition wall between cabins is comprised of two

PVC-coated steel sheets backed by a 15-mm layer of mineral wool, with a 40-mm air gap between. This insures the best possible sound insu- lation between cabins.

The main navigation equipment in the spacious wheelhouse is con- centrated in a cockpit type desk, making it possible for one man to control the navigation of the ship in a sitting position. The radar system is from Racal-Decca; it comprises one 10-cm ARPA radar that is inter- switched with a 3-cm true motion unit.

The ARPA radar antenna is in- stalled on the mast atop the wheel- house, with the 3-cm antenna on the radar mast on the forecastle deck. In addition, there is a third indepen- dent 10-cm radar with a true motion display and an antenna atop the wheelhouse. Other navigation equipment includes a Raytheon

DSN-450 dual-axis doppler speed log, a Simrad ED 61 echo sounder with a digital repeater, and an An- schutz Standard 4 gyrocompass.

The partially enclosed lifeboats supplied by Fiskars have a total capacity of 536 persons. The 62 dav- it-launchable life rafts supplied by

Viking each have a capacity of 25 persons. All lifeboat and life raft davits are equipped with a remote control for the brake.


Southern Shipbuilding

The dredge Chicago, said to be the world's largest and most power- ful combination clamshell/dipper dredge, was completed recently for

Great Lakes International, Inc. (GLI). According to the owner, the new vessel will provide unequaled capability and versatility for the dredging industry in both the clam- shell and dipper modes.

The Chicago's hull, built by

Southern Shipbuilding Corporation in Slidell, La., is more than twice the size, by volume, of other clamshell and dipper dredges. In order to effectively utilize the great produc- tion capacity of the new dredge, two split-hull, hopper dump barges were designed and have been built by

Bay Shipbuilding Corporation in

Sturgeon Bay, Wise. With a 6,000 cubic yard capacity each, these ves- sels, called Hydro-Dump barges, are 1 lA times the size of the next largest barge of this type in use. They have an overall length of 277 feet and beam of 63.5 feet, and will be towed by 5,600-bhp tugs with twin screws and Kort nozzles. Additionally, these barges can be operated re- motely by a radio transmitter lo- cated on the towing tugs which allows the barges to be operated unmanned.

The main power source on the

Chicago is two generators driven by two GM Electro-Motive Division 20-710G diesel engines with a total output of 8,800 bhp at 900 rpm.

This horsepower is almost four times greater than any previous dip- per dredge, and seven times more than any other clamshell.

The Chicago develops a dipper hoist pull of 480,000 pounds at a line speed of 240 feet per minute, about twice that of the next largest dipper currently in operation anywhere in the world. In addition, the new dredge has been designed to operate with a 27-cubic-yard dipper bucket, compared with the 14-cubic-yard bucket that was the biggest pre- viously in use.

The first design criterion for the

Chicago was to double the capabili- ty of any clamshell or dipper dredge in existence. Constructed by the

Harnischfeger Corporation of Mil- waukee, Wise., the dredge will con- sist of a P&H model 5700 electric excavator mounted on a self-pro- pelled 75-by 220-foot hull. It will operate with either the 27-cubic- yard dipper or a 50-cubic-yard clamshell bucket for excavation of harbors and river channels. The ex- cavator will be readily convertible from shovel configuration to clam- shell boom operation to maximize its versatility.

Operating weight of the 5700 ex- cavator, excluding the hull, is about two-million pounds. The 5700's slewing rim (or turntable) will be attached to the hull on a large adapter mounting designed by Har- nischfeger for the project using

CADAM-NASTRAN computer en- gineering technology. This design capability not only optimized the configuration and costs of the hull adapter, but also reduced manhours significantly to speed the design process.

As a dipper dredge, the 5700 has a 92-foot shovel boom and 92-foot handle equipped with 27-yard dip-

Main generator engines .... EMD

Auxiliary generators . . . . Caterpillar

Hydraulics Heath Engineering

Electrical instrumentation GE

Dredge computer . Dredge Technology

Spud winches Falk

Deck winches Mobile Pulley

Deck crane . . .Mariner

Main crane Harnischfege

Hydraulic power unit . . . . . Sheffer

Cooling water, bilge, ballast, fire & general service pumps . . Goulds

F/O transfer pumps . . . . . . .Viking

L/O & dirty oil pumps . . . . . Roper

Fuel separator . . Alfa Laval

O/W separator .... Hyde

Moisture separators . . . . . . Quincy

Air compressors . . . Quincy

A/C cooling water pumps . . . Goulds

Watermaker .... Nirex

A/C & heating . Thermacon

Firefighting system . . . . . . . Kidde

Gyrocompass . . . Sperry

P/A system . . Atkinson

Sewage treatment system . Microphor

Quarters International Building Systems

Coatings International Paint

Clock . . .Chelsea



Harnischfeger P&H milwaukee. Wisconsin 53201

The digging power of P&H electric excavators is now available for channel and harbor excavation

The P&H model 5700 dipper dredge has a 92-ft. boom and 92-ft. handle with 27-yd. dipper, providing 70-ft. digging depth. Also available with 50-yd clamshell that digs to 150-ft. depth.

P&H electrics are the world's most reliable excavators and match requirements of large-scale deep water projects.

Call 14141 671-7344 for details.

Circle 115 on Reader Service Card



Leaders and innovators for over 25 years in the design, engineering, con- struction and conversion of special purpose commercial and industrial vessels.

Dredge "Chicago" — World's Largest Combination

Dipper/Clamshell Dredge (27 Cu. Yd. Dipper, 50 Cu. Yd.


For additional information please contact:


P.O. BOX 1089


Telephone (504) 643-3144 or (504) 523-6394

FAX 5046438060 TWX 9102405064

Circle 139 on Reader Service Card 14 Maritime Reporter/Engineering News

Maritime Reporter

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