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MAN B&W 4.01
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MAN Diesel
198 57 40-2.0 MAN B&W S65ME-C/ME-GI, S60MC-C/ME-C/ME-GI/ME-B,
S60MC, L60MC-C/ME-C, S50MC-C/ME-C, S50MC, S50ME-B
Electricity Production
• PTO/GCR
(Power Take Off/Gear Constant Ratio):
Generator coupled to a constant ratio stepup
gear, used only for engines running at constant
speed.
The DMG/CFE
(Direct Mounted Generator/Con-
stant Frequency Electrical)
and the SMG/CFE
(Shaft Mounted Generator/Constant Frequency
Electrical) are special designs within the PTO/CFE
group in which the generator is coupled directly to
the main engine crankshaft and the intermediate
shaft, respectively, without a gear. The electrical
output of the generator is controlled by electrical
frequency control.
Within each PTO system, several designs are
available, depending on the positioning of the
gear:
• BW I:
Gear with a vertical generator mounted onto the
fore end of the diesel engine, without any con-
nections to the ship structure.
• BW II:
A freestanding gear mounted on the tank top
and connected to the fore end of the diesel en-
gine, with a vertical or horizontal generator.
• BW III:
A crankshaft gear mounted onto the fore end
of the diesel engine, with a sidemounted
generator without any connections to the ship
structure.
• BW IV:
A freestanding stepup gear connected to the
intermediate shaft, with a horizontal generator.
The most popular of the gear based alternatives
are the BW III/RCF types for plants with a fixed
pitch propeller (FPP) and the BW IV/GCR for
plants with a controllable pitch propeller (CPP).
The BW III/RCF requires no separate seating in
the ship and only little attention from the shipyard
with respect to alignment.
Introduction
Next to power for propulsion, electricity produc-
tion is the largest fuel consumer on board. The
electricity is produced by using one or more of the
following types of machinery, either running alone
or in parallel:
• Auxiliary diesel generating sets
• Main engine driven generators
• Steam driven turbogenerators
• Emergency diesel generating sets.
The machinery installed should be selected on the
basis of an economic evaluation of first cost, ope-
rating costs, and the demand for manhours for
maintenance.
In the following, technical information is given re-
garding main engine driven generators (PTO) and
the auxiliary diesel generating sets produced by
MAN Diesel.
The possibility of using a turbogenerator driven by
the steam produced by an exhaust gas boiler can
be evaluated based on the exhaust gas data.
Power Take Off
With a generator coupled to a Power Take Off
(PTO) from the main engine, electrical power
can be produced based on the main engine’s
low SFOC and the use of heavy fuel oil. Several
standardised PTO systems are available, see Fig.
4.01.01 and the designations in Fig. 4.01.02:
• PTO/RCF
(Power Take Off/RENK Constant Frequency):
Generator giving constant frequency, based on
mechanicalhydraulical speed control.
• PTO/CFE
(Power Take Off/Constant Frequency Electrical):
Generator giving constant frequency, based on
electrical frequency control.