Marine Installation Manual 2022-03 2-15
2 Engine Power and Speed
2.7 Prohibited operation area
X62DF-S2.0
Prohibited operation area for different speed rated engines
As the prohibited operation area of the engine is between 70 % and 100 % of the
R1 —R2 speed, the prohibited area is smaller when the speed rating of the engine
is lowered.
Figure 2-8 Calculating the prohibited operation area for the CMCR speed
Figure 2-8 shows an engine with a CMCR speed which is rated at 85% of the
R1 —R2 speed and therefore is only affected by a portion of the prohibited area
of the R1 —R2 speed range. The final graph for a CMCR at this speed is shown
in Figure 2-9,  2-16.
SM-0523
11
12
E
F
40 50 60 70 80 90 100
40
30
20
10
0
5
7
8
Field A
Prohibited
operation area
Engine speed
Engine power [% Rx]
[% R1 - R2]
[% CMCR]
50
60 70
80
90 100