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
Digital Wave Publishing