Page 39: of Maritime Reporter Magazine (November 15, 1981)

Jeffboat was to develop a fuel- handling system which could be adapted to the standard 145-foot boat with a minimum of change and make the system flexible enough so that the main fuel tanks could hold 2-D later if the blended fuel was unavailable or the price difference made it un- economical to use blended fuel.

The final scheme selected basic- ally was: when the vessel is op- erating on blended fuel, the fuel is drawn from the unheated main bunker and preheated in a sump external to the main tank. From there, the fuel goes directly to the fuel heating package or "HOPS" unit as ACBL refers to it. In the HOPS unit, the fuel is strained and then pumped into the loop by a positive displace- ment pump. From there it passes through a heat exchanger which utilizes engine jacket water as a heating medium. Following fur- ther filtration, the fuel goes through a regulating valve and on to a three-way valve system that is used to select the correct routing of the fuel. Controls built into the system also evolved from this meeting and are designed to provide an automated system.

ACBL is enthusiastic about the benefits to be gained from using blended fuels. They anticipate be- ing able to recover the additional cost per vessel within a year, so thereafter, they will have flexi- bility to make use of that fuel which provides the most econom- ical operation.

John G. Lynch, Mayank Jain and Deepak Varshney spoke on "Selecting Heavy Fuel Engines—

The Operators' Viewpoint." This article is an informal summary on some advantages and disad- vantages of heavy-fuel engines.

Specifically, the investigation in- volves tugboats/towboats and the comparison between non-U.S. built medium-speed (500 to 900 rpm) diesel engines of 2,400 hp, operating on heavy fuels, and

U.S.-built engines in the same

Mayank Jain

Hannah Inland Marine range presently on the market, operating on 2-D oil.

While most engine manufac- turers claim to be able to operate on bunkers equivalent to No. 6 oil or Bunker "C", in reality there is very little, if any, long-term operating experience involving medium-speed diesels in the lower horsepower range burning bunk- ers with a viscosity greater than 180 centistokes at 50°C (1,500 sec. RW1 at 100 °F). The state- of-the-art for smaller engines seems to be in the intermediate fuel level, IF 60 to IF 80. This is the fuel oil most manufactur- ers would recommend for con- tinuous duty in towboats or tugs; it also seems to be the economic break-even point between higher capital costs and reduced oper- ating costs.

Whether the dilemma of rising operating costs can be solved totally or partially by utilizing heavy fuel oil can only be an- swered by each individual owner or operator. An important con- sideration is that, while heavier fuel oil may be the economic an- swer to a vessel owner's problem, it will also be the cause of main- tenance and engineering prob- lems. It is, however, apparent that increasingly volatile fuel costs will play a more prominent role in the future selection of tugboat and towboat engines.

William Smith, vice-president of Modern Diesel Power, Inc. of

New Orleans, La., presented an interesting account of a retrofit performed at Bender Ship Repair

Inc., Mobile, Ala., on the towboat

Great America, owned by the

Great America Boat Company.

The vessel was fitted with two

S.E.M.T. Pielstick engines, model 12VPA6 280, that develop 3,600 bhp each and which were sup- plied by Modern Diesel Power.

Basing his remarks on his expe- rience with the engines and the repowering of the vessel, Mr.

Smith explained the reasons for vessel design changes and de- scribed benefits expected from the first use of the French-built engines on the Mississippi River.

Both Modern Diesel Power and the Great America Boat Company are owned by the Smith family.

Mr. Smith explained the deci- sion to retrofit was made for several reasons. It is faster than constructing a new vessel and provides a practical demonstra- tion of engine performance in ac- tual river operations in a vessel with an existing record of previ- ous performance for comparison.

The engines burn heavy diesel fuel No. 5 — approximately 600

Redwood Sec. I—which, Mr. Smith contended, along with engine effi- ciency, will achieve significant savings for the operator, Bunge

Towing. The Great America once held the record for barge towing on the Mississippi — moving 62 barges from New Orleans to

Cairo, 111.

The new Pielstick engines will drive 117-inch-diameter stainless- steel propellers in new Kort noz- zles through Falk model 3548 reverse/reduction gears at 900 rpm.

In addition to the engine retro- fit, other work was done on the towboat. Thought to have a draft problem, it was discovered by

Bender Ship Repair officials that the Great America actually had a trim problem that could not be solved with existing tank ar- rangements. To solve the prob- lem, Bender changed the tanks around completely. In addition, the center of gravity of the ves- sel was changed with the new

William Smith

Modern Diesel Power machinery, producing an accept- able draft on the Mississippi

River. The towboat has also been fitted with sophisticated moni- toring equipment to measure fuel use, engine wear, and vessel ef- ficiency, Mr. Smith noted.

For further information and copies of the above presentations, write the appropriate number on the Reader Service Card:

ACBL ("The ACBL Blended Fuel

Program") — write 50 ; Alfa-

Laval, Inc. ("Recommendations for Pretreatment and Cleaning of Heavy Fuel Oil") —write 51;

B&W Alpha Diesel ("Alpha Pro- pulsion Systems Intermediate

Fuel Oil Recommendations") — write 52; B&W Diesel ("The Low

Speed Diesel and the Future En- ergy Scenario")—write 53; Ber- gen Diesel ("Bergen Diesel En- gines Operating on Intermediate

Fuels")—write 55; Krupp MaK

Maschinenbau GmbH ("Prospects of Medium Speed Four-stroke

Diesel Engines in View of Future

Fuel Problems") — write 56; Mo- bil Oil Corporation ("Trends in

Marine Fuel Quality and Econom- ics That Will Affect U.S. Medium-

Speed Diesel Operators")—write 57; Modern Diesel Power (Repow- ering the Great America)—write 58; S.E.M.T. Pielstick ("Heavy

Fuels and PA.6 Ship Propulsion

Engines") — write 59; Sulzer

Brothers, Ltd. ("Recent Develop- on the Sulzer AS25-Engine") — write 60; "Selecting Heavy Fuel

Engines — The Operators' View- point" by Messrs Lynch, Jain and

Varshney — write 61.

Tankers to bulk carriers, tankers to

Ro-Ros, general cargo to container- ships, bulk carriers to car carriers.

Jumboising every ship type.

Let MacGregor convert you to profitability.

MacGREGOR transfer and access equipment

MacGregor Comarain lnc.,135 Dermody Street,Cranford,NJ 07016,USA. Telephone:(201)272-8440. Telex: 138618 MACGREGOR N CNFD.

November 15, 1981 Write 134 on Reader Service Card 43