Marine Installation Manual
2021-08
2-16
2 Engine Power and Speed
2.7 Prohibited operation area
X72DF
Power/speed range for
CMCR [Rx] =
85% R1
—
R2 speed
In
, the engine’s CMCR speed is rated at 85 % of the R1
—
R2 speed. At
this speed, a minimum engine power (point F) of 10.4 % is required, below this is
the prohibited area of operation for the CPP at small (to zero) pitch and discon
-
nected propeller.
Point E is always defined at 70% of the R1
—
R2 speed and has a minimum
this equates to approximately 82% CMCR
speed.
Figure 2
-
9 The prohibited operation area (CMCR speed = 85% of R1
—
R2)
40
50
60
70
80
90
100
[rpm]
110
100
90
80
70
60
50
40
30
20
10
0
5
7
8
CMCR [Rx]
Field A
Engine speed
Engine power [% Rx]
[% Rx]
E
F
11
12
Prohibited operation area
10.4 [% Rx]
37.8
30.3
45.4
53.0
60.5
68.1
75.7
X72DF
SM-0398
